Lower facial remodeling with botulinum toxin type A for the treatment of masseter hypertrophy

BACKGROUND: Masseter hypertrophy has been treated with botulinum toxin injections because of esthetic complaints especially in Asians. OBJECTIVES: The goal of the present study was to evaluate the efficacy of abobotulin toxin use in masseter hipertrophy treatment in Brazilians. METHODS: Ten Brazilian female patients with masseter hypertrophy were subjected to injections of 90U of abobotulinum toxin A applied on each side respecting the safety zone stabilished in literature and were followed up for 24 weeks. RESULTS: When analyzing the coefficients between measures of middle and lower third of the face obtained from standardized photographs, an increase was observed, with statistical significance at 2 weeks (p=0.005) and 12 weeks (p=0.001). The progression of lower third reduction was 3.94%, 5.26%, 11.99%, and 5.47% (2, 4, 12, and 24 weeks respectively). All patients showed improvement in bruxism after treatment. Observed adverse effects were masticatory fatigue, smile limitation, and smile asymmetry. CONCLUSION: The use of abobotulinum toxin A for masseter hypertrophy is effective in Brazilians and reached its maximum effect of facial thinning at 12 weeks. Smile limitation had a higher incidence compared to that reported in the literature and may result from risorius muscle blockage caused by toxin dissemination. Despite its side effects, 80% of the patients would like to repeat the treatment. .

Change of Distribution and Timing of Bite Force after Botulinum Toxin Type A Injection Evaluated by a Computerized Occlusion Analysis System

PURPOSE: The aim of this study was to determine the force distribution and pattern of mastication after injection of botulinum toxin type A (BTX-A) into both masseter muscles. The hypothesis to be tested was that the difference between right and left balance of occlusal force diminishes over time following BTX-A injection. MATERIALS AND METHODS: Fifteen patients were submitted to BTX-A injection therapy for subjective masseter hypertrophy. A total of 25 U of BTX-A (50 U in total) was injected into two points located 1 cm apart at the center of the lower one-third of both masseter muscles. All patients were examined using the T-Scan occlusion analysis system before and 4, 8, 12, and 24 weeks after BTX-A injection. RESULTS: A significant change in force balance was found between the right and left sides over time and the difference between the two sides decreased with the time post-injection, reaching a minimum at 12 weeks. Comparison of the force balance between the anterior and posterior occlusions revealed no significant difference at any of the time points. The occlusion and disclusion times (right and left sides) did not differ significantly with time since BTX-A injection. CONCLUSION: A decline in the difference in the clenching force between the left and right sides was found with increasing time up to 12 weeks following BTX-A injection.

Miectomia com acesso extraoral para hipertrofia benigna de Masseter: relato de caso / An extraoral approach for miectomy in Masseter muscle hipertrophy: case report

A hipertrofia benigna de masseter é uma patologia caracteriza por um abaulamento indolor da região de ângulo mandibular, podendo ser uni ou bilateral. O diagnóstico é exclusivamente clínico, confirmado durante o ato operatório. O presente trabalho apresenta um caso de hipertrofia benigna de Masseter tratado cirurgicamente com miectomia por acesso extra-oral, onde o resultado foi satisfatório, com controle de três anos sem recidiva. Além dessa modalidade de tratamento, a hipertrofia benigna de masseter pode ser tratada com outras técnicas cirúrgicas ou modalidades conservadoras. A comparação da eficácia entre as diferentes técnicas é discutida no presente trabalho

Hipertrofia do masseter: relato de caso / Masseteric hypertrophy: report of a case

A hipertrofia do músculo masseter é definida como um crescimento excessivo desta musculatura, relativamente incomum, de origem indefinida e que pode ser tratada através de métodos cirúrgicos e não-cirúrgicos. O tratamento cirúrgico envolve intervenções que são realizadas, apenas, na musculatura comprometida, na estrutura óssea do ângulo mandibular ou na associação de ambos os procedimentos. Neste trabalho, relatou-se um caso clínico tratado cirurgicamente por intervenção apenas óssea e discutiu-se a etiopatogenia, o diagnóstico e o tratamento desse tipo de hipertrofia.

Hemifacial microsomia. A case report and review.

