[Effect of inferior vestibular and part of mandibular branch of trigeminal neurotomy on sound-induced masseter reflex potentials].
OBJECTIVE
To evaluate the influence of inferior vestibular and part of mandibular branch of trigeminal neurotomy on sound-induced masseter reflex potentials.


METHODS
Twenty guinea pigs were randomly divided into four groups, including 5 normal control guinea pigs, 5 received unilateral inferior vestibular neurotomy, 5 received unilateral inferior alveolar nerve neurotomy, and 5 received auriculotemporal nerve neurotomy. Click sound-induced masseter reflex potentials were recorded in four groups, respectively.


RESULTS
The thresholds of negative peak (NP) of click sound-induced masseter reflex potentials in normal control group were (90.00 +/- 8.16) dBnHL. The response rates of the NP of the masseter reflex potentials using 100, 90, 80 and 70 dBnHL monaural acoustic stimulation with unilateral recording were 100%, 70%, 40% and 0, respectively. The mean latencies of the NP were (6.55 +/- 0.25) ms, (6.61 +/- 0.16) ms and (6.70 +/- 0.13) ms, when elicited by 100,90 and 80 dBnHL acoustic stimulation respectively. There was no significant difference between the stimulus intensity and the mean latency of the NP (P > 0.05). Negative peak of click sound-induced masseter reflex potentials was not observed in the inferior vestibular neurotomy group. The NP was preserved in the inferior alveolar nerve and auriculotemporal nerve neurotomy groups. There were no significant difference of the mean thresholds and latencies of NP between normal control group and inferior alveolar nerve and auriculotemporal nerve neurotomy group (P > 0.05).


CONCLUSIONS
Click sound-induced masseter reflex potentials originates from vestibular afferents. Afferent of inferior alveolar nerve and auriculotemporal nerve can not influence the vestibular evoked masseter reflex potentials.
Sun
Wei
W
Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
Kong
Weijia
W
Li
Dan
D
D000344:Afferent Pathways / Q000601:surgery; D000818:Animals; D006168:Guinea Pigs; D008406:Masseter Muscle / Q000502:physiology*; D012022:Reflex, Acoustic; D014276:Trigeminal Nerve / Q000601:surgery*; D014725:Vestibular Nerve / Q000601:surgery*