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Fibers of the facial muscles occasionally extend, cross the midline, and connect to surrounding structures on the contralateral side, perhaps enabling the mouth to make more delicate movements and generate more facial expressions. This case report describes a variant in which the extended fibers of the mentalis crossed the midline and indicates the relationship of these fibers to the surrounding structures. Some of the deepest fibers of the mentalis descended inferomedially and crossed transversely just below the chin prominence to attach to the periosteum of the mandible on the contralateral side. The variation presented in this study shed light on the interactions of the mentalis with the surrounding muscles.

Background Botulinum toxin type A (BTA) injection is a widely-used procedure to correct cosmetic problems caused by muscular hyperactivity. "Cobblestone chin" refers to the appearance of remarkable chin creases caused by mentalis contraction. Aims The aim of this case report is to raise the awareness of paradoxical bulging after BTA injection in mentalis. Patient/methods A 26-year-old female asked for cosmetic correction of the "cobblestone chin". BTA injection was performed routinely to the mentalis muscle. However, on the second day after injection, an unusual paradoxical bulging at chin was presented. Results We speculated that the imbalanced relaxation of mentalis caused by improper injection and uneven diffusion of BTA is responsible for the bulging. After a supplementary injection of BTA in the remaining hyperactive muscle fibers based on the ultrasound examination, the bulging was relieved and chin contour improved significantly. Conclusion Injection of BTA in mentalis should cover the whole thickness of the muscle to prevent imbalanced paralysis and paradoxical chin bulging, especially in severe mentalis hyperactivity cases.

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.

Summary:. In this article, we present a new surgical approach to the mandible that can be used for implant placement or osseus genioplasty. This approach is virtually scarless, helps in reducing blood loss due to a subperiosteal dissection, may theoretically reduce the risk of mental nerve damage, and helps reduce postoperative functional recovery time, as the mentalis muscle is never transected, only reflected.

OBJECTIVE The purpose of this study is to determine if different facial muscle groups demonstrate different responses to facial nerve stimulation, the results of which could potentially improve intraoperative facial nerve monitoring (IOFNM). METHODS IOFNM data were prospectively collected from patients undergoing cochlear implantation. At different stages of nerve exposure, three sites were stimulated using a monopolar pulse. Peak electromyography (EMG) amplitude (μV) in four muscle groups innervated by four different branches of the facial nerve (frontalis-temporal, inferior orbicularis oculi-zygomatic, superior oribularis oris-buccal, and mentalis-marginal mandibular) were recorded. RESULTS A total of 279 peak EMG amplitudes were recorded in 93 patients. At all three stimulating sites, the zygomatic branch mean peak EMG amplitudes were statistically greater than those of the temporal, buccal, and marginal mandibular branches (P

The mentalis muscle is now considered key structures when performing procedures for rejuvenating the lower face. The aim of this study was to determine the anatomical morphology and location of the mentalis muscle and thereby provide anatomical information for facilitating clinical procedures designed to rejuvenate the lower face. Forty-four adult hemifaces from five Thai cadavers and 21 Korean cadavers were dissected to identify the locations of the mentalis muscle. Sixty-six hemifaces from 33 healthy young Korean subjects were included in an ultrasonographic study. The depth of the mentalis muscle below the skin surface, the thickness of the mentalis muscle, and the distance from the bone to the mentalis muscle were measured at the two points that were 5 mm lateral to the most-prominent point of the chin. The mentalis muscle was classified into two types based to its shape: in type A (86.4%, 38 of the 44 cases) it was dome shaped in three dimensions, while in type B (13.6%, 6 of the 44 cases) it was flat. The mentalis muscle was present mostly at the area 5–10 mm from the midsagittal line and 20–30 mm from a horizontal line connecting the mouth corners. The mentalis muscle was present between depths of 6.7 to 10.7 mm below the skin. This new information about the location of the mentalis muscle may help when identifying the most effective and safe botulinum toxin injection points and depths during esthetic procedures for weakened facial rhytides on the lower face.

