Age-dependent effects of tonsillar hypertrophy on craniofacial morphology and hyoid compensation in children: a retrospective study

Tonsillar hypertrophy (TH) is a common obstructive upper airway disease in children, closely related to craniofacial growth and development. Hyoid bone position compensation plays an important role in this process. This study aimed to elucidate the age-dependent compensatory mechanisms of the hyoid bone in response to TH and to delineate their implications for craniofacial morphology in children. Lateral cephalograms and cone-beam computed tomography (CBCT) scans from 174 patients aged 6–12 years (71 males, 103 females) were retrospectively analyzed. The participants were stratified into two age groups (6–9 years, n = 88; 10–12 years, n = 86) and further categorized based on tonsillar status into a tonsillar hypertrophy group (TG) and a control group (CG). Multiple linear regression was used to assess the independent effects of TH on craniofacial and hyoid parameters, with subsequent stratified analysis by age and sagittal skeletal pattern to analyze the compensatory patterns. At ages 6–9, TG was significantly associated with mandibular retrognathia (SNB, B = -1.60, P = 0.040) and lower incisor proclination (L1-NB, B = 2.76, P = 0.041). At ages 10–12, TG showed significant associations with underdevelopment of the mandibular body and ramus (Go-Po, B = -1.90, P = 0.041; Go-Co, B = -2.17, P = 0.008) and a reduced distance between the hyoid bone and the lower border of the third cervical vertebra (H-C3, B = -1.57, P = 0.008). Compensatory changes in hyoid bone position varied depending on age and skeletal facial pattern. The influence of tonsillar hypertrophy on the craniofacial morphology and hyoid bone position of children shows significant age-dependent characteristics. Children aged 6–9 years with TH are characterized by compensatory mandibular retrognathia and lower incisor proclination. Children aged 10–12 years with TH exhibit mandibular ramus and mandibular body growth inhibition and compensatory forward head posture. Early recognition of age-specific phenotypes and implementation of stratified interventions are of paramount clinical importance for optimizing craniofacial developmental outcomes in children with tonsillar hypertrophy.