Extensive gunshot wound to the face: a case report

Facial fractures caused by gunshots are a major challenge for oral and maxillofacial surgeons. Underdeveloped countries present a higher rate of homicides committed by gunshots than developed countries. This case report presents a 25 year-old male victim of a gunshot wound to the mandible, evolving into a complex fracture. The fracture was treated using rigid internal fixation. After 18 months of follow-up, the patient presents good facial appearance and masticatory activity. The gunshot caused the permanent paralysis of the right mandibular branch of the facial nerve. We managed to preserve the involved teeth and mandibular integrity, with complete bone healing. Despite the late infection following plate fixation, healing occurred without further complications, indicating that blood supply was maintained.

Extracranial Non-Gasserian Ganglion Application of Radiofrequency Thermocoagulation on the Mandibular Branch of the Trigeminal through the Foramen Ovale for Trigeminal Neuralgia

BACKGROUND: Percutaneous radiofrequency ablation (RFA) of the trigeminal Gasserian ganglion via the foramen ovale is still one of the classic treatments for primary trigeminal neuralgia. However, the Gasserian ganglion is deep in the middle cranial fossa. Although it is a structure outside the brain tissue, the puncture needle must enter the encephalic to reach the Gasserian ganglion and so it is difficult to completely avoid the risk of intracranial hemorrhage and infection caused by puncture damage to intracranial blood vessels. It is not clear whether if it is possible for RFA at the extracranial non-gasserian-ganglion site via the exit of the cranial channel (foramen ovale) for patients with V3 trigeminal neuralgia (TN). STUDY DESIGN: Prospective, clinical research study SETTING: Department of Anesthesiology and Pain Medical Center, Jiaxing, China. METHODS: One hundred and seven patients with isolated mandibular branch trigeminal neuralgia were included. Radiofrequency thermocoagulation was performed by CT-guided percutaneous puncture through the foramen ovale. The puncture target was the midpoint of the horizontal transverse diameter of the oval foramen. If the tingling sensation in the mandibular nerve innervation area could be detected, the radiofrequency thermocoagulation (90°C, 120 sec) under intravenous anesthesia would be performed. We investigated the inclination angle, puncture angle and depth, puncture operation time, intraoperative complications and short-term and long-term results after operation. RESULTS: After radiofrequency thermocoagulation, the pain in the mandibular branch dominant area was completely diminished in 104 patients. Two patients were cured after the second radiofrequency treatment. No intracranial hemorrhage not infection complications occurred, except for facial hematoma during operation in 21 cases. After 12-24 months of follow-up, 9 patients had recurrence and were still effective after receiving additional extracranial radiofrequency treatment. LIMITATIONS: A control group should be established and more clinical data should be collected in future work. CONCLUSION: Extracranial non-Gasserian-ganglion RF can achieve satisfactory results and improve the safety of radiofrequency treatment for trigeminal neuralgia. KEY WORDS: Trigeminal neuralgia, foramen ovale, trigeminal ganglion

The path from trigeminal asymmetry to cognitive impairment: a behavioral and molecular study

Trigeminal input exerts acute and chronic effects on the brain, modulating cognitive functions. Here, new data from humans and animals suggest that these effects are caused by trigeminal influences on the Locus Coeruleus (LC). In humans subjects clenching with masseter asymmetric activity, occlusal correction improved cognition, alongside with reductions in pupil size and anisocoria, proxies of LC activity and asymmetry, respectively. Notably, reductions in pupil size at rest on the hypertonic side predicted cognitive improvements. In adult rats, a distal unilateral section of the trigeminal mandibular branch reduced, on the contralateral side, the expression of c-Fos (brainstem) and BDNF (brainstem, hippocampus, frontal cortex). This counterintuitive finding can be explained by the following model: teeth contact perception loss on the lesioned side results in an increased occlusal effort, which enhances afferent inputs from muscle spindles and posterior periodontal receptors, spared by the distal lesion. Such effort leads to a reduced engagement of the intact side, with a corresponding reduction in the afferent inputs to the LC and in c-Fos and BDNF gene expression. In conclusion, acute effects of malocclusion on performance seem mediated by the LC, which could also contribute to the chronic trophic dysfunction induced by loss of trigeminal input.