Hemifacial microsomia (HFM) is a variable asymmetric craniofacial malformation resulting in hypoplasia of the components of the first and second branchial arches. Because of the extremely variable expressively of the HFM, treatment measures also vary considerably from the use of activator to total reconstruction of TM joint and management of secondary deformities of maxilla, nose, orbit and zygomatic bone. We present a case of HFM type I of mild deformity treated with onlay bone grafting.

Frecuencia de pseudoprognatismo y actividad del músculo masetero en pacientes fisurados / Pseudoprognathism frequency and masseter muscle activity in operated cleft lip patients

Background: As a consequence of a growth inhibition of middle third of the face, cleft lip surgery could lead to a pseudoprognathism. However, this is not always the case. Also, when facial architecture is changed, the activity of muscles such as the masseter could be disturbed. Aim: To study masseter electromyographic activity in operated cleft lip patients. Material and methods: Forty two patients with cleft lip (25 male, aged 13 to 35 years old) were studied. All were operated during their first year of life. An electromyography of masseter muscle was performed and from a teleradiography, ANB and Gonion angles were obtained. Forty healthy subjects conformed the control group Results: The sample was divided in two groups. A group of 20 patients had a significantly lower EMG voltaje than control subjects (662 ñ 228 and 1511 ñ 340 µV respectively, p < 0.001). Only seven patients had an anteriorly inverted bite with a mean ANB of + 1.7 and a mean molar relation of -4.8, figures that confirm the presence of pseudoprognathism. Conclusions: Eighty three percent of cleft lip patients do not have cephalometric parameters of pseudoprognathism and half of the patients have a lower masseter activity

Revisión bibliográfica actualizada sobre cambios dentofaciales y malformaciones congéticas inducidas por deficiencia aguda de riboflavina / A current review of the literature on dentofacial changes and congenital malformations induced by acute riboflavin deficiency

La riboflavina no es sintetizada por animales superiores en cantidad suficiente como para cubrir las necesidades nutricionales, por lo cual debe ingerirse en los alimentos. La deficiencia aguda de riboflavina en edad embrionaria puede ocasionar malformaciones esqueléticas y alteraciones bucofaciales, siendo el esqueleto membranoso el primero en manifestar los signos de este sindrome. Entre las diferentes anomalías tenemos: braquignacia, fusión de las costillas superiores, ausencia de tibia, atresia del esófago, excenfalia, protrusión de la lengua, incisivos inferiores ausentes, paladar hendido, atrofia de los músculos milhoideo y masetero, sindactilia, abducción de las manos. Se acepta que el agentes causante de estas alteraciones es la hiporriboflavinosis, la cual afecta la multiplicación de células mesenquimatosas durante la vida intrauterina. Si bien estas anomalías no son exclusivas de la deficiencia de riboflavina, se puede afirmar que ciertas deficiencias nutricionales en madres durante el período de gestación pueden causar defectos congénitos en los descendientes.

Tratamento cirúrgico da heipertrofia benigna do masseter por abordagem intra-oral / Surgical treatment of the benign masseteric hypertrophy through an intraoral approach

Os autores, neste trabalho, após suscintas consideraçöes sobre a etiologia, incidência, sintomatologia e diagnóstico da hipertrofia benigna do masseter, apresentam seus dois casos tratados cirurgicamente por abordagem intra-oral com ressecçäo da metade medial do masseter e do ângulo da mandíbula. Chamam atençäo para o ponto de vista de autores modernos, isto é, atuais, que lidam com o problema, que näo é visto por eles como um problema cosmético raro e nem com um problema diagnóstico como no passado, além de enfatizarem o osso como a chave para uma adequada ressecçäo, dando ao músculo importância secundária

Hipertrofia de maseteros : Revisión bibliográfica y reporte de casos en el Hospital Calderón Guardia / Masseteric hypertrophy : bibliographic review and report of cases at Hospital Calderón Guardia

El propósito de esta revisión fue el efectuar una revisión bibliográfica completa sobre la Hipertrofia Idiopática de Maseteros e ilustrada con dos pacientes tratados en el Hospital Calderón Guardia. Consideramos importante dicha patología debido al gran número de anomalías que pueden confundirse en el diagnóstico diferencial. Por esta razón, resaltamos el papel que tiene la enfermedad en el bagaje de conocimientos para múltiples especialidades de la Medicina y la Cirugía. Asimismo, presentamos una modalidad quirúrgica (aborde extraoral) que ofrece buenos resultados en el manejo de estos pacientes