The mentalis muscle is now considered key structures when performing procedures for rejuvenating the lower face. The aim of this study was to determine the anatomical morphology and location of the mentalis muscle and thereby provide anatomical information for facilitating clinical procedures designed to rejuvenate the lower face. Forty-four adult hemifaces from five Thai cadavers and 21 Korean cadavers were dissected to identify the locations of the mentalis muscle. Sixty-six hemifaces from 33 healthy young Korean subjects were included in an ultrasonographic study. The depth of the mentalis muscle below the skin surface, the thickness of the mentalis muscle, and the distance from the bone to the mentalis muscle were measured at the two points that were 5 mm lateral to the most-prominent point of the chin. The mentalis muscle was classified into two types based to its shape: in type A (86.4%, 38 of the 44 cases) it was dome shaped in three dimensions, while in type B (13.6%, 6 of the 44 cases) it was flat. The mentalis muscle was present mostly at the area 5–10 mm from the midsagittal line and 20–30 mm from a horizontal line connecting the mouth corners. The mentalis muscle was present between depths of 6.7 to 10.7 mm below the skin. This new information about the location of the mentalis muscle may help when identifying the most effective and safe botulinum toxin injection points and depths during esthetic procedures for weakened facial rhytides on the lower face.

A 17-month-old boy was evaluated for a midline mass on his chin. The mass was anchored to the mentalis muscle with a stalk-like structure. The pathological diagnosis of the mass was rhabdomyomatous mesenchymal hamartoma. This is the first report of rhabdomyomatous mesenchymal hamartoma presenting as a midline chin mass in Korean pediatric patients.

Botulinum toxin for the inferior third of the face can help address several areas such as marionette lines, masseter hypertrophy, perioral lines, correction of gummy smile, mentalis muscle strain, facial asymmetries, and improvement of platysmal bands.

Background: The number of TOETVA surgeries has increased worldwide but the anatomical passage of trocars is not clearly defined. We aimed to define detailed surgical anatomical passage of the trocars in cadavers. The incisions in oral vestibule, anatomical pathways of trocars, affected mimetic muscles, neurovascular relations of trocars and histological correlation of surgical anatomy were investigated. Methods: Four cadavers and 6 six patient oral vestibules were used. The locations of optimised vestibular incisions were measured photogrammetrically. Initial steps of TOETVA surgery were performed on cadavers according to those optimal incisions. TOETVA preformed cadavers dissected to determine anatomical passages of the trocars. Afterwards, flap of lower lip and chin were zoned by software appropriate to the trocars routes. Histological analyses of the zones were made in correlation with dissections. Results: Mimetic muscles associated with median (MT) and lateral trocars (LT) are orbicularis oris, mentalis, depressor anguli oris, depressor labii inferioris and platysma muscles. Trocars affect mimetic muscles in the perioral, chin and submental regions in different ways. The risk of mental nerve injury by MT is low. LT pass through the DLI muscle. The transmission of LT to the subplatysmal plane in the submental regions can be in two different ways. The arterial injury risk is higher with LT than the MT. Conclusions: The surgical anatomy of the perioral, chin and submental regions for the initial TOETVA steps has been defined. Detailed surgical anatomical passages of the MT and LT were determined. Anatomical pattern to reach subplatysmal plane are presented. Mimetic muscles effected by trocars were determined. Endocrine surgeons should know the anatomical passage of TOETVA trocars. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

A 13-year-old girl presented at an emergency department after she had fallen on her face when she fell from her horse. During physical examination no apparent extraoral injury was visible, such as lacerations, bruises or oedema. However, intraoral examination revealed extensive laceration of soft tissue. The diagnosis was a degloving injury of the mandible, which is very rare. The treatment consisted of debridement, suturing of the mentalis muscle, the approximate closing of the mucosa, accompanied by treatment with broad-spectrum antibiotics. The injury healed well without any residual complaints. This case underlines the importance of intraoral examination during the evaluation of patients with potential facial injury.Een 13-jarig meisje presenteerde zich op een spoedeisende hulppost nadat ze door een val van een paard op haar gezicht was gevallen. Bij extraoraal onderzoek werden geen afwijkingen gezien zoals laceraties, blauwe plekken of oedeem. Bij intraoraal onderzoek werd echter een uitgebreide laceratie gezien van de weke delen. De diagnose was degloving-letsel of ‘afstropings­letsel’ van de mandibula, hetgeen erg zeldzaam is. De behandeling bestond uit uitgebreid débridement, het hechten van de musculus mentalis, het approximerend sluiten van de mucosa met daarnaast behandeling met een breedspectrumantibioticum. Het letsel is restloos genezen. Deze casus onderstreept het belang van intra­oraal onderzoek tijdens de evaluatie van een patiënt met mogelijk aangezichtsletsel.

