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. .

Effect of triiodothyronine on the maxilla and masseter muscles of the rat stomatognathic system

The maxilla and masseter muscles are components of the stomatognathic system involved in chewing, which is frequently affected by physical forces such as gravity, and by dental, orthodontic and orthopedic procedures. Thyroid hormones (TH) are known to regulate the expression of genes that control bone mass and the oxidative properties of muscles; however, little is known about the effects of TH on the stomatognathic system. This study investigated this issue by evaluating: i) osteoprotegerin (OPG) and osteopontine (OPN) mRNA expression in the maxilla and ii) myoglobin (Mb) mRNA and protein expression, as well as fiber composition of the masseter. Male Wistar rats (~250 g) were divided into thyroidectomized (Tx) and sham-operated (SO) groups (N = 24/group) treated with T3 or saline (0.9 percent) for 15 days. Thyroidectomy increased OPG (~40 percent) and OPN (~75 percent) mRNA expression, while T3 treatment reduced OPG (~40 percent) and OPN (~75 percent) in Tx, and both (~50 percent) in SO rats. Masseter Mb mRNA expression and fiber type composition remained unchanged, despite the induction of hypo- and hyperthyroidism. However, Mb content was decreased in Tx rats even after T3 treatment. Since OPG and OPN are key proteins involved in the osteoclastogenesis inhibition and bone mineralization, respectively, and that Mb functions as a muscle store of O2 allowing muscles to be more resistant to fatigue, the present data indicate that TH also interfere with maxilla remodeling and the oxidative properties of the masseter, influencing the function of the stomatognathic system, which may require attention during dental, orthodontic and orthopedic procedures in patients with thyroid diseases.

Estudio clínico de una nueva asociación (tolperisona + acetaminofén) en contractura de los músculos maseteros / Clinical study of a new association (tolperisone and acetaminophen) in the contracture of masseter muscles

Se estudiaron los efectos de la combinación del clorhidrato de tolperisona, como relajante muscular, y acetaminofén, cuyo efecto es analgésico, en 32 pacientes adultos que presentaban contractura muscular de los maseteros, acompañada de dolor. Los pacientes no habían recibido tratamiento alguno durante las 72 horas anteriories; la dosificación empleada fue de una cápsula cada 8 horas por un periodo de 3 a 5 días. Los efectos secundarios fueron mínimos, sólo 2 pacientes acusaron náusea que se corrigió al ajustar la dosis. En ningún caso hubo necesidad de suspender el tratamiento. Los autores consideran de utilidad la asociación terapéutica mencionada, en el posoperatorio de cirugía bucal