Anatomical study of the zygomaticofacial foramen and zygomatic canals communicating with the zygomaticofacial foramen for zygomatic implant treatment: a cadaver study with micro-computed tomography analysis

In the present study, anatomical assessment of zygomaticofacial foramina (ZFFs) and zygomatic canals communicating with ZFFs were performed using cadaver micro-computed tomography images. It was suggested that all ZFFs were located above the jugale (Ju)-zygomaxillare (Zm) line, which is the reference line connecting the Ju and Zm, and most were located in the zygomatic body area (ZBA). The anteroposterior position of the ZFF in the ZBA was within a middle to posterior region and was most often located slightly posteriorly in males and closer to the middle of the region in females. The mean distance from the Ju-Zm line to the ZFF in the ZBA was 12.36 mm (standard deviation [SD] 1.52 mm) in males and 11.48 mm (SD 1.61 mm) in females. In zygomatic canals communicating with ZFFs, most zygomatic canals were type I canals, communicating from the zygomaticoorbital foramen and harboring the zygomaticofacial nerve, and the others were type II canals, communicating from the zygomaticotemporal foramen and located near the posterior margin of the frontal process. These results provide useful anatomical information for preventing nerve injury during surgical procedures for zygomatic implant treatment.

Lateral rectus pulley concerning the orbital wall. Area of a stereotyped bony insertion

Purpose

To examine the lateral rectus muscle pulley and its bony insertion concerning the orbital rim and periorbita.

Design

Prospective. An observational anatomic study.

Methods

Study population: Twenty postmortem orbits (10 right, 10 left) of 10 Caucasian cadavers (8 females, 2 males; age range at death, 57-100 years; median age, 79.5 years) fixed by the Thiel method.Intervention: The floor of the temporal fossa was exposed, and a bone window on the lateral wall of the orbit, posterior to the sphenozygomatic suture, was created, keeping the periorbita intact. The lateral canthus and lateral palpebral ligament were isolated and opened, and the eyelids were folded back. The frontozygomatic suture was identified, and the orbital septum opened adjacent to the orbital rim. The conjunctiva was opened at the limbus, and the lateral rectus insertion was isolated. The bone pillar containing the frontozygomatic suture and the insertion of the periorbita and the pulley was isolated and removed en bloc. The lateral rectus muscle was isolated and excised.Main outcome measures: Position of the pulley ring on the lateral rectus muscle belly and its bony attachment area in the lateral wall of the orbit.

Results

The pulley bony attachment was roughly quadrilateral with an approximate area of 90 mm2, 3 mm (mean, range 1-5 mm) posteroinferior to the frontozygomatic suture and 1 mm posterior to the orbital rim. The anterior margin of the pulley sleeve was found at 21.0 mm (median, p25-75 20.0-22.8) from the scleral insertion.

Conclusions

The lateral rectus pulley is stereotyped in its position in the muscle belly and its bony insertion, coinciding with the point of greatest adhesion of the periorbita to the anterior part of the lateral wall of the orbit.

Anatomical variations of the zygomaticofacial foramen and its related canal through the zygomatico-orbital and zygomaticotemporal foramina in dry human skulls

PURPOSE

The aim of this study is to reveal the location of the zygomaticofacial foramina, the variations of their numbers, and their connections between the zygomatico-orbital and zygomaticotemporal foramina.

METHODS

Ethics committee approval of our study was received by the Istanbul Medical Faculty Clinical Research Ethics Committee (date:30.07.2021, number:358356). 171 zygomatic bones of unknown gender from the Department of Anatomy, Istanbul University, were included in this study. The number of zygomaticofacial foramina and their connections with the zygomatico-orbital foramen and the zygomaticotemporal foramina were examined. Also, the morphometric distances between the zygomaticofacial foramen were calculated. Evaluation of the data was done with SPPS v.21.