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.

A 67-year-old male patient presented to our department with severe mentalis spasm secondary to Parkinson's disease unable to retain upper and lower complete dentures. Injection of the mentalis muscle with Botulinum Toxin (Botox®) gave limited improvement. Restrictions on the placement of dental implants within our Trust meant we were unable to offer them to the patient. We, therefore, placed two titanium IMF screws into both the mandibular and maxillary alveolar ridges. The patient's existing dentures were modified to accommodate the IMF screws enabling pleasing denture retention. The screw placement and denture addition procedures were carried out with excellent healing and no complications. The IMF screws remain stable in situ 9 months after placement. This technique for retaining complete dentures in a Parkinson's patient is simple and cost-effective, with the added advantage of being easily reversible as their use does not prevent future implant placement.

Because of the soft-tissue envelope and the dimensional complexity of the muscular contraction of the mentalis muscle, the projection and shape of the chin is not determined by only the bony projection. In a subset of patients with a seemingly underprojected chin, a hyperactive, high-riding mentalis muscle contributes to a blunted chin contour.To evaluate the use of onabotulinumtoxinA (botulinum toxin A) for improving chin aesthetics in patients with an underprojected bony chin and a high-riding hyperactive mentalis muscle.This case series and photographic analysis included 11 patients presenting with an underprojected bony chin and a high-riding hyperactive mentalis muscle at a private facial plastic surgery practice from August 25, 2006, to November 10, 2012. Data were analyzed from November 13, 2012, to April 9, 2013.Injection with 12 to 15 U of onabotulinumtoxinA into the mentalis muscle.Photographic analysis of the vertical and horizontal positions of the pogonion relative to fixed facial points before and after injection. A patient satisfaction scale was also used to assess improvement in overall chin aesthetic.Eleven patients (3 men and 8 women; mean [SD] age, 46.3 [16.4] years) participated in the study, including 2 who had undergone prior chin implantation. The vertical position of the pogonion was more inferior after injection in 10 of 11 patients (mean [SD] vertical position, 1.36 [0.18] preinjection and 1.44 [0.18] postinjection; P = .005). Although the horizontal position of the pogonion changed in all patients, this change was not statistically significant (mean [SD] horizontal position, 0.11 [0.13] preinjection and 0.14 [0.13] postinjection; P = .32). All patients experienced improvement in their overall chin aesthetic and a subjective decrease in chin tension. Chin contour was improved, with soft-tissue volume overall displaced more inferiorly with a rounded rather than blunted appearance. No adverse effects were reported after injection.OnabotulinumtoxinA is effective at improving chin aesthetics by altering the position of the pogonion. In this first photographic analysis to date of the influence of onabotulinumtoxinA treatment, patients demonstrated a measurable change in the position of the pogonion, in addition to improvements to the chin contour on profile. This nonsurgical mentoplasty may be used as an independent procedure or as an adjunct to optimize traditional chin augmentation in carefully selected patients.4.

Purpose To investigate the relationship between mentalis muscle activity and mandibular symphysis morphology in patients with Class I or II skeletal patterns. Materials and methods 123 female Thai patients (17 years old+) participated in the present study. Subject pretreatment lateral cephalometric radiographs were examined. All subjects were diagnosed as having a skeletal normal bite. Subjects were grouped according to their sagittal skeletal pattern (ANB angle) into Class I (ANB 2–6) or Class II (ANB > 6). For each skeletal type, the subjects were divided into 2 groups, normal mentalis muscle activity (control group) and hyperactivity (experimental group). The skeletal Class I group comprised 37 subjects with mentalis muscle hyperactivity and 31 subjects with normal activity, while the skeletal Class II group comprised 30 hyperactive and 25 normal activity subjects. Eight cephalometric variables (angular, linear, and proportional measurements) were measured to evaluate mandibular symphysis morphology. The data were statistically analyzed using the Mann–Whitney U test or Independent-Sample t-test based on the normality of the data. Results In the skeletal Class I type, the experimental group revealed a trend of narrower alveolar symphysis width and greater symphysis height compared to the control group, but this was not significant. However, in the skeletal Class II type, the experimental group demonstrated significantly narrower alveolar symphysis width and significantly greater symphysis height compared to the control group (p Conclusion An increase in mandibular symphysis height and decrease in alveolar symphysis width may relate to mentalis muscle hyperactivity, and such relationship is more obvious in patients with Class II skeletal pattern.

