A study of anatomical relations of supraorbital notch and foramen

H. Firdus Fareen, M.S. Thenmozhi

Department of Anatomy, Saveetha Dental College and Hospitals. 162, Poonamelle High Road, Chennai-600077.

*Corresponding Author E-mail: aafreenhyathbasha@gmail.com

ABSTRACT:

Aim and Objective: The supraorbital foramen is a bony elongated path located above the orbit (eye socket) and under the forehead. The supraorbital foramen lies directly below the eyebrow. The aim of the study is to analyse the anatomical relations of supra orbital notch and foramen in south indian skulls at saveetha dental college Chennai.

Materials and methods: The study will be done in 21 dry skulls. The occurrence of supraorbital foramen is examined in those skulls. The distance between the supraorbital foramen from nasal midline, and its horizontal and vertical diameter is measured using a Vernier calliper.

Results: The mean distance of SOF/SON from nasal midline on the right are 30.18±3.78 and on the left are 29.51±3.01. and The mean vertical and horizontal diameters of SOF on the right side are 2.45±2.96 and 4.69±1.72, while those on the left side are 1.01±2.90 and 4.55±1.53, respectively

Conclusion: This study helps to determine the precise location of supraorbital foramen or notch in relation to various anatomical structures which is essential for performing invasive surgical procedures involving anesthetic and therapeutic procedures.

KEYWORDS: Supraorbital foramen, suoraorbital notch, nasal midline.

INTRODUCTION:

Supraorbital foramen (SOF) or notch is present at the junction of lateral two-third and medial one third of supraorbital margin. According to previous studies in 25% of cases supraorbital notch is converted into foramen by ossiﬁcation of periosteal ligament bridging it. (1) The supraorbital foramen/notch transmits the neurovascular structures namely the supraorbital artery, veins and nerve and supplies the area around the eye, skin over the forehead. These neurovascular structures are prone to get injured during various procedures performed at their areas of supply and will lead to damage of the structures being supplied by them. (2).

In this study, measurements were made on cadaveric dry skulls of South India to determine the location and dimensions of the supraorbital notch (SON) or the supraorbital foramen (SOF). (3) Morphometric study of the supraorbital foramen/notches is essential to decide their normal location from anatomical reference points and facilitates various procedures like surgical, diagnostic, therapeutic, local anesthetic and other invasive procedures, without causing any injury to the vital structures present within. (2) hence, this study of the supraorbital foramen will therefore entail a careful examination of adult human skulls in order to ascertain the prevalence of notches and foramina. (4)

MATERIALS AND METHODS:

31 dry south Indian skulls of unknown age and sex were examined from the collection of Anatomy department of Saveetha dental college, Chennai. The skulls selected for the study were without any abnormalities. The following parameters were studied to evaluate the location of SOF on both sides of skull.

a) distance of SOF/SON from nasal midline

a) vertical diameter of SOF/SON

b) horizontal diameter of SOF/SON

The measurements were done using a veriner calliper scale. Observations thus made was compiled, tabulated and statistical data was calculated.

DISTANCE OF SOF FROM NASAL MIDLINE

HORIZONTAL DIAMETRE OF SOF

VERTICAL DIAMETRE OF SOF

Observations:

The observations made on the dimensions of SOF are summarized in (Table1). The mean distance of SOF/SON from nasal midline on the right are 30.18±3.78 and on the left are 29.51±3.01. and The mean vertical and horizontal diameters of SOF on the right side are 2.45±2.96 and 4.69±1.72, while those on the left side are 1.01±2.90 and 4.55±1.53, respectively (Table 1).

DISCUSSION:

The supraorbital notch (SON) or supraorbital foramen (SOF) is situated along the supraorbital margin, which is entirely formed by the frontal bone. The supraorbital margin is interrupted at the junction of its sharp lateral two-thirds and rounded medial one-third by the supraorbital notch or foramen. Supraorbital notch or foramen transmits supraorbital nerve and vessels. Supraorbital nerve is the larger terminal branch of the frontal nerve, which is a branch of ophthalmic division

of trigeminal nerve and it traverses through the SON/SOF and divides into medial and lateral branches to supply the palpebral filaments to the upper eyelid, conjunctiva and skin of the scalp as far back as the lambdoid suture. Supraorbital artery is a branch from the ophthalmic artery which in turn is from the internal carotid artery. It leaves the orbit through the SON/SOF, divides into superficial and deep branches to supply the skin and muscles of the upper eyelid, forehead and scalp. The supraorbital vein unites with the supratrochlear vein near the medial angle of the eye to form the facial vein. (5) The injury of supraorbital vessels and nerves may lead to complications such as haematoma formation in the subgaleal plane, anaesthesia and hair loss. (6) To preserve these neurovascular bundles coming out from supraorbital foramina, proper understanding of the exact position of SON/F is of great importance. Various studies quoted the anatomical variations in incidences of supra orbital notch and foramen in adult human skulls. In our study, the mean distance between the SOF and midline was found to be 30.18±3.78 and 29.51±3.01mm on right and left sides respectively. It is interesting to note that in one of the studies conducted on North Indian skulls, the average distance between the SOF/SON and the midline was 24 mm, which is slightly lesser than the current observation. However, a much equal (29 mm) distance between the SOF and midline was observed in a study conducted on a Korean population. Since large variation is seen in location of SOF/SON from midline, another important landmark which is considered is fronto-zygomatic suture. This suture is easily palpable on the skin at a notch along the lateral orbital margin at the level of the lateral end of palpebral ﬁssure. (1) Hence, it may be helpful for the surgeon in anticipating the location of SON/F during the routine coronal dissection. (7) .

