Periodontal-masseteric reflexes decrease with tooth pre-load.
The responses of incisal periodontal mechanoreceptors to increasing mechanical stimulation are known to follow a hyperbolic-saturating course. The implications of these properties for the reflexive control of bite-force have not been examined directly. In line with the above mentioned receptor characteristics, we hypothesized that the periodontal-masseteric reflex will reduce as a function of increasing incisal pre-load. In 10 participants, a central incisor was repeatedly tapped (0.4 N). We measured the modulation by pre-load (0.2-2.0 N) of the reflex frequency-response at and between 3 and 20 Hz. The entrainment of the reflex increased with frequency up to 20 Hz and diminished with increasing pre-load. Importantly, the hyperbolic relationship shown here between the periodontal-masseteric reflex and tooth pre-load agreed with the load/response relationships predicted by single-receptor and tooth movement studies. This study demonstrated that periodontal mechano-receptors are able to contribute to the ongoing control of only small bite-forces.
Sowman
P F
PF
Research Centre for Human Movement Control, Discipline of Physiology, School of Molecular and Biomedical Science, University of Adelaide, SA 5005, Australia.
Türker
K S
KS
D000293:Adolescent; D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage; D001732:Bite Force; D004576:Electromyography; D005246:Feedback / Q000502:physiology; D005260:Female; D006801:Humans; D007180:Incisor / Q000294:innervation / Q000502:physiology*; D008297:Male; D008406:Masseter Muscle / Q000502:physiology*; D008465:Mechanoreceptors / Q000187:drug effects / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D010519:Periodontium / Q000187:drug effects / Q000294:innervation*; D010812:Physical Stimulation; D011930:Reaction Time / Q000502:physiology; D012018:Reflex / Q000502:physiology*; D012677:Sensation / Q000187:drug effects
D000779:Anesthetics, Local