RESULTS

The number of zygomaticofacial foramina was found as 299. It was found single, double, three, four, five and six foramina, in 52 (30.4%), 52 (30.4%), 24 (14.03%), 10 (5.85%), 5 (2.93%), 1 (0.58%) zygomatic bone, respectively. Zygomaticofacial foramen was absent in 27 (15.8%) bones. Of these 299 foramina, 129 were found to be connected with zygomatico-orbital foramen and 23 with zygomaticotemporal foramen. It was noted that 147 zygomaticofacial foramina had no connection with any foramina. The distances between the zygomaticofacial foramen and the frontozygomatic suture, temporal process, maxillary process, the lowest point of the zygomatic bone, and orbital rim were found as 25.30 ± 2.81mm, 18.74 ± 3.56mm, 21.56 ± 4.16mm, 18.72 ± 2.57mm, 6.67 ± 3.27mm, respectively.

CONCLUSION

Consequently, the location and variations of ZFF are of great importance for maxillofacial surgery and regional block anesthesia. Knowing its location and variations will help prevent complications during any surgical intervention in this region.

Frequency and location of the zygomaticofacial foramen and its clinical importance in the placement of zygomatic implants

PURPOSE

Anatomical knowledge of the zygomatic region is important, because the zygomatic nerve and its branches may suffer lesions during surgical procedures in the periorbital region. The position and frequency of zygomaticofacial foramina (ZFF) may vary between individuals, and between one side and the other in the same individual. In the present study, we analysed the presence and location of ZFF, as well as the distance between them and the orbital cavity, in macerated skulls of adult individuals.

METHODS

We examined 287 macerated skulls, of individuals of both sexes, analysing the frequency and location of ZFF and the distance from the ZFF to the margin of the orbital cavity (OC).

RESULTS

Zygomaticofacial foramina are very frequent structures which tend to appear singly. They are generally located in the temporal process of the zygomatic bone, but in many cases, they may be located in the mid portion of the bone. They also tend to appear at the same distance from the OC when left and right sides are compared. Sex was an important factor in determining differences in ZFF; the distance from the ZFF to the margin of the OC was greater in males than in females. Sex, age, side and skin colour did not affect the frequency and location of the ZFF.

CONCLUSION

We consider that the mid portion of the zygomatic bone is the safest place to anchor zygomatic implants (ZI), since ZFF are less frequently located there than in the temporal process of the zygomatic bone.

Radiographic evaluation of percutaneous transfacial wiring versus open internal fixation for surgical treatment of unstable zygomatic bone fractures

Introduction

The fixation of unstable zygomaticomaxillary complex (ZMC) fractures can be achieved by open reduction with rigid internal fixation (ORIF) and/or by closed reduction with percutaneous transfacial Kirschner wire fixation (CRWF). The aim of this study was to tomographically assess the symmetry and the protrusion of the cheekbone with unstable ZMC fractures that had been treated by ORIF vs. CRWF.

Materials and methods

Sixty patients exhibiting a surgically unstable tetrapodal ZMC fracture were included in this multicenter retrospective study. The coordinates of 5 landmarks representing the zygomatic protrusion were comparatively studied on the healthy and on the broken side using preoperative and postoperative tridimensional computed tomography (CT) scans or cone beam CT.

Results

No significant difference was found in the zygomatic protrusion irrespective of the surgical technique that was used. The zygomatico-maxillary ansa was found to be the most complicated area to reduce, particularly in the frontal plane with both the CRWF and the ORIF technique (p₁ = 0.001 and p₂ = 0.0009, respectively). There was no difference in terms of the level of complications, while the mean duration of the surgery was significantly less for the CRWF group.

Conclusion

With good postoperative radiographic outcomes, the CRWF can be proposed as an alternative or in association with the ORIF technique for fixation of tetrapodal fractures of the ZMC.

Anatomical Description of Zygomatic Foramina in African American Skulls

PURPOSE

The zygomaticofacial/temporal/orbital nerve is a terminal branch of the zygomatic nerve and exits the orbit through zygomatic foramina. The nomenclature in the literature varies with some studies identifying all 3 foramina on the malar surface of the zygoma, while others describe each along different aspects of the zygoma. In this study, foramen on the malar surface of the zygoma is termed zygomatic foramen, and the authors describe anatomical variations in the position and number of these foramina in an African American population.