Study Objectives To compare two electromyographic (EMG) montages, isolated mentalis muscle versus mentalis in combination with upper limb muscles in the baseline diagnostic video-polysomnography (V-PSG) of patients with idiopathic REM sleep behaviors disorder (IRBD) who eventually were diagnosed with a clinically defined neurodegenerative syndrome. Methods Forty-nine patients were included. At baseline, diagnosis of RBD was based on a typical history of dream enactment behaviors plus V-PSG showing REM sleep with qualitative increased EMG activity and/or abnormal behaviors. Quantification of EMG activity (tonic, phasic and "any") in the mentalis and upper limb muscles (biceps brachii-BB, n = 36 or flexor digitorum superficialis-FDS, n = 13) was performed manually and compared with published cut-offs. Results Nine (18.4%) patients had either tonic or phasic EMG below the cut-offs for the isolated mentalis and four of them (11.1 %) also had values below the cut-off for the mentalis combined with BB. All 13 patients recorded with the FDS were above the mentalis combined with FDS cut-off. For the diagnosis of IRBD, sensitivity of isolated mentalis was 81.6% and of the combination of mentalis plus upper limb muscles was 91.8% (p = .03). Audiovisual analysis showed abnormal REM sleep behaviors in all nine patients with values below the cut-offs. Conclusion Quantification of EMG activity in the upper limbs combined with the mentalis increases the ability to diagnose IRBD when compared with the isolated measurement of the mentalis. Detection of typical abnormal behaviors during REM sleep with audiovisual analysis is essential for the diagnosis of IRBD in patients with EMG values below the published cut-offs.

The trajectory of the medial fibers of depressor anguli oris muscle that pass deep to the depressor labii inferioris muscle (dDAO) and the anatomic relationship have not yet been examined. The aim of this study was to clarify the arrangement of the dDAO and its relationships with the surrounding structures. The dDAOs were investigated in 40 hemifaces from Korean cadavers. The dDAOs were observed in 18 of the 40 specimens (45%). The anatomic relationships of the dDAO were classified into the following 4 categories according to their connection with the incisivus labii inferioris muscle (ILI): (1) connected to the ILI and attached to the inferior border of the mandible lateral to the mentalis muscle (14 specimens, 35%), (2) connected to the ILI and intermingled with the lateral lower fibers of the mentalis muscle (2 specimens, 5%), (3) connected to the ILI but neither attached to the mandible nor intermingled with the mentalis muscle (1 specimen, 2.5%), and (4) not connected to the ILI but intermingled with the mentalis muscle (1 specimen, 2.5%). Therefore, in 17 specimens, the dDAOs were connected to the ILI (42.5%), in 14 specimens, they were attached to the inferior border of the mandible (35%), and, in 3 specimens, they were intermingled with the mentalis muscle (7.5%). The new anatomic data regarding the dDAO will contribute toward the understanding of movements of the mouth and lower face, which will be helpful when designing effective botulinum toxin type A therapies and performing various types of facial surgery.

Incisor and canine mandibular regions are a key mechanical vault, which strives with strong muscle and occlusal centripetal forces. In cases of dental and / or periodontal weakness and / or excessive mechanical stress, situations of imbalance can affect the stability of orthodontic treatments and periodontal durability. This article reports two surgical techniques to prevent and treat these situations: The labiomental weakening in growing children and adolescents; Alveolar corticotomy with vestibular allograft bone in adults; Both techniques allow functional management of mechanical imbalance, improvement of the periodontal biotype, and promote lower incisors’ relocation.

