The Role of Nociceptors in Orthodontic Tooth Movement, Pain, and Alveolar Bone Remodeling

Abstract

Objective: To determine the effects of selectively ablating transient receptor potential vanilloid 1 (TRPV1)-expressing nociceptors on orthodontic tooth movement, pain, and alveolar bone remodeling. Methods: Resiniferatoxin (RTX) or vehicle was stereotaxically injected into left trigeminal ganglia in adult C57BL/6 mice. After 1 week, orthodontic spring was placed between left maxillary first molar and upper incisors. Pain level was evaluated by measuring mouse grimace scale (MGS) and bite force before and after 1, 3, and 7 days following the procedures. After 12 days, micro-CT was used to quantify tooth movement and analyzing alveolar bone changes. Results: Experimental tooth movement increased MGS scores and decreased bite force. RTX ablation of TRPV1+ nociceptors attenuated MGS scores and relieved the reduction in bite force. The extent of tooth movement was decreased in RTX-treated group, but interradicular alveolar bone volume was not affected. Conclusion: Selective ablation of TRPV1+ nociceptors significantly decreases tooth movement and pain.