Discerning a Smile -- The Intricacies of Analysis of Post-Neck dissection Asymmetr

Introduction Iatrogenic facial nerve palsy is distressing to the patient and clinician. The deformity is aesthetically displeasing, and can be functionality problematic for oral competence, dental lip trauma and speech. Furthermore such injuries have litigation implications. Marginal mandibular nerve (MMN) palsy causes an obvious asymmetrical smile. MMN is at particular risk during procedures such as rhytidoplasties, mandibular fracture, tumour resection and neck dissections. Cited causes for the high incidence are large anatomical variations, unreliable landmarks, an exposed course and tumour grade or nodal involvement dictating requisite nerve sacrifice. An alternative cause for post-operative asymmetry is damage to the cervical branch of the facial nerve or platysmal dysfunction. This tends to have a transient course and recovers. Distinction between MMN palsy and palsy of the cervical branch of the facial nerve should therefore be made. In 1979 Ellenbogen differentiated between MMN palsy and “Pseudo-paralysis of the mandibular branch of the facial nerve”. Despite this, there is paucity in the literature & confusion amongst clinicians in distinguishing between these palsies, and there is little regarding these post-operative sequelae and neck dissections. Method This article reflects on the surgical anatomy of the MMN and cervical nerve in relation to danger zones during lymphadenectomy. The authors review the anatomy of the smile. Finally, we utilise case studies to evaluate the differences between MMN palsy and its pseudo-palsy to allow clinical differentiation. Conclusion Here we present a simple method for clinical differentiation between these two prognostically different injuries, allowing appropriate reassurance, therapy & management.

Key Anatomical Clarifications for the Marginal Mandibular Branch of the Facial Nerve: Clinical Significance for the Plastic Surgeon

Background The marginal mandibular branch (MMBr) of the facial nerve is the least likely to recover from injury due to infrequent anastomosis with other branches. The MMBr has been described as coursing superior to the inferior border of the mandible. However, studies have reported variations in its location in embalmed and fresh specimens. It’s been postulated that the embalming process may effect its anatomical position. Objective Re-evalulate the location of the MMBr relavtive to the inferior border of the mandible in both fresh and embalmed cadavers, and compare its poition with sex, side of the face, and age. Methods Superficial fascial planes were dissected to reveal the MMBr and its anatomical relationships. Distance between the most inferior branch of the MMBr and antegonial notch were measured bilaterally. The most inferior position of the MMBr between the antegonial notch and gonion was measured. Fresh heads were used as a comparison, with an additional measurement taken between the MMBr and gonial angle. Results The MMBr was located inferior to the border of the mandible (90.3%) more often than above (9.6%). No significant differences were found between fresh and embalmed cadavers, sex, side of body, or age (p > .05). No significant difference was found between intact cadavers and fresh heads (p > .05). Conclusions This study confirms and describes reliable landmarks for safety zones for the MMBr during plastic and reconstructive surgery of the lower face and upper neck. This data adds reliability to studies using embalmed cadavers to investigate nerve locations.

Trigeminal schwannoma presenting with malocclusion: A case report and review of the literature

Background: Trigeminal schwannomas are rare tumors of the trigeminal nerve. Depending on the location, from which they arise along the trigeminal nerve, these tumors can present with a variety of symptoms that include, but are not limited to, changes in facial sensation, weakness of the masticatory muscles, and facial pain. Case Description: We present a case of a 16-year-old boy with an atypical presentation of a large trigeminal schwannoma: painless malocclusion and unilateral masticatory weakness. This case is the first documented instance; to the best of our knowledge, in which a trigeminal schwannoma has led to underbite malocclusion; it is the 19th documented case of unilateral trigeminal motor neuropathy of any etiology. We discuss this case as a unique presentation of this pathology, and the relevant anatomy implicated in clinical examination aid in further understanding trigeminal nerve pathology. Conclusion: We believe our patient’s underbite malocclusion occurred secondary to his trigeminal schwannoma, resulting in associated atrophy and weakness of the muscles innervated by the mandibular branch of the trigeminal nerve. Furthermore, understanding the trigeminal nerve anatomy is crucial in localizing lesions of the trigeminal nerve.