Association between petrotympanic fissure and condylar morphology on CBCT: a retrospective pilot study

Aims: This pilot study aimed to investigate the relationship between petrotympanic fissure (PTF) classification and mandibular condyle morphology using cone-beam computed tomography (CBCT), and to analyze the effects of age and sex on these anatomical characteristics. Methods: A retrospective, cross-sectional analysis was conducted on 88 patients, yielding 176 temporomandibular joints (TMJs). PTF types were categorized on sagittal CBCT sections according to Sato’s classification (Types 1-3), while condylar morphology was assessed on coronal sections using the Yale system (Types 1-4). To maintain statistical independence, right and left joints were evaluated separately. A supplementary analysis was performed on the pooled dataset. Associations were evaluated using Pearson’s chi-square with permutation-derived p-values. A multinomial logistic regression model incorporating intra-patient clustering was applied for multivariate analysis. Results: The cohort mean age was 36.0±13.2 years; 79.5% were female. No significant association between PTF type and condylar morphology was detected in side-specific analyses (Right: p=0.252; Left: p=0.244). A marginal association emerged only in the pooled analysis (χ²=13.12, p=0.041), which is interpreted as a statistical artifact driven by duplicated TMJ counts and within subject dependency, rather than a biologically meaningful correlation. Multivariate modelling demonstrated a weak inverse association between age and Type 4 condylar form (p=0.028). Sex did not exert a significant influence on morphology. Conclusion: When analyzed under conditions that respect joint independence, PTF type is not correlated with condylar morphology. Observed pooled-data significance reflects sample inflation bias. PTF classification should therefore not be used as a clinical predictor of condylar shape.