Clinical characteristics and risk factors of major oral ulcers in the mandibular retromolar region in children

Objectives To describe the characteristics of major aphthous ulcers (MjOU) in children and analyze its potential risk factors. Materials and methods Data were collected from the National Clinical Research Center for Oral Diseases of China between 2012 and 2017. Children younger than 15 years old, who had a giant mucosa ulcer (≥ 1 cm in diameter) and met the diagnostic criteria for MjOU were included in this study. Differences were compared between two subgroups of patients based on the location of the ulcerous lesions. A measurement of ratio (TBR) between the length of the mandibular second molar tooth germ and the height of the mandible was performed in children with MjOU lesions located in the mandibular retromolar pad region (MjOU-P) and their age- and sex-matched controls. Results A total of 1067 children were diagnosed with oral ulcers during the study period, of which 125 (11.7%, 95% CI: 9.8%–13.7%) met the diagnostic criteria for MjOU. More than half ( n = 64, 51.2%) of the MjOU cases were MjOU-P, which had a male predilection ( n = 52, 81.3%) with a significant majority at 7 to 9 years of age ( n = 43, 67.2%). In comparison to the MjOU located in other regions, MjOU-P lasted longer in duration and had more comorbidities. Logistic regression analysis showed that MjOU-P was statistically significantly associated with TBR controlling age and gender. Conclusions MjOU-P is a predominant form of MjOU in children and is a distinct subgroup of major ulcers that is likely associated with the development of the mandibular second molars. Clinical relevance This study is the first to describe the demographic and clinical features of MjOU in children, which may facilitate the identification and treatment of these patients.