Revista Română de Anatomie funcţională şi clinică, macro- şi microscopică şi de Antropologie

Vol. XVII – Nr. 4 – 2018 UPDATES

Anatomical Particularities of the Dento-Maxillary System

Corina Ciupilan1*, Alexandra Pangal2, Şt. Şelaru3, R. Maxim1, C.I. Stan1 “Grigore T. Popa” University of Medicine and Pharmacy, Iasi, Romania Faculty of Medicine 1. I-st Morpho-Functional Sciences Department 2. Mother and Child Department 3. Student

ANATOMICAL PARTICULARITIES OF THE DENTO-MAXILLARY SYSTEM (Abstract): The entire is essentially represented by an entry-exit mechanism, which is supple- mented by the management of the defence, stabilization and repair elements. In effect, these so intricate and complicated transport channels have the role of maintaining the other protected systems, viable and on-going. The arterial, venous and lymphatic vascularization of the dento- maxillary system presents many interesting problems, due to the wide variability of these vessels, their distribution territory and especially by the wide practical applicability in dentistry of these variants. Material and Method: In order to highlight the vascular pedicles in three old patients, we used 3 dead bodies 3 anatomical parts (head and ) of the “Ion Iancu” Institute of Anato- my of the “Gr. T. Popa” University of Medicine and Pharmacy Iaşi. Results and discussions: The reports and its situation were quite constant, in the Carotid triangle, in the subangular mandibular region as well as in the parotid region. Conclusions: A single dead body showed the most varia- tions, both in the arterial system and in the lymphatic venous one. By correlating this fact with other circulatory system abnormalities in the same dead body, we can conclude that in this case we are talking about a congenital disorder of the circulatory system. Key-words: DENTO-MAX- ILLARY SYSTEM, CAROTID TRIANGLE, SUBANGULAR MANDIBULAR REGION, PA- ROTID REGION

INTRODUCTION The external carotid starts laterally The of the oral cavity and of the from the upper edge of the thyroid cartilage, at adjacent region come, with a few exceptions, the level of the intervertebral disc between the from the external carotid artery. The external third and fourth thoracic vertebra. It represents carotid artery is sometimes called the facial the artery of the face, neck and dura mater. It carotid, because of the vascularization of the is born in the upper edge of the thyroid cartilage superficial and deep structures of the face, (2, 3). while the internal carotid is often called by the The facial artery is also called the external name of the cerebral carotid, due to the fact ; it comes from the outer ca- that in most of its part it vascularises the brain. rotid, slightly above the lingual. In terms of The left common carotid arteries are up to reports, the facial artery has two portions: the the back of the left sternoclavicular joint (1). cervical portion of the Farabeuf triangle area, The cervical part of the common carotid delimitated by the internal jugular , ante- arteries begins at the level of the sternoclavicu- rior to Farabeuf’s thyroid-lingual-pharynx-fa- lar joint and is identical for both common ca- cial trunk and above the nerve XII (4, 5). It rotid arteries: left and right. The arteries climb then arrives in the paratonsillar region and then up and outside to the upper edge of the thyroid in the sub-maxillary region, finding itself on cartilage, where they are divided into external the inside of the parotid gland, then passes to and internal carotid arteries. the front; in the facial area, the artery passes