Objective: The aim of this study was to assess the presence of oral myofunctional alterations before and after first premolar extraction in Class II/1 malocclusion patients that could endanger the long-term dental arch stability. Material and Methods: The study was performed by means of morphological, functional and electromyographic analyses in 17 Class II/1 malocclusion patients (group T) and 17 Class I malocclusion patients (group C -control), both groups with 12-30-year age range (mean age: 20.93 ± 4.94 years). Results: Data analyzed statistically by Student's t-test showed a significant decrease (p0.05). The Kruskal-Wallis test analyzed data from lip posture (orbicularis oris muscle) at rest and during swallowing, as well as the mentalis muscle behavior during the above-mentioned function, not showing statistically significant differences (p>0.05) after treatment (groups T1 and T2). However, group T differed significantly from group C (p

Background/Objectives: Although the electromyographic (EMG) activity of the perioral muscles, including the orbicularis oris and mentalis muscles, has been described in individuals with lip incompetence during lip sealing, blood flow through these muscles remains to be elucidated. The purpose of this study was to examine the blood flow associated with EMG activity in the perioral muscles using laser speckle imaging in individuals with lip incompetence. Subjects/Methods: Blood flow and EMG activity of the superior and inferior orbicularis oris and mentalis muscles were measured with the lips in contact (C condition) and apart (O condition) in lip incompetence (experimental) and control subjects ( n = 15 in each group; mean age: 29.5 years). The change ratios of blood flow and EMG activity in the C condition versus O condition (C/O ratios) were calculated and plotted in a scattergram. The Mann–Whitney U -test, Wilcoxon signed-rank test, discriminant analysis using the Mahalanobis generalized distance, and Spearman correlation were used for statistical analysis. Results: In the experimental group, blood flow and EMG activity in all muscles were significantly greater in the C condition than in the O condition. The plots of C/O ratios in the experimental group showed a distinct and wide distribution and were significantly different than those in the control group. In both groups, a significant positive correlation was observed between blood flow and EMG activity in the mentalis muscle. Conclusions/Implications: The present findings suggest that observing blood flow in the mentalis muscle is an effective and easily performed method of evaluating lip incompetence.

Purpose: The aim of the present study was to record the electromyographic (EMG) activity of the mentalis muscle (Ment) during various jaw functions in healthy young subjects.Methods: Twelve healthy males were enrolled for the study. A portable EMG recording device was used to record the EMG activity from the Ment, anterior belly of the digastric muscle (Dig), and the masseter (Mm) muscles. The EMG activities of these muscles were recorded during maximal voluntary clenching (MVC), maximal voluntary jaw opening (MVO), and the masticatory process. The EMG activity of Ment was compared with the EMG activities of Dig and Mm during various jaw functions.Results: (1) The EMG activities of Ment and Dig were significantly greater during MVO than during MVC (P

Dentists are often faced with extensively resorbed mandibular ridges with shallow buccal vestibule and high insertion of the mentalis muscle in relation to the crest of the ridge, causing the displacement of the prosthesis. Vestibuloplasty techniques aim at eliminating the muscle insertions, reposition the mucosa, and increase the area chapeável, giving more stability to the prosthesis. Among the techniques to deepen the vestibule are submucosal vestibuloplasties by secondary epithelialization and with mucosal and skin grafts. We will discuss vestibuloplasty by secondary epithelialization with emphasis on the so-called modified Kazanjian technique. This technique provides an appropriate result and does not require hospitalization, additional surgery at the donor, or prolonged periods without the use of prosthesis.

The mentalis muscle (MT) is the only elevator of the lower lip and the chin, and it provides the major vertical support for the lower lip. However, there are few reports on the relationship between the MT and its surrounding muscles. The aim of this study was to clarify the morphology of the MT, especially in relation to the orbicularis oris muscle and the incisivus labii inferioris muscle (ILI), thereby providing data to understand the function of the MT in relation to the surrounding muscles. The MT was examined in 40 specimens of embalmed adult Korean cadavers. The medial fibers of both MTs descended anteromedially and crossed together, forming a dome-shaped chin prominence in all specimens. The lateral fibers of the MT descended inferomedially in 38 specimens (95%) and inferolaterally in 2 specimens (5%). The upper fibers of the MT were short and ran horizontally, whereas the lower fibers were long and descended inferomedially or vertically. The upper fibers of the MT were intermingled with the inferior margin of the orbicularis oris muscle in all specimens. The originating muscle fibers of the ILI were intermingled with the upper lateral MT in all specimens. Some of the ILI fibers extended inferomedially to the middle or lower portion of the MT in 22 specimens (55%). The results of this study constitute new anatomical knowledge regarding the MT and will be useful to surgeons performing various surgical procedures of the chin area.

