Orbital restoration surgery in the zygomaticotemporal and zygomaticofacial nerves and important anatomic landmarks

A marginal process of the zygomatic bone predicts a lateral exit of the zygomaticotemporal nerve: An anatomical study with application to surgery around the midface

Previous studies have not verified the contents of accessory foramina of the zygomatic bone on dry skulls and thus could not conclude whether they carried accessory zygomaticofacial nerve branches or branches or the entire trunk of the zygomaticotemporal nerve (ZTN). Therefore, the aim of the current study is to present findings from cadaveric dissections to clarify this relationship. Fifty, fresh frozen, adult cadaveric sides underwent dissection of the ZTN. When identified, these nerves were quantified and their relationship to the zygomatic bone further documented by dissecting through the bone following the course of the nerve from a superficial to deep perspective. Additionally, 100 dry, adult, human skulls were analyzed looking for lateral foramina on the zygomatic bone. On three cadaveric sides (6%), the ZTN was found to pierce the zygomatic bone deeply and exit its superficial lateral surface. For dry skull specimens, a lateral zygomaticotemporal foramen (ZTF) was identified on nine sides (4.5%). For both groups, the presence of a strong marginal process of the zygomatic bone was strongly correlated to a ZTF exiting the lateral surface of the zygomatic bone. Although relatively uncommon, the ZTN can pierce the lateral aspect of the zygomatic bone and thus can be located superficial to the cheek. Such findings should be borne in mind during surgical or other invasive procedures in this area in order to minimize iatrogenic injury to the ZTN.

Site V Surgery for Temporal Migraine Headaches

Background:

Auriculotemporal nerve is demonstrated to contribute to migraine pain in temporal area. In particular, its relationship with the superficial temporal artery in the soft tissues superficial to the temporal parietal fascia has attracted researchers’ attention for many decades. The objective of this review was to explore whether site V nerve surgical decompression is effective for pain relief in temporal area.

Methods:

A literature search, according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, was conducted to evaluate the surgical treatment of auriculotemporal migraine. Inclusion was based on studies written in English, published between 2000 and February 2020, containing a diagnosis of migraine in compliance with the classification of the International Headache Society. The treatment must consist of surgical procedures involving the auriculotemporal nerve and/or arteries in site V, with outcome data available for at least 3 months.

Results:

Three hundred twenty-four records were identified after duplicates were removed, 31 full-text articles were assessed for eligibility, and 2 records were selected for inclusion. A total of 77 patients were included in the review. A direct approach at the anatomical site identified with careful physical examination and confirmed with a handheld Doppler probe is generally performed under local anesthesia. Blunt dissection to the superficial temporal fascia to expose the auriculotemporal nerve and the superficial temporal artery is followed by artery cauterization/ligament and eventual nerve transection/avulsion. Site V surgery results in a success rate from 79% to 97%.

Conclusions:

Despite the recent advances in extracranial trigger site surgery and a success rate (>50% improvement) from 79% to 97%, site V decompression is still poorly described. Elaborate randomized trials are needed with accurate reporting of patient selection, surgical procedure, adverse events, recurrencies or appearance of new trigger points, quality of life outcome, and longer follow-up times.

Evaluation of Long-term Outcomes of Facial Sensation following Cranial Vault Reconstruction for Craniosynostosis

Supplemental Digital Content is available in the text.

Background:

Cranial vault reshaping to correct craniosynostosis in infants may injure terminal branches of the trigeminal nerve, namely the supraorbital, supratrochlear, zygomaticofacial, and zygomaticotemporal nerves, especially if a fronto-orbital advancement is performed. Despite numerous studies demonstrating successful esthetic outcome after FOA, there are no long-term studies assessing facial sensation after possible damage to these nerves as the result of surgery.

