Cubical Anatomy of Several Ducts and Vessels by Injection Methods of Acrylic Resin V

Cubical Anatomy of Several Ducts and Vessels by Injection Methods of Acrylic Resin V. Arterial distribution of the temporal muscle in some mammals

Tokuo Fujimoto

Department of Anatomy, Osaka Dental College, Osaka

(Director : Prof. Y. Tani g u c h i)

(With 33 figures in 10 plates and one table.)

Argument of this research was announced at 64th Annual Session of the Japanese Association of Anatomists, March, 1959, Tokyo.

Preface

On carotid arteries and their ramifications, anthropological and comparative anatomical or other works have been abundantly seen. But, those on the arterial supply for the muscle of the head and neck, from a different new point, are few. Especially no observation on the finer vascular distribution in the individual muscle has been made. The author has here undertaken cubical comparative anatomical study on blood supplying routes for temporal muscles of mammals easy to obtain and of human fetuses, by corrosion specimens of acrylic resin. Diverging features of all arteries from the external carotid or its branches taking part in this muscle, ramifications and anastomoses in the inner or outer part of the muscle, and distributing territories of each branch in the muscle, are observed. The temporal muscle as well as the masseter, being rich in red muscle fibres, play a strong (dynamically) and important role in the mastication, and it is thought to be significant to throw light on the arterial distribution of them. Although, many comparative results of the carotid arterial system in mammals have been published, they can 389 390 Tokuo Fujimoto not be said to be faultless and perfect on the deeper part. And the human fetus was selected, because external carotid ramifications seemed to be fully studied in adults by many scholars, though not on each muscle. Encountering with unknown points on the comparative anatomy of the temporal muscle itself, the author felt many difficulties to perform this investigation, therefore, the muscle was dissected in advance. And especially on this point of rabbit and goat, the author will take it up in a separate paper to study on many more examples. The temporal muscle is most developed in carnivora, ruminant next, and rodentia poorest. On the human subject, it developes rapidly in the first dentition stage of an infant, but in the fetal stage it should not yet grow enough, being poorer than that of rabbit, also in the function.

Materials and Methods

Following animals are used : 18 dogs, 12 cats, 12 rabbits, 10 goats and 11 human fetuses. The acrylic resin is injected into the common or external carotid artery (the vertebral artery ligated) of the body after depletion to death. The injection method published by T a n i g u c h i, O h t a and T a j i r i ('52) and its supplement ('55), are adopted. Tissues of the injected head are digested with thick NaOH solution after curing the resin to make corrosion specimens. While, for the dissection, a few of injected heads in each species are preserved in formalin solution without digesting tissues. Since the cured resin injected into finer parts is somewhat fragile for the dissection, aceton solution (14%) of the polymer is employed in order to prevent breaking. This material is better, being more elastic and tolerable to the movement of surrounding tissues resulting from the dissection. Through the dissection of the muscle, relations between supplying arteries and other organs or tissues are observed. Corrosion specimens are used comparing them with dissecting specimens at every step. Distributions of these arteries in layers of the muscle are observed at each different digesting stage of tissues. For the observation and micrometry of finer portions, the microscope and binocular magnifier are employed. Arterial Distribution of Temporal Muscle 391

Observations

On each species of the animals, branching features of all arteries supplying the temporal muscle, relations to their sources and adjacent branches, distributing appearances within the muscle, anastomoses (mainly above 50 au.in thickness) with others and the distributing region of each branch, are described here. Anatomical views, which are not enough to know from references concerning with the temporal muscle, will be respectively supplemented briefly at first.

Dog : Among the animals observed, the temporal muscle of dog as well as of cat is the strongest, composed of the superficial and deep layers, though both can not clearly be classified. Arteries supplying this muscle are four, the posterior auricular, the superficial temporal, the posterior deep temporal and the anterior deep temporal. 1. Posterior Auricular Artery (Figs. 1, 2, 3 and 4) Thicknesses at the root are 1.5-2.4, M. 1.8 mm.. This artery originates from the supraposterior convex wall of the external carotid (2.8-4.0, M. 3.0 mm.), which goes around a sharp curve anteromedially between Bulla ossea (E 11 e n b e r g e r, 1891) and Proc. postglenoideus of the temporal bone. It takes course at first backwards 8-12 mm. along the outside of the bulla, gets to between the base of the jugular process (occipital) and the lateral end of the superior nuchal line, bending upwards (the first curvature, its convex faces infra- posteriorly), and turns to the posterior (the second curvature, its convex faces to the supranterior) (Figs. 1, 2 and 3). R. mastoideus and R. auricularis posterior at the first curvature next to A. stylomastoidea, and R. auricularis anterior just before the second curvature, originate respectively. In literature, branches distributed to the temporal are reported only on R. temporalis post. s. occipitalis (E 11 e n b e r g e r), but the author observes four branches and calls them as follows in their diverging order : Rr. musculares temporales primus, secundus , posterior et anterior (Figs. 1, 2, 3 and 4). 1) R. m. temp. primus (0.69-1.05, M. 0.87 mm.) branches at the first curvature of the posterior auricular artery, having a relation- ship with the mastoid ramus and the posterior auricular ramus as 392 Tokuo Fujimoto follows : They diverge at the same point, on 14 examples in 24 ; the posterior auricular ramus diverges from this muscular branch, on 8 exs. ; the mastoid ramus diverges from this muscular, on one ; or all diverge with one common stem, on one (Fig. 1). Under the above- mentioned relations, this branch, originated from the lateral wall of the mother artery, meanders along the posterior margin of the muscle drawing an arch. After reaching the supraposterior corner of the muscle, it runs forwards along the sagittal margin (crest) (Figs. 1 and 4) and gets to the supra-orbital margin. Supplies en route are to the fascia and the superficial muscle part of the supraposterior and nearby the superior margin, while, one or two branches are given to the superior nuchal muscles and subcutis, and one small branch to auricular muscles. 2) R. m. temp. secundus (0.37-0.74, M. 0.51 mm.) is the smallest. Branching from the lateral wall at the second curvature of the posterior auricular artery, it proceeds right upwards. Between the auricle and temporal muscle, its main current is distributed to auricular muscles and subcutis. One weak branch, drawing a small semicircle before R. m. temp. primus, is distributed just before the area of the primus (Figs. 1, 2 and 4). 3, 4) Rr. mm. temp. posterior (0.68-1.24, M. 0.91 mm.) et anterior (0.5-1.11, M. 0.74 mm.) are branched via a very short (7-9, M. 8.2 mm.) and S-shaped common stem medialwards from 2-4 millimetres posterior to the second curvature of the posterior auricular artery. Then, penetrating the fascia at the infraposterior corner to get to the bony surface, the stem divides into two. The posterior takes its course to the supraposterior in the muscle and goes up along the posterior margin of it. The anterior proceeds antero-inferiorly or anterosuperiorly (Figs. 1, 2, 3 and 4). Both are main streams distributed to the posterior 1/3 of the muscle. The posterior sends out at first a branch in all cases from the lateral wall at the infraposterior corner, which again penetrates out the muscle onto its surface and runs to the supranterior beneath the fascia (Fig. 4). It supplies the lower superficial layer of the posterior 1/3 of the muscle. Next to this, en route the posterior reaches the supraposterior corner of the muscle, 2-3 parallel branches rise regularly to the anterior or supranterior, and serve the posterior 1/3 of the muscle (Figs. 1 and 2). At the supraposterior region, they anastomose (c. 124 it) with branches split supraposteriorly from the superficial temporal artery. The anterior takes a stand with the posterior anteroposteriorly, direct- Arterial Distribution of Temporal Muscle 393 ing to the antero-inferior or anterosuperior (Figs. 1, 2, 3 and 4). Branches of it are shown, at first, emerging along the ventral margin of the muscle, and then, 2-4 rungs directing to the anterior and posterior regularly with almost the same intervals (Figs. 1 and 2). They anastomose (c. 155 /1) with the supraposterior branch of the posterior deep temporal artery in the deep superior portion of the muscle centre, and near the ventral margin of the muscle, several upper and lower parallel branches (120-150 A) anastomose rung-shapedly with the periphery of the posterior branch of the posterior deep temporal artery (Figs. 1 and 2).

2. Superficial Temporal Artery (Figs. 1, 2 and 3) Thicknesses are 1.4-2.0, M. 1.5 mm., some about half as thick as the peripheral portion of the external carotid. The artery separates from the upper surface of the convex, where the external carotid makes a strong curve medially before the auricle as the maxillary artery (on one example from the root of the posterior auricular). The artery gets beneath the temporal fascia at just or about 10 mm. above the zygomatic arch, proceeds straight to the parietal, bends to the frontal (about 90-110°) at the centre of the temporal muscle, continues as R. frontalis to proceed to the zygomatic process of the frontal bone, and at last penetrates out of the fascia at the supra- anterior corner of the muscle onto the subcutis. Two groups of muscular branches en route are recognized and both have their sources at the medial wall of the superficial temporal. (1) Several branches run chiefly through the superficial layer tangential to the muscular surface, and some out of them get in the deeper portion splitting in a right angle (Figs. 1 and 2). (2) En route to pass the region of the muscle, branches directly enter into the muscle (Figs. 1 and 2). The former (1) gives (i) (0.5-1.3, M. 0.86 mm.) from about supranterior curvature of the mother artery (at, a„ a3 in Figs. 1, 2 and 3), and (ii) (0.25-0.43, M. 0.34 mm.) from nearby the anterior end of it (b3, b2 in Figs. 1 and 3). (i) Composed of one to four (two or three in most cases), the first of which going out at a distance of 14-34, M. 25 mm. beyond the origin of the mother artery, they spread generally in a fan shape (18 exs. in 29) (Fig. 1). Sometimes many small twigs diverge from one branch (resembling R. parietalis in man) almost as thick as R. frontalis proceeding to the parietal (7 exs.). While, fine branches from a thick branch runs backwards (4 exs.), terminal branch of R . 394 Tokuo Fujimoto frontails seems to be so little that it splits from the branch backwards. These branches supply the superficial muscular layer and fascia of the middle 1/3 with an expanse at 95-110° from the posterior to the supranterior. (ii) Two or three in number, diverging upwards or downwards from the curved portion of the superficial temporal artery, the root of branches thereof, and also en route in the muscular region of R. frontalis, supply the superficial of the muscle and the fascia of anterior 1/3. Their respective sources are almost regular (Figs. 1 and 3). Ascending ones of them anastomose thickly (c. 280 #) with the superior branch from the posterior deep temporal artery in the deep, near the muscular sagittal margin.