This article is a logical extension of previous articles written on the topic of aesthetic chin surgery. In it, the authors expand on previously published surgical techniques and provide specific updates to increase success in some unusual situations. They review the indications for and uses of reduced-height implants, discuss the validity of centralized chin incisions in both reconstruction and revisions, show the diversity of mentalis muscle anatomy and chin pad variations, reveal the importance of the lip-to-labiomental crease inclination in cases of macrogenia, note a key update on reefing the mentalis muscle to a higher position for permanent sulcus position, discuss the issues of lower lip position and lower incisor show, and expound on the horizontal smile/chin ptosis phenomenon.

Cysticercosis, a helminthic disease commonly seen in India, Latin America, Eastern Europe and Southern Africa, results from extraintestinal encystation of the larval form of Taenia solium. It is a condition in which man acts as intermediate host instead of definitive host. The most frequent sites of cysticercosis are subcutaneous layers, brain, muscles, heart, liver, lungs, and peritoneum. Oral cysticercosis is considered rare and cause cystic swellings or nodules in the mouth and a precise clinical diagnosis is not usually established. Here, we report a case of oral cysticercosis in a 32-year-old female occurring in the mentalis muscle presenting as asymptomatic nodule.

OBJECTIVE To determine the value of using a multichannel facial nerve (FN) monitoring setup in detecting mechanically elicited EMG activity during vestibular schwannoma (VS) surgery. STUDY DESIGN Prospective study. SETTING Tertiary referral center. PATIENTS AND METHODS This study was conducted on 42 patients operated for VS removal. The FN was monitored using a 5-channel setup with electrodes inserted in mentalis, o.oris, nasalis, o.oculi, and frontalis. The number of channels activated simultaneously in response to a particular event was recorded together with the amplitude of response on each muscle. EMG activity occurring simultaneously on all 5 channels was referred to as "all-channels activity." Postoperative FN function was assessed immediately and 1 year postoperatively using the House-Brackmann classification. RESULTS The 5-channel setup detected a significantly higher number of mechanically elicited EMG activity than would have been possible using a 2-channel setup. The number and amplitude of EMG activity detected on the mentalis muscle was significantly higher compared with other muscles. Patients with higher percentage of events in which the mentalis fired while o.oris and o.oculi did not were more likely to develop a better long-term outcome. Positive correlation was found between the number of all-channels activity and postoperative outcome (p < 0.001). CONCLUSION The use of a multichannel setup allowed earlier and efficient detection of mechanically elicited EMG activity. Including the mentalis muscle significantly increased the detection rate, which tended to reflect as improvement in the long-term outcome. The occurrence of all-channels activity should be considered a prompt warning sign.

Hemangiomas of skeletal muscle are extremely rare benign neoplasms. In the head and neckregion, intramuscular hemangiomas occur most frequently in the masseter and trapezius muscles.However, intramuscular hemangiomas (IMH) arising from the mentalis muscle are relativelyrare. Preoperative diagnosis of head and neck IMH is rendered difficult by its rarity andnonspecific clinical findings. Total excision of the hemangioma with a margin of normal muscleis recommended. In this report, a case of mentalis muscle hemangioma, which was surgicallyexcised by transoral approach and histopathologically confirmed the diagnosis of capillary-typeIMH, was presented and the clinical, histologic fîndings and treatment modalities are discussed.

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.

To study the electroneurographic facial muscle pattern in Bell's palsy over time, electroneurographic recordings in the frontalis, orbicularis oculi, nasalis, and mentalis muscle regions were performed early (mean, day 11) and 1 and 3 months after the onset of the condition in 30 consecutive patients. The correlation between facial muscle electroneurographic recordings over time was also calculated. An additional aim was to assess whether further prognostic information could be obtained by electroneurographic recordings in more than one facial region. The recovery pattern was similar in all 4 facial regions. Initially, the correlation between the facial recordings was weak (r = 0.20-0.27), but it was improved at follow-up examinations (r = 0.33-0.65). Favorable outcome in 23 of 24 patients (96%) could have been predicted by the initial nasalis and/or mentalis recordings. The gap between patients with favorable outcome and patients with unfavorable outcome increased when the average electroneurography values were calculated from 1, 2, and 4 muscle recordings (4%, 8%, and 15%, respectively). Our results indicate that in Bell's palsy, electroneurographic examination of more than one facial muscle region may add prognostic information and that the degree of degeneration is initially different in the nerve branches.

