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In MVD operations assisted by AMR monitoring, the reliability and validity of decompression can be evaluated by observing whether AMR disappears. Although intraoperative AMR monitoring has been used widely, debate exists over its reliability and positive contribution. In this series, 115 cases of HFS treated with MVD operations with AMR monitoring were enrolled. All MVD procedures were performed via a suboccipital retrosigmoid approach. Microscope and endoscope were used alternately as was needed. Medtronic Nim-eclipse system was used for intra-operative AMR monitoring. The zygomatic branch of the facial nerve was stimulated and AMRs were recorded form the mentalis muscle. In 112 of the 115 cases, AMR was recorded during operation. In the 112 cases with typical AMR, AMR disappeared in 105 cases. Among the 105 cases, 79 achieved immediate cure after operation, 21 were spasm-free within 6-month follow-up, and the symptom of 5 cases persisted at 6-month follow-up. Among the 7 cases whose AMR did not disappear at the end of operation, 2 cases achieved immediate cure and 2 cases achieved delayed relief. For those cases with electrophysiological relief, the overall relief rate was 95.2% (100/105); for those with persistent AMR, the overall relief rate was 57.1% (4/7, P 0.05). In conclusion, AMR monitoring provide valuable information to MVD operation for HFS. The use and investigation of AMR will undoubtedly contribute to the understanding and curing of HFS.

When properly diagnosed, a cutaneous fistula of dental origin has a favorable therapeutic prognosis. An erroneous diagnosis, however, can lead to inappropriate treatment; also, orocutaneous fistulas occur in about 1% of patients with odontogenic lesions. The objective of this work is to describe the clinical case of a 21-year-old patient with a fistula near the mentalis muscle, who was mistakenly treated for a dermatologic lesion for 8 years. When referred to the stomatology service, an initial radiologic examination found no apparent dental cause. Surgical treatment was then performed under general anesthesia, followed by anatomopathologic examination, with a final diagnosis of apical granuloma, requiring dental removal to eliminate the infection and the fistula. We can conclude that whenever a facial skin lesion is observed, a dental cause must be sought to avoid prescribing the wrong treatment.

The purpose of this article is to review soft tissue considerations for orthodontic treatment planning so that specific treatment objectives can be defined before making any treatment decisions. Soft tissue objectives that must be considered in the treatment planning process include the following: retract, maintain, or protract upper and/or lower lip; increase, maintain, or decrease vermilion display (lip thickness); reduce lip strain, mentalis muscle strain, and interlabial gap or maintain lip competence; increase, maintain, or decrease nasolabial angle; increase, maintain, or decrease mentolabial angle; increase or maintain cervicomental angle; reduce, maintain, or increase the gingival display on smiling; improve facial asymmetry; increase, maintain, or decrease width of the alar base; and increase, maintain, or decrease the vertical and/or antero-posterior projection of the soft tissue chin. To formulate these treatment objectives, a review of the literature in terms of soft tissue changes with growth, soft tissue changes with treatment (effects of extraction and nonextraction therapy, headgear and functional appliances, protraction facemask, orthognathic surgery), and the smile is provided.

Objective: To describe the age-related changes in the number of movements in rapid eye movement (REM) sleep, and to quantify the functional maturation of motor inhibition. Study design: Gross movements, phasic mentalis muscle activity (PMMA), and a new index that expressed the shortness of PMMA (the proportion of short PMMA among all PMMA) were examined cross-sectionally in 87 healthy children from premature babies to preadolescents by means of a single (all-night) polysomnography. Results: The incidence of gross movements and long PMMA decreased with age, whereas that of short PMMA increased with age. The new index exhibited an age-related increase, with the highest correlation with age among sleep parameters examined, and reached an adult level after 6 years of age. Conclusion: We found that the age-related reduction of PMMA duration, which was expressed by a new index, occurred in parallel with the maturation of the inhibitory system that is tonically activated during REM sleep. We named this index the tonic inhibition index and concluded that the neuronal system involved in motor inhibition during REM sleep was still maturing during early childhood. We propose the tonic inhibition index as a useful quantitative indicator for the maturity of the inhibitory system. (J Pediatr 1997;130:117-22)

