The surgical anatomy of the deep temporal nerve: A cadaveric study.

BACKGROUND: The aims of this study were to investigate the surgical anatomy of the deep temporal nerve (DTN) and find (fixed/static) anatomical landmarks that could be used during surgery to localise the DTN branches. METHODS: Ten hemifaces of Dutch cadavers were dissected at the Department of Anatomy of the Radboudumc. Landmarks and measurements of interest were number of branches of the DTN, distance from the tragus to the DTN, and distance from the cranial and caudal parts of the posterior root of the zygomatic bone until the DTN. RESULTS: In this cadaveric study, 10 hemifaces were dissected (male, n = 6 [60%]; female, n = 4 [40%]) with an equal left/right side division. The number of deep temporal branches varied from 2 (30%) to 3 (70%) per side. The mean distance to the tragus varied from 40 to 53 mm, with a mean distance of 44.3 ± 4.4 mm. The mean distance from the cranial part of the posterior root of the zygomatic bone to the DTN varied from 29 to 35 mm, with a mean distance of 31.3 ± 2.1 mm. The distance from the caudal part of the posterior root of the zygomatic bone to the DTN varied from 8 to 17 mm, with a mean distance of 13.4 ± 3.4 mm. CONCLUSION: This study investigated the surgical anatomy and landmarks used for identification of the DTN and its branches. It suggested using firm landmarks for nerve identification, such as the posterior root of the cranial and/or the caudal zygomatic bone.

A Clinical and Anatomical Study on the Localization of the Temporal Branch of the Facial Nerve Crossing the Zygomatic Arch / Estudio Clínico y Anatómico sobre la Localización del Ramo Temporal del Nervio Facial que Cruza el Arco Cigomático

SUMMARY: To clarify the path of the temporal branch of facial nerve (TB) crossing the zygomatic arch (ZA). Eighteen fresh adult heads specimens were carefully dissected in the zygomatic region, with the location of TB as well as its number documented. The hierarchical relationship between the temporal branch and the soft tissue in this region was observed on 64 P45 plastinated slices. 1. TB crosses the ZA as type I (21.8 %), type II (50.0 %,), and type III (28.1 %) twigs. 2. At the level of the superior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 36.36±6.56 mm, for the posterior trunk is 25.59±5.29 mm. At the level of the inferior edge of the ZA, the average distance between the anterior trunk of TB and the anterior part of the auricle is 25.77±6.19 mm, for the posterior trunk is 19.16±4.71 mm. 3. The average length of ZA is 62.06±5.36 mm. TB crosses the inferior edge of the ZA at an average of 14.67±6.45 mm. TB crosses the superior edge of the ZA at an average of 9.08±4.54 mm. 4. At the level of the ZA, TB passes on the surface of the pericranium while below the SMAS. The TB obliquely crosses the middle 1/3 part of the superior margin of the ZA and the junction of the middle 1/3 part and the posterior 1/3 part of the inferior margin of the ZA below the SMAS while beyond the periosteum. It is suggested that this area should be avoided in clinical operation to avoid the injury of TB.

El objetivo de estudio fue esclarecer el trayecto del ramo temporal del nervio facial (RT) que cruza el arco cigomático (AC). Se disecaron la región cigomática de 18 especímenes de cabezas sin fijar de individuos adultas y se documentó la ubicación del RT y su número de ramos. La relación jerárquica entre el ramo temporal y el tejido blando en esta región se observó en 64 cortes plastinados o P45. 1º El RT cruza el AC como tipo I (21,8 %), tipo II (50,0 %) y tipo III (28,1 %). 2º A nivel del margen superior del AC, la distancia promedio entre el tronco anterior de RT y la parte anterior de la aurícula fue de 36,36±6,56 mm, para el tronco posterior fue de 25,59±5,29 mm. A nivel del margen inferior del AC, la distancia promedio entre el tronco anterior del RT y la parte anterior de la aurícula era de 25,77±6,19 mm, para el tronco posterior era de 19,16±4,71 mm. 3º La longitud media de RT fue de 62,06±5,36 mm. EL RT cruzaba el margen inferior del AC a una distancia media de 14,67±6,45 mm. El RT cruzaba el margen superior del AC a una distancia media de 9,08±4,54 mm. 4º Anivel del AC, el RT pasaba por la superficie del pericráneo mientras se encuentra por debajo del SMAS. El RT cruza oblicuamente el tercio medio del margen superior del AC y la unión del tercio medio y el tercio posterior del margen inferior del AC por debajo del SMAS, más allá del periostio. Se sugiere que esta área debe evitarse en la operación clínica para evitar la lesión de la RT.

