[Percentage of tonsil hypertrophy in orthodontic patients with different sagittal skeletal relationship].

To investigate the prevalence of tonsil hypertrophy in patients with different sagittal skeletal craniofacial patterns, as well as the correlation between tonsil hypertrophy and the type of skeletal pattern. Lateral cephalograms of patients who visited the Department of Orthodontics Division 1, School of Stomatology, Wuhan University during January to August, 2019 were retrospectively collected. Patients (children: age≥6 and ≤12 year; adults: age≥18 year) were divided into three groups according to the ANB (subspinale-nasion-supramental) angle: the skeletal class Ⅰ group (0°≤ANB≤4°), skeletal class Ⅱ group (ANB>4°) and skeletal class Ⅲ group (ANB<0°). Tonsil hypertrophy was diagnosed with lateral cephalogram by two specifically trained orthodontists independently, according to the Baroni's method. The between-group differences in tonsil hypertrophy prevalence were analyzed using chi-square tests with Bonferroni correction (α=0.017). A total of 1 776 patients (593 children and 1 183 adults) were included, among which 672 (37.8%) were with class Ⅰ, 849 (47.8%) with class Ⅱ, and 255 (14.4%) with class Ⅲ skeletal pattern. The prevalence of tonsil hypertrophy in children was 66.3% (393/593). The proportion of children with tonsil hypertrophy in class Ⅲ group [87.0% (60/69)] were significantly higher than that in class Ⅰ [65.6% (145/221), χ²=11.56, 0.017] and class Ⅱ [62.0% (188/303), χ²=15.69, 0.017] groups. The prevalence of tonsil hypertrophy in adults was 23.2% (275/1 183). The proportion of adults with tonsil hypertrophy in class Ⅲ group [42.5% (79/186)] was significantly higher than that in class Ⅰ [19.1% (86/451), χ²=36.50, 0.017] and class Ⅱ [20.2% (110/546), χ²=35.00, 0.017] groups. However, there was no significant difference in the prevalence of tonsil hypertrophy between class Ⅰ and class Ⅱ groups for both children (χ²=0.70, 0.017) and adults (χ²=0.18, 0.017). The prevalence of tonsil hypertrophy in skeletal class Ⅲ patients was significantly higher than that in patients with skeletal class Ⅰ and Ⅱmalocclusion. Tonsil hypertrophy could be an important risk factor for skeletal class Ⅲ patients.