3. Posterior Deep Temporal Artery (Figs. 2, 3, 5, 6, 7, 8 and 9) This (1.11-1.86, M. 1.40 mm.) emerges from the maxillary (2.1-3.5, M. 2.6 mm. at the branching portion) next to the inferior alveolar artery (Figs. 3 and 6), keeping relations with it as follows : apart from each other (the distance 1.5-3.0, M. 2.5 mm.) on 16 exs. in 34 (Fig. 6), keeping close to each other (K-type) on 14 exs., and from a common stem (1.3-3.0, M. 1.8 mm. in thickness, 1.0-2.5, M. 1.8 mm. in length) on 4 (Fig. 7). In case of being apart from each other, though both diverge from the anterior wall of the maxillary, the inferior alveolar turns to the inferior, and the posterior deep temporal to the superior. And the more they start apart from, the more this tendency is obvious. The posterior deep temporal ascends right upwards or with a sharp turn, and enters into the temporal muscle. After giving off pterygoid muscular branches, Rr. anteriores to the insertion of the temporal muscle, masseteric artery and anastomosing branches with the anterior deep temporal, it is distributed to the temporal with three branches in most cases : Rr. superior, posterior et supraposterior (Figs. 2, 3, 5, 6, 7 and 8). Pterygoid muscular branches, mostly one fine but in some cases a few, originated 3 mm. after the starting point of the posterior deep temporal, run antero-inferiorly nearly parallel with the inferior alveolar artery (Figs, 3, 5, 6 and 7). Rr. anteriores, one or two (0.31 -0 .56, M. 0.4 mm.), 3-4 mm. beyond the pterygoid muscular branch to the lateral or supranterior, reach the antero-inferior portion of the temporal muscle, just above the coronoidal process of the mandible (Figs. 5, 6 and 7). Varieties of them, such as well-developed, small or defective, are found. The massetric artery as thick as the stem goes Arterial Distributionof TemporalMuscle 395 out after 2-4 mm., and reaches the masseter through the mandibular notch (Figs. 3, 5, 6, 7 and 8), is recognizable on almost all examples but two. It includes two, viz., one bending anteromedio-inferiorly then supramedially, and the other directly supramedially. They make anastomoses, in a V-shape, with those from the anterior deep temporal (Figs. 5 and 8). Of temporal muscular branches, the superior, not one but a few fine branches, frequently proceed right upwards to get to the sagittal margin. The posterior takes its direction backwards, and in more developed cases, it stretches as far back as to the inferior margin of the muscle. The supraposterior is well-developed, extending inter- medially to the superficial layer of the muscle. These three branches are distributed to the whole layer of the middle 1/3 of the muscle, keeping at expansions of 75-90° (Figs. 2, 3, 5 and 6).

4. Anterior Deep Temporal Artery (Figs. 1, 2, 3, 5, 8, 9, 10 and 11) The artery originates from the superior or supralateral wall of the maxillary after penetrating the anterior pterygoid foramen. It is 0.74-0.99, M. 0.87 mm. in thickness, a little less than a half of that part of the maxillary (1.8-3.0, M. 2.2 mm.). It is attractive to be observed various branching types of this artery in relation with the ophthalmic and ethmoidal, which diverge right before this artery from the anterior wall of the maxillary as follows : (1) The ophthalmic and ethmoidal arteries are originated with a short common stem and separately from this artery, on 12 exs. in 26 (Figs. 5 and 9) ; (2) both are in contact with each other and separately from this artery. on five (Fig. 8) ; (3) both with one common stem, besides in contact with this artery, on three (Fig. 10) ; (4) the ophthalmic being separate, the ethmoidal and this are in contact, on one ; (5) the ethmoidal, ophthalmic and this separate from one another in order, on one (Fig. 11) ; (6) the ethmoidal and ophthalmic are with a common stem and separately from this artery , on two ; (7) the ethmoidal and ophthalmic are with a common stem and in contact with this artery, on two. Accordingly, the order of the arrangement of the ophthalmic , ethmoidal and anterior deep temporal arteries is on 21 examples , and a replacement between the former two occures on 5. The anterior deep temporal artery separates from the ethmoidal or ophthalmic or a common stem of them on 20, being distances 1.5-3.0, M. 2.2 mm.. The common stem (2.0-4.0, M. 2.6 mm. in length, on 19 396 Tokuo Fujimoto examples) appears to an adhesion of them at their branching points (Figs. 9 and 10). Diameters of sections here are L5-2.0, M. 1.7 mm. in longer and 1.0-1.6, M. 1.3 mm. in shorter. Relations between those and A. anastomotica (R. anastomoticus, Ell e n b e r g e r) with the posterior communicating artery or the posterior cerebral artery in the cranium, are as follows : (1) Branch- ing off from the above-mentioned common stem on 14 exs. in 29 (Fig. 9) ; (2) from the ophthalmic on 8 (Figs. 8, 10 and 11) ; (3) from the ethmoidal on 6; (4) directly from the maxillary on one. In all cases (except (4)), this artery originates just from or several millimetres after the diverging point of each mother artery. On four cases in peculiar (three from (3), and (4)) the ophthalmic diverges from A. anastomotica. The anterior deep temporal artery proceeds right upwards or supranteriorly and enters into the temporal muscle. After a distance of 12-18 mm. it diverges one branch to the lateral (Figs. 2 and 3), which is distributed to the superficial layer along the anterior margin of the muscle. The course of the main stream is taken along the anterior to superior via supranterior margin, and at last, posteriorly in parallel with the sagittal crest (Figs. 1 and 2), and it spreads to the whole layer and fascia of the muscle. The anastomosing branch with the posterior deep temporal runs posteromedially, branching from just after the divergence or right before the first branch (Figs. 5, 8, 10 and 11).

Cat : The temporal muscle of cat as well as of dog, is well-developed with two layers, superficial and deep. The superficial subdivides into the anterior and posterior, showing a V-shape. The former originates from the antero-inferior margin of the fascia, the medial surface of the frontal and temporal processes of the zygomatic bone. While the latter consists of fibres running forwards from the postero- inferior margin of the fascia, i. e., the lambdoidal margin of the occipital and temporal bones. Arteries distributed are five, the posterior auricular, the superficial temporal, the posterior deep temporal, the anterior deep temporal and the buccal.

1. Posterior Auricular Artery (Figs. 12, 13, 14 and 15) Thicknesses at the root are 0.6-1.2, M. 1.0 mm.. This artery, Arterial Distributionof TemporalMuscle 397 originated from the supraposterior surface of the second curvature (H u rliman n, 1912) of the external carotid (1.7-2.0, M. 1.9 mm.) at the anterior margin of Bulla ossea, proceeds supraposteriorly beneath the osseous external auditory foramen along the lambdoidal margin of the temporal and occipital bones. En route, branching a masseteric muscular branch, stylomastoid artery, auricular branches and nuchal branches, the artery divides into two termini which supply the auricle and temporal muscle. Branches distributed to the temporal muscle are as follows : 1) Rr. mm. temporales anterior, 2) medius, 3) posterior et 4) posterior accessorius. All of 1), 2) and 3) originate with one short (3-5, M. 4.0 mm.) S-shaped stem (Figs. 12, 14 and 15), which branches medially just before the mother artery, reaches the infraposterior corner of the temporal muscle, then takes supraposteriorly along the lambdoidal margin, and after getting to the muscle, diverges at almost the same point. 1) R. m. temp. anterior (0.37-0.56, M. 0.44 mm.), proceeds anteriorly or supranteriorly along the lambdoidal margin of the muscle, and supplies the superficial layer of the posterior 1/3 of it (Figs. 12, 14 and 15). 2) R. m. temp. medius (0.19-0.43, M. 0.34 mm.), ascends straight for the superficial layer of the posterosuperior part of the posterior 1/3 of the muscle (Figs. 12, 14 and 15). 3) R. m. temp. posterior (0.37-0.65, M. 0.52 mm.), ascends along the posterior margin of the muscle and is distributed to the posterior 1/3 of the whole muscle layer and the fascia (Figs. 12, 14 and 15). The periphery of the posterior auricular artery bifurcates at the postero-inferior corner or at the centre into 4) R. m. temp. posterior accessorius (0.25-0.37, M. 0.31 mm.) and the deep auricular artery for the posterior deep portion of the auriale. The former proceeds upwards beneath or above the fascia along the posterior muscular margin, then forwards along the sagittal margin via the posterosuperior margin. On this way it is distributed to the superficial muscle layer and the fascia of the supraposterior (Fig. 12, 14 and 15). Courses and distribution to the muscle , resemble those of R. m. temp. primus in dog (cf. Figs. 12, 14, 15 and 1, 2).