Subfascial dissection and extended temporal muscle detachment for middle fossa approach.

BACKGROUND: The soft tissue dissection for the middle fossa approach requires adequate management of the neuro, vascular, and muscular structures in order to maximize exposure and diminish morbidities. METHODS: An incision anterior to the tragus is performed, extending from the zygomatic process to the superior temporal line. The superior temporal artery is exposed, followed by a subfascial dissection of the frontalis nerve. The temporal muscle is dissected and released from the zygoma. All cranial landmarks are exposed for the 5 × 5 cm temporal fossa craniotomy. CONCLUSION: This novel approach provides a safe and adequate access to perform an extended middle fossa craniotomy.

Anatomic landmarks for masseteric nerve identification: Anatomic study for a new reference point.

The masseteric nerve is often used as a donor nerve in the treatment of facial paralysis. Even if several anatomical studies described landmarks for its identification, their main disadvantages are the anatomical variability and the changes due to surgery. Sixteen dissections were performed on cadaveric specimens. The masseteric muscle (MM), the zygomatic arch (ZA), the masseteric nerve (MN) and the zygomatic branch of the facial nerve (ZB) were identified and their relationships were measured. The relationships between MN and ZB resulted to be constant, with MN intersecting ZB at a depth of 0,78 cm in the muscle, 1,6 cm below ZA and 0,8 cm from the posterior border of MM. The measures obtained demonstrated as the main zygomatic branch of the facial nerve can be a suitable landmark for the identification of the masseteric nerve, with no variations due to the surgical procedure or patient characteristics.

Masseteric-zygomatic nerve transfer for the management of eye closure-smile excursion synkinesis.

OBJECTIVE: The purpose of this study is to illustrate the efficacy of masseteric-to-zygomatic nerve transfer to address eye closure-smile excursion synkinesis after facial nerve paralysis. BACKGROUND: Synkinesis after facial nerve paralysis represents a wide range of facial movement disability. One manifestation is involuntary smiling with eye closure and a concomitant reduction of oral commissure movement with attempted smile ("frozen smile") - arising as a result of aberrant fibers populating the zygomatic branch-muscle complex. This is a particularly difficult area to treat with conservative management. We propose a single-stage procedure to sever the dysfunctional zygomatic nerve and perform a masseteric-zygomatic nerve coaptation to recover a voluntary smile. METHODS: We present a case series of eight patients with eye closure/smile excursion synkinesis who underwent single-stage masseteric-zygomatic nerve transfer by a single surgeon. The surgical technique and indications for surgery were reviewed. Patients underwent facial movement analysis using Emotrics. RESULTS: We analyzed the pre- and post- surgical photographic images of 8 patients with synkinesis (7 female, 1 male). Masseteric-facial nerve transfer was performed from 18 months to 22 years after the initial facial paralysis. Eyelid and brow positioning were more symmetric after surgery, with discrepancy between affected and unaffected side decreasing from 2.1 to 1.0 mm (p < .05) and 1.74 to 1.29 mm (p < .05), respectively. Symmetry of smile excursion postoperatively was also improved with commissure excursion discrepancy decreasing from 8.8 to 3.78 mm (p < .05). Discrepancy in the smile angle when comparing affected to unaffected side improved postoperatively from 10.3 to 5.2 degrees (p < .05). Improvement in oral commissure height was noted, but not statistically significant. CONCLUSIONS: The masseteric-zygomatic nerve transfer is a useful technique for the treatment of eye closure/smile excursion synkinesis after failure of chemodenervation and/or physical therapy.

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.

