Accessory auricle: Classification according to location, protrusion pattern and body shape

Background Accessory auricles (AAs) are common congenital anomalies. We present a new classification according to location and shape, and propose a system for coding the classifications. Methods This study was conducted by reviewing the records of 502 patients who underwent surgery for AA. AAs were classified into three anatomical types: intraauricular, preauricular, and buccal. Intraauricular AAs were divided into three subtypes: intracrural, intratragal, and intralobal. Preauricular AAs were divided into five subtypes: precrural, superior pretragal, middle pretragal, inferior pretragal, and prelobal. Buccal AAs were divided into two subtypes: anterior buccal and posterior buccal. AAs were also classified according to their protrusion pattern above the surrounding surface: pedunculated, sessile, areolar, remnant, and depressed. Pedunculated and sessile AAs were subclassified as spherical, ovoid, lobed, and nodular, according to their body shape. Cartilage root presence and family history of AA were reviewed. A coding system for these classifications was also proposed. Results The total number of AAs in the 502 patients was 1,003. Among the locations, the superior pretragal subtype (27.6%) was the most common. Among the protrusion patterns and shapes, pedunculated ovoid AAs were the most common in the preauricular (27.8%) and buccal areas (28.0%), and sessile lobed AAs were the most common in the intraauricular area (48.7%). The proportion of AAs with a cartilage root was 78.4%, and 11% of patients had a family history. The most common type of preauricular AA was the superior pretragal pedunculated ovoid AA (13.2%) with a cartilage root. Conclusions This new system will serve as a guideline for classifying and coding AAs.