Role Of Rhoa/Rock Pathway In Early Tmj Ankylosis Development

To investigate the role of the RhoA/ROCK signaling pathway in the early development of traumatic temporomandibular joint ankylosis (TTMJA) using a murine model. Surgical induction of left-sided temporomandibular joint (TMJ) complex trauma was performed on 28 male 4-week-old C57/BL6 mice to induce ankylosis. Postoperatively, the mice were randomly divided into two groups: the experimental group (n=14) received injections of the RhoA/ROCK pathway inhibitor Y-27632 into the affected joint cavity every other day for 2 weeks, while the control group (n=14) received equivalent volumes of saline. After 6 weeks, the TMJ complex tissues were collected from the mice. Bone volume and structural changes were assessed by Micro-CT scanning. Histopathological changes were evaluated through histological and immunohistochemical analyses. The expression of Runx2, Osterix, and RhoA/ROCK1 was analyzed using immunofluorescence and immunohistochemistry. All experiments in this study were approved by the relevant animal ethics committee (approval number: 2024-kq-008). Micro-CT analysis revealed significantly decreased bone volume and trabecular number in the experimental group. Histological staining indicated milder pathological changes in this group. Immunofluorescence and immunohistochemistry showed significantly reduced expression of Runx2, Osterix, and RhoA/ROCK1. The RhoA/ROCK signaling pathway plays a significant role in the early development of temporomandibular joint ankylosis.