Structural and functional impact of lingual frenulum alterations on oral and craniofacial development in children during the mixed dentition stage

Background The clinical relevance of ankyloglossia in children remains controversial, largely due to the absence of standardized diagnostic criteria and the predominant reliance on morphological assessment. Evidence linking the combined anatomical and functional characteristics of the lingual frenulum to objective functional outcomes during mixed dentition remains limited. Therefore, this study aimed to evaluate the association between lingual frenulum characteristics and oral and craniofacial functional outcomes in children during the mixed dentition period. Methods In this cross-sectional study, 170 children aged 7–12 years were evaluated. Anatomical and functional characteristics of the lingual frenulum were assessed using the Marchesan Lingual Frenulum Protocol. Oro facial functions, including breathing pattern, mentalis muscle activity, and swallowing, were examined using selected components of the Orofacial Myofunctional Evaluation with Scores (OMES/OMES-E). Upper airway patency was evaluated using the Mallampati and Brodsky classifications, malocclusion was assessed clinically, and postural alignment was analyzed using the New York Posture Scale. Intergroup comparisons were performed (p < 0.05). Multivariate logistic regression analyses were conducted to identify independent predictors of swal lowing dysfunction. Results Maximum mouth opening did not differ significantly between groups (p = 0.137). However, reduced tongue range of motion (≤ 50%) was significantly more frequent in children with an altered frenulum (p < 0.001). No significant differences were observed in respiratory pattern, mentalis muscle activity, Mallampati or Brodsky scores (p > 0.05). Swallowing-related dysfunction, involving lip (p = 0.012) and tongue (p = 0.002) behavioral alterations, as well as malocclusion (p = 0.010), were significantly more prevalent in the altered frenulum group. Regression analyses demonstrated that altered frenulum independently predicted tongue-related swallowing dysfunction (OR = 2.513, p = 0.015), whereas breathing disturbance showed the strongest independent predictor (OR = 5.249, p < 0.001). Conclusion Lingual frenulum morphology was associated with reduced tongue mobility and domain-specific functional impairments, particularly in swallowing. These findings support the integration of functional evalua tion alongside structural assessment in the clinical management of ankyloglossia.