Morphometric analysis and anatomical variations of infraorbital foramen: a study in adult North Indian population

Location of infraorbital and accessory infraorbital foramina in Iranian population: a retrospective radiological study with crucial clinical implications

PURPOS

The location of infraorbital foramen (IOF) and the prevalence of accessory IOF vary among different populations. It may lead to infraorbital nerve (ION) blockage during surgery. This study aimed to assess the IOF location and AIOF frequency in Iranian people.

METHOD

In this retrospective cross-sectional study, 500 paranasal sinus computed tomography scans of adults were examined using the INFINITT PACS system.

RESULT

The distance from IOF to infraorbital margin (IOM), mid-pupillary line (MPL), midsagittal line (MSL), canine eminence (CE), and skin thickness (ST) was 8.97 ± 1.79, 5.73 ± 1.84, 24.86 ± 2.23, 20.39 ± 3.47, and 10.90 ± 2.59 mm, respectively. The vertical and transverse diameters of the foramen were 3.03 ± 0.65 and 3.71 ± 0.76 mm, respectively. In addition, the shape of 63.5% of the foramina was oval. The prevalence of AIOF was 9%, and its most common location was superomedial to IOF.

CONCLUSION

We believe that in this study, landmarks like IOM, MPL, MSL, CE and ST could help the clinicians localize IOF and improve the ION anesthesia success rate. Furthermore, the occurrence of AIOF should be considered by physicians to reduce the chance of injuries to the infraorbital neurovascular complex.

The relative locations of the supraorbital, infraorbital, and mental foramina: A cadaveric study

The purpose of this study is to investigate the applicability of the current surgical guideline stating that the main facial foramina that transmit cutaneous nerves to the face (supraorbital notch/foramen, infraorbital foramen, and mental foramen) are equidistant from the midline in European and Hispanic populations. Previous studies suggest this surgical guideline is not applicable for all ethnicities; however, to our knowledge, no data have been published regarding the accuracy of this guideline pertaining to the Hispanic population. An experimental study was performed on 67 cadavers donated to the Human Anatomy Program at UT Health San Antonio. The supraorbital, infraorbital, and mental foramina were dissected and midline structures including the crista galli, internasal suture, anterior nasal spine, and mandibular symphysis were identified. The distance from each foramen to midline was recorded using a digital caliper. For all cadavers/ethnicities studied, the supraorbital, infraorbital, and mental foramina were 25.32 mm, 29.57 mm, and 25.55 mm to the midline, respectively. Thus, the infraorbital foramen is located significantly more lateral compared to the supraorbital (p < 0.0001) and mental foramina (p < 0.0001). After dividing the sample based on ethnicity, this relationship was also true for the European sample and tended to be true for the Hispanic sample. Significant anatomical variations exist in the current surgical guideline stating that the supraorbital foramen, infraorbital foramen, and mental foramen are equidistant from the midline. Clinicians may need to adjust their methodology during surgical procedures of the face in order to optimize patient care.

False and true accessory infraorbital foramina, and the infraorbital lamina cribriformis

The infraorbital nerve (ION) and artery (IOA) course in the infraorbital canal (IOC) to exit through the infraorbital foramen (IOF). Few previous studies brought evidence of accessory IOF. Evaluation of the IOF in Cone Beam Computed Tomography (CBCT) is more accurate to determine whether or not foramina of maxilla are supplied by canaliculi deriving from the IOC. We performed a retrospective anatomical study of the CBCT files of 200 patients. An accessory infraorbital foramen located inferior to the infraorbital margin (AIOF) was found in 18/200 right maxillae and in 13/200 left ones. Canaliculi deriving from the IOC supplied accessory foramina in the sutura notha- AIOF(SN) - in 15 maxillae. Noteworthy, the AIOF(SN)-negative maxillae displayed the SN and the vascular foramina of Macalister. In 94% of cases the AIOF were unique. A single maxilla (3%) had a double AIOF. In a different case (3%) were found three accessory infraorbital foraminules transforming the anterior wall of the antrum into a veritable lamina cribriformis infraorbitalis. A single prior study distinguished AIOF from AIOF(SN), while most of different other ones were performed on dry bones. Therefore, the reports of prevalence for the number and location of AIOF should be regarded with caution. Foramina of the SN could equally get intraosseous and extraosseous supply, this distinction being accurately made in CBCT.

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.