Localization of infraorbital foramen and accessory infraorbital foramen with reference to facial bony landmarks: predictive method and its accuracy

Abstract

The infraorbital nerve block is used for mid-facial anesthesia. We aim to determine the location of infraorbital foramen (IOF) and accessory infraorbital foramen (AIOF) with reference to anterior nasal spine (ANS) and the lowest point of zygomaticomaxillary junction (Z) and assess the accuracy of the predictive method. Two hundred and sixteen dry skulls were examined. A reference line was drawn from ANS to Z (line A) and its length was measured (distance A). The location of IOF was predicted by using the mean vertical distance from IOF to line A (line B) which was 15.14±1.99 mm and the mean ratio of the distance between ANS and the intersecting point of line B and line A (distance D) to distance A (D:A) which was 63.35%±3.90%. Eighty-six AIOFs were found. Most of them located superomedial to IOF, except for 3 AIOFs which located in the inferolateral position. For localization the AIOF, the mean vertical distance was 19.34±3.36 mm and the mean ratio was 51.8%±5.90%. No statistically significant difference of the predicted distances for both foramens was found between sex and sides. The accuracy of the predictive method was assessed in 15 embalmed cadavers. Predicted IOFs were 50% accurate and the mean distance error of the predicted IOF was 1.10±1.44 mm lateral and 0.59±1.39 mm inferior to the exact IOF. Therefore, this study provides an alternative method for localization of IOF and AIOF which could be useful in clinical settings.

Accessory infraorbital foramen location using cone-beam computed tomography

“…Approximately 7.6% of 105 Lebanese adults have one accessory foramen, while 1% of them possessed two accessory foramina in a study by Sokhn et al [ 7 ]. A larger number of identified patients with AIOF had unilateral occurrence with a single foramen in this study (22 of 36 patients with AIOF), which is consistent with previous studies [ 6 7 8 11 ].…”

“…In 2022, Suntiruamjairucksa and Chentanez studied 216 dry skulls in Thailand and found 19.91% prevalence of AIOF [ 11 ]. Overall, the prevalence rate in this study was corroborated by a systematic review conducted in 2015 that revealed the prevalence of AIOF in skulls and cadavers ranging between 0.8–27.3% [ 19 ].…”

“…Various anatomical studies on AIOF using dry human skulls, cadavers, and CBCT have been reported [ 5 6 7 8 9 11 12 13 14 15 ]. Two studies by Agthong [ 12 ] and Apinhasmit [ 13 ] on Thai dry human skulls have showed a 4% frequency of AIOF occurrence.…”

Morphometric Analysis of Infraorbital Foramen in Human Dry Skulls

“…Another study investigated 1400 dry human skulls and found that the prevalence of foramina (>3), double, and triple foramina was 4 (0.3%), 131 (9%), and 7 (0.5%) respectively [36]. Agarwal et al [37] reported that the incidence of AIOF was 6.4% vs. 8.7%, 12.5% vs. 7.9%, and 18.2% vs. 12.5% in males and females respectively.…”

“…The morphometric and anatomical variations of infraorbital foramen is the critical factor for avoiding iatrogenic nerve injuries during surgery on the middle third of the face with safe regional anesthesia [1]. A small channel is located within the infraorbital foramen (IOF) on the maxilla of anterior face, about a centimeter below the infraorbital border [2,3]. The nerve and artery of infraorbital are accounted for the vascular-nervous supply to the face vital zones through IOF [4].…”