Based on current, high-level evidence, which occlusal feature has demonstrated the strongest, albeit weak, statistical association with an increased prevalence of pain-related Temporomandibular Disorders (TMD)?

 # Based on current, high-level evidence, which occlusal feature has demonstrated the strongest, albeit weak, statistical association with an increased prevalence of pain-related Temporomandibular Disorders (TMD)?

A. Anterior Open Bite

B. Class II Division 2 Malocclusion

C. Overjet greater or equal to 6 mm

D. Posterior Unilateral Crossbite

The correct answer is D. Posterior Unilateral Crossbite

High-level evidence from systematic reviews, such as the 2025 review by Alghamdi et al. in Frontiers in Neurology (analyzing 17 studies on children/adolescents), identifies posterior unilateral crossbite as having the strongest association with pain-related TMD signs/symptoms, including TMJ/muscle pain and tenderness. Pooled data show odds ratios (ORs) of 2.25–5.74 (95% CIs: 1.15–4.43 to 1.18–27.85; p<0.05 across studies like Pereira et al. 2009 and Perrotta et al. 2018), indicating a 2–6-fold increased risk, though with low GRADE certainty due to cross-sectional designs and heterogeneity. This exceeds associations for other features: anterior open bite (OR ~1.5–2.0 in select studies, e.g., Sonnesen 1998); Class II Division 2 (OR 2.61 for general Class II, but weaker/subgroup-specific for Div 2, per Šimunović et al. 2024); and overjet ≥6 mm (OR ~1.8–2.5, less consistent in mixed/permanent dentition per Manfredini et al. 2010). A 2025 meta-analysis by Chen et al. in BMC Oral Health reports 59% TMD prevalence in unilateral crossbite cases (95% CI: 46%–72%), vs. 40%–44% for others. Overall, while all links are weak (ORs <6, multifactorial etiology), crossbite shows the most consistent statistical signal.