Effects of facemask therapy on the mandibular retromolar space. A follow-up study.

OBJECTIVES: To evaluate the mandibular retromolar space after facemask therapy and a follow-up period.  Methods: This retrospective study was conducted between May and September in 2014. The sample consisted of pre-treatment (T1), post-treatment (T2), and follow-up(T3) panoramic radiographs of 19 skeletal and dental Class III patients (7 female, 12 male; mean age: 10.5 years) treated with facemask and a removable intraoral upper appliance in the Faculty of Dentistry Gazi University, Ankara, Turkey. Each patient's lower arches were evaluated as right and left segments. As third molars were congenitally absent in 3 segments, a total of 35 segments were evaluated. The average treatment time was one year. The average follow-up period was 2.4 years. The positions, angulations, dental maturations of lower third molars, and mandibular retromolar spaces (DJ) were assessed. Friedman's 2-way Analysis of Variance, multiple-comparison, Pearson's correlation, and Chi-square tests were used for statistical evaluation. A p less than 0.05 was considered as significant.

RESULTS: The angulation of the first molar (ϒ) increased significantly only in the follow-up period (T3). Mandibular retromolar spaces were increased significantly during all periods. The most commonly determined position of the third molar, by Winter's classification, was vertical angulation in all periods. Moderate and significant correlations were found between third molar angulation(ß) and DJ at T2 and T3. Significant correlations were also found between DJ and Demirjian classification stages during all periods.

CONCLUSION: Facemask therapy did not have an adverse effect on the mandibular retromolar space during treatment and follow up periods.