The effect of ankyloglossia on the development of malocclusion
Abstract
Objectives: To determine the association between anatomic and functional ankyloglossia (tongue-tie), and malocclusion development. Secondarily, to investigate the association between ankyloglossia and obstructive sleep apnea risk.
Material and Methods: This was a cross-sectional chart review of 235 subjects from a university orthodontic clinic. Anatomic and functional ankyloglossia, measured with Kotlow free tongue measurement and tongue range of motion ratio (TRMR) respectively, were assessed for association with cephalometric and dental cast variables, representative of maxillofacial skeletal and dental structures. OSA risks were estimated with age-appropriate questionnaires and assessed for association with the tongue measurements.
Results: TRMR measurements of free tongue mobility, and Kotlow measurements of free tongue length were found to be moderately and positively correlated. Both TRMR and Kotlow measures were associated with molar occlusion, with more severely tongue-tied groups presenting with lower proportions of Angle Class I relationships. However, no other cephalometric or dental cast variables were consistently associated with both TRMR and Kotlow tongue measurements, including those indicative of maxillary transverse deficiency. Although Kotlow classification showed some association with patient-reported mouth breathing, neither TRMR nor Kotlow measures were associated with increased risks of obstructive sleep apnea.
Conclusions: These findings suggest that restricted tongue mobility and lingual frenulum attachment level may affect the development of malocclusion. However, this was mostly evident in only the most severe cases of ankyloglossia, and the degree of impact may not be clinically significant.