Int Orthod. 2026 Apr 24;24(3):101168. doi: 10.1016/j.ortho.2026.101168. Online ahead of print.
ABSTRACT
OBJECTIVE: To evaluate three-dimensional (3D) hard and soft tissue symmetry changes following sequential stabilization splint (SS) and fixed orthodontic treatment in patients with temporomandibular disorders (TMD) and mandibular deviation (MD).
METHODS: This retrospective study analysed cone-beam computed tomography (CBCT) scans of 32 adults with TMD and MD treated between July 2015 and July 2024. Scans were evaluated at three stages: before SS therapy (T0), after SS therapy (T1), and after orthodontic treatment (T2). Facial asymmetry was quantified using the Asymmetry Index (AI), while chin deviation was assessed by measuring the Menton’s displacement relative to the midsagittal plane. Statistical analyses were performed using the Friedman and Wilcoxon signed-rank tests (P<0.05).
RESULTS: Significant reductions in AI were observed in mandibular hard tissue landmarks (Pog, Me, Sig, and Go; all P<0.05) and corresponding soft tissue landmarks (Pog’ and Me’; P<0.05). Hard tissue Me deviation decreased by a mean of 1.95mm (95% CI: 1.4-2.5mm) and soft tissue Me’ deviation by 1.62mm (95% CI: 1.1-2.2mm). The proportion of patients with≤2mm chin deviation increased from 0% to 50% (hard tissue) and 0% to 69% (soft tissue), with improvement observed in 87-88% of patients. Following SS therapy, pain intensity decreased by 4.3 points (95% CI: 3.8-4.9), maximum mouth opening increased by 5.5mm (95% CI: 4.2-6.8mm), and joint sounds were markedly reduced (all P<0.001). The greatest improvements occurred during the SS phase, with further refinement after orthodontic treatment.
CONCLUSIONS: Sequential SS and orthodontic therapy effectively improved both hard and soft tissue symmetry in adults with TMD and MD, primarily by stabilizing condylar position and reestablishing occlusal balance.
PMID:42034921 | DOI:10.1016/j.ortho.2026.101168
