Prevalence of Posterior Crossbite for Orthodontic Treatment Timing.

OBJECTIVE: To evaluate the prevalence and distribution of posterior crossbite in different dentition stages in a Turkish sample.

STUDY DESIGN: 1554 subjects (843 girls, 711 boys) aged 4-25 years were evaluated to determine the prevalence of posterior crossbite in a Turkish sample. The subjects were classified according to four dentition stages (primary, early mixed, late mixed and permanent) and transversal occlusal status. The statistical evaluation was done by Chi-square, Fischer exact tests.

RESULTS: Bilateral and unilateral crossbite on the right and left sides had the highest frequency in the permanent dentition (51.0%, 47.3%, and 53.6%; respectively). No significant differences were found between unilateral (right and left) and bilateral crossbite with regard to dentition stages. No significant differences were found between unilateral right or left side posterior crossbite with regard to dentition stages.

CONCLUSION: An increasing trend in the prevalence of posterior crossbite was observed from the primary dentition towards permanent dentition in this study.