Radiographic assessment of maxillary incisor position after rapid maxillary expansion in children with clinical signs of eruption disorder

Background and objective. In this study we assessed the influence of rapid maxillary expansion (RME) on the intraosseous vertical position and inclination of the impacted incisors diagnosed at an early developmental stage on panoramic radiographs and subsequently