Methods:

A cross-sectional case-control research design was used to evaluate facial sensory threshold in the trigeminal branches after cranial vault reconstruction in children with isolated, nonsyndromic metopic, and unicoronal craniosynostosis, compared with those with sagittal craniosynostosis and age-matched nonaffected controls. Study participants were recruited from the Hospital for Sick Children between the ages of 6 and 18 years. Sensory outcome was determined using the Weinstein Enhanced Sensory Test, the Ten Test, and self-reported facial sensibility function questionnaire.

Results:

The sensory outcomes of 28 patients and 16 controls were examined at an average age of 9.6 years and 10.3 years, respectively. No subjective or objective sensory deficit was noted in supraorbital, supratrochlear, zygomaticofacial, or zygomaticotemporal nerve distributions between groups. Qualitative reports of facial sensibility function indicated no difference in subjective sensation, protective sensation, or motor behavior between groups.

Conclusions:

These results suggest that while sensory nerve injury during routine FOA may occur, it does not result in a quantifiable nor clinically significant long-term sensory deficit threshold. Patients do not develop long-term neuropathic pain following surgical intervention.

Morphology and Navigational Landmarks of the Cranio-orbital Foramen in a Portuguese Population

PURPOSE

The cranio-orbital and accessory foramina are located in the lateral wall of the orbit and adjacent to the superior orbital fissure. In the literature, there is a lack of consistency concerning the location and morphology of these foramina in different populations. Therefore, considering its clinical importance during orbital surgeries, it was the authors' aim to determine the incidence, location, and number of cranio-orbital and accessory foramina in a Portuguese population and compare the findings with data from other studies.

METHODS

A total of 310 orbits from 155 dry skulls from the collection of the Museum of Anatomy of the Faculty of Medicine of Porto were studied. The characterization of both cranio-orbital and accessory cranio-orbital foramina was performed.

RESULTS

The cranio-orbital foramen was present in at least 1 orbit per skull in 58.17% with a median diameter of 0.60 ± 0.33 mm. No relation was found between the presence of this foramen and the gender of the individuals or a tendency for laterality. However, it was found that the presence of 1 or more accessory foramina was related to higher diameters of the cranio-orbital foramen.

CONCLUSIONS

There might be a relationship between the localization, diameter, and communication of foramina with the cranial fossae. Foramina located on the greater wing of the sphenoid bone presented a larger diameter and communicated with the middle cranial fossa. High diameters of the main vessel in the cranio-orbital foramen may imply more developed branches and collateral irrigation of the orbital structures using 1 or more accessory foramina. Surgeons should be aware of the location of the cranio-orbital foramen to reduce potential sources of hemorrhage during orbital dissections.

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.

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.

Navigational area of the cranio-orbital foramen and its significance in orbital surgery

The cranio-orbital foramen (COF) is located on the lateral wall of the orbit. It is a potential source of hemorrhage during deep lateral orbital dissection, since it functions as an anastomosis between the lacrimal artery and the middle meningeal artery. The aim of this study was to guide and facilitate the surgical procedures in the orbit, so as to determine a navigational area and the precise location of the COF and to standardize certain anatomical marks. The navigational area of the COF and topographical features were studied in 75 craniums with presented COF. 33 bilateral main COFs, 41 (18 on the right, 23 on the left) unilateral main COFs at the main cranium and 19 accessory COFs were studied for their navigational features on the orbit. The distances between the COF and the fronto-zygomatic suture, supraorbital notch, lateral angle of the superior orbital fissure (SOF) and Whitnall's tubercle were measured. The mean distance of the COF from the fronto-zygomatic suture, supraorbital notch, lateral angle of the SOF and Whitnall's tubercle was 26.3, 37.3, 92 and 27.1 mm, respectively. For the navigational area signs of the COF, areas of the orbit that form the transversal and vertical lines are generated on the reference points. Whilst the upper outer area of the orbit contains a potential bleeding risk, the bottom section of the outer column is identified as safe for the surgical operations of the lateral orbital wall. The fronto-zygomatic suture and Whitnall's tubercle are recommended as the most reliable navigational landmarks for identifying the COF. Hence, the transversal and vertical orientation of the COF should be mastered by the surgeons reconstructing the anterior base of the skull and the orbit.