Aim: (1) To investigate the potential association between tongue rolling and the increased risk of a posterior crossbite and (2) to study the cephalometric differences between patients that can roll the tongue and those who can not.
Subjects and Method: A sample of 105 patients, with a complete pretreatment orthodontic documentation (study models, photographs, and radiographs) were randomly selected and asked to clearly show the ability to roll their tongue. From this sample, 30 patients were found to be unable to roll their tongue. They were matched by age, sex and ethnic origin to 30 patients who could roll their tongue. Study models were used to determine the presence of a posterior crossbite and to measure intercanine and intermolar widths. On the lateral cephalograms, a standard cephalometric evaluation (the Geneva analysis) was carried out. Odds ratios and independent sample t-tests were used to determine statistically significant differences between groups.
Results: Non tongue rolling patients were found to have a reduced risk of presenting crossbite, shown by an odds ratio of 0.262 (95% CI: 0.079-0.870), but no difference was found when looking at intercanine and intermolar widths. They also showed an increased gonial angle (p=0.023), a greater maxillary incisor angle (p=0.035) and a larger interincisal angle (p=0.003) when compared to tongue rolling patients.
Conclusions: Tongue rolling patients from an orthodontic population show a greater risk of presenting a posterior crossbite. Non tongue rolling patients demonstrate a more obtuse gonial angle, more proclined maxillary incisors and a smaller interincisal angle.