A Groove in the Lateral Wall of the Orbit

Home , Foramen spinosum

J. Anat. (1973), 115, 3, pp. 461-465 461 With 3 figures Printed in Great Britain A groove in the lateral wall of the orbit

GAVIN ROYLE* Department ofAnatomy, Charing Cross Hospital Medical School, 62-65 Chandos Place, London, W.C. 2 (Accepted 13 April 1973)

INTRODUCTION This paper describes a groove which was found to be present in the lateral wall of the human orbit. The groove arose either from the lateral extremity of the superior orbital fissure (Fig. 1) or from a foramen meningo-orbitale. It passed inferiorly down the orbital surface of the greater wing of the sphenoid to terminate at the posterior end of the inferior orbital fissure. The origin of the intraorbital groove suggested that it might be connected with the grooves of the middle meningeal vessels in the middle cranial fossa, and a study of both middle meningeal vessel markings and intraorbital grooves was therefore undertaken.

MATERIAL Thirty-two dried adult human skulls were examined. They were the total collection of the Anatomy Department of Charing Cross Hospital Medical School and the majority had been used for undergraduate teaching purposes. The skulls were all probably of Asiatic origin.

FINDINGS Examination of the middle cranial fossae of the 32 left hemiskulls showed that the main stem of the groove for the middle meningeal artery arose from the foramen spinosum in all 32 cases (Fig. 2). In 31 cases the main stem gave off anterior and posterior divisions (Fig. 2). In one case only the main stem continued as the posterior division, the anterior division arising from the groove lodging the sphenoparietal sinus. In all 32 left hemiskulls there was an orbital branch of the anterior division (Figs. 2, 3). The orbital branch was double in 5 cases. In 15 hemiskulls the orbital branch passed solely to the superior orbital fissure (Fig. 3), and in 2 cases it passed solely to a foramen meningo-orbitale. In the other 15 left hemiskulls the orbital branch connected with the orbit both via a foramen meningo-orbitale situated along the course of its groove and also via the superior orbital fissure. Examination of the orbits of the 32 left hemiskulls showed that a groove was present in the lateral wall in 11 cases (Fig. 1). In 10 of these the groove passed from the lateral extremity of the superior orbital fissure to the posterior end of the inferior orbital fissure (Fig. 1). In one case only the groove passed from a foramen meningo-orbitale * Present address: Department of Surgery, Royal Postgraduate Medical School, Hammersmith Hospital, London, W. 12. 30-2 462 GAVIN ROYLE

l ..M

:z .... 'pw'-;U..

FtOC

:...

....

SZ .: .,..... *W... *1,. ji B' .,:;,, Fig. 1. Example of skull orbits showing a bilateral groove (G) in the lateral orbital wall. A foramen meningo-orbitale (FMO) is present in the right orbit but the intraorbital groove passes bilaterally from the superior to the inferior orbital fissure.

OE inlIn.'Ga

FS.. : ~~~Aq C-.

S .bA._8; ZIISi; +. _s_- ..... w.r.X.'-'. , FS

: ......

szs

* >. ... .! * S ---

Fig. 2. Middle cranial fossa showing middle meningeal vessel markings. OB, Orbital branch middle meningeal artery. AD, Anterior division middle meningeal artery. PD,~~~~~~PDPosterior division middle meningeal*...... t...... artery....7S-:.;.. FS,..- Foramen: spinosum. Same skull as Fig. 1. A groove in the lateral wall ofthe orbit 463

::: !:.:s :. ;1. i: .:.. s.::...... :f;. f'::...... ':; .: ... ::

l ¢ -o *,_t ~~~~FMO *~~~~~~~~~~~~~~~~VF";~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~..M

Fig. 3. Orbital branch markings (OB) of middle meningeal vessels. LSO, left superior orbital fissure. FMO, foramen meningo-orbitale. Same skull as Fig. 1. to the posterior end of the inferior orbital fissure. The intraorbital grooves were continuous with the grooves in the middle cranial fossae made by the orbital branches of the middle meningeal vessels. Examination of the middle cranial fossae of the 32 right hemiskulls showed that the middle meningeal artery arose from the foramen spinosum and divided into anterior and posterior divisions in all 32 cases (Fig. 2). In all 32 cases there was an orbital branch of the anterior division (Fig. 3). The orbital branch was double in 4 cases. In 11 cases the orbital branch passed solely to the superior orbital fissure, and in one case it passed solely to a foramen meningo-orbitale. In 20 cases it connected with the orbit both via a foramen meningo-orbitale and also via the superior orbital fissure (Figs. 1, 3). Examination of the orbits of the 32 right hemiskulls showed a groove to be present in the lateral wall in 11 cases (Fig. 1). In 8 of these it arose from the lateral limit of the superior orbital fissure (Fig. 1). In 2 cases it arose from a foramen meningo- orbitale. In one case, 2 grooves were present, one arising from the superior orbital fissure, the other from a foramen meningo-orbitale. All grooves passed inferiorly, to terminate at the posterior end of the inferior orbital fissure. Thus a total of 64 orbits was examined and a groove was found in the lateral wall of the orbit in 22 cases (34-4 0). 464 GAVIN ROYLE Eight of the 32 skulls examined had bilateral intraorbital grooves. In 7 of these the grooves arose bilaterally from the superior orbital fissure (Fig. 1) and in one case bilaterally from a foramen meningo-orbitale. Thus 16 of the 22 orbital grooves found were bilateral (727 Go).