Aims The motor function of cranial nerves (CN) can be continuously monitored by transcranial corticobulbar motor evoked potentials (CoMEPs) during neurosurgical interventions. Despite their advantages, CoMEPs are not yet widely used. While there are several publications of CoMEPs in adults ( Sarnthein et al., 2013 ), the feasibility and safety of CoMEPs in children has not yet been documented. Methods We included 13 consecutive procedures involving 12 patients (median age 5 y, range 1–15 y, 4 female) that were operated since 2013 and in whom CoMEPs were monitored. While most authors use a 50% reduction of CoMEP response amplitudes as a warning criterion, our approach was to keep the response amplitude constant by increasing the stimulation intensity and to establish a warning criterion based on the “threshold-level” method. For the facial nerve, a threshold increase greater than 20 mA for eliciting CoMEPs in the most reliable facial nerve target muscle was considered a prediction of reduced postoperative facial nerve function, and subsequently a warning was issued to the surgeon. Preoperative and early postoperative function was documented using the House-Brackmann (HB) grading system. Results Monitoring of CoMEPs was feasible in all 13 surgeries in at least one facial nerve target muscle. The mentalis muscle yielded the best result (92% of trials), followed by orbicularis oris (91%) and orbicularis oculi muscles (86%). The median stimulation threshold was initially 60 mA (range 40–100 mA) for CoMEPs and 60 mA (15–95 mA) for MEP of the thenar muscles. The initial CoMEP threshold exceeded the MEP threshold in 7/13 cases. CoMEP deterioration showed specificity for HB deterioration of 83%. Conclusions Intraoperative CoMEP monitoring is feasible and safe also in young children. Stable facial nerve CoMEP predict stable HB grade. We found no evidence that procedures and thresholds should differ from CoMEP in adults. CoMEP monitoring is a valid indicator of CN function in skull base surgery. It should be used as an adjunct to direct electrical CN stimulation and continuous EMG monitoring of CN target muscles.

Hemagiomas of skeletal muscle are relatively uncommon and often difficult to diagnose. In the head and neck, the masseter and trapezius muscles are most commonly reported as being involved. The cause of these lesions is unknown, although theories of development include trauma and abnormal sequestration of embryonic tissue. Treatment has included corticosteroids, sclerosing agents, radiation therapy, embolization, and surgical excision. A review of the literature and the first case report of hemangioma involving the mentalis muscle are presented.

Fifty mentalis muscles were examined on 25 adult human cadavers with edentulous mandibles. The following observations were made: 1. 1. The right and left mentalis muscles were symmetrically placed on either side of the midline of the edentulous mandible, and they were found to be apart by a mean distance of 12 mm. 2. 2. The mean width of the mentalis muscle at the origin was approximately 5 mm. 3. 3. The medial fibers of the mentalis muscle crossed the midline to join the mentalis muscle of the opposite side. The most superficial fibers of the mentalis muscle coursed upward to join the obicularis oris. 4. 4. Sixty-seven per cent (20 of 30) of the muscles examined originated on the crest of the bone of the residual ridge. Twenty-seven per cent (8 of 30) of the muscles examined originated between the crest of the bone of the residual ridge and the fornix of the labial vestibule. 5. 5. Twenty-one of 30 (70 per cent) mentalis muscles examined in Group B had origins which correlated with elevations on the mucous membrane surface as recorded in modeling compound.

The described procedure will allow more freedom for the muscles under the basal seat of the lower denture to move in the region of the mentalis muscle. Consequently, the tendency of the denture to move is lessened. The lower lip should be mechanically elevated by the dentist in the border-molding procedure, because the mentalis muscles will not be activated and they will not be recorded in the impression surface in any great detail.