Morphometric study on the infraorbital foramen in relation to sex and side of the cranium in northeastern Brazil

Positional Variation of the Infraorbital Foramen in Caucasians and Black Africans from Britain: Surgical Relevance and Comparison to the Existing Literature

BACKGROUND

Midface augmentation and orbital surgery carry an inherent risk of injury to the infraorbital vascular bundle, especially the infraorbital nerve where it exits the infraorbital foramen (IOF). This can result in significant morbidity for the patient, including paresthesia and neuralgia. Studies report significant heterogeneity in IOF position according to gender, ethnicity, and laterality. A knowledge of the relationship of the IOF to regional soft tissue, bony landmarks, and its variation among ethnicities is likely to reduce iatrogenic injuries.

METHODS

A single-center retrospective computed tomography (CT)-based study was conducted. Twenty Caucasians and 20 Black Africans patients were selected from an existing radiologic database at Moorfields Eye Hospital, London, UK. DICOM image viewing software (Syngo, Siemens Healthineers) was used to record the position of the IOF using standardized sagittal and axial views.

RESULTS

There was a statistically significant difference in the horizontal position of the IOF in the 2 races (P = 0.00). The combined measurements were used to derive a rectangular zone of variability measuring 14.30 mm by 10.60 mm. This zone was found to lie 3.50 mm below the infraorbital rim, 7.10 mm medial to the piriform aperture, and 11.60 mm from the lateral orbital rim.

CONCLUSION

A sound knowledge of key facial landmarks is necessitated when performing midface augmentation and orbital surgery. An anatomical safe zone depicting the variation of the IOF will help reduce iatrogenic injury to the infraorbital nerve and prevent patient morbidity.

Anatomic Study of Accessory Infraorbital Nerves and Foramina: Application for a Better Understanding of Complications of Le Fort Fractures and Osteotomy

PURPOSE

Neurosensory disturbance of the infraorbital nerve is one of the many complications of the Le Fort osteotomy. An accessory infraorbital foramen (AIOF) can be one reason for such complications. Therefore, the purpose of the present study was to elucidate the distribution of the accessory infraorbital nerve (AION) arising from the AIOF.

MATERIALS AND METHODS

We dissected 60 sides from 30 fresh-frozen cadaveric heads.

RESULTS

An AIOF was found in 36.7% of the heads examined. When an AIOF was detected, the nerve was traced distally and proximally. The mean horizontal and vertical diameters of the AIOF were 1.64 ± 0.88 and 1.75 ± 0.87 mm, respectively. The largest AIOF was 3.42 × 3.79 mm. All AIOFs were located medial to the infraorbital foramen. Most of the AIONs (87.5%) had branches to the external nose.

CONCLUSIONS

The AION should always be remembered by surgeons to allow for improved outcomes and better understanding of the complications such as those occurring after Le Fort osteotomy.

The Infraorbital Foramen in a Sample of the Lebanese Population: A Radiographic Study

Purpose

The infraorbital foramen (IOF) is an important structure in the maxillofacial region through which important structures pass. Wide variability in the shape and location of the infraorbital foramen among different populations and ethnic groups is present. So we conducted this study to specify the IOF shape, the presence of accessory foramina, and the IOF location with respect to anatomic landmarks in the Lebanese population.

Patients and method

A cross-sectional retrospective study was conducted on cone-beam computed tomography (CBCT) scans of 105 Lebanese adult patients. Images were reviewed and the shape, diameter, and location of the IOF were recorded. The presence of an accessory foramen was also noted. Then, SPSS version 21 (IBM Corp., Armonk, NY, US) was used for the statistical analysis.

Results

Concerning the distances from the IOF to the anatomic landmarks, the distance from the IOF to the infraorbital margin measured 7.98 ± 1.41 mm, to the lateral nasal wall 10.61 ± 2.39 mm, and to the midline 24.71 ± 2.09 mm. When distances were compared, a statistical difference was only identified in the distance between the IOF and the lateral nasal wall (p=0.00), and the distance between the IOF and the middle of the face (p=0.016) between genders. For the shape of the IOF, 54.8% of the IOF were circular in shape, and this shape was the most common shape in females. An accessory foramen was present in 8.6% of the cases. Finally, the mean diameter of the foramina measured 3.71 ± 0.63 mm.

Conclusion

The IOF shows a lot of variability between different populations. Thus, the exact location should always be remembered during an infraorbital nerve (ION) block, during maxillofacial surgeries, and during esthetic procedures involving the facial region in order to prevent unnecessary complications.