The mean vertical diameter of SOF on the right and left side was observed to be 2.45±2.96 and 1.01±2.90mm respectively. which is comparatively less with that of the report given by Sharma N et al.[1] 2.75 ± 0.55 mm on the right side and 2.35 ± 0.23 mm over the left side, also less than the value reported by Trivedi et al.[3] 2.49mm on the right side and 2.45 mm over the left side. (2). The mean transverse diameter of SOF on the right and left side was observed to be 4.69±1.72 and 4.55±1.53 which coincides with that of reported by Sharma N et al.[6] 4.62 ± 0.83mm on the right side and 4.31 ± 0.51 mm on the left side and found to be more than that of reported by Trivedi et al.[8] 3.67 mm on the right side and 3.54 mm over the left side. (2). The transverse and vertical diameters of the SOF displayed significant results while comparing both sides. Information regarding the size and symmetry of the skull foramina is helpful for radiologists when diagnosing difficult pathologies of the skull foramina by using computed tomography and magnetic resonance imaging. Such parameters prove to be very informative in locating the position of foramen during anaesthetic block and surgical interventions. (1)

CONCLUSION:

The knowledge provided by various measurements recorded in this study will be helpful for the surgeons to localize these important maxillofacial openings and avoid injuring the neurovascular bundles and facilitate surgical, local anesthetic, and other invasive procedures. (6) The results from these measurements will help them identify the correct location of the supraorbital foramen during surgeries to prevent the injury or damage of any other nerves passing near the foramen. The landmarks described could be identiﬁed and eﬀectively applied with success in various clinical scenarios, thereby decreasing the risk of failures and complications. (1)

REFERENCES:

1. Nidhi Sharma, Rohit Varshney, Naﬁ S Ahmad Faruqi, Farah Ghaus. Supraorbital Foramen - Morphometric Study and Clinical Implications in Adult Indian Skulls. Acta Medica International Jan - Jun 2014; Vol 1 Issue 1.

2. S. Ilankathir, M. P Mathivanan. Localization and Morphometric Study of Supraorbital Foramen in Adult Human Dry Skulls. Sch. J. App. Med. Sci., August 2015; 3(5B):1946-1948.

3. L. Sri Varsha, M.S. Thenmozhi. Incidence and Morphological Study of Supraorbital Foramen in South Indian Skulls. J. Pharm. Sci. & Res. Vol. 7(9), 2015,711-713.

4. Nishtha Singh, Alok K. Singh, Rakesh Gupta, Syed H.H. Zaidi and Navneet S. Chauhan. A study of the supraorbital notch and foramen in North Indian human crania. Eur. J. Anat. 18 (1): 21-25 (2014).

5. Ashwini LS, Mohandas Rao KG, Sharmila Saran, and Somayaji SN. Morphological and Morphometric Analysis of Supraorbital Foramen and Supraorbital Notch: A Study on Dry Human Skulls. Oman Med J. 2012 Mar; 27(2): 129–133.

6. Jaiswal Sonia, Pasricha Navbir , Bedi Ravinder Singh. A study of the anatomy of supraorbital notch and foramen and its clinical co-relates. Int J Anat Res 2016, Vol 4(1):1869-73.

7. Wandee Apinhasmit, P, Supin Chompoopong, Dolly Methathrathip, Roengsak Sansuk, Wannapa Phetphunphiphat. Supraorbital Notch/Foramen, Infraorbital Foramen and Mental Foramen in Thais: Anthropometric Measurements and Surgical Relevance. J Med Assoc Thai 2006; 89 (5): 675-82.

8. D. J. Trivedi, P. S. Shrimankar, V.B. Kariya, C. A. Pensi. A Study of Supraorbital Notches And Foramina In Gujarati Human Skulls. NJIRM 2010; Vol. 1(3). July-Sept.

Received on 09.05.2016 Modified on 27.05.2016

Research J. Pharm. and Tech. 2016; 9(7):769-771.

DOI: 10.5958/0974-360X.2016.00146.3

MEAN DISTANCE OF SOF/SON FROM NASAL MIDLINE (in mm)		MEAN VERTICAL DIAMETRE OF MAIN SOF (in mm)		MEAN HORIZONTAL DIAMETRE OF MAIN SOF (in mm)
RIGHT	LEFT	RIGHT	LEFT	RIGHT	LEFT
30.18±3.78	29.51±3.01	2.45±2.96	1.01±2.90	4.69±1.72	4.55±1.53