Anatomical study of the zygomatic and buccal branches of the facial nerve: Application to facial reanimation procedures.

The facial nerve is responsible for any facial expression channeling human emotions. Facial paralysis causes asymmetry, lagophthalmus, oral incontinence, and social limitations. Facial dynamics may be re-established with cross-face-nerve-grafts (CFNG). Our aim was to reappraise the zygomaticobuccal branch system relevant for facial reanimation surgery with respect to anastomoses and crossings. Dissection was performed on 106 facial halves of 53 fresh frozen cadavers. Study endpoints were quantity and relative thickness of branches, correlation to "Zuker's point", interconnection patterns and crossings. Level I and level II branches were classified as relevant for CFNG. Anastomoses and fusion patterns were assessed in both levels. The zygomatic branch showed 2.98 ± 0.86 (range 2-5) twigs at level II and the buccal branch 3.45 ± 0.96 (range 2-5), respectively. In the zygomatic system a single dominant branch was present in 50%, two co-dominant branches in 9% and three in 1%. In 66% of cases a single dominant buccal twig, two co-dominant in 12.6%, and three in 1% of cases were detected. The most inferior zygomatic branch was the most dominant branch (P = 0.003). Using Zuker's point, a facial nerve branch was found within 5 mm in all facial halves. Fusions were detected in 80% of specimens. Two different types of fusion patterns could be identified. Undercrossing of branches was found in 24% at levels I and II. Our study describes facial nerve branch systems relevant for facial reanimation surgery in a three-dimensional relationship of branches to each other. Clin. Anat. 32:480-488, 2019. © 2019 Wiley Periodicals, Inc.

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 ±â€Š2.0 mm superior to the inferior margin of the orbit and 4.3 ±â€Š1.6 mm medial to the lateral margin of the orbit. The ZFFOUT was located 1.2 ±â€Š2.9 mm inferior to the inferior margin of the orbit and 1.1 ±â€Š3.0 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.

Facial Nerve Axonal Analysis and Anatomical Localization in Donor Nerve: Optimizing Axonal Load for Cross-Facial Nerve Grafting in Facial Reanimation.

BACKGROUND: Donor nerve axonal count over 900 in two-stage reconstructions using cross-facial nerve grafts is possibly associated with improved outcomes in facial reanimation. Facial nerve axonal analysis was performed to determine the ideal location for optimizing axonal load. Correlation of axonal number, branch diameter, and age was also assessed. METHODS: Twenty-eight fresh unpreserved cadaveric hemifaces were dissected exposing the extracranial facial nerve branches. Axonal counts at 2-cm intervals from the pes anserinus along branches inserting into the zygomaticus major muscle were taken, noting position relative to the zygomatic arch, posterior ramus border, lateral border of the zygomaticus muscle, and anterior parotid gland border. Nerves were fixed, sectioned, and stained with SMI-31 antineurofilament stain for digital axonal analysis. RESULTS: All specimens had one or more intraparotid zygomatic branches with over 900 axons, and 96 percent had an extraparotid branch with over 900 axons. The likelihood that a zygomatic branch would have over 900 axons at its last intraparotid point (mean, 6 mm posterior to the parotid border) was 92 percent (range, 67 to 100 percent) in contrast to 61 percent (range, 25 to 100 percent) when sampled at the first extraparotid point (mean, 14 mm anterior to the parotid border). Nerve cross-sectional area was positively correlated to its axonal count (R° = 78 percent; p < 0.0001), with nerve diameter over 0.6 mm predicting over 900 axons. Age did not correlate with axonal counts. CONCLUSIONS: Branches with adequate axonal load were found in all specimens. The likelihood of adequate branch selection improved from 61 percent to 92 percent with short retrograde intraparotid dissection. Nerve diameter correlated with axonal load.

Silent squamous cell carcinoma invading the orbit following the course of the zygomaticotemporal nerve.