Anatomy of Infraorbital Foramen: Influence of Sex, Side, and Cranium Size

Several researchers have analyzed the collocation of infraorbital foramen, but no study has so far considered the possible influence of cranial size.Three measurements (distances from anterior nasal spine, inferior orbital rim, angle at the intersection between the line from anterior nasal spine and the transversal plane parallel to the Frankfurt plane) were taken on 100 skulls belonging to a contemporary skeletal collection. In addition, maximum cranial length, maximum cranial breadth, cranial height, and bizygomatic breadth were measured, together with 2 indices (horizontal cephalic index and Giardina Y-index). Differences according to sex and side were assessed through 2-way analysis of variance test (P <0.05). Measurements showing statistically significant differences according to sex were further assessed through 1-way analysis of covariance test including cranial measurements and indices as covariates (P <0.05).Statistically significant differences according to sex and side were found respectively for the distance from anterior nasal spine and the angle at infraorbital foramen (P <0.05). One-way analysis of covariance test verified that the sexual dimorphism of infraorbital foramen- anterior nasal spine distance was independent from the general measurements of cranium.The present study first proved that sexually dimorphic parameters useful for the localization of infraorbital foramen do not depend upon the cranium size.

Supraorbital nerve exits: positional variations and localization relative to surgical landmarks

Significant variations exist in the occurrence, form, and position of supraorbital nerve exits through the frontal bone. Detailed knowledge of the positional variations of supraorbital exits is important to ensure safe and successful regional anesthesia, and to avoid iatrogenic nerve injuries during surgery of the orbitofacial region. Supraorbital nerve exits from 116 sides of 58 dry intact adult skulls (37 male and 21 female) in a Sri Lankan population were examined to determine the morphological features and the precise position in relation to the facial midline, temporal crest of frontal bone, and frontozygomatic suture. A majority of supraorbital nerve exits existed as notches (73.8%) and the rest as foramina (26.2%). Accessory exits were seen in 18.9% skulls. Of the skulls examined, 55.1% displayed bilateral supraorbital notches, 8.6% had bilateral supraorbital foramina, and 36.3% had a notch on one side and a foramen on the contralateral side. In males, the supraorbital nerve exit was located 23.64±3.49 mm laterally from the facial midline, 27.86±2.76 mm medially from the temporal crest of the frontal bone, 28.66±2.56 mm from the frontozygomatic suture, and 2.12±1.07 mm above the supraorbital margin in the case of a foramen, and in females 22.69±3.28 mm laterally from the facial midline, 26.32±3.02 medially from temporal crest of frontal bone, 27.29±3.05 from the frontozygomatic suture, and 2.99±1.49 mm above the supraorbital margin when it existed as a foramen. The observations made in this study will be useful when planning a supraorbital nerve block and surgery in the supraorbital region.

The Infraorbital Foramen Is Located Midway Between the Nasospinale and Jugale: Considerations for Infraorbital Nerve Block and Maxillofacial Surgery

Identification of the infraorbital foramen is important in infraorbital nerve block and the prevention of iatrogenic injury of the infraorbital nerve in maxillofacial surgeries. This study assessed the location of 887 infraorbital foramina from 518 adult crania of varied sex and population. The study assessed the midpoint of a line segment spanning from nasospinale to jugale (NS-J) relative to the infraorbital foramen. The mean distance of the NS-J midpoint from the infraorbital foramen was 2.1 ± 1.9 mm (mean ± SD) with a mode of 0 mm (266:887; 30%). The NS-J midpoint was located in the same plane or inferior to the infraorbital foramen in 98.4% of sides (873:887). There were no significant differences between sexes, populations, or sides with regard to the NS-J midpoint to infraorbital foramen distance. The NS-J midpoint can be used to locate the infraorbital foramen in both females and males of varied populations regardless of craniofacial diversity. The results of this study will aid in infraorbital nerve block procedures and maxillofacial surgery.

Morphometric Analysis of the Infraorbital Foramen: The Clinical Relevance

The present study was conducted to ascertain the shape, size, presence of accessory foramina, direction, and the precise position of the infraorbital foramen (IOF) in relation to the inferior orbital margin (IOM), anterior nasal spine (ANS), nasion (Na), maxillary teeth, and supraorbital foramen/notch (SOF/N) in adult skulls in a Sri Lankan population. Fifty-four skulls (42 males and 12 females) were analyzed. The IOF was oval in shape (38.6% and 36.3% on the right and left side, resp.) in a majority of skulls. The direction of the IOF was mostly medially downward (48.6%). Accessory foramina were found in 7.4% of the skulls. The infraorbital foramina were located at a mean distance of 6.52 ± 2.03 mm and 7.30 ± 1.57 mm, vertically below the IOM on the right and left side, respectively; 33.81 ± 2.68 mm and 34.23 ± 2.56 mm from the ANS on the right and left side, respectively; and 42.37 ± 3.52 mm and 42.52 ± 3.28 mm from the Na on the right and left side, respectively. In relation to the upper teeth the majority of IOF (37.5% and 55.9% on the right and left side, resp.) were located in the same vertical axis as the tip of the buccal cusp of the maxillary second premolar tooth.