Effects of a liquid diet on temporomandibular joint mechano-receptors.
Load during mastication is an important factor for the development and maintenance of mechano- receptor properties. The purpose of this study was to examine property changes in the rat TMJ mechano-receptors under conditions of liquid diet feeding and low articular load during the growth period. The hypothesis was that alterations in mastication of liquid diet might increase TMJ mechano-receptor sensitivity. Sixty-six two-week-old male Wistar rats were divided into two groups: a control group that was fed on whole pellets, and an experimental group that was fed a liquid diet. Electrophysiological recordings from the TMJ units were obtained from the trigeminal ganglion when the rats were 5, 7, and 9 weeks old. In the experimental group, TMJ mechanoreceptor sensitivity increased, because the firing threshold gradually decreased and the maximum instantaneous frequency gradually increased. In conclusion, functional properties of TMJ mechano-receptors under low articular loading conditions cannot mature normally within the growth period.
Ishida
T
T
Orthodontic Sciences, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School, Tokyo Medical Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. takaorts@tmd.ac.jp
Yabushita
T
T
Soma
K
K
D000818:Animals; D003799:Dental Stress Analysis; D005526:Food, Formulated; D008297:Male; D008409:Mastication / Q000502:physiology*; D008465:Mechanoreceptors / Q000502:physiology*; D009431:Neural Conduction; D051381:Rats; D017208:Rats, Wistar; D012684:Sensory Thresholds; D013704:Temporomandibular Joint / Q000254:growth & development* / Q000294:innervation; D012668:Trigeminal Ganglion / Q000502:physiology