The influence of sympathetic nerve activity on axial position of the rabbit incisor tooth.
Changes in position of the upper front tooth in response to sectioning and subsequent electrical stimulation of the cervical sympathetic nerves were studied in 25 anesthetized rabbits. The position was continuously recorded by an ultrasonic transit time technique. Sectioning of the nerves was found to induce an average tooth extrusion of about 7 microns. Sympathetic nerve stimulation for periods of 20-30 s caused intrusion of the tooth, with about 70% of maximum occurring at 2 Hz stimulations. The intrusive response was reduced by phentolamine. Neither atropine nor propranolol affected the stimulation response, but the latter drug led to marked extrusion of the tooth. In conclusion, the position of the rabbit's front tooth was found to be highly sensitive to alterations in sympathetic nerve activity to the vasculature of the tooth-supporting tissues.
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D007180:Incisor / Q000502:physiology; D008297:Male; D010513:Periodontal Ligament / Q000098:blood supply* / Q000294:innervation; D010646:Phentolamine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D013564:Sympathetic Nervous System / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects*
D001285:Atropine; D011433:Propranolol; D010646:Phentolamine