METHODS

Sixty-two African American skulls from the Hamann-Todd collection of the Cleveland Museum of Natural History were studied. The primary outcome was the number of zygomatic foramina on the malar surface of the zygomatic bone. Secondary outcomes included the location of foramina relative to the orbital rim and the frontozygomatic suture. Mean and standard deviation were used to describe measurements. Chi-squared and Wilcoxon signed rank tests were used to analyze measurements between left and right hemicrania.

RESULTS

The average number of foramina was 1.98 ± 0.93. More foramina were found on the right (2.13 ± 0.98) when compared with the left (1.68 ± 0.79; p = 0.001). The average distance between the lateral-most and medial-most foramina was 9.7 ± 5.0 mm. The distance from the orbital rim to the lateral foramen was 8.4 ± 4.2 mm, and distance from the orbital rim to the medial foramen was 7.7 ± 2.1 mm. The frontozygomatic suture was 22.9 ± 3.9 mm from the lateral foramen and 27.9 ± 3.6 mm from the medial foramen.

CONCLUSION

The locations of the foramina in relation to the frontozygomatic suture and orbital rim were consistent with other populations. However, in this African American population, more zygomatic foramina were noted compared with previously published results in Korean, Indian, Brazilian, and West Anatolian populations. Surgeons should be cognizant of zygomatic foramina in this population to reduce potential neurovascular complications.

Zygomaticofacial, Zygomaticoorbital, and Zygomaticotemporal Foramina

This study aimed to assess the anatomical and morphometric characteristics of the main zygomaticofacial (ZFF), zygomaticoorbital (ZOF), and zygomaticotemporal (ZTF) foramina in Brazilian dry skulls. 61, 69, and 42 skulls for ZFF, ZOF, and ZTF were evaluated by a single calibrated examiner for format, transverse and vertical diameters, and distances from the foramina to anatomical landmarks. Paired t test, Wilcoxon test, Pearson and Spearman correlations were used. Circular outline was the predominant format for ZFF and ZTF, while oval format was the most frequent for ZOF. Median distances from ZFF to frontozygomatic and zygomaticomaxillary sutures were higher on right and left sides of the skulls, respectively (P < 0.005). Mean ZOF transverse diameter was significantly higher on the right sides of the skulls and presented positive correlation between sides (P < 0.05). No differences were observed for mean vertical diameter and distance from the ZOF to the inferolateral angle of the orbit (P > 0.05). No significant difference was found for distance from the ZTF to zygomatic arch between sides (P > 0.05), although there was a positive correlation (P < 0.05). Significant differences were found when analyzing the anatomical and morphometric aspects of ZFF, ZOF, and ZTF.

Anatomical Study of the Zygomaticofacial Foramen and Its Related Canal

The zygomaticofacial branch (ZFb) of the zygomatic nerve passes through the lateral wall of the orbit anterolaterally and traverses the zygomaticofacial foramen (ZFFOUT). However, in terms of intraorbital course, only a few studies have focused on the orbital opening of the ZFb (ZFFIN) and related canal. Therefore, this study aimed to locate the orbital opening and exit of the ZFb of the zygomatic nerve. Twenty sides from 10 fresh frozen cadaveric Caucasian heads were used in this study. The vertical distance between inferior margin of the orbit and ZFFIN (V-ZFFIN), the horizontal distance between the lateral margin of the orbit and ZFFIN (H-ZFFIN), diameter of the ZFFIN (D-ZFFIN), the vertical distance between the inferior margin of the orbit and ZFFOUT (V-ZFFOUT), the horizontal distance between the lateral margin of the orbit and ZFFOUT (H-ZFFOUT), and the diameter of the ZFFOUT (D-ZFFOUT) were measured, respectively. The ZFFIN were located 5.1 ± 2.0 mm superior to the inferior margin of the orbit and 4.3 ± 1.6 mm medial to the lateral margin of the orbit. The ZFFOUT was located 1.2 ± 2.9 mm inferior to the inferior margin of the orbit and 1.1 ± 3.0 mm lateral to the lateral margin of the orbit. The diameter of the ZFFOUT was significantly larger than that of the ZFFIN. Additional knowledge of the zygomatic nerve and its branches might decrease patient morbidity following invasive procedures around the inferolateral orbit.