DISCUSSION There is no mention of a groove in the lateral wall of the orbit, either as a normal occurrence or as an anomaly, in the anatomical texts of the following authors and editors: Thane (1890), Frazer (1920), Whitnall (1932), Wolff (1954), Duke-Elder (1961), Davies (1967) and Romanes (1972). The paper of Low (1946) on an anomalous middle meningeal artery is the only reference that could be found mentioning a groove in the lateral wall of the orbit. This, however, was a single case of a skull with bilateral absence of the foramen spinosum. An intraorbital groove passed bilaterally from a foramen meningo- orbitale to the inferior orbital fissure. Low deduced that in this single skull the middle meningeal artery arose bilaterally from the infraorbital artery. In the 32 skulls described in this paper a foramen spinosum was present in all cases. In one skull, however, there was a bilateral groove similar to that described in Low's case, passing from a foramen meningo-orbitale to the inferior orbital fissure. There was also one case of a similar unilateral groove. The other 19 examples of an intraorbital groove described in this paper arose from the superior orbital fissure. Wood Jones (1911) states that the middle meningeal vessel markings on the inside of a skull are made by the veins, but indicate the position of both vein and artery. The intraorbital grooves described in this paper were found to be continuous with those of the orbital branches of the middle meningeal vessels in the middle cranial fossae. Thus it is probable that the intraorbital grooves indicate the position of blood vessels. Hayreh (1962) and Hayreh & Dass (1962) undertook a series of studies of the ophthalmic artery and its branches by injection techniques. An anastomosis between the middle meningeal artery and the recurrent meningeal branch of the lacrimal artery was found to be usual. The anastomosis passed either through a foramen meningo- orbitale or through the superior orbital fissure. Anastomoses were also noted between the lacrimal artery and the infraorbital artery and between the infraorbital artery and muscular branches of the ophthalmic artery. Thus an anastomosis may be postulated in some cases between the infraorbital and middle meningeal artery via the lacrimal artery. It is probable that the intraorbital groove described in this paper indicates the position of blood vessels taking part in such an anastomosis.

SUMMARY Examination of 32 dried adult human skulls showed a groove to be present in the lateral wall of 22 of the 64 orbits (34-4 %o). The intraorbital groove was bilateral in 16 of the 22 cases (72-7 %o). The groove probably lodges blood vessels taking part in an anastomosis between the middle meningeal and infraorbital blood vessels. No previous reference to this groove occurring in skulls with normal origins of the middle meningeal arteries could be found. A groove in the lateral wall of the orbit 465 I would like to thank Professor T. W. A. Glenister for advice concerning this paper, Mr R. S. Barnett (Department of Photography, Charing Cross Hospital Medical School) for taking the photographs and Miss S. Nichols for secretarial assistance.

REFERENCES DAVIES, D. V. (1967). Gray's Anatomy (34th Edition). London: Longmans, Green. DUKE-ELDER, S. & WYBAR, K. C. (1961). System of Ophthalmology. Vol. ii. Anatomy of the Visual System. London: Henry Kimpton. FRAZER, J. E. (1920). The Anatomy ofthe Human Skeleton (2nd Edition). London: Churchill. HAYREH, S. S. (1962). The ophthalmic artery. III. Branches. British Journal of Ophthalmology 46, 212-247. HAYREH, S. S. & DASS, R. (1962). The ophthalmic artery. I. Origin and intracanalicular course. British Journal of Ophthalmology 46, 65-97. Low, F. N. (1946). An anomalous middle meningeal artery. Anatomical Record 95, 347-351. ROMANES, G. J. (1972). Cunningham's Textbook of Anatomy (11th Edition). London: Oxford University Press. THANE, G. D. (1890). Quain's Anatomy (10th Edition, Vol. ii, part i). Osteology. London: Longmans, Green. WHITNALL, S. E. (1932). The Anatomy of the Human Orbit (2nd Edition). London: Oxford University Press. WOLFF, E. (1954). The Anatomy ofthe Eye and Orbit (4th Edition). London: Lewis. WOOD JONES, F. (1911). On the grooves and origins upon the ossa parietalia commonly said to be caused by the arteria meningea media. Journal ofAnatomy andPhysiology 46, 228-236.