2. Superficial Temporal Artery (Figs. 12 and 13) Being 0.8-1.0, M. 0.9 mm. in thickness , the artery is a little less than a half of the periphery of the external carotid . It diverges from the supraposterior wall of the third curvature (H ti r I i man n) 398 Tokuo Fujimoto of the external carotid in front of the osseous auditory foramen (in only one case from the root of the posterior auricular artery). After sending out the masseteric muscular branch, the anterior auricular artery and the transverse facial artery, the artery goes over the lateral surface of the root of the zygomatic process, and turns supra- anteriorly towards the orbital ligament on the surface of the fascia parallel to the zygomatic arch. After passing over the lateral side of the ligament, it parts into the upper and lower palpebral arteries. Somewhat slender muscular branches (0.12-0.31, M. 0.19 mm.) for the temporal, are given just before the above-mentioned bending point of the artery. They supply the superficial part of the middle deep layer (having no superficial layer at this part) and its fascia (Fig. 12). Branches to the posterior of the superficial layer are rarely found. Only two or three slender branches are given, while the artery runs parallel to the zygomatic arch. They take courses superiorly and inferiorly, to supply the superficial layer of the upper part of the anterior 1/3 of the muscle (Fig. 12), but none of them reaches the superior margin.

3. Posterior Deep Temroral Artery (Figs. 13, 16, 17, 18, 19 and 20) This artery (0.5-0.7, M. 0.6 mm.) emerges from the superior wall of the maxillary (1.0-1.8, M. 1.4 mm.) next to the inferior alveolar. Relations among this artery, the inferior alveolar and R. communicans posterior (0.32-0.57, M. 0.48 mm.) to the infraposterior corner of Rete externum (D a v i s and St o r y, '43) from both or either, are kept as follows : (1) The inferior alveolar and the posterior deep temporal branch separate from each other (the former from the inferior wall of the maxillary, the latter from the superior wall), on 16 exs. in 23. Distances between both measure 1.0-2.5 mm. long (Figs. 16, 17 and 18). In this case, the more diverging points of both from the maxillary artery separate, the more the inferior alveolar turns towards the inferior, while the posterior deep temporal towards the superior, as well as in dog. (2) Both diverge in contact with each other on 2 exs. (3) Both emerge with a short common stem to the inferior on 2 exs. In case of (2) and (3), the arteries diverge from the anterior wall of the maxillary. (4) On the others, especially, both start from the above-mentioned R. communicans posterior on one, the posterior deep temporal from the posterolateral side of the rete on one (R. communicans posterior comes out of the inferior wall of the mother artery to Rete externum), furthermore Arterial Distributionof TemporalMuscle 399 in one case, the posterior deep temporal is defective. Stretching right upwards through the centre of the temporal muscle, the posterior deep temporal artery sends out the masseteric muscular branch as thick as the mother artery. Subsequently, it ascends with the supraposterior curve and becomes two or three small branches directing to the supraposterior. They supply the deep layer of the middle 1/3 of the temporal (Figs. 13, 16 and 19). The artery diverges anteromedially a fine branch anastomosing with one from the anterior deep temporal. In most cases, the pterygoid muscular branch appears from R. communicans posterior (from the inferior alveolar in one), is observed. A great variety is inspected in R. communicans posterior to the supraposterior corner of the rete as follows : (1) Originated from the posterior deep temporal on 10 exs. in 22 (Fig. 17) ; (2) from the inferior alveolar on 3 (Fig. 18) ; (3) from both arteries, and then at once adhere to one, on 6 (Fig. 20) ; and (4) on one example, from the maxillary. This ramus, in all cases , appears within 1 mm. from the diverging point of the mother artery, being constricted at the root, then thickned sooner (Fig. 18). Although, on only one example , the ramus is considerably thick (c. 0.7 mm. as thick as on this point of the maxillary), taking its origin just before the normal branching point of the inferior alveolar, and gives the inferior alveolar and posterior deep temporal, on the contrary , and then proceeds straight, on the anterolateral side of the maxillary , to the rete (Fig. 19). Anastomoses (90-110, M. 105 /2) between branches of the posterior and anterior deep temporals are found in all examples , infranterior in the muscle and supralateral to the rete .

4. Anterior Deep Temporal Artery (Figs . 13, 16, 17, 18 and 20) One main branch measured 0.28-0.56, M. 0.4 mm. and a few fine accessories are found. They are originated from the anterolateral margin of the rete, located just anterolateral to the optic canal , lateral to the basal portion of orbital contents , surrounding the maxillary at the dorsal (Figs. 16, 17 and 18). The following features are recognized in the diverging point of the main branch : (1) Branching from an arterial loop making the external rete at the anterolateral margin of it , on 8 exs. in 19 (Fig. 17) ; (2) from a peculiarly projected loop out of the rete , on 5; (3) from a point turned to the inferior to the rete at its anterior 400 Tokuo Fujimoto margin, on 5 (Fig. 16) ; (4) directly from the superior wall of the maxillary, on one. The main branch ascends along the anteromedial margin of the temporal muscle, soon enters into the muscle, and gives two or three branches at 5-8 mm. from its root directing to the supraposterior. One of them directs a little laterally (laterale Aeste, H il r 1 i ma n n). The divergency of this resembles that of dog, though poorer and not so regular. The main stream curves gradually in a supraposteri- or driection along the sagittal margin, and is distributed to the whole muscular layer and the fascia of the anterior 1/3 (Figs. 12, 13 and 16). In many cases, branches proceeding laterally originate at far inferior part. Accessory branches in contact with the main emerge from both medial and lateral of the rete to supply the small region of the anterior margin (Figs. 16, 17 and 20). 5. Buccal Artery (Figs. 16, 17 and 20) This (0.49-0.68, M. 0.56 mm.) emerges from the anterolateral corner of the rete. Twigs from a dorsal branch (dorsale Aeste, H il r 1 i- m a n n) among branches of this artery take courses to the supramedial and supply the inferior portion of the anterior muscular margin. Thicknesses of the twigs (0.22-0.37, M. 0.3 mm.) range from those of the main branch of the anterior deep temporal to those of a little less one than the accessories.

Rabbit : The definite description on the temporal muscle of rabbit up to now is limitted to those located on the external surface of the temporal bone. But, the author noticed other bundles of this muscle originated from the posterior orbital wall and posterior supra-orbital ligament, during this investigation. Accordingly, now, the muscle should be classified into the temporal and orbital portions (Figs. 21, 22 and 23), though detailed observations of this problem will be post- poned to a separate thesis. Arteries taking part in the temporal muscle are three, the superficial temporal, the inferior ophthalmic and the buccal.

1. Superficial Temporal Artery (Figs. 21, 22, 23 and 24) The external carotid artery bends almost at a right angle postero- laterally, after sending forth the maxillary, and appears right before Arterial Distribution of Temporal Muscle 401 the osseous external auditory foramen via the infralateral side of Bulla ossea. Here, giving a small branch to the auricle (separately from the posterior auricular artery), the artery finally derives two termini, the thicker transverse facial artery (0.9-1.6, M. 1.04 mm.) and the finer superficial temporal (0.6-0.8, M. 0.7 mm.) (Fig. 21). The former is so well-developed (as thick as the external carotid at this portion), bending accurately forwards, that as if the latter seems to diverge from the supraposterior corner of the curvature of the former, directing upwards or supraposteriorly (Fig. 21). And the latter, on 5 exs. out of 20, is actually seen as branches of the former. The superficial temporal artery goes around the osseous external auditory foramen from the anterior to the supraposterior and passes between the foramen and the temporal portion of the temporal muscle. Meanwhile, the auricular branch to the posterior margin of the auricle, masseteric muscular branch from near its root (from the transverse facial artery on one case) for the supraposterior portion of the muscle, and two fine temporal muscular branches, Rr. mm. temp. anterior et posterior are given. They are distributed to the posterior half of the temporal portion (Figs. 21, 22, 23 and 24). The anterior (0.2-0.3, M. 0.27 mm.) proceeds right upwards. The posterior (0.25- 0.35, M. 0.3 mm.) proceeds to the supranterior, and in somewhat well-developed one, its branches expand in a fan shape just after some meandering. They make anastomoses (49-62 p) with each other and supply the muscle (Figs. 21, 22 and 24).

