Somatosensory evoked magnetic fields of periodontal mechanoreceptors

Hiroki Hihara; Hiroyasu Kanetaka; Akitake Kanno; Eriya Shimada; Satoko Koeda; Ryuta Kawashima; Nobukazu Nakasato; Keiichi Sasaki

doi:10.1016/j.heliyon.2020.e03244

Somatosensory evoked magnetic fields of periodontal mechanoreceptors

Heliyon. 2020 Jan 22;6(1):e03244. doi: 10.1016/j.heliyon.2020.e03244. eCollection 2020 Jan.

Authors

Hiroki Hihara¹, Hiroyasu Kanetaka², Akitake Kanno^{3

4}, Eriya Shimada⁵, Satoko Koeda⁶, Ryuta Kawashima⁷, Nobukazu Nakasato^{3

4}, Keiichi Sasaki¹

Affiliations

¹ Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan.
² Liaison Center for Innovative Dentistry, Tohoku University Graduate School of Dentistry, Sendai, Japan.
³ Department of Epileptology, Tohoku University School of Medicine, Sendai, Japan.
⁴ Department of Electromagnetic Neurophysiology, Tohoku University, Sendai, Japan.
⁵ Division of Oral Dysfunction Science, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
⁶ Yokohama Clinic, Kanagawa Dental University, Yokohama, Japan.
⁷ Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.

Abstract

To evaluate the localization of responses to stimulation of the periodontal mechanoreceptors in the primary somatosensory cortex, somatosensory evoked fields (SEFs) were measured for stimulation of the left mandibular canine and first molar using magnetoencephalography in 25 healthy subjects. Tactile stimulation used a handmade stimulus device which recorded the trigger at the moment of touching the teeth.SEFs for the canine and first molar were detected in 20 and 19 subjects, respectively. Both responses were detected in the bilateral hemispheres. The latency for the canine was 62.1 ± 12.9 ms in the ipsilateral hemisphere and 65.9 ± 14.8 ms in the contralateral hemisphere. The latency for the first molar was 47.4 ± 6.6 ms in the ipsilateral hemisphere and 47.8 ± 9.1 ms in the contralateral hemisphere. The latency for the first molar was significantly shorter than that for the canine. The equivalent current dipoles were estimated in the central sulcus and localized anteroinferiorly compared to the locations for the SEFs for the median nerve. No significant differences in three-dimensional coordinates were found between the canine and first molar. These findings demonstrate the precise location of the teeth within the orofacial representation area in the primary somatosensory cortex.

Keywords: Canine; Clinical research; Dentistry; First molar; Medical imaging; Nervous system; Neurology; Neuroscience; Periodontal mechanoreceptor; Physiology; Primary somatosensory cortex; Somatosensory evoked fields.