Endoscope-Assisted Avulsion of the Masseter Nerve Attached to the Temporomandibular Joint Disc for the Treatment of Hemimasticatory Spasm: A Report of Two Cases

Arthroscopic osteoplasty of the medial and anteromedial wall of temporomandibular joint: surgical technique and anatomical considerations

The anterior displacement of the articular disc is the most frequent cause of pathological alterations in the TMJ. Although it is an extremely common pathology, there is no certainty about the aetiopathogenesis of this disease. The main aim of the present report is to describe new anatomical findings that could help clarifying the aetiopathogenesis of this disease and determine a typology of treatment based on the cause of the disease. All the operative records of patients who underwent arthroscopic osteoplasty of the medial TMJ wall in our centre from January 2021 to September 2021 were reviewed and analysed to identify specific anatomical features observed in every procedure. Fifty-two joints were included for analysis in this study. Twenty-two joints were classified as Wilkes stages II-III and 30 as Wilkes stages IV-V. The most common complication observed in our sample was the dysaesthesias found in the temporal and preauricular regions. Other complications observed were frontal branch paresis (n = 2), intraoperative bleeding (n = 1), and postoperative malocclusion (n = 1). The compression of the superior head of pterygoid lateral muscle (SPLM) on the medial bony wall and the consequent muscle atrophy could be key for the aetiology of the anterior TMJ disc displacement. Therapeutic actions on the osseous and muscular component in this anatomical area could improve the outcomes of patients affected by TMJ internal derangement. A meticulous dissection of the fascia of the superior fascicle of the lateral pterygoid muscle allows a remodelling of the bone surfaces with minimal complications.

Treatment of hemimasticatory spasm secondary to parry-romberg syndrome via partial resection of the trigeminal nerve motor branch under intraoperative neurophysiological monitoring: A case report and literature review

Parry-Romberg syndrome (PRS) combined with hemimasticatory spasm (HMS) is a rare craniofacial disorder characterized by unilateral facial tissue atrophy with paroxysmal involuntary contractions of the jaw-closing muscles. Although a majority believe that this is a result of demyelination changes from the effect of the facial involvement of PRS on the trigeminal nerve motor branches, the mechanism of PRS is presently unclear. Moreover, the therapeutic effects of existing drugs that target PRS have not been satisfactory. For intolerable spasms of the masticatory muscles, botulinum toxin injection may temporarily relieve the symptoms of spasms. We report a case of HMS secondary to PRS that was treated via a partial resection of the trigeminal nerve motor branch under intraoperative neurophysiological monitoring.

Long-Term Outcome of Hemimasticatory Spasm

Objective

This study aims to identify the demographic, clinical, and therapeutic characteristics of four patients with hemimasticatory spasm (HMS) seen in our outpatient department over a period of 20 years.

Methods

We performed a retrospective chart review of four patients with HMS who visited outpatient services in the Department of Neurology from 2001 to 2020.

Results

The follow-up for all patients ranged from 2 years to 9 years. Three patients had facial or bucco-oral morphea. Two patients maintained long-term improvements in symptoms after being treated with botulinum toxin for 4–7 years, while one patient reported improvement in symptoms with treatment of carbamazepine that subsequently remitted after pregnancy.

Conclusion

This report highlights the long-term outcome of HMS in our patients. Our patients reported a significant reduction or complete resolution of symptoms after treatment, and eventually, two patients were asymptomatic while off treatment.

Parry-Romberg Syndrome With Hemimasticatory Spasm: A Rare Combination

Parry-Romberg syndrome is a rare craniofacial disorder characterized by progressive hemifacial atrophy with systematic manifestations. The combination with hemimasticatory spasm is rare, with only 9 patients reported before. In this study, a study of a young male patient with Parry-Romberg syndrome and hemimasticatory spasm on his left side was presented. Radiologic examinations showed severe atrophy limited to subcutaneous tissue and electromyography demonstrated as hemimasticatory spasm. Injection of botulinum toxin type A was applied for the treatment of hemimasticatory spasm and after 2 separated injections, the patient was significantly relieved from symptom. The theory of focal demyelination of the trigeminal nerve peripheral brunches is the possible link between hemifacial atrophy and hemimasticatory spasm, although the pathogenesis of both diseases requires further study and current therapeutic methods are still limited to symptomatic treatments. Injection of botulinum toxin type A is an effective way to treat hemimasticatory spasm and autologous fat transplant is a promising solution to correct facial asymmetry.