# Anatomical versus functional classification of ankyloglossia and their association with temporomandibular joint disorders in adults: a cross sectional study

## TL;DR

This study explores how tongue tie (ankyloglossia) relates to jaw disorders in adults, finding a weak but significant link when using specific classification methods.

## Contribution

The study introduces a novel analysis of ankyloglossia's association with temporomandibular disorders in adults using two classification systems.

## Key findings

- TMD was found in nearly half of the adult participants.
- Mild to severe ankyloglossia showed a significant association with TMD using Kotlow’s classification.
- No significant link was found using the TRMR criteria for anterior or posterior tongue restriction.

## Abstract

Background: Restrictive lingual frenula, commonly referred to as
ankyloglossia, are well documented in pediatric literature, with established
impacts on breastfeeding, swallowing, reflux, speech, maxillary development,
breathing, and sleep in children. However, data on its effects in adolescents and
adults remains limited. This study aimed to investigate the correlation between
restrictive lingual frenula and the development of temporomandibular disorders
(TMD) in an adult population. Methods: A total of 129 patients (aged
18–80 years; 41 males and 88 females) were assessed for TMD signs and symptoms
using the three Lövgren screening questions, supplemented by a clinical
examination following the German Association for Craniomandibular Function and
Diagnostics (DGFDT) screening protocol. The presence and severity of
ankyloglossia were evaluated using the Tongue Range of Motion Ratio (TRMR 2019)
and Kotlow’s free tongue classification. Association between variables were
analyzed using Chi-square tests. Results: TMD was identified in 49.1%
of the cohort, while ankyloglossia was observed in 46.7% based on the TRMR. No
significant association was found between TMD and either anterior (39.6%) or
posterior (34.9%) tongue restriction using the TRMR criteria. However, when
categorized according to Kotlow’s classification, mild to severe ankyloglossia
(59.2%) showed a statistically significant association with TMD (p =
0.026). Age and sex were not significantly associated with the presence of
ankyloglosson, while TMD occurrence was found to be correlated with sex. Conclusions: A weak but significant correlation was observed between TMD and the
degree of ankyloglossia, particularly when assessed using Kotlow’s method.
Further studies with larger sample sizes, stratified by age and sex,
incorporating occlusal factors, and employing a standardized validated assessment
tool adapted for adults, accounting for both anatomical and functional criteria
are warranted to explore potential causal relationships.