PURPOSE: To evaluate the clinical and histopathological characteristics of silent skin squamous cell carcinomas (SCC) with invasion routes to the orbit. METHODS: Retrospective case studies. Clinical records and histopathological material, therapy and complications were evaluated, together with MRI imaging analyses and literature review on the anatomy of the lateral orbital wall in relation to the zygomatico-temporal nerve channel. RESULTS: Two recent cases of metastatic SCC from het lateral zygomatic region to het orbit are reported. Originally the skin tumors of the first case was diagnosed as benign, but a review of the pathology of these skin tumors showed an invasive SCC. The second case was diagnosed as an atypical SCC. Analysis of possible invasion routes, using both computer tomography (CT) and magnetic resonance imaging (MRI), indicated neither skin nor bone involvement. However, the lateral temporal fossa near the entrance of the zygomatico-temporal channel showed small tumors and pseudo-cysts. The original skin tumor specimens did not show malignant tissue in the surgical margins nor intra- or perineural invasion. CONCLUSIONS: Because the course of the zygomatico-temporal nerve bundle was exactly in line with the original skin tumor, the channel and the orbital tumors, this route should be considered when malignant orbital tumors have a history of or a relation with a periorbital skin-tumor.

[DIAGNOSTICS OF POSITION OF THE MOTOR AND TRIGGER POINTS: OF THE CHEWING MUSCLES FOR ZYGOMATIC COMPLEX FRACTURES].

Existing treatment methods of zygomatic complex fractures, which are complicated by contrac- ture of the masseter as a result of displaced bone fragments, have to be improved. Lack of muscle relaxation leads to the formation of local hypertonicity. In spasmodic muscle fibers varies perfusion and hypoxia occurs, which is accompanied by the release of inflammatory mediators and activation of pain receptors. Over time, areas formed local hypertonicity specific trigger points that contain multiple sensory loci and include one or more sensitive nerve endings. A device for the effective electromyographic study of masseters as a source of their condition and the dynamics of changes in masticatory muscles during patient treatment by improving the fixation system on the face of the patient and the introduction of more perfect spatial coordinate system for mathematical calculations masseter motor position (or triggered) point. Patients were examined before and in the dynamics of treatment according to our methodology, which included proper masseter relaxation, reposition and fixation of bone fragments and further medical therapy.

Reconstruction for facial nerve defects of zygomatic or marginal mandibular branches using upper buccal or cervical branches.

BACKGROUND: Many reconstructive methods for facial nerve defects have been described previously, such as the greater auricular nerve graft, the sural nerve graft, or hypoglossal-facial nerve anastomosis. Herein, we want to instruct a new technique of repairing facial nerve defects of zygomatic or marginal mandibular branches using upper buccal or cervical branches when we have to face segment defects of facial nerve with wide gaps between facial nerve stumps. METHODS: The distal part of the upper buccal or cervical branches with peripheral tissue was removed to repair the defects of zygomatic or marginal mandibular branches. Clinical and electromyographic examinations were employed to investigate the clinical efficacy of this method. RESULTS: Killed branches of facial nerve included 11 marginal mandibular branches and 16 zygomatic branches in 26 patients. The length of facial nerve defects ranged from 0.9 cm to 2.3 cm with a mean gap of 1.87 cm (SD, 0.89). Seventeen patients finally showed a superb facial function (grade I), 6 patients an excellent outcome (grade II), and 3 patients a good result (grade III). A fair or poor result (grade IV or V) was not observed. CONCLUSIONS: The essence of this method is equivalent to direct facial-facial nerve anastomosis which seems to be able to avoid synkinesis between the upper and lower face. We believe that this method is adaptable to the length of facial nerve defects less than 2 cm.

Transection of inferior orbital fissure contents for improved access and visibility in orbital surgery.

