The Mandibular Deformity in Hemifacial Microsomia: A Reassessment of the Pruzansky and Kaban Classification

Background: The authors examined hemifacial microsomia using three-dimensional computed tomography and the Kaban modification of the Pruzansky classification to determine its relationship with traditional evaluation and its reproducibility among evaluators. Methods: A retrospective review of all patients diagnosed with hemifacial microsomia was performed. Three-dimensional computed tomographic scans were reviewed by expert evaluators and rated according to evaluators' understanding of the Kaban modification of the Pruzansky classification. The clinical Kaban-Pruzansky score was recorded at the time of initial clinical presentation and an in-house score stratified the population into mild (0-I), moderate (IIA), and severe (IIB-III). These two standards and the evaluators' scores were compared. Fleiss's kappa was used to assess interrater variability (p < 0.05). Results: Forty-one patients met inclusion criteria, and 38 had documented clinical Kaban-Pruzansky scores. Sixteen craniofacial surgeons with an average of 15.5 years (range, 6 to 38 years) of experience were surveyed. Fair interrater reproducibility was found among all expert evaluators (Fleiss ? = 0.238). When comparing raters' three-dimensional computed tomography-based classification to the clinical Kaban-Pruzansky scores, the average agreement was 39.17 8.83 percent (average ? = 0.257 0.147) (p = 0.90). When comparing raters' classification to the in-house score, the average agreement was 69.71 +/- 9.42 percent (p = 0.97) (average ? = 0.576 +/- 0.140). Conclusions: The introduction of three-dimensional computed tomography into the diagnostic paradigm highlights the inaccuracy and variability of traditional classification systems. The results question the accuracy and reproducibility of the current clinical paradigm, suggesting the need to reexamine the classification of hemifacial microsomia.