Effects of pain associated with orthodontic tooth movement on tactile sensation of periodontal ligaments

Abstract

Abstract Objectives Pain associated with orthodontic tooth movement reportedly reduces periodontal ligament tactile sensation. However, the mechanism at the central nervous system remains unclear. This study was designed to clarify the effects of pain associated with orthodontic tooth movement on periodontal ligament tactile sensation by measuring somatosensory evoked magnetic fields (SEFs) during mechanical stimulation of teeth being moved by separator elastics. MethodsSEFs were measured using magnetoencephalography during the application of mechanical stimulations to the mandibular right first molars of 23 right-handed healthy subjects (0 hr). Separator elastics were then inserted into the mesial and distal interdental portions of the mandibular right first molars. The same mechanical stimulations were applied to them again 24 hr later. Then the SEFs were measured (24 hr). After each SEF measurement, pain was also evaluated using the Visual Analog Scale (VAS). Results The VAS values were significantly higher at 24 hr than at 0 hr (p<0.05). Although no significant difference in the peak latencies was found between those obtained at 0 hr and 24 hr, the intensities around 40.0 ms in the contralateral hemisphere were significantly lower at 24 hr than at 0 hr (p<0.01). ConclusionsPain associated with orthodontic tooth movement might suppress periodontal ligament tactile sensation in the primary somatosensory cortex. Clinical Relevance Pain associated with orthodontic tooth movement might affect periodontal ligament sensation, consequently causing discomfort during occlusion.