BACKGROUND: Selective inferior orbital fissure (IOF) content transection for the purpose of surgical access to the posterior orbital floor is a technique that facilitates visualization of the posterior bony ledges of traumatic orbital floor defects. It also has potential advantages in achieving stable placement of reconstructive materials. Although not new, the surgical technique has not yet been described, and the morbidity of the technique has not been quantified. This article describes the procedure and assesses the morbidity specific to the division of related neural structures. METHODS: The technique and surgical anatomy are described and illustrated with intraoperative photographs. Postoperative assessment of neural structures relevant to the division of IOF contents is performed. These values are compared with the nonoperated side to evaluate the morbidity of the technique. RESULTS: The technique, which is consistently used by the senior author in the repair of orbital floor defects with very small posterior ledges or which extend to and involve the IOF, facilitates better visualization of the posterior ledge and posterolateral ledge in such cases. Surgical outcomes including facial sensation and lacrimal function on the operated side remain within the reference range and are not significantly different when compared with the contralateral nonoperated side. CONCLUSIONS: Selective IOF transection aids in the direct visualization of the posterior bony ledges in the repair of posterior orbital floor defects. It therefore may facilitate the placement of reconstructive materials on bony ledges circumferentially, providing stable reconstruction, potentially reducing implant-related complications without causing increased morbidity.

Perineural invasion of cutaneous squamous cell carcinoma along the zygomaticotemporal nerve.

The vast majority of periocular squamous cell carcinoma spreads intraorbitally along the supraorbital and infraorbital nerves into the cavernous sinus. A patient presented with a history of resected squamous cell carcinoma and pain in the zygomatic distribution. She was found to have temporalis involvement of the malignancy and invasion of the zygomaticotemporal nerve by histopathology. She underwent aggressive resection and adjuvant treatment with no evidence of recurrence at 8-month follow up. This case illustrates an uncommon route of squamous cell carcinoma spread through the zygomaticotemporal sensory nerve distribution.

Branching of the foramen rotundum. A rare variation of the sphenoid.

The human orbit communicates with the middle cranial fossa through several canals and openings. Some of them (optic canal, superior orbital fissure) are constant, others (meningo-orbital foramen, Warwick's foramen, metoptic canal) are less frequent. Here we report a rare variation of the foramen rotundum which, opening into the orbit with a branching canal, represented a further connecting pathway between the orbit and the middle cranial fossa. Such variation was detected in about 1.06% of individuals and it was almost always located on the right side. Only in one cases it could be found left-sided and in another skull it was spotted bilaterally. The vari- ation consisted of the branching of a 5 mm long canal from the lateral wall of the foramen rotun- dum that opened into the orbit. In general the diameter of the canal was comprised between 0.5 and 0.6 mm but it could be as large as 1 mm or as thin as 0.2 mm. The canal, straight and directed slightly superolaterally, likely transmitted the zygomatic nerve and/or part of the infraorbital nerve. To our knowledge, an independent entrance through a dedicated canal of such nerves has never been reported. The surgeons operating in this region, either neurosurgeons or ophthalmologists, should be aware of the possible variation in the course of these nerves.

Evaluation of facial nerve following open reduction and internal fixation of subcondylar fracture through retromandibular transparotid approach.

The objective of this study was to evaluate any damage to the facial nerve after a retromandibular transparotid approach for open reduction and internal fixation (ORIF) of a subcondylar fracture. We studied 38 patients with 44 subcondylar fractures (3 bilateral and 38 unilateral) treated by ORIF through a retromandibular transparotid approach. All patients were followed up for 6 months. Postoperative function of the facial nerve was evaluated within 24h of operation, and at 1, 3, and 12 weeks, and 6 months. Variables including type of fracture, degree of mouth opening, postoperative occlusion, lateral excursion of the mandible, and aesthetic outcome were also monitored. Nine of the 44 fractures resulted in transient facial nerve palsy (20%). Branches of the facial nerve that were involved were the buccal (n=7), marginal mandibular (n=2), and zygomatic (n=1). In the group with lateral displacement, 2/15 showed signs of weakness, whereas when the fracture was medially displaced or dislocated 7/23 showed signs of weakness. Of the 9 sites affected, 7 had resolved within 3 months, and the remaining 2 resolved within 6 months. The mean (range) time to recovery of function was 12 weeks (3-6 months). There was no case of permanent nerve palsy. The retromandibular transparotid approach to ORIF does not permanently damage the branches of the facial nerve. Temporary palsy, though common, resolves in 3-6 months. Postoperative occlusion, mouth opening, and lateral excursion of the mandible were within the reference ranges. We had no infections, or fractured plates, or hypertrophic or keloid scars.

