Search PubMed⌕ Search

Biomedical subjects

E Mushimoto

Publications and source records attributed to E Mushimoto.

12 recordsLinked to original sources
PubMed1995

Pilot study of the heterogeneous patterns of masticatory muscle coordination in nonpatient population.

This pilot study characterized coordination patterns of the muscles of mastication during voluntary chewing in a nonclinical population. Dental students (n = 177) who did not exhibit symptoms of temporomandibular disorder were screened by a comprehensive muscle and temporomandibular joint palpation examination. A group of 44 students was identified on the basis of the presence of four or more tender points indicated during palpation. This group was further subgrouped by the absence (group A-1) and presence (group A-2) of temporomandibular joint clicking. Five volunteers from groups A-1 and A-2 and five volunteers without any palpation tenderness and joint clicking (control group) were examined by simultaneous recordings of electromyography of bilateral masseter and posterior one third of the temporalis muscles and by mandibular kinesiography. The electromyographic coordination pattern for the control group demonstrated predominantly working masseter muscle activity. This "predominant working masseter" pattern was not observed in groups A-1 or A-2. Additional analyses of the recordings indicated that a hypoactive tendency of the working side masseter muscle particularly outlasting the tooth contact was present in group A-1, whereas significant hyperactivity of the posterior one third of the temporalis was present in group A-2. The data suggested that an asymptomatic nonpatient population may be functionally diverse.

Adult↗
PubMed1981

An excitatory response preceding the silent period in masseter electromyographs.

A masseteric excitatory reflex response preceding the silent period which appears following tapping movement of the jaw, was investigated in order to evaluate its origin. In the pre-anaesthetic state, the latency of response did not change with the intensity of tapping. However, its amplitude increased depending on the intensity of tapping. The response did not disappear even after the anaesthesia. After the anaesthesia the lighter the intensity of tapping was, the longer the latency of the response, coming up to that of the jaw-jerk reflex. The pre-anaesthetic response had an intricate wave form comparing with the post-anaesthetic one. From the above findings it was concluded that the response must be a complex one in nature originating in the muscle spindle of jaw closing muscles and in a certain receptor of the structures surrounding the tooth.

Adult↗
PubMed1981

The role in masseter muscle activities of functionally elicited periodontal afferents from abutment teeth under overdentures.

Five overdenture wearers with a small number of remaining natural teeth were selected to evaluate the effect of the afferent input from periodontal mechanoreceptors on masseter activity in man. As a control, a full denture wearer was included. The subjects were instructed to chew a piece of gum, and/or tap their teeth. Surface EmG from the bilateral masseter muscles were recorded and analysed. When functional pressure was applied, during chewing, to the abutment teeth as well as to mucosa through the denture base, masseter activities were encouraged. Following application of anaesthesia to the periodontal membrane of the abutments, masseter activities were reduced. The duration of the silent period (SP) appearing in the EMG burst following tooth tapping was significantly increased with root support compared to mucosal support only. With topical anaesthesia of the periodontal tissues, SP duration decreased significantly. In conclusion, it has become apparent that the pressure sensibility of abutment teeth bearing functional pressure under an overdenture base is capable of facilitating masseter activity, as one of the sources of oral sensory input during mastication.

Adult↗
PubMed1980

The delay time of tooth vibration signal recorded at facial skin surface.

The onset of a tooth vibration signal with a mini acceleration pickup attached to the skin on the forehead was delayed by 0.1788 ms on average after the actual tooth impact. When the signal was recorded at the zygomatic arch, the delay time was 0.1008 ms on average, which was significantly shorter than that obtained from the forehead (P less than 0.001). The difference due to a transposition of the vibrated tooth was also smaller (0.025 less than P less than 0.05) and had almost no effect on the intensities of the tooth flipping force. The delay time was even more prolonged when a poor frequency specification pickup and/or low pass filter were applied.

Adult↗