2. Inferior Ophthalmic Artery (Figs. 21, 22 and 24) After splitting the inferior alveolar, the maxillary artery makes head towards a space between the medial and lateral laminae of the pterygoid process (postsphenoid), then penetrates supranteriorly the anterior sphenoid foramen of the basal portion of the lateral lamina, and finally makes a slight curve forwards and a little downwards at the infraposterior portion of the orbita. The inferior ophthalmic artery (1.1-1.8, M. 1.4 mm.) emerges upwards from this curvature. After sending out the anterior meningeal (T s u s a k i, '54 ; A. meningea media, Kr au s e) and then the external ophthalmic, this artery forks into the lacrimal and ophthalmic (the lacrimal, ophthalmic and external ophthalmic, from the lateral in order) (Figs . 21 and 22). Arteries distributed to the temporal muscle are out of the lacrimal, which bends supraposteriorly around the medial side of the major alar crest (postsphenoid) and leaves the orbita through the 402 Tokuo Fujimoto

posterior supra-orbital foramen. Distances as far as the foramen are 20-23, M. 20.8 mm. long. One muscular branch (0.15-0.25, M. 0.21 mm.) emerges backwards from here and makes head for the anterior tip of the temporal portion of the muscle, to spread to the anterior half of this part. Within the muscle, it anastomoses (c. 56 it) with branches from the superficial temporal. After that , the artery appears at the temporal corner of the orbita as the supra-orbital artery, sending out forwards the superior and inferior palpebral arteries. In addition, it becomes into many branches radiating anteriorly and posteriorly, surrounding the supraposterior orbital foramen to supply the subcutis around there (Figs. 21, 22 and 24)

3. Buccal Artery (Fig. 23) It splits to the lateral nearly at a right angle out of the lateral wall of the maxillary, 5-6, M. 5.6 mm. distal to the inferior ophthalmic, and before the minor palatine. It measures as thick as the maxillary (0.63-0.9, M. 0.78 mm.). No description is seen on it in literature. It corresponds to the same named artery in human subject. In rabbit, the masseter muscle, however, is well-developed, but narrow the cheek is, and the main stream is distributed to the supra,- anterior portion of the masseter and besides to the cheek. The artery diverges anterolaterally the fine superior alveolar artery, and next, supraposteriorly the medial temporal muscular branch (8-12, M. 9.7 mm. apart from the root of the buccal artery) supplying the orbital portion of the temporal, then ramifies into the buccal branch distributed to the cheek, the lateral temporal muscular branch and the masseteric muscular branch (Fig. 23). Relations among them are as follows : (1) The buccal divides into the lateral temporal muscular and the buccal (the buccal sends out the superior and inferior branches, and from the latter the masseteric muscular emerges), on 8 exs. in 17 ; (2) after emerging the lateral temporal muscular, it becomes into the buccal and the masseteric muscular, on 5 exs. ; (3) into three at the same point, on 4 (Fig. 23). The medial and lateral temporal muscular branches (0.22-0.36, M. 0.27 mm., almost equal on both) ascend side by side slopewise along the anterior side of the orbital portion of the muscle and supply this portion (Fig. 23). On some examples, in which both branches and inferior ophthalmic artery are well-developed, anastomoses (c. 62 At) are found among them. Arterial Distribution of Temporal Muscle 403

Goat : The temporal muscle, being undergrown, is thin, and narrow at the vertical height, not getting to the superior margin of the orbita. The side view is like a long eggplant, curved downwards at its pos- tenor half. In comparison with that of the carnivora, it is noticed that the development is so poor at the superior and posterior for- tons that no temporal prominence by this muscle is found as seen in dog and cat. At the inserting portion, muscular fibres are rich and no strong tendon is observed. The coronoid process of the mandible is so large and long that it is longer, thicker and more curved. supraposteriorly than the condyle process, and that the external margin of the process is exposed to the lateral musclar surface. Arteries distributed to the muscle are four, the posterior auricular, the superficial temporal, the deep temporal and the buccal.

1. Posterior Auricular Artery (Figs. 25, 26, 27, 29 and 30) Measuring 1.9-2.1, M. 2. 0 mm., it emerges out of the common carotid (4.9-5.4, M. 5.2 mm.), 5.5-11.0, M. 7.8 mm. proximal to the transverse facial (or the superficial temporal or common stem of both), next to the lingual. It goes supraposteriorly under the osseous external auditory foramen, and gives two thick branches to the occipital portion and the auricle, and then gets onto the temporal crest (S i s s o n, '53) right behind the foramen, to bifurcate into Rr. mm. temp. superficialis et profundus. (Figs. 25, 26 and 27). 1) R. m. temporalis suPerficialis (0.6-1.3, M. 0.9 mm.) ramifies to four branches distributed to the posterior 1/3 of the superficial muscular layer from the infraposterior portion. Three of them, running parallel anteroposteriorly, make anastomoses (100-300 ,a) with muscular branches from the superficial temporal mentioned later, and another is distributed to the posterior extreme portion of the muscle (Fig. 26). 2) R. m. temporalis profundus (0.7-1.2, M. 1.0 mm.) enters a small foramen (communicated with the temporal canal) located on the temporal crest, and proceeds within the diploe, dividing into three to seven branches. They come out of some small foramina on the posterior portion of the temporal fossa to be distributed to the deep layer of the posterior of the muscle. One or two of them continue to run forwards within the diploe and get to the root of the zygomatic process. And they, coming out of small foramina there, supply 404 Tokuo Fujimoto the inferior margin of this muscle (Figs. 27 and 30), and communicate (50-200, M. 170 /2) with the main stream of the deep temporal artery.

2. Superficial Temporal Artery (Figs. 25, 26 and 28) Being most developed (1.8-2.0, M. 1.9 mm.), the artery ramifies from the common carotid infranterior to the osseous external auditory foramen. It makes a common stem with well-developed transverse facial instead of the facial (none in goat), on 18 exs. in 20 (Fig. 25), or both emerge at the same point (K-type) on two. This vessel takes its course right upwards and proceeds on the surface of the thick fatty tissue on the lateral side of this muscle, differing from of dog and cat. Meanwhile, ramifying the superior and inferior palpebral arteries, it reaches the posterolateral extreme of the orbital margin, finally to terminate in two branches which supply the horn process of the frontal bone and also the frontal region (Figs. 25 and 26). Muscular branches from the artery, during it reaches the above- mentioned orbital margin, include next four, the superior (0.37-0.93, M. 0.56 mm.), the medial (0.3-0.74, M. 0.58 mm.), the inferior (0.6-0.96, M. 0.76 mm.) and the supraposterior (0.49-1.3, M. 0.8 mm.) (Figs. 26 and 28). The last one leaving for the supraposterior corner of the muscle, supplies about there. Though seldom, the superior and medial musculars at times originate from this. The former three, directing to the supramedial, penetrate the fatty tissue to arrive at the temporal muscle. Each of them turns into two branches spreading anteroposteriorly in a T-shape on the muscular surface. In case of lacking one of them, it is surely supplemented by branches from ' other. Branches going forwards from the superior and the medial put the upper and lower surfaces of the coronoid process between them. They anastomose (100-400, M. 300 p) with temporal muscular branches left the buccal artery (Fig. 28). As for branches going backwards, anastomoses are found between them and branches of the superficial temporal muscular of the posterior auricular artery (mentioned already) (Fig. 26), and between the superior, inferior temporal muscular branches and the musculars from the deep temporal artery.

3. Deep Temporal Artery (one only) (Figs. 27, 28 and 29) This (1.0-1.4, M. 1.2 mm.) ramifies from the lateral wall of the Arterial Distribution of Temporal Muscle 405 maxillary, at the same point with the inferior alveolar from the infranterior wall, and Aa. retis mirabiles cerebri posteriores from the medial wall (M a s u i, '31). The artery runs forwards almost parallel to the lateral of the maxillary artery, arriving at the infraposterior margin of the temporal muscle (corresponding to the medial of the mandibular notch). After sending out the masseteric mascular branch (8-12, M. 10 mm. apart from the branching point, markedly undergrown in comparison to the other animals) (Fig. 28), the artery directs upwards with an acute curve facing to the anterior along the inferior margin of the temporal muscle. It gives one branch backwards to the temporal muscle, and gets to the posterior corner of it, drawing a wave-like course. En route, six to nine branches are scattered on this muscle, and ascend within the deepest layer (Fig. 27), just on the external surface of the temporal bone. At the superior muscular margin they anastomose with the superior and inferior muscular branches left the superficial temporal. Also at the infraposterior corner of the muscle, they communicate with branches out of the posterior auricular.

4. Buccal Artery (Figs. 25 and 28) The artery (1.5-2.2, M. 1.9 mm.) ramifies from the infralateral wall of the maxillary, 11-12, M. 11.5 mm. distal to the origin of the deep temporal (between the anterior and posterior retial arteries). Splitting many small branches to the pterygoid muscle and the posterior part of the cheek, the artery continues to stretch forwards. In contact with the anterior surface of the coronoid process or the temporal muscular insertion, the artery bends to the lateral and supplies the cheek. One or two temporal muscular branches (0.5-0.91, M. 0.8 mm .) which emerge at the most lateral, namely, anterolateral corner of the muscle, are distributed to its inserting portion (Fig. 28). When alone, it soon subdivides into two, both going forwards in the muscle along the superior and inferior margins of the coronoid process , and they anastomose with the superior and inferior (or medial) temporal muscular branches of the superficial temporal (Fig . 28).

Human Fetus :

The temporal muscle is not yet so fullgrown that its thickness is not over 5 mm. Distributed arteries are three , the medial temporal, 406 Tokuo Fujimoto the posterior and anterior deep temporals.

1. Medial Temporal Artery (Figs. 31, 32, 33 and 34) Thicknesses are 0.5-1.2, M. 0.97 mm. of 10 months old, 0.3-0.5, M. 0.43 mm. of 6-7 months. The artery originates from the medial wall of the superficial temporal (1.5-2.0, M. 1.74 mm. of 10 months, 0.7- 0.9, M. 0.87 mm. of 6-7 months) at a height of, or something below the inferior margin of the temporal muscle. The artery, with one root, ascends along just medial of the mother artery, penetrates the fatty layer, then divides into the anterior and posterior branches at the inferior margin of the muscle, on 9 exs. in 15 (Figs. 32, 33 and 34). On five examples, these two branches diverge at the same point. Furthermore, one branch splits out of the root of the transverse facial artery, and divides into two, on one. In all examples, the anterior branch is finer and more superficial than the posterior. The former, running in the superficial of the fascia, supplies it and the subcutis between the frontal ramus of the superficial temporal artery and the zygomatico-orbital (Figs. 32 and 33). The latter im- mediately enters into the muscle and runs backwards along its inferior margin, suddenly curves upwards (nearly right angle) at the infraposterior corner of the muscle, and is distributed to the posterior 1/3-1/2 of the muscle (Figs. 32, 33 and 34). Small branches from this penetrate the fascia, and after supplying the occipital subcutis, their superior ends reach the muscular sagittal margin. Branches forwards from this anastomose with branches of the deep posterior temporal artery (90-180, M. 130 z of 10 months), and some backwards with branches of the posterior auricular in the occipital region (c. 480g, of 10 months) (Fig. 34), both independent of the muscle.

