Search PubMed⌕ Search

Biomedical subjects

D M Watt

Publications and source records attributed to D M Watt.

6 recordsLinked to original sources
PubMed1978

Gnathosonic monitoring of patients with gnathic dysfunctions.

The progress of 23 adult patients during treatment for gnathic dysfunctions was monitored by gnathosonic techniques and graphs of the fluctuations in occlusal sound duration were studied. It was concluded that this method gave a useful insight into the progress of patients under treatment and aided the assessment of the effects of treatment.

Adaptation, Physiological↗
PubMed1978

Study of a classification of occlusion.

A functional classification of occlusion based on the sounds produced by tooth contact was first proposed in 1970. The classification was found useful for identifying patients prone to gnathic dysfunctions as a significantly higher proportion of these patients were in Class C than in Class A. In the studies described in this paper other parameters of occlusion were measured to find if there were differences between the classes in addition to the differences in occlusal sound duration which identified the classes. The first study found highly significant differences in co-ordination between Class A and Class C as measured by the coincidence of sound patterns. Many significant differences at the 1% level were found in the F test of samples of 5 successive occlusal sounds in series of 25 sounds in Classes A and C, but these differences diminished as the series of sounds was prolonged, suggesting that the subject's ability to find stable occlusal positions improved with successive occlusal contacts. No significant differences were found in time intervals between the sounds in different classes, but significant differences were found in masseter muscle activity in relation to the presence or absence of silent periods between occlusal classes. It was concluded that the functional classification of occlusion based on the duration of tooth contact sounds was valid.

Adolescent↗
PubMed1976

The influence of percussion, occlusion and mastication on the occurrence of silent periods in masseter muscle activity.

The occurrence of silent periods in masseter muscle activity was investigated during percussion of the bony structures of the head and neck, during occlusion of the teeth on surfaces of varying hardness, and during chewing of different food-stuffs. Silent periods were demonstrated on percussion during isometric and isotonic contraction of the masseter muscles and the occurrence of silent periods was influenced by the force of occlusion and by the nature of the surface contacted. Mandibular velocity was investigated during tapping and chewing sequences by ultra-high-speed cinematography, but it was not found possible to identify a critical change in mandibular velocity associated with the occurrence of silent periods. More silent periods were observed during the chewing of hard foods than of soft foods and there were more silent periods near the beginning of chewing sequences than towards the end. Differences in latency and duration of silent periods were observed in relation to artificial changes in the occlusion.

Dental Occlusion↗