A 13-month-old boy presented with repeated episodes of tongue biting during sleep. On evaluation, he was found to have hereditary chin trembling, a rare autosomal dominant condition characterized by continuous or intermittent tremulous activity of the mentalis muscle. This is the first report of this kind from India. The tongue biting appeared to be the result of parasomnia. Treatment with clonazepam was very effective; it completely ameliorated the symptom of tongue biting but had no effect on chin trembling. (J Child Neurol 2006;21:985—987; DOI 10.2310/ 7010.2006.00220).

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)

A 61-year-old female presented with a rare case of hemifacial spasm (HFS) resulting from facial nerve compression near the internal acoustic meatus. She underwent a first surgery for microvascular decompression at the root entry zone of the facial nerve, but this did not achieve resolution of the HFS. During the second surgery, the meatal loop of the anterior inferior cerebellar artery (AICA) was found to be the offending artery near the internal acoustic meatus. When the AICA was dissected and separated from the facial nerve, abnormal muscle responses of the mentalis muscle due to electrical stimulation of the zygomatic branch of the facial nerve were abolished. Following surgery the patient was completely free of the HFS.

Objective: Functional brain mapping is an important presurgical tool for optimized resection planning of brain tumors in eloquent locations. In addition to functional MRI, motor mapping by navigated Transcranial Magnetic Stimulation (nTMS) has been established for clinical routine in recent years. Facial[for full text, please go to the a.m. URL], 63. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie (JNS)

The patient was a 16-year-old girl with a lower lip sucking habit with increased overjet, maxillary and mandibular generalized spacing. Hyperactivity of the mentalis muscle and deepening of the labiomental sulcus because of the abnormal sucking habit was observed. Orthodontic treatment was started with a lip bumper appliance to break the lower sucking habit and continued with fixed orthodontic mechanotherapy. The lip bumper appliance therapy resulted in the elimination of the lower lip sucking habit, musculus mentalis hyperactivity, and labiomental strain, and also an overjet reduction. The use functional appliance in the treatment of malocclusions must be carefully selected according to the requirement of the case. It must be understood that the action of the mentalis muscle was the primary activator of the bumper.

Introduction: The objective of this study was to evaluate and compare the electromyographic (EMG) activity of the orbicularis oris—lower fascicle (LOO) muscle and the mentalis muscle (MT)—in predominantly nose-breathing (PNB) and mouth-breathing (PMB) subjects. Methods: Thirty-four subjects, 22 PNB and 12 PMB, with Class II Division 1 malocclusions were evaluated in 2001 (T1) and again in 2004 (T2), 2 years 5 months later. The age ranges of the sample were 11 years to 14 years 11 months at T1, and 13 years 4 months to 16 years 6 months at T2. EMG activity was recorded with bipolar surface electrodes at rest and during 12 movements; data were processed and normalized by the EMG highest value. The Student t test and the Mann-Whitney nonparametric test were used to compare the mean values and the variables between the observation times. Results: Greater EMG activity of the MT was observed in the PMB group at rest and swallowing at T1 and T2. At T2, increased EMG activity of the LOO at blowing and pronunciation of the phoneme \b\ was observed as well as a greater increment of EMG activity of this muscle at blowing, pronunciation of the phoneme \m\, and chewing in the PMB group. In addition, greater EMG activity of the MT at chewing in the PMB group was observed at T2. Conclusions: These results suggest that mouth breathing influences EMG activity of the LOO and MT muscles.

Hereditary trembling chin is an autosomal dominant condition characterized by recurrent bouts of tremor involving the chin. These episodes are precipitated by emotional upset. There has been considerable debate about the gravity of this condition. This may be a benign movement disorder; however, the rhythmic trembling of mentalis at rest or during times of stress in these patients is often misinterpreted as betraying an incipient emotional upset. For this reason, some patients with this condition may find it socially disabling. We have recently successfully treated one such family with regular botulinum toxin injections to the mentalis muscle. ( J Child Neurol 1992;7:154-156).