2. Posterior Deep Temporal Artery (Figs. 32 and 34) The artery (0.8-1.2, M. 1.0 mm. of 10 months, 0.4-0.6, M. 0.5 mm. of 6-7 months) originates from the superior wall of the maxillary (1.36-1.98, M. 1.62 mm. of 10 months, 0.68-0.86, M. 0.79 mm. of 6-7 months) 2.5-6.0, M. 3.5 mm. (10 months) distal to the inferior alveolar, via a common stem (2.0-4.0, M. 3.2 mm. of 10 months, 2.0-3.0, M. 2.5 mm. of 6-7 months, in length) with the masseteric artery, on 13 exs. in 15. In two cases, the artery starts apart, distal to the masseteric, and in one of them, diverging from the anterior wall of the maxillary at the same point with the inferior alveolar, and the medial meningeal artery is sent out abnormally about 7 mm. distal to Arterial Distribution of Temporal Muscle 407 the artery. This artery ascends within the temporal muscle, makes a curve to the supraposterior along the superior muscular margin, and branches out of its end anastomose with posterior branches of the medial temporal. En route, it gives some twigs anteriorly, some of them backwards, far larger in number and stout, also anastomose with posterior branches of the medial temporal (Fig. 34).

3. Anterior Deep Temporal Artery (Figs. 32, 33, 34 and 35) The artery (0.7-1.2, M. 0.9 mm. of 10 months, 0.4-0.5, M. 0.47 mm. of 6-7 months) comes out of the superior or supranterior wall of the maxillary just at the diverging point of the buccal artery. It proceeds supraposteriorly after gone a little forwards forming a hook at the beginning, on 12 exs. in 18, or right upwards, on 6 exs. . The main stream ascends supraposteriorly along the anterior muscular margin, and several branches backwards of it are distributed to the anterior 1/3 of the muscle, and anastomose (150-300A of 10 months) with branches of the posterior deep temporal (Fig. 34). Continuation of the artery reaches the subcutis of the lateral part of the supra-orbital margin, penetrating the fascia. Branches here make anastomoses (350-500, M. 410 g of 10 months) with the supra- orbital artery, and one of them arrives at the orbita through the zygomatic canal, and anastomoses (279 ,u of 10 months) with the lacrimal artery, as well as (200-300, M. 250 A of 10 months) with the lateral palpebral artery (Fig. 32). The artery, at a distance of c. 4.5 mm. of 10 months, c. 3.5 mm. of 6-7 months from its diverging point, derives two in a T-shape, viz., a main stream which ascends in the anterior muscular margin, and a branch which proceeds infralaterally. The latter will be named R. m. massetericus, being considerably thick (0.45-0.6, M. 0.5 mm. of 10 months, 0.2-0.3, M. 0.28 mm. of 6-7 months), is distributed to the buccal subcutis, proceeding infralaterally along the anterior masseter muscular margin, and then produces several branches for the muscle (Figs. 32 and 35).

Summary and Discussion On the basis of above results, the author wishes to compare and discuss with those of his predecessors, on diverging features , ramifications, anastomosing views and distributing features , involving 408 Tokuo Fujimoto the temporal muscle.

1. Posterior Auricular Artery : In dog, cat and goat, branches from this artery are distributed to the temporal muscle. Ellenberger describes in dog, R. temporalis posterior s. occipitalis of A. auricularis magna s. posterior supplies the posterior margin of the muscle. In cat, H U r l i m a n n states a thick R. muscularis temporalis of A. auricularis magna is distributed to the posterior portion of the deep layer of the muscle, and R e i g h a r d and Jennings ('30) also state of one thick branch of the same artery to the temoral muscle and muscles of the occipital region. The artery, except in human subject, supplies mainly the auricle, and partly the temporal muscle. So, of the auricular branches it has fairly been reported in detail in literature, but of temporal muscular branches nothing is beyond the above-mentioned. Temporal muscular branches from this artery are not one only, but four in every case of dog and cat, in the author's paper. To examine each of muscular branches in dog and cat, R. m. temp. primus of dog diverges from the lateral wall of the first curvature near the origin of the mother artery, and its supplying territories are the posterior and supraposterior portions of the superficial muscular layer and fascia, while, R. m. temp. post. accessorius of cat, one of end branches of the posterior auricular, show almost the same feature in its course and distributing territories with the primus of dog. And each end of these muscular branches in both species proceeds forwards along the sagittal margin of the muscle, and some of them get to the supra-orbital region. It is considered that muscular branches pointed out by scholars will correspond to either R. m. temp. secundus or anterior or posterior in dog, and either anterior or medius or posterior in cat by author, judging from their descriptions and illustrations. But, as these are extremely incomplete, the author denominates them as aforesaid to systematize them. Common features in dog and cat are that, these three branches begin with a thick and short stem, and the branches from it spread on more medial plane than of other branches of the mother artery. Besides, among these three, Rr. mm. temporales anterior et posterior of dog correspond to the same named ones of cat, respectively, and the secundus of dog to the medius of cat. In goat, no description of the temporal musculars of this artery is seen, nor in textbooks by Sisson et al. and M a s u i. The Arterial Distribution of Temporal Muscle 409 temporal muscle of goat is not so well-developed as of carnivora, especially the height of its posterior portion is low. Therefore, such a feature is unrecognizable as the infraposterior and posterior margins are enclosed by three muscular branches in dog and cat. The superficial and deep muscular branches are seen, and the course of the latter shows peculiar appearances not found in other species, that is, it enters a small foramen on the temporal crest and ramifies within the diploO, and the' branches come out near the root of the zygomatic process of the temporal. To proceed and branch in the diplod is attractive, though the significance is not understood. In human fetus, this artery has nothing to do with the temporal muscle, but the distributing appearance of the medial temporal artery entirely resembles that of muscular branches of the posterior auricular of dog and cat. Moreover, branches of the medial temporal make anastomoses with those of the posterior auricular in the occipital region, having no relation with the temporal muscle.

2. Superficial Temporal Artery : Muscular branches originated from this artery are usually one medial temporal artery in human fetus, and many in goat, dog and cat, especially rich in goat and dog, but markedly poor in cat. In rabbit, two muscular branches from this artery supply the posterior half of the temporal portion of the muscle, being considerably large for the size of it. So far, studies on the human medial temporal artery are few. What is known is only that it supplies this muscle, proceeding in the medial arterial groove after getting to the temporal squama. The course and ramifications of it, the author observed, are worthy of special mention. It runs just the medial of the superficial temporal, and turns into two branches, the anterior and posterior. The former nourishes the subcutis and fascia on the muscular anterior half at most. The branch for the muscle is the latter, and it at first arrives at the infraposterior corner of the muscle and proceeds in the depth of it making an acute curve superiorly or supranteriorly. Bluntschuli et al.('29), Dalla Rosa (1886) and Freis- f e 1 d ('27) describe that temporal muscles of the human fetus and neonatal baby are not yet up to the mark and their vertical extents are better than the horizontals, and being oval, semicircle or pentag- onal their external forms, and development of them proceeds rapidly towards the posterior , then furthermore towards the posterior and 410 Tokuo Fujimoto superior during the second dentitional period. Studies in this paper are on fetuses, 10 and 6-7 months old. The thickness of the medial temporal artery is also comparatively large for the development of the muscle, one half or above as thick as the mother artery. The course of the branch for the muscle resembles closely the temporal musculars of the posterior auricular (unrelated to the muscle in human fetus) in the other mammals observed. This fact is noteworthy for the comparative anatomy. A d a c h i ('28) publishes that arteries within medial arterial sulci originate from the maxillary on 2 exs. in 10. As the sulci are not yet seen on the temporal bone of 10 months old, it should be studied furthermore on this item in case of the more developed muscle. In goat, the superficial temporal, being also thick and strong, runs between the subcutis and fatty layer on the surface of the temporal fascia as well as of human fetus, and supply the horn process. So, muscular branches of this must penetrate the fatty zone obliquely, to reach the surface of the muscle, and three of them are characteristically in similar T-shape. Each of them gets to neither the depth of the muscle nor the bony surface. In carnivora, Dall Aqua ('01) states, this artery in general, having no parietal ramus, its main stream bends forwards to show the feature of the frontal ramus in man. E 11 e n b e r g e r, however, describes in dog, the following portion after bending forwards to call A. zygomatico-orbitalis, while Reighard and Htirlimann in cat, keep name of superficial temporal. The author is of opinion of the latter, that R. parietalis in dog and cat is defective and even the portion after bending is a continuation of the original superficial temporal, because several fine branches corresponding to A. zygomatico-orbitalis are seen on the zygomatic arch in addition (Figs. 1, 3 and 12). The superficial temporal runs through the most superficial of the temporal muscle in dog, and on its fascia in cat, as previous scholars mention. Muscular branches of it are especially well-developed in dog, while very faint in cat. In dog, majority of them diverge from near the curvature of this artery in several features. They spread in the most superificial of the muscle tangentially, differing from the other mammals, as they run intramuscularly, and from the medial wall of them fine branches are sent into the muscle. The above-described branching type (1) shows the feature like R. parietalis in man, but the branches nourish only the muscle, and do not Arterial Distribution of Temporal Muscle 411 come out to the subcutis. And the main muscular branch from the superficial temporal in goat, dog and cat never gets to the temporal bony surface in contrast with the medial temporal in man. Accord- ingly, the name " medial temporal artery " is unsuitable to this branch. It should be named rather " superficial temporal branch ", in contrast with those of the other mammals studied. In rabbit, muscular branches of the superficial temporal consist of two, the anterior and posterior. B e n s l e y ('18), Baldwin ('20) and T s u s a k i make no mention of them. The temporal portion of this muscle is so thin that no division of the depth is shown on arterial distributions.