277 Corina Ciupilan et al. over the buccinator muscles, the canine one, and deep bifurcation branch of the external the muscle lifting the upper lip and the . Although the temporal superfi- one of the upper lip and the nose’s wing, being cial continues the external carotid path upwards covered by the skin muscle of the neck and the from an embryological and phylogenetic point major and minor zygomatic one (6). of view, the internal maxillary is the continua- The is located behind the artery, tion of the external carotid. It is born at the forming the arc end described by the artery. level of the ’s condyle cervix, passes The lingual artery comes off the antero-in- through the Juvara’s retrocondylar buttonhole, ternal side of the external carotid, underneath accompanied by the auriculo-temporal nerve. the facial artery. The lingual artery tract can be The superficial temporal artery is the exter- divided into four portions: the first portion nal bifurcation branch of the external carotid extends to the posterior edge of the hyoglossus, artery (final branch). It is born in the parotid it lies in the Carotid portion in the Farabeuf lodge at the level of the mandible’s condyle. It triangle area, the second portion is in the lat- then comes out of the parotid lodge together eral suprahyoid region, the lingual artery being with the auriculo-temporal nerve located be- situated under the hyoglossus (first it is hori- hind it. It then faces the tragus, crosses the zontal and is located in Beclard’s triangle, then posterior root of the zygomatic arch, and 2-3 ascends being located in the Pirogoff triangle); cm above it divides into two terminal branches: the third part, very short, is found in the sub- anterior (frontal) and posterior (parietal). Dur- lingual region. The artery is very sinuous and ing its course, the artery is joined by the satel- comes in relation internally with the genioglos- lite vein, which can be found either anterior or sus, externally to the muscular hiatus delimited posterior and by the auriculo-temporal nerve, by genioglossus, mylohyoid and mucosa of the which is most often found behind the artery buccal floor (7, 8 ,9). By this hiatus, the ante- (13). rior extension of the sub-maxillary gland and The venous vascularization of the dento- Wharton’s canal passes, the fourth portion is maxillary system – the venous blood of the found in the thickness of the tongue, where the head and neck is drained almost entirely by the artery has the name of ranine artery (after it internal , which connects with the has given the main collateral flank, the sublin- sternoclavicular vein behind the sternoclavicu- gual artery). lar joint to form the brachiocephalic venous The lingual artery ends at the tip of the trunk. The two trunks join together to form the tongue, where it is anastomosed with the same upper vein. Two superficial are added to artery on the opposite side, constituting May- the inner jugular vein: the er’s ranine arc (10). and the . At the root of the The ascending pharyngeal artery is the thin- neck, the two superficial veins flow into the nest collateral branch in the outer carotid ar- deep veins. The superficial and deep veins are tery. It is born from the internal face of this joined by a few anastomoses: they are joined artery, at the same level as the lingual one. It together, and the great variability of the veins turns vertically on the side wall of the pharynx, on the face and neck is caused by the large in which it branches. It is distributed to the number of possible drainages of venous blood. pharynx and especially to the upper and middle Thus, anastomotic branches can provide large constrictor (11). proportions of drainage, while typical veins The upward pharyngeal artery sends three may diminish in calibre (10, 14). pharyngeal arteries to the pharynx: upper, The intracranial veins, draining the blood of middle and inferior. In addition to these col- the brain, are connected by multiple anastomo- lateral branches, the ascending pharynx one ses with extracranial veins, allowing the blood also gives the following branches: the tym- to pass in both directions. panic branch, two meningeal branches, a pre- Anastomoses between the veins of the skull, vertebral branch, a lymph node branch, and a included in a rigid capsule, and extracranial tubular branch for the lower wall of the Eus- veins represent safety valves. Their existence tache tube (12). prevents an increase in intracranial pressure, The internal maxillary artery is the internal which may occur if the ,

278 Anatomical Particularities of the Dento-Maxillary System the main drainage of the cranial blood is com- open, favouring the entry of the air and the pro- pressed. In this case, the cerebral blood can be duction of gas embolism, almost always fatal (6). drained in many directions. The external jugular vein drains the regions These communications represent a potential that are vascularized by the internal maxillary of infection spread, primarily involving an ex- arteries and by the superficial temporal artery. tracranial vein, for example the facial vein, an The external jugular vein is formed by the un- infection that can reach the intracranial veins, ion of superficial temporal veins. with implications of the meninges and the brain. The superficial temporal artery and its The risk of retrograde spread of infection is branches are often accompanied by two veins. greatest, as the facial veins have few or no The two internal represent the valves, valves that prevent a retrograde spread exit of the large and dense pterygoid venous of the infection. This adds to the fact that the plexus that surrounds the internal maxillary intracranial veins are not collapsible (10, 15). artery in the infratemporal fossa. The sinuses of the cranial dura mater do not The anterior jugular vein represents the have their own walls, but there are spaces or second superficial vein of the neck (after the canals between the dura mater coatings. They external jugular vein). However, this vein is are bounded by the endothelium characteristic variable and often absent on one or both sides of blood vessels. The stiffness of sinus walls of the throat. Sometimes the two veins merge prevents any changes in their lumen and makes to form a medial vein of the neck. Close to the them open for spreading the infection (6). sternoclavicular joint (immediately above it), The internal jugular vein originates at the the anterior jugular vein curves around the an- level of the posterior aperture (jugular fora- terior border of the sternocleidomastoid muscle men), where the lateral venous sinus continues. and perforates the superficial cervical fascia to Immediately after the origin, the vein widens straighten laterally toward the lowermost part considerably to form the inner jugular vein golf of the sub-clavicular vein or the external jugu- situated in the jugular fossa on the posterior- lar vein (10). inferior side of petrous part of the temporal The anterior jugular vein drains the blood bone. The internal jugular vein is located be- from the skin and the superficial fascia from a neath the internal carotid artery that enters the narrow portion of the anterior part of the neck skull through the inferior opening of the ca- on both sides of the median line. rotid canal. The internal jugular vein first de- Changes in superficial neck veins and their scends with the internal carotid artery, then connection with facial veins are very important with the common carotid artery, being vaguely from the point of view of medical practice. located at the dihedral angle with a posterior These variations are explained by the fact that opening between the artery and the vein. At the the superficial veins originated in irregular sub- lower end, at the junction with the sub-clavic- cutaneous venous networks; there are many ular vein, the internal jugular vein widens again anastomoses between superficial and deep to form the internal jugular vein sinus. In its veins (4). course, the internal jugular vein exhibits one The lymph system of the dento-maxillary or more valves. The right and left internal jug- system ular veins are rarely equal in diameter, the Lymphatic vessels and lymph nodes of the right vein being usually wider than the right head and neck have great clinical significance. vein (4, 10). Malignant infections and tumours can spread Of great importance in surgical practice is through the lymphatic vessels. In spite of fre- the fact that mid-cervical aponeurosis sends quent and large communications between large extensions to large vessels at the base of the and small lymph vessels, the lymph in a par- neck (internal jugular vein, sub-clavicular vein, ticular region is transported to well-defined brachiocephalic venous trunk), a provision that lymph nodes with a precise topography. Lymph maintains these large vessels opened during nodes that receive the lymph in a particular inspiration, favouring venous return circulation region before the lymph passes through other of the head and neck. lymph nodes are called regional lymph nodes. Their disadvantage is that in the accidental They represent the first place where a patho- plagues at the base of the neck, the veins remain logical process is manifested.

