myositis ossificans (mo) is a pathologic bone formation in soft tissue with unknown pathogenesis. in this article, we reported a case of long standing mo of right medial pterygoid muscle with severe limitation of mouth opening.

The medial and lateral pterygoid muscles are different in structure as well as in function. The medial pterygoid muscle is concentrically active during jaw closing, and the superior head of the lateral pterygoid muscle is eccentrically active during jaw closing, while its inferior head is concentrically active during jaw opening. Architecturally, the medial pterygoid can deliver higher forces t...

PURPOSE We investigated the pathways of spread of odontogenic infection in the facial and neck spaces. METHODS CT scans of 45 patients with extensive spread of odontogenic infection into the facial and neck spaces were analyzed to document pathways of spread. RESULTS Odontogenic infections arising in the mandible first spread upward, into the masseter and/or medial pterygoid muscles in the ...

A lthough there have been a number of studies that involved the function of jaw muscles, due to its deep placement, the action of the superior belly of the lateral pterygoid (SLP) muscle has not been studied widely. The electromyographic (EMG) activities of the superior and inferior bellies of the lateral pterygoid muscles have been shown to be reciprocal in humans’-‘,+ and rhesus monkeys. *-lo...

The objectives of this study were to figure out the prevalence of sideways disc displacement of the temporomandibular joint (TMJ) in symptom-free volunteers and to compare signal. The study was based on bilateral Magnetic Resonance Images (MRI) of 112 joints in 56 symptom-free volunteers. Sideways displacements were identified as medial disc displacement (MDD) and lateral disc displacement (LDD...

This work is a retrospective study of magnetic resonance imaging (MRI) and T-stage subclassifications of nasopharyngeal carcinoma (NPC) involving the masticatory muscles (MMs). We examined how involvement of MMs influences the clinical T-stage classifications and the survival outcomes of NPC patients. MRI data as well as the medical records from 816 NPC patients were analyzed retrospectively. A...

Muscle activation varies with different behaviors and can be quantified by the level and duration of activity bursts. Jaw muscles undergo large anatomical changes during maturation, which are presumably associated with changes in daily muscle function. Our aim was to examine the daily burst number, burst length distribution and duty time (fraction of the day during which a muscle was active) of...

Myositis ossificans (MO) is a disease where heterotropic bone forms within a muscle or other type of soft tissue. MO is classified into two groups, MO progressiva and post-traumatic MO. It rarely occurs in the masticatory muscles and thus, only 20 cases involving the masticatory muscles have been reported since 2001. The majority of the reported cases occurred due to trauma, repeated injury or ...

The masticatory motor patterns of three tammar wallabies and two red kangaroos were determined by analyzing the pattern of electromyographic (EMG) activity of the jaw adductors and correlating it with lower jaw movements, as recorded by digital video and videoradiography. Transverse jaw movements were limited by the width of the upper incisal arcade. Molars engaged in food breakdown during two ...