Study of anatomical variations of the zygomaticofacial foramen and calculation of reliable reference points for operation

Dissection on to the facial aspect of the zygoma is common in procedures of the midface for trauma, craniofacial deformity, and cosmesis. These procedures carry the risk of injury to the neurovascular structures that exit from the zygomaticofacial foramen (ZFF). The purpose of this study was to map the ZFF, and to establish reliable reference points from which to identify it before and during operation. We also aimed to compare the anatomy of the ZFF between sexes and among geographical populations. A total of 429 adult skulls from nine geographical sites were used. A cross-line laser was superimposed on to each zygoma to generate consistent landmarks (lines 1 and 2) from which to measure the ZFF, and the number of ZFF on each zygoma was recorded. The site and incidence of ZFF differed significantly among geographical populations, but not between sexes. Of all 858 sides, no foramina were found in 16.3%, one foramen in 49.8%, two foramina in 29%, three in 3.4% and four in 1.4%. A total of 93% of foramina were within a 25mm diameter zone (ZFF zone) centred 5mm anterior to the intersection of lines 1 and 2 on the right zygoma, and 94% were within equivalent measurements on the left. Using these landmarks, we propose a new method of identifying a ZFF zone that is irrespective of sex or geographical population. This technique may be useful in the prevention of iatrogenic damage to the ZFF neurovascular bundle during procedures on the midface and in local nerve blocks.

Bilateral Absence of the Zygomatic Nerve and Zygomaticofacial Nerve and Foramina

The zygomaticofacial branch (ZFb) of the zygomatic nerve travels along the inferolateral angle of the orbit, traverses the zygomaticofacial foramen (ZFF) in the zygomatic bone, and then perforates the orbicularis oculi muscle to finally reach the skin of the malar area, which it innervates. The bilateral absence of the ZFb and the ZFF was found in an 80-year-old Caucasian cadaver. In addition, both zygomatic nerves were absent. A thin nerve arising from the lacrimal nerve passed below it and gave rise to the lacrimal branch and a communicating branch to the lacrimal nerve. This then entered the small bony canal, which opened at the medial aspect of the lateral wall of the orbit on the right and left sides. The bilateral absence of the ZFb of the zygomatic nerve and its foramen appears to be uncommon but should be realized during surgery or invasive procedures over the cheek or infraorbital region. The additional absence of both zygomatic nerves is exceptional.

The small foramina of the orbit and periorbital region: assessment with multi detector computed tomography

BACKGROUND

Familiarity with the variants of the foramina of the orbit and periorbital region is important in planning anesthesiological blocks and during orbital and maxillofacial surgery to avoid damage to nerves and vessels.

PURPOSE

To assess the visibility and the incidence of variants of the small foramina of the orbit by multidetector computed tomography (MDCT).

MATERIAL AND METHODS

The MDCT scans of 400 orbits from 200 patients were evaluated retrospectively. Slice thickness of the reconstructed images were in the range of 0.5-1.0 mm. The visibility and the variants of the foramen supraorbitale, the foramen infraorbitale, the foramen zygomaticofaciale, the foramen ethmoidale anterius et posterius, and the foramen cranio-orbitale were assessed using three-dimensional reconstruction tools.

RESULTS

The foramen infraorbitale (100%; n = 400), foramen supraorbitale (99.5%, n = 398), foramen zygomaticofaciale (76.5%; n = 307), and foramen zygomatico-orbitale (74.5%; n = 298) were most reliably detected by MDCT, while the foramen ethmoidale anterius (58.7%; n = 235) et posterius (56.7%; n = 225) were depicted less frequently. The foramen cranio-orbitale could not be identified in any case. Doubling was found for the foramen supraorbitale in 3.25% (n = 13), the foramen infraorbitale in 1.75% (n = 7), the foramen zygomaticofaciale in 16% (n = 64), and the foramen zygomatico-orbitale 14% (n = 56). Three foramina zygomatico-orbitale and foramina infraorbitale were found in 1.5% (n = 6) and in 0.5% (n = 2) of orbits, respectively.

CONCLUSION

The foramina supraorbitale, infraorbitale, zygomatico-orbitale, and zygomaticiofaciale and their variants are well visible on MDCT. Knowledge of the exact number of these small foramina is relevant for preoperative evaluation.