279 Corina Ciupilan et al.

The posterior part of the oral cavity, the By longitudinal section of the profound sheet nasal fossa and the neighbouring parts of the of the sternocleidomastoid muscle sheath, the pharynx contain lymph tissue accumulations neck vasculo-nerve pack covered in a sheath that form distinct lymphatic organs (6). formed by the common carotid artery was shown. These accumulations of lymphatic tissue in By drawing the median vasculo-nerve pack- the pharynx form together Waldeyer’s major et of the neck, the prevertebral region with the lymphatic ring; both the pillars and the adja- prevertebral aponeurosis and, in its subdivi- cent part of the pharyngeal mucosa contain sion, the sympathetic cervical chain, is revealed. numerous solitary lymphoid follicles. This lym- The suprahyoid region was dissected to re- phatic tissue that has the role of guarding the veal the facial artery; the skin and the super- entrance in the deep parts of the digestive tract ficial cervical aponeurosis were dissected and is very well developed in children but then suf- lifted, and on one side and the other of the fers regressive changes and almost completely median line the anterior belly of the digastricus disappears in the elderly. was highlighted; we have the submaxillary The head and neck nodules are topographi- gland between the two digastricus trunks and cally constant, their large variability being in the mandible. number and size. Three triangles, particularly important in In the areas of the face and neck the lymph dental practice, were highlighted in this region: nodes are extremely important in oral surgery, the Farabeuf’s triangle (bifurcation of the prim- being divided into superficial and deep groups. itive carotid artery with its terminal branches A few nodal groups called auricular lymph and the origin of the lingual artery); the Bé- nodes (anterior, inferior and posterior) are clard’s triangle, through the area of which the found around the external ear. hypoglossal nerve passes and the superficial The anterior and lateral surface of the face lingual vein pass, and on the deep face of the is the frequent location of some accessory hyoglossus muscle the lingual artery and the lymph nodes. They are found along the facial two deep pass; the Pirogoff’s vein (accessory nodules) and are divided into triangle, through which the lingual artery with three groups (oral lymph nodes, mandibular the two satellite veins pass through the deep lymph nodes, submental lymph nodes) (10). face of the hypoglossal muscle,. The facial vein, although it has a straighter MATERIAL AND METHOD tract, accompanies the facial artery, the vein In order to highlight the vascular pedicles highlighting itself along with the dissection of in three old patients, we used 3 dead bodies 3 the facial artery. anatomical parts (head and neck) from the “Ion Along with the dissection of the face, the Iancu” Institute of Anatomy of the “Grigore T. dissection of the parotid lodge was taken into Popa” University of Medicine and Pharmacy of account, considering its relationship with some Iaşi. regions of the face and the vasculo-nerve ele- The incision of the skin was made on the ments, largely common. median line of the neck from the menton to the Parotid aponeurosis was first cut in the pos- sternal furca, then the upper extremities of the terior edge of the mandible’s vertical branch, incision were extended to the anterior edge of it was reclined posteriorly and the intermaxil- the trapezium muscle. Under the skin muscle, lary-parotid septum was highlighted, which sepa- laterally the external jugular vein was high- rates the parotid fossa from the submaxillary lighted, and its anastomosis with the facial vein one. Under parotid aponeurosis, we can find in through a venous vessel that passes through the the retromandibular fossa the parotid gland, the intermaxillary-parotid septum. adipose cellular tissue surrounding the parotid The superficial sheet of the sternocleido- gland and the elements crossing the parotid. mastoid muscle was sectioned longitudinally, Inside the parotid gland, the facial nerve is showing the muscle with its upper and lower highlighted, located superficially, deeper there inserts. The sternocleidomastoid muscle was is the external jugular vein, and the deepest is cut in its middle portion and the superficial the external carotid artery. cervical aponeurosis. In order to reveal the internal maxillary ar-

