OBJECTIVE To investigate the involvement of microglial and astrocytic activation in the medullary dorsal horn (MDH) during the mediation of masseter area allodynia induced by experimental tooth movement (ETM). DESIGN Five groups of adult Sprague-Dawley rats (n=60) were divided into control (CON), minocycline (MIN), ETM, and 10mg/kg or 30mg/kg MIN plus ETM (METM) groups. The upper-first-molar ...

The electromyographic activity of the right masseter and digastric muscles was recorded in 10 subjects. A jaw-opening reflex was observed shortly after a mechanical stimulation in subjects performing clenching and active jaw-opening exercises. The latency of this reflex activity was about 28 ms, coinciding with the termination of the silent period of the masseter muscle. The experiments show th...

Intramuscular injection of nerve growth factor (NGF) into rat masseter muscle induces a local mechanical sensitization that is greater in female than in male rats. The duration of NGF-induced sensitization in male and female rats was associated with an increase in peripheral N-methyl-d-aspartate (NMDA) receptor expression by masseter muscle afferent fibers that began 3 days postinjection. Here,...

The aim of this study was to determine the detailed anatomical structures of the superficial part of the masseter and to elucidate the boundaries and locations of the deep tendon structure within the superficial part of the masseter. Forty-four hemifaces from Korean and Thai embalmed cadavers were used in this study. The deep tendon structure was located deep in the lower third of the superfici...

This study was undertaken to examine the alteration of masseter and plasma interleukin-6 after inducing occlusal interference and chronic stress. Male Wistar rats were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mentioned procedures. Whole blood and masseter tissue were collected to determine interleukin-6 level, measured by means of ELISA. Masset...

Masseter muscle hypertrophy is a rare condition of unknown cause which is important in the differential diagnosis of head and neck masses, located in the cheek. Several treatment options reported for masseter hypertrophy, which range from simple pharmacotherapy to more invasive surgical reduction. Botulinum toxin type A is a powerful neurotoxin which is produced by the anaerobic organism Clostr...

Masseter muscle hypertrophy also called as Benign Massetric hypertrophy (BMH) or Idiopathic Massetric Muscle Hypertrophy (IMMH) is a rare condition of unknown cause which is important in the differential diagnosis of head and neck masses, located in the cheek. It can occur unilaterally or bilaterally. Most patients consult a physician for esthetic correction of the resultant facial asymmetry. S...

The purpose of this report is to highlight how an unusual, outdated, unpopular and overlooked reconstructive method such as the masseter flap can be a reliable, straightforward and effective solution for oral reconstruction in selected cases. We report the transposition of the masseter crossover flap in two previously pre-treated patients presenting a second primary oral squamous cell carcinoma...

Previous results have shown that the adult human masseter muscle contains myosin isoforms that are specific to early stages of development in trunk and limb muscles, i.e. embryonic and fetal (neonatal) myosin heavy chains (MHC) and embryonic myosin light chain (MLC1emb). We wanted to know if this specific pattern is the result of a late maturation or of a distinct evolution during development. ...