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.

We aimed to use repetitive transcranial magnetic stimulation (rTMS) to disrupt speech with the specific objective of dissociating speech disruption according to whether or not it was associated with activation of the mentalis muscle. Repetitive transcranial magnetic stimulation (rTMS) was applied over two sites of the right and left hemisphere while subjects counted aloud and recited the days of the week, months of the year, and nursery rhymes. Analysis of EMG data and videotaped recordings showed that rTMS applied over a posterior site, lateral to the motor hand area of both the right and the left hemisphere resulted in speech disruption that was accompanied by activation of the mentalis muscle, while rTMS applied over an anterior site on the left but not the right hemisphere resulted in speech disruption that was dissociated from activation of the mentalis muscle. The findings provide a basis for the use of subthreshold stimulation over the extrarolandic speech disruption site in order to probe the functional properties of this area and to test psychological theories of linguistic function.

The authors have studied the hand-mouth reflex of Babkin on 422 newborns. 413 out of 422 newborns were considered normal. We have found responses not yet published such as accentuation of inferior limb flexion, trunk flexion, upper limb adduction, contraction of the mentalis muscle, contraction of the orbicular of the lips, extension of the inferior limb, extension of the pododactiles and cry. We obtained the same responses by pressing the infraclavicular space just near the esternal bone. We compared statistically: a) responses to the stimulus on the palm of the hand and on the new reflexogenous zone; b) responses presented by term and preterm newborns; c) responses of newborns less than 12 hours of age and more than 24 hours of age.

This study examined skeletal stability and the remodelling process following advanced pedicled genioplasty. Twenty patients who had advancement genioplasty concomitant with other adjunctive orthognathic surgery were evaluated. A finite element analysis method was used to assess these changes. The stability of the advanced segment was excellent after 6 months. At 6 months bone remodelling was observed in the form of bone apposition at B point and Pogonion with bone resorption at the superior aspect of the advanced segment. The genial segment rotated about 12 degrees antero-superiorly which was thought to be due to the action of the mentalis muscle. Finite element analysis is a sensitive tool for assessing changes after genioplasty and was able to separate them from the effects of other adjunctive orthognathic surgery.

The lip is an organ consisting mostly of muscle similar to the tongue. While the tongue is known as a muscular hydrostat, it is unclear whether the lip is also. In this paper the muscular hydrostat issue was explored from the anatomical and functional point of view using high‐resolution static MRI (hr‐MRI; 0.125 mm/pixel) and tagged‐cineMRI (t‐MRI). A 3‐D reconstruction of the lips and its muscles was obtained from hr‐MRI during sustained vowels /i/ and /u/. The muscular geometry of the orbicularis oris, mentalis, and depressor labii inferior muscles were superimposed onto the principal strains that depicts compression and expansion of the internal tissue obtained from t‐MRI. It is shown that (1) orbicularis oris muscle shape can predict both the borderline of glabrous and hairy skin and the manner in which the lips are protruded; (2) the lips volume is almost identical for both speech tasks; and (3) direction and intensity of compression of orbicularis oris and mentalis muscle bundles imply the role of these muscles in the protrusion appearance. These results indicate that the muscular architecture and volume preserving characteristics of the lips are consistent with a muscular hydrostat. [This work was supported by NIH (USA) and NiCT (Japan).]

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.

• Extension of neuromuscular pedicles and direct nerve implants was investigated in ten rabbits. All rabbits underwent facial nerve resection bilaterally. In five rabbits a neuromuscular pedicle, based on the ansa cervicalis nerve, was implanted into the denervated mentalis muscle unilaterally. On the opposite side, reinnervation was attempted using a neuromuscular pedicle with an interposed nerve graft. In the other five rabbits, reinnervation was attempted using a direct nerve implant on one side and a direct nerve implant extended with a nerve graft on the opposite side. Evoked electromyographic muscle tension and histologic studies were used to evaluate reinnervation. Functional neuromuscular units were consistently produced with neuromuscular pedicles, direct nerve implants, and extended direct nerve implants, while extended neuromuscular pedicles failed to produce detectable reinnervation. ( Arch Otolaryngol Head Neck Surg 1989;115:217-223)

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.