280 Anatomical Particularities of the Dento-Maxillary System tery, it is necessary to dissect the zygomatic The lingual artery has its origin constantly fossa, which has the form of a four-angle pyr- in the external carotid artery; this origin of amid with the base upward formed internally which is done in 2 cases by a separate trunk, of the exobase, and externally to the space in one case by a common trunk with the upper between the zygomatic arcade and the skull, thyroid artery and in the other case by a com- communicating with the temporal region. The mon trunk with the facial artery. tip is located downward, at the level of insertion The termination of the lingual artery through of the internal pterygoid muscle on the man- the ranine arcade is present in 2 cases. dible. The facial artery has a high facial origin, In order to highlight the content of the zy- above the hypoglossal nerve. The facial artery’s gomatic fossa, it was necessary to section the trajectory came closest to the one currently malar bone as well as the vertical branch of the described, both in the cervical and facial area, mandible after a previous disinsertion of the and the termination of the facial artery was muscles and deperiostation. constantly made in all cases by the angular The vertical section of the mandible is made artery and its anastomosis with the nasal artery, by two sections, one above the condyle and the the branch of the ophthalmic artery. other slightly below the half of the vertical The internal maxillary artery was present as branch, taking the necessary precautions to a terminal branch of the external carotid artery avoid cutting the artery and the lower dental in all 3 cases studied (2 maxillary arteries had nerve when they enter the upper orifice of the a superficial tract and one case showed a pro- lower dental channel. found character). We penetrated into the pterygomaxillary The superficial temporal artery has a con- fossa through its external wall, which repre- stant origin as a terminal branch of the external sents the pathway of communication between carotid artery. It has shown variability only in the zygomatic fossa and the pterygomaxillary relation to the auriculo-temporal nerve 1 case fossa. The external wall of the pterygomaxillary having the artery before the nerve and 2 cases fossa is represented by the gap between upper having the nerve before the artery. maxillary tuberosity and pterygoid apophysis. Its collateral and terminal branches have shown the usual trajectory. RESULTS AND DISCUSSIONS To study the venous vascularity of the dento- The homeostatic control mechanisms are maxillary system, we studied the internal and directly subordinated to the circulatory system. external jugular veins with their main affluents. There is no exception in case of the dento- Their topographic status was constant, their maxillary system. variability consisted of tributaries and anasto- Based on the study we made, we found that mosis systems. the external carotid artery exhibits a variability Among the affluents of the inner jugular of its origin as it arises from the bifurcation of vein, the most variable was represented by Fara- the common carotid artery above or below the beuf’s thyroid-pharynx venous trunk; resulting upper edge of thyroid cartilage. from the union of the 4 venous trunks it was Its reports and situation were quite constant, present in 2 cases. The other case studied flew in the Carotid triangle, in the sub-angulo-man- directly into the internal jugular vein. dibular region as well as in the Parotid region. The most varied system studied was the lym- In the sub-angulo-maxillary region, the ar- phatic system, where the only lymph node found tery retains the 1.5-1.7 cm distance from the regularly in all 3 cases studied was Küttner’s palatine tonsil, only in a case approaching 1 sub-digastric ganglion. cm from the tonsil. There were no cases in Another case found regularly was Stahr’s which the artery would approach a 0.5 cm submaxillary ganglion. distance from the tonsil, as some cases quoted Of the three cases studied, a dead body in the research literature. showed the most variations, both in the arte- There has been a case where the superior rial and lymphatic venous system. This case thyroid artery originates in the common ca- presented: high bifurcation of the common rotid artery. carotid artery; the lingual and the facial have

281 Corina Ciupilan et al. originated from a common trunk; the lingual CONCLUSIONS artery was terminated by the ranine artery, The vascular pedicles of the dento-maxillary the mesenteric artery, branch from the facial system exhibit great variability, both in terms was absent, the internal maxillary artery had of the topographic situation, as well as in terms a profound tract; the alveolo-antral artery had of collateral branches and distribution territory. a common origin with the suborbital artery All arteries studied showed variations in col- through a common trunk detached from the lateral branches and anastomosis systems. internal artery; the lingual venous trunk was The most variable system was the lymphat- shed directly into the internal jugular vein; the ic system, which is of great importance in the posterior auricular veins were shed in the oc- malignant tumour therapy of the dento-maxil- cipital vein. lary system.

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* Corresponding author

Corina Ciupilan e-mail: [email protected]

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