Observation of Effects of Different Surgical Treatments on Unilateral Masticatory Muscle Spasm

Hemimasticatory spasm: a series of 17 cases and a comprehensive review of the literature

Hemimasticatory spasm (HMS) is a rare movement disorder characterized by paroxysmal spasms or twitches of the unilateral jaw-closing muscles. This study aimed to comprehensively evaluate the clinical features of patients with HMS. Data from 17 patients newly diagnosed with HMS (12 females and 5 males; mean age at onset: 46.7 years) who visited our department were retrospectively analyzed, and a literature search based on electronic medical databases from their inception until November 30, 2023, was conducted. A manual search was conducted for articles cited in the related literature. A total of 117 cases (72 females and 45 males; mean age at onset: 37.1 years) from 57 studies were analyzed. The muscles involved were the masseter (97.4%), temporalis (47.9%), and medial pterygoid (6%). Morphea or scleroderma was observed in 23.9% of the patients, and facial hemiatrophy in 27.4%. In 17.9% of the cases, Parry-Romberg syndrome was either complicated or suspected. Typical electromyographic findings included the absence of a silent period during spasms (23.9%) and irregular brief bursts of multiple motor unit potentials. Oral medicines, such as clonazepam or carbamazepine, alleviated the symptoms for some patients but were often unsatisfactory. Botulinum toxin therapy was effective in most cases. Recently, microvascular decompression surgery is increasingly being used, resulting in complete relief in some cases. In conclusion, highly effective modalities are currently available, and it is necessary to raise awareness of HMS to ensure that it can be diagnosed and treated accurately by both medical and dental professionals.

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.

Clinical application of flap or flapless buccal surgery on the extractions of mesially/horizontally impacted 3rd molar with high or medium position impact: A comparative study

PURPOSE

To investigate and compare the clinical application of flap or flapless buccal surgery on the extractions of mesially/horizontally impacted 3rd molar with high or medium position impact in terms of the average surgery duration, number of root fracture, postoperative pain degree and duration, postoperative swelling degree and duration, degree of limitation of mouth opening.

MATERIALS AND METHODS

The present study was conducted of 28 patients who were examined and underwent bilateral extraction of impacted mandibular 3rd molar. One molar was randomly extracted with flap buccal surgery (Control Group, CG) and the other one with flapless buccal surgery (Experimental Group, EG) in the same patient.

RESULTS

Gender distribution, average age, average surgery duration and number of root fracture between the two groups were not statistically significant (P>0.05). The postoperative pain degree, swelling degree and degree of limitation of mouth opening were all significantly greater in CG than EG. Moreover, the duration of postoperative pain and swelling were all were all significantly longer in CG than EG (0.01<P<0.05).

CONCLUSION

Compared with the flap buccal surgery on the extractions of mesially/horizontally impacted 3rd molar with high or medium position impact, the clinical use of the flapless buccal surgery is a safe and effective method with less swelling, pain and degree of limitation of mouth opening. However, we need further study based on the broader indications, a much larger number of patients included and a follow-up in the longer term to confirm our point.

Hemi Masticatory Spasm: Series of 7 Cases and Review of Literature

Background

Hemi masticatory spasm (HMS) is a rare movement disorder affecting muscles of mastication attributed to dysfunction of motor branch of trigeminal nerve and is characterized by painful spasm of masticatory muscles. Microvascular compression leading to focal demyelination of motor branch of trigeminal nerve is the most speculated on mechanism of HMS. Treatment options range from medical to surgical approaches, but botulinm toxin (BTX) has now become the preferred treatment.

Cases

We report a retrospective review of 7 cases of HMS, supported by electrophysiological and clinical findings. All the cases had excellent response to BTX therapy.

Discussion and Conclusion

In this article, we highlight the delay in diagnosis of HMS attributed to rarity, long course of illness, association with hemiatrophy, "Lichen Sclerosus et Atrophicus," and scleroderma/morphea. Considering the favorable outcome to BTXs, surgical treatment can be avoided or delayed in majority except secondary cases.