Rapid and accurate identification of cut ends of facial nerves using a nerve monitoring system during surgical exploration and anastomosis.

PURPOSE: Surgical exploration and end-to-end neurorrhaphy is the preferred management for traumatic facial nerve injury. Traditionally, finding the cut ends of facial nerves depends mainly on a surgeon's experience. In this study, a nerve monitoring system to help the surgeon quickly and accurately identify, confirm, and locate the cut ends of facial nerve branches was investigated. PATIENTS AND METHODS: Six patients with traumatic facial nerve injury were selected, and the nerve monitoring system was applied during the surgical process of facial nerve exploration and anastomosis. Operation time and surgical outcome were used to evaluate the effect of this method. RESULTS: The surgical procedures required 6 to 15 minutes (mean, 10 minutes) for detecting and dissecting each cut end of a facial nerve branch. All cut ends of injured facial nerve branches were found during surgery in all 6 patients, and no intraoperative complications were encountered. The postoperative function of the facial nerve, evaluated by clinical examination and diagnostic electroneurography, was satisfactory and symmetrical in all 6 patients at 3 months. CONCLUSION: Using a nerve monitoring system could effectively help surgeons achieve rapid and accurate identification of the cut ends of facial nerves during surgical facial nerve exploration for traumatic facial nerve injury.

Three-dimensional courses of zygomaticofacial and zygomaticotemporal canals using micro-computed tomography in Korean.

The zygomatic nerve (ZN), which originates from the maxillary nerve at the pterygopalatine fossa, enters the orbit through the inferior orbital fissure. Within the lateral region of the orbit, the ZN divides into the zygomaticofacial (ZF) and zygomaticotemporal (ZT) nerves. The ZF and ZT nerves then pass on to the face and temporal region through the zygomaticoorbital foramen and enter their own bony canals within the zygomatic bone. However, multiple zygomaticofacial and zygomaticotemporal canals (ZFCs and ZTCs, respectively) can be observed, and their detailed intrabony courses are unknown. The aim of this study was clarify the three-dimensional intrabony courses and running patterns of the ZFCs and ZTCs, both to obtain a detailed anatomical description and for clinical purposes. Fourteen sides of the zygomatic bones were scanned as two-dimensional images using a micro-computed tomography (CT), with 32-µm slice thickness. Intrabony structures of each canals were three-dimensionally reconstructed and analyzed using Mimics computer software (Version 10.01; Materialise, Leuven, Belgium). We found that some ZTC was originated from ZFC. In 71.4% of the specimens, the ZTC(s) divided from the intrabony canal along the course of the ZFC(s). In other cases, 28.6% of ZTCs were opened through each corresponding ZT foramen. Zygomaticofacial canal originates from zygomaticoorbital foramen, divided into some of ZTCs, and is finally opened as ZF foramen. This new anatomical description of the intrabony structures of the ZFC(s) and ZTC(s) within the zygomatic bone by micro-CT technology provided helpful information to surgeons performing clinical procedures such as Le Fort osteotomy and reconstructive surgeries in the midface region.

Deep subfascial approach to the temporal area.

PURPOSE: Surgical access to the temporomandibular joint (TMJ) and zygomatic arch is a challenge even to the experienced maxillofacial surgeon. The conventional subfascial approach to these structures carries the potential risk of transient paralysis of the frontalis and orbicularis oculi muscles. This article discusses the use of a deep subfascial approach to access the TMJ and zygomatic arch. This surgical technique provides a safe operating field without jeopardizing the branches of the facial nerve. PATIENTS AND METHODS: A study was carried out on 12 patients, wherein 15 surgical exposures were made, to access the TMJ and zygomatic arch. A deep subfascial approach was used that preserved the structural and functional integrity of the temporal and zygomatic branches. RESULTS: Postoperatively, no functional deficit was noted in either the temporal or zygomatic branches of the facial nerve as ascertained by clinical examination. CONCLUSIONS: The deep subfascial approach preserves and protects the branches of the facial nerve. It relies on distinct anatomic planes that are easily identified during surgery; and hence, the technique becomes relatively simple and easy to use.