The regulation by muscle spindles of jaw-closing muscle activity during mastication was evaluated in anesthetized rabbits. Simultaneous records were made of the discharges of muscle spindle units in the mesencephalic trigeminal nucleus, masseter and digastric muscle activity (electromyogram [EMG]), and jaw-movement parameters during cortically induced rhythmic jaw movements. One of three test s...

Fabrication of interocclusal splint at a thickness determined by the vertical dimension at which the jaw muscle EMG amplitude is minimum has been recommended. However, the effect of prior jaw motion and the effect of the recording site on the EMG amplitudes and on the vertical dimension of minimum EMG activity have not been documented. IEMG amplitudes at various static jaw positions achieved du...

Exposure to environmental contaminants can disrupt normal development of the early vertebrate skeleton. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) impairs craniofacial skeletal development across many vertebrate species, and its effects are especially prominent in early life stages of fish. TCDD activates the aryl hydrocarbon receptor, a transcription factor that mediates most if not all TCDD r...

a 25-yr-old iranian woman with incomplete abortion who was diagnosed and scheduled for dilatation and curettage procedures under general anesthesia. after premedication with fentanyl 50µg and midazolam 2mg and enough pre-oxygenation, anesthesia was induced by sodium thiopental 250 mg and succynilcholine 60 mg with mask ventilation. after completion of procedure, the patient had a period of lary...

Dlx transcription factors are implicated in patterning the mammalian jaw, based on their nested expression patterns in the first branchial arch (primordium for jaw) and mutant phenotypes; inactivation of Dlx1 and Dlx2 (Dlx1/2-/-) causes defects in the upper jaw, whereas Dlx5/6(-/-) results in homeotic transformation of the lower jaw into upper jaw. Therefore, the 'Dlx codes' appear to regionali...

A two-dimensional rigid-body model of jaw movement was used to describe jaw opening and closing gestures for vowels and for bilabial and alveolar consonants. Jaw movements were decomposed into three components: (a) rotation about the terminal hinge axis, (b) the horizontal translation of that axis, and (c) the vertical translation of that axis. Data were collected for 3 subjects in two separate...

Although there is a great deal of work on facial animatic’n, there is not much research on the effect of jaw motion on the movement of the face. The complex nature of the jaw bones makes it difficult to implement all the motions the jaw can do. The human jaw has :wo widely separated identical joints behaving like a single joint. Widely separated joints of the mandible (lower jaw bone) allow it ...