3. Posterior Deep Temporal Artery : This is the main among distributed arteries. Especially in human fetus, this is stronger than in others, and originates from the maxillary next to the inferior alveolar, with only one exception of starting both arteries at the same point. While in dog and cat, both arteries originate also separately as the general type, though it gives considerable numbers of coming out at the same point of making a common stem. Besides, the more the distance increases, the more the emerging point of the inferior alveolar transfers to the inferior, and vice versa the posterior deep temporal to the superior, from the anterior wall of the maxillary. About this, Bradley ('27) and Ellenberger describe only that the posterior deep temporal in dog diverges at about the same point with the inferior alveolar, next to it. In cat, R e i g h a r d et al. regard the posterior deep temporal as the medial meningeal artery, but later Norris ('06) corrects their error. Davis et al. call it also A. masseterica, in cat, from which the posterior deep temporal ramus (always finer than the masseteric branch) is given. The author has seen the masseteric artery diverg- ed from the posterior deep temporal in all cases of dog, cat and human fetus (except two). Records of the above seniors, however, that the posterior deep temporal and the inferior alveolar make a common stem on 2 exs. in 11, mostly agree with the author's. H U r 1 i- man n in cat, calling it A. temporalis profunda caudalis, reports in detail, that it ramifies, proceeding superiorly, to the medial and lateral branches to supply the respective layer of the muscle. The author recognizes pterygoid muscular branches and some to the temporal in all cases, the former being two or three of well-developed 412 Tokuo Fujimoto and the latter important to supply the inserting portion of the temporal and the anterior temporal muscle (L u b o s c h, '13, in carnivora). These views are more marked in dog than in cat. Moreover, fine branches emerging laterally, before the artery enters into the temporal, supply the M. zygomatico-mandibularis (T o 1 d t, '05) (superior part of the deeper layer of the masseter). The main current in the temporal muscle is so irregular and slender in cat, that it is often difficult to classify H U r 1 i man n's medial and lateral branches. While in dog, it is able to classify the branches into the superior, posterior and supraposterior, and the end of the last one of them exposes on the superficial layer between the two formers. Besides in cat, a communicating branch to the external rete diverges from the posterior deep temporal. H U r l i m a n n and Davis et al. find a branch communicating this artery with the infraposterior corner of the rete, and Norris states vessels to form the plexus begin to appear as far back as the inferior alveolar, and one small branch commonly rises from the base of the posterior deep temporal. R. communicans posterior described by the author corresponds to the latter. It can be observed, in addition, the corn- municans emerges emergesfrom the inferior alveolar, or both from it and the posterior deep temporal, then are united to one and it gets to the rete. Interesting peculiar views concerning the above are that the posterior deep temporal diverges from the posterolateral corner of the rete and the communicans from the maxillary, and also the communicans is so thick that the posterior deep temporal and inferior alveolar both diverge from the very communicans. It is thought these facts are brought about by aberrant origins of both arteries a little more distally. It is considered that the constriction at the root of the communicans serves somewhat control of the blood stream and pressure of the internal and external carotid systems, as one of functions of the rete. In goat, the deep temporal artery is only one, and it runs backwards along the inferior muscular margin, not ascending in the muscle as in dog, cat and human subject. On this artery, Sisson et al. only state its name but no details.

4. Anterior Deep Temporal Artery : The artery ascends along the anterior intramuscular margin and is distributed to the whole layer of the anterior 1/3 of the muscle and fascia, in all mammals observed. Arterial Distribution of Temporal Muscle 413

On diverging appearances of this artery and its adjacent ones, are found attractive views in dog, cat and human fetus. In dog, Ellenberger describes the medial and anterior deep temporals, and Bradley one or two anterior deep temporals, and Br adl e y shows some cases in which either of the two is defective, or the arteries come from the buccal artery. Subjects in the author's observation are relations among the anterior deep temporal, ophthalmic and ethmoidal arteries. The diverging order is ophthalmic, ethmoidal and anterior deep temporal, but on 5 exs. in 26, two formers are replaced with each other. Besides, these three diverge apart from one another, or connecting with, or via a common stem. The anastomosing artery which communicates with the cerebral arterial circle and the anterior deep temporal, Ellenberger calls R. anastomoticus (Aa. anastomoticae by Davis et al. connecting with the external and internal retes, or distale Reteaste by H ti r 1 i m a n n), while the author names it the artery, because of being so thick and one in number. Relations among this artery, the ophthalmic and ethmoidal already described in this paper, are made clear for the first time by the author. In cat, H U r I imann states A. temp. profunda nasalis s. anterior emerges from the anterior margin of the rete and makes the medial and lateral branches (separate from the beginning at times), or from the buccal artery, and Davis et al. describe to be two or more, and one of them emerges always from a strong branch out of the superior wall of the maxillary beyond the origin of the ciliary artery (with the lacrimal), while others from the anterior part of the rete or the maxillary, then they ascend in the muscular anterior part to supply the muscle. The author observes one thick anterior deep temporal artery, and two or three accessories in the medial and lateral sides of it, commonly originating from the anterior margin of the rete, except one case out of the maxillary, but none from the buccal artery. In human fetus, the anterior deep temporal communicates with the lacrimal artery through the zygomatic canal, besides, the end of this main anastomoses with the supra-orbital artery at the lateral supra-orbital margin. K a m i j o et al. ('58) describe that the anterior deep temporal in human adult divides into the superior and inferior branches in a T-shape, and the former to the temporal muscle, the latter to the posterior surface of the maxillary bone. In this thesis in human fetus, the artery also bifurcates T-shapedly, 414 Tokuo Fujimoto

but one towards the infralateral gives small branches to the masseter and cheek, proceeding a little more laterally along the masseteric anterior margin. Further investigations are required to de- cide whether this branch corresponds with the inferior branch by K a m i j o et al., or its supplying tributary is altered by age.

5. Inferior Ophthalmic Artery : In rabbit, one of end branches of the lacrimal artery supplies the temporal portion of the temporal muscle. The lacrimal diverges from the inferior ophthalmic with the supra-orbital and superior and inferior palpebral arteries near the posterior supra-orbital foramen, and a muscular branch out of it proceeds backwards from the anterior end of the temporal portion of the muscle. The distributing region of the muscular branch corresponds right to that of the posterior deep temporal or the superficial temporal in other mammals studied (except human fetus), as the portion in rabbit is equal to the middle of the others. The diverging of the muscular branches from the inferior ophthalmic, is similar to the anastomosis at one end of the anterior deep temporal with the supra-orbital in human fetus.

6. Buccal Artery : This artery has to do with the temporal muscle in cat, rabbit and goat, more developed in the latter two. In all cases, it gives branches to the lateral pterygoid, masseter and temporal muscles and the cheek. In cat, H U r 1 i m a n n states the dorsal branch of the artery is to the temporal and masseter. The author also observes one branch, as thick as the anterior deep temporal, of the buccal, distributed to the inserting portion of the temporal. In rabbit, an artery almost as thick as the maxillary is observed to supply the lateral pterygoid, temporal and masseter muscles and the cheek, and it is described as the buccal artery in this thesis. But no description about it is seen until now. The artery gives the masseteric, temporal muscular and buccal branches. The temporal muscular enters into the muscle running backwards along the orbital portion of the temporal. Its distributing regions agree with those of the anterior deep temporal in dog, cat and human fetus. In goat, the temporal muscular branch divides into two, and they show a characteristic feature that they put the upper and lower Arterial Distribution of Temporal Muscle 415 margins of the muscular process of the mandible between themselves. Distributing sphere of these branches extends to the middle of the muscle, to make up the only one deep temporal.

7. Thick Anastomoses among Arteries or their Branches Distributed to the Temporal Muscle : In the fascia, anastomoses making fine meshworks are seen in all species observed, though some of them are broken off by washing. It is difficult to find those above 50 ,u in thickness. In the muscle of dog, thick and stout anastomoses are easily seen. Muscular branches of the superficial temporal and superior branches of the posterior deep temporal make thick communications, and the latter anastomoses with anterior muscular branches of the posterior auricular, of which several anastomosing branches run parallel with muscular fibres of the infraposterior portion of the temporal. In dog and cat, strong and thick anastomoses are always observed between the anterior and posterior deep temporals in a V-shape near the temporal insertion. In rabbit, the inferior ophthalmic artery and muscular branches from the superficial temporal anastomose each other in the temporal part of the muscle. Rarely, on the orbital part of the muscle, the inferior ophthalmic connects with muscular branches of the buccal artery. In goat, the buccal and superficial temporal arteries, besides, the latter and the posterior auricular, make anastomoses among muscular branches of themselves, respectively, in the superficial of the muscle. These anastomoses are so strong, running regularly along the

Table DOG 416 Tokuo Fujimoto

CAT

RABBIT

GOAT

HUMAN FETUS Arterial Distribution of Temporal Muscle 417 superior and inferior margins and the middle of the muscle. In human fetus, anastomosing branches are thick, especially between the anterior and posterior deep temporals, though all mother arteries are not so thick. And besides, marked communications are seen extramuscularly between the anterior deep temporal and supra- orbital arteries or the lacrimal, and between the medial temporal and branches of the posterior auricular.

Conclusions

1. Whole arterial branches in temporal muscles of dog, cat, goat, rabbit and humman fetus are observed through the injection method of acrylic resin, as follows : diverging form of each artery, relation with adjacent arteries, branching appearance, distributing territories and anastomoses with one another within and without the muscle. Besides, measurements of thicknesses of arteries or muscular branches and distances to each other are recorded. 2. Arteries for the temporal muscle have many variations and are complicated on individual species. Regions distributed can be divided into 3 parts, anterior, middle and posterior (Table). 3. Many close relations are found between dog and cat. Pos- terior auricular artery, superficial temporal, posterior and anterior deep temporals are concerned with the muscle of both. Furthermore, buccal artery is added to the above in cat. Posterior auricular artery has : Rr. mm. temporales primus, secundus, anterior et posterior in dog ; anterior, medius, posterior et posterior accessorius in cat. (About the diverging interrelation among the anterior deep temporal artery, the ethmoidal, the ophthalmic and the anastomosing artery in dog, and about the communicating branch, named R. communicans posterior which connects the external rete with the posterior deep temporal or inferior alveolar in cat, many interesting views were obtained.) 4. Since the temporal muscle in rabbit is different in form from that of other species, it is studied in two parts, the temporal and orbital. The former is supplied with the anterior and posterior temporal muscular branches of the superficial temporal and a branch of the lacrimal (branch of the inferior ophthalmic), and the latter with the medial and lateral temporal muscular branches out of the buccal artery, are pointed out by the author. Branches to the buccal part and the masseter diverge also from this artery. No discription on 418 Tokuo Fujimoto the buccal artery of rabbit has been found hitherto. 5. On goat, branches from the posterior auricular artery, the superficial temporal, the deep temporal (single) and the buccal, are sent into the muscle. The posterior auricular artery has the superficial and deep temporal muscular branches. The latter has the singularity, viz., once enters into the diploe of the temporal bone, branches and appears again onto the bony surface, then the branches take their courses into the muscle. Muscular branches from the superficial temporal artery are regularly parallel, superior, medial and inferior. 6. On human fetus, the medial temporal artery from the superficial temporal, the posterior and anterior deep temporals take part in. The medial temporal diverges into the anterior and posterior branches. The former goes to the fascia and subcutis, and the latter to the muscle. Morphological appearances of the latter are similar to those of the posterior auricular of the other mammals. While, one of the anterior deep temporal arteries runs down anterolaterally to the masseter muscle and buccal subcutis. 7. Strong anastomoses within the muscle are commonly found as follows : between the anterior and posterior deep temporal arteries in dog and cat, between the superficial temporal artery and buccal artery or posterior auricular artery in goat, between the anterior and posterior deep temporals, besides, between the posterior deep temoral and medial temporal in human fetus.

In conclusion the author wishes to express his obligation to his respected Professor Y. Taniguchi for guidance and encouragement shown to him, besides, is much indebted to Assistant Professor Y. O h t a for his help in various experiments. Part of this research was made possible by favour of the Grant- in-Aid for Fundamental Scientific Research of the Ministry of Edu- cation, for that the author expresses his gratitude.

References 1) Adach i, B.; 1928. Arteriensystem der Japaner. Kyoto Bd. 1, 58. 2) B a 1d w i n, F. M.; 1919. Variations inisthe carotid arteries of the rabbit. Anat. Rec. 16, 309. 3) B e n s l e y, B. A.; 1948. Practical anatomy of the rabbit. 8th Ed. Phila., 109. 4) Bluntschl i, H. &Schreibe r, H.; 1929. tther die Kaumuskulatur. Fortschr. d. Zahnhlk. Bd. 5, 1. 5) Br adl e y, 0. C.; 1927. Topographical Anatomyof the dog. 2nd Ed. London. 172. 6) Dall A c q u a, U.; 1901. Jber. tiber d. Fortschr. d. Anat. u. Entw. Bd. 6, 201. Arterial Distribution of Temporal Muscle 419 7) D a 11 a R o s a, L; 1896. Das postembyonale Wachstum des menschlichen Schla- fenmuskels. Stuttgart, Verlag Ferd. Enke. (cited by Freisfeld). 8) D a v i s, D. D. and Story, H. E. ; 1943. The carotid circulation in the domestic cat. Zool. series, Field Mus. of nat. history. 28, 5. 9) E 11 e n b e r g e r, W. & B a u m, H.; 1891. Systematische und topographische Anatomie des Hundes. Berlin, 131 & 370. 10) F r e i s f el d, H.; 1927. Uber die K.aumuskeln des menschlichen Neugeborenen. Vierteljhschr. f. Zahnhlk., Bd. 43, 552. 11) H U r 1 i man n, S.; 1912. Die arteriellen Kopfgefdsse der Katze. Intern. Mschr. Anat., 29, 371. 12) Kr a us e, W.; 1884. Die Anatomie des Kaninchens. (cited by Tsusaki). 13) K a m ii o, Y., Takarad a, T. & Tak a yam a, Y.; 1958. Anatomical studies on the maxillary artery. Kaibo Z., 33, 165 (abstract on the sesssion). —in Japanese. 14) L u b o s c h, W.; 1913. Die Kaumuskulatur der Amphibien, verglichen mit der Saugetiere und Sauroposiden. Anat. Anz., Ergheft. z. Bd. 64, 67. 15) M a s u i, K.; 1931-32. Comparative anatomy of the domestic animals. Tokyo, Bd. 1, 26, Bd. 2, 1. —in Japanese. 16) N o r r i s, H. W.; 1906. The carotid arteries and their relation to the circle of Willis in the cat. Proc. Iowa Ac. Sci., 13, 251. 17) R e i g h a r d, J. & J e n n i n g s, H. S.; 1930. Anatomy of the cat. New York. 2nd Ed., 110. 18) S i s s o n, S. & Gros s m a n, J. D.; 1953. Anatomy of the domestic animals. Phila., 4th Ed., 718. 19) T a n i g u c h i, Y., 0 h t a, Y. & Tajir i, S.; 1952. New improved method for injection of acrylic resin. Okajimas Fol. anat. jap. 24, 259. 20) Taniguchi, Y., Ohta, Y., Tajiri, S., Okano, H. & Hanai, H.; 1955. Supplement to new improved method for injection of acrylic resin. Okajimas Fol. anat. jap., 27, 401. 21) T o 1 d t, C.; 1905. Der Winkelfortsatz des Unterkiefers u. die Beziehungen der Kaumuskelen zu demselben. S. B. Ak. Wien Math-naturw. KI., Bd. 114, 381. 22) Tsusak i, T.; 1954. Anatomy of the laboratory animals. Vol. 1, Rabbit. Tokyo, 10.—in Japanese.

Expranation of Figuers

Abbreviations Used in Figures Broken line corresponds to outline of temporal muscle. cc Common carotid artery ce External carotid artery mx Maxillary artery zo Zygomatico-orbital artery fa Facial artery ft Transverse facial artery me Medial meningeal artery (=Anterior meng. art., Tsusak i) ali Inferior alveolar artery ans A. anastomotica (=R. anastomoticus, Ellenberge r) op Ophthalmic artery et Ethmoidal artery 420 Tokuo Fujimoto

pa Palpebral artery re Rete externum ri Rete internum ® Posterior auricular artery pr R. muscl. temp. primus sc Do. secundus an Do. anterior ps Do. posterior tr A short common stem of the above muscular branches and R. muscl. temp. medius ac Do. posterior accessorius sp Do. superficialis pf Do. profundus ® Superficial a temporal artery b,bib2,'aa2' a81 Temporal muscular branches mm'Anterior branch of medial temporal artery mm Posterior branch of the above ® Posterior deep temporal artery c R. superior d R. supraposterior e R. posterior at R. anterior ms Masseteric artery pt Pterygoid muscular branch ast Anastomosing branch with the same of anterior deep temporal artery cp R. communicans posterior ® Anterior deep temporal artery ® Accessory branches of the above f An intramuscular branch lateralwards ® Buccal artery g, k, 1, Muscular branches R. muscul. temp. internus j Do. externus bc Buccal branch als Superior alveolar artery ® Inferior ophthalmic artery h Muscular branch oe External ophthalmic artery la Lacrimal artery

Plate I. Fig. I. Dog, lateral view of left half. R. m. temp. primus pr at the 1st curvature and the secundus sc at the 2nd curvature, of posterior auricular artery ®. In this case, the primus, posterior auricular branch (cutting edge. x) and mastoid branch (cutting edge) are derived with a short common stem. The anterior an, anastomoses with branches of posterior deep temporal artery ® (above and below the mark an), besides, backwards with the posterior ps. Muscular branches a1, a2, a3, being equivalent for (i) of the text, of superficial temporal artery ®, and other muscular branches b1, b2 Arterial Distribution of Temporal Muscle 421

for (ii) of the text (page 5-6), originated from frontal branch of it. Small branches (zygomatico-orbital artery ?) running near zygomatic arch C). Anterior deep temporal artery 0 runs backwards along supranterior muscular margin. C. x 1. 0. Fig. 2. Dog, medial view of Fig. 1. Posterior deep temporal artery ® branches into three musculars ; superior c, supraposterior d and posterior e, and the latter two anastomose with muscular branches of posterior auricular artery 0. Main stream of anterior deep temporal artery ® runs backwards along superior muscular margin, and branch f out of it supplies superficial layer of the muscle, proceeding lateralwards along anterior muscular margin. C. x 1. 5.

Plate II. Fig. 3. Dog, medial view of right half. Fine arterial branches and capillary plexuses are removed to show general view of arteries supplying temporal muscle. Small branches (zygomatico-orbital artery ?) ® running near zygomatic arch. C. xl. O. Fig. 4. Dog, occipital region from the postero-inferior to show posterior auricular artery 0 and its ramifications of left side. R. m. temp. primus pr, secundus sc, anterior an and posterior ps. A branch from the posterior ps runs forwards and upwards beneath the fascia after proceeding a distance as thick as the muscle. C. x 1. 5. Fig. 5. Dog, medial view of left side. Three muscular branches c, d, e of posterior deep temporal artery ®, anatomoses x between anastomosing branches ast of both posterior and anterior ® deep temporals. Anterior branch at pterygoid muscular branch pt and R. supraposterior e or posterior deep temporal are well developed in this case. C. x 1. 8.

Plate HI. Fig. 6. Dog, lateral view of right posterior deep temporal artery ®. Whole ramifications of it are shown, it branches apart from inferior alveolar artery ali. C. x 1. 6. Fig. 7. Dog, lateral view of right posterior deep temporal artery ®, out of a short common stem with inferior alveolar ali. C. x 2. 4. Fig. 8. Dog, view of left side from above. Anastomosis x between anastomosing branches ast of anterior ® and posterior ® deep temporals. Ophthalmic op and ethmoidal et arteries start from maxillary artery mx close to each other, and anterior deep temporal artery ® separating from thein. A. anastomotica ans diverges from ophthalmic artery. C. x 2. O. Fig. 9. Dog, view of right side from a little above. Ophthalmic and ethmoidal take origins with a short common stem, but anterior deep temporal ® separating from the stem, and A. anastomotica ans also arises from it. C. x 2.7. Fig. 10. Dog, lateral view of left side. Ophthalmic and ethmoidal arteries originated with a short common stem and anterior deep temporal in close with it. A. anastomotica ans arises from ophthalmic artery . C. x 2. 4. Fig. 11. Dog, lateral view of left side. Ophthalmic op, ethmoidal et and anterior deep temporal arteries ® start from the maxillary mx separately. A. anastomotica ans arises from ophthalmic artery . C. x 1. 8. 422 Tokuo Fujimoto

Plate IV. Fig. 12. Cat, lateral view of right side. See explanation of Figs. 14 and 15. Mus- cular branches al, a2, b of superficial (:), and anterior 0, posterior deep temporal arteries. Large branches x out of posterior auricular 0 are auricular branches. Branches (zygomatico-orbital artery ?) ® running on the lateral of zygomatic arch. C. x 2. O. Fig. 13. Cat, medial view of left side. Posterior auricular ®, superficial temporal ®, posterior ® and anterior deep temporal arteries. C. x2. 0.

Plate V. Fig. 14. Cat, medlial view of right side. R. m. temp. anterior an, medius md, posterior ps and an auricular branch x, are originated with a short common stem tr out of posterior auricular artery ri), and besides, posterior accessorius ac. C. x 1. 7. Fig. 15. Cat, medial view of left side. See explanation of Fig. 14. R. m. temp. posterior ps is pulled backwards to show its posterior accessorius ac. C. x 2. 2. Fig. 16. Cat, view of left side from the infralateral. Posterior deep temporal and inferior alveolar arteries ali arise separately, the former from upper wall of maxillary artery mx and the latter from inferior wall. Anterior deep temporal artery ® and its three accessories ® are derived from Rete externum re. C. x2. 6. Fig. 17. Cat, view of left side from the supramedial. Divergences of the posterior deep temporal ® and the inferior alveolar au are also the same as in Fig. 18. R. communicans posterior cp originates from the posterior deep temporal ® and its accessories ® arise from anterior margin of Rete externum re, and buccal artery ® from anterolateral corner of the rete. C. x3. 0. Fig. 18. Cat, same view as Fig. 17. Posterior deep temporal ® and inferior alveolar all arteries originate from maxillary artery mx separately. R. communicans posterior cp arises from inferior alveolar artery. C. x 3. 0. Fig. 19. Cat, medial view of left side. R. communicans posterior cp, of about the same thickness as of maxillary artery, arises from it and runs forwards at the lateral of it. From superior wall of origin of this communicans, posterior deep temporal artery ® diverges. C. x 3. 6. Fig. 20. Cat, view of left side from the infranterior. Two of the communicantes arise from both inferior alveolar au and posterior deep temporal 0 arteries. Near their origins they once connect each other x, and again adhere to one, right in front of the rete x x. Anterior deep temporal artery 0 and its accessories arise from anterior margin of the rete, and buccal artery ® from anterolateral corner of it. C. x4. 3.

Plate VI. Fig. 21. k a bb t, lateral view of right side. Superficial temporal artery ® diverges from transverse facial artery ft. It derives masseteric branch ms, anterior a and posterior b temporal muscular branches. Inferior ophthalmic artery ® (lacrimal artery la) sends out temporal muscular branches h. C. x 1. 0. Fig. 22. Rabbit, medial view of right side, looking at Fig. 21 from a little above. Especially, ramifications of inferior ophthalmic artery ® are shown. C. x1.8. Arterial Distribution of Temporal Muscle 423

Fig. 23. Rabbit, view of right side from the supralateral. Buccal artery ® sends out superior alveolar artery als and medial temporal muscular branch i, then spreads to lateral temporal muscular j, buccal branch bc and masseteric branch ms. C. xl. 5. Fig. 24. Rabbit, left side. In the midst of digesting soft tissues, but osseous tissues are still existent. Relations between temporal muscular branch h out of inferior ophthalmic artery (lacrimal artery (a) and temporal branches a, b out of superificial temporal artery ®, are shown. C. x1. 2.

Plate VII. Fig. 25. Goat, lateral view of right side. Posterior auricular 0, superficial C), deep temporal ® and buccal arteries. C. xl. 6. Fig. 26. Goat, the same of Fig. 25. Superior al, medial a2, inferior ch and supraposterior a out of superficial temporal artery ®, and Rr. m. temp. superficialis sp et profundus pf from posterior auricular artery T. Anastomoses among superficial muscular branch of posterior auricular artery, superior muscular and supraposterior branches of superficial temporal artery. C. x 1. 7.

Plate VIII. Fig. 27. Goat, medial view of right side. Branching features of R. m. temp. superficialis sp and profundus pf (cf. Fig. 26, dottedlined parts of the profundus are compacted in diploe), and course of deep temporal artery ® and its first muscular branch c. C. x1. 6. Fig. 28. Goat, lateral view of left side. Superior a3, middle a2 and inferior a3 muscular branches of superficial temporal artery ®, buccal artery 0 and its muscular branches k, I and anastomoses among branches of superficial temporal and bucal arteries. C. xl. 4. Fig. 29. Goat, medial view of right side. R. m. temp. superficialis sp and profundus pf, temporal muscular branches of posterior auricular 0 and deep temporal arteries. C. xl. 0. Fig. 30. Goat, lateral view of right side. Temporal muscle and part of other compact osseous plate of temporal crest, are removed, to show the profundus pf of posterior auricular artery (D. Ramifications of this branch are carried on within the diploe, then again expose onto the temporal surface . C. x O.7.

Plate IX. Fig. 31. Human fetus (10 months old), lateral view of left side. Anterior branch mm' of medial temporal artery is distributed to subcutaneous region between zygomatico-orbital artery zo and frontal branch of superficial temporl artery ®, and posterior branch mm of medial temporal artery to temporal muscle. Origin of posterior auricular artery 0 is removed . C. xl. 2. Fig. 32. Human fetus (10 months old), view of right side from a little anterior . Anterior deep temporal artery ® branches into a branch proceeding intramuscularly and a masseteric branch Anastomoses x between anterior deep temporal ® and lateral palpebral arteries. C. x2 . 1. 424 Tokuo Fujimoto

Plate X. Fig. 33. Human fetus (10 months old), lateral view of left side. This photograph is taken in focus to anterior mm' and posterior mm branches of medial temporal artery. Course of posterior branch mm of the medial temporal and distributing surface of anterior branch mm' of it. Distributing surface is deeper than that of zygomatico-orbital artery zo. Anterior auricular branch x. C. xi. 8. Fig. 34. Human fetus, medial view of Fig. 33. Rich anastomoses between posterior branch mm of medial and posterior deep temporal arteries ®. C. xl. 8. Fig. 35. Human fetus (10 months old), right side from the anterior. Vascular bushes of orbital and buccal regions are removed and infra-orbital x and sphenoplatine x x arteries are cut off. Anterior deep temporal artery (j) devides into a branch ascending within the muscle and another infralaterally as masseteric branch C. x2. 3. Arterial distribution of the temporal muscle Plate I .

T. Fujimoto Arterial distribution of the temporal muscle Plate II .

T. Fujimoto Arterial distribution of the temporal muscle Plate .

T. Fujimoto Arterial distribution of the temporal muscle Plate IV.

T. Fujimoto Arterial distribution of the temporal muscle Plate V .

T. Fujimoto Arterial distribution of the temporal muscle Plate VI.

T. Fujimoto Arterial distribution of the temporal muscle Plate V11.

T. Fujimoto Arterial distribution of the temporal muscle Plate VI.

T. Fujimoto Arterial distribution of the temporal muscle Plate 1X,

T. Fujimoto Arterial distribution of the temporal muscle Plate X .

T. Fujimoto