Location of facial foramina and mandibular angle from cone beam computed tomographic scans

PURPOSE

The current study's purpose was to determine morphometric analysis of all facial foramina and mandibular angle relative to surgical landmarks from cone beam computed tomographic scans.

MATERIALS AND METHODS

Three-dimensional computed tomographic scans were reconstructed from data of 100 patients (200 sides) aged between 19 and 76 years. Morphometric measurements of all facial foramina relative to surgical landmarks were taken. Mandibular angle was measured.

RESULTS

There was no statistically significant difference between the left and right sides for all parameters (P > 0.05). Therefore, we found bilateral symmetry in the position of all facial foramina and mandibular angle. However, statistically significant differences were determined in sexes in some of these parameters and mandibular angle.

CONCLUSIONS

The knowledge about locations of facial foramina and mandibular angle is important for performing local nerve block and surgery in the face to avoid the neurovascular structures. This study provides a guideline for locations of facial foramina and mandibular angle, which may help surgeons to understand the nerve location precisely during surgery.

The transeyelid midface lift

The transeyelid approach to midface lift is an elegant approach for mild descent of malar soft tissue. The subciliary approach is the most commonly used and technically less challenging for surgeons experienced in facelift techniques. This technique in midface rejuvenation also has the advantage of ease of combining with other periocular and mid and upper face rejuvenation, such as blepharoplasty and forehead lift. Complication is rare with lid malposition, scaring, and temporary nerve function impairment being the most common.

Zygomaticofacial foramen location accuracy and reliability in cone-beam computed tomography

OBJECTIVE

This study aimed to evaluate the possibility of detecting the zygomaticofacial foramen (ZFF) in cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

This study evaluated ZFFs in 151 macerated skulls (302 zygomatic bones, ZBs) by physical inspection, in which the presence and diameters of the ZFFs were determined. These data were compared with the CBCT images of the skulls to determine the accuracy of CBCT in detecting ZFFs. The diameters were measured by insertion of steel wires with known thicknesses into the ZFFs. The CBCT images were acquired by an i-CAT Classic® (International Imaging Sciences, Hatfield, PA) connected to a workstation (Model ITOX Midtower Workstation; Imaging Sciences International®) with a 20-inch Eizo monitor. The images were generated in coronal, sagittal and axial slices to evaluate the best tomographic plane for ZFF visualization.

RESULTS

The incidence of ZFF found by physical inspection was one foramen in 44% of ZBs (n = 133), two foramina in 28% (n = 86), three foramina in 8% (n = 24) and four foramina in 1% (n = 2). ZFF was absent in 19% (n = 57) of ZBs. The average diameter was 0.57 mm (± 0.27 mm). All foramina were observed in all tomography images.

CONCLUSION

This preliminary study supports the conclusion that a CBCT scan has excellent accuracy in evaluating ZFFs.

Location of the zygomatico-orbital foramen on the inferolateral orbital wall: clinical implications

PURPOSE

To describe the location of the zygomatico-orbital foramen on the inferolateral orbital wall.

METHODS

This anatomic study examined 28 orbits of 14 dry human adult skulls. The zygomatico-orbital foramen was identified by passing a thin wire from the zygomatico-facial foramen to its orbital aspect and a thin flexible ruler was used to measure 1) the distance perpendicular to the closest point on the inferior orbital rim, 2) the distance from the inferior orbital fissure, and 3) the distance from the area used for retrobulbar injections.

RESULTS

The mean distance from the zygomatico-orbital foramen to the closest point on the inferior orbital rim was 4.7 mm (range from 1 to 7 mm). The mean distance from the inferior orbital fissure was 14.9 mm (range from 10 to 18 mm). The mean distance from the area of retrobulbar injection was 6.0 mm (range from 3 to 10 mm).

CONCLUSIONS

The location of the zygomatico-orbital foramen within the inferolateral orbit is quite variable. This is the first study to attempt to quantify its proximity to the site of retrobulbar injection. We conclude that it is an important anatomical structure to consider when giving retrobulbar anesthesia, especially given the variability in technique among ophthalmologists.