Objective: To compare the validity and reliability of 3 mandibular condylar segmentation planes—conventional Frankfort-parallel (C), adjusted global (F), and condylar long-axis-based (P) planes—in patients with unilateral craniofacial microsomia (CFM). Methods: This retrospective methodological study included 47 patients with unilateral type IIA CFM. Condyles were segmented from 3-dimensional CT scans using the 3 planes. Validity was assessed using a custom 4-grade integrity score (grades 1–2 were considered valid). Reliability was evaluated using intraclass correlation coefficients (ICCs) for intra- and interoperator volume measurements. Statistical analyses included the Friedman test, the Cochrane Q test, and the Bonferroni correction. Results: Plane P demonstrated the highest valid segmentation rate (97.9%), significantly greater than plane C (40.4%, adjusted P <0.001) but not significantly different from plane F (78.7%, adjusted P =0.069). All planes showed good to excellent reliability (ICCs: 0.939–0.998). Condylar volumes and asymmetry ratios differed significantly among planes ( P <0.001). Conclusions: The choice of segmentation plane significantly affects condylar volumetric measurement validity in CFM. Plane P provides the most valid segmentation, but requires enhanced standardized training. Plane F is a viable alternative. The conventional plane C frequently results in incomplete segmentation, limiting its validity in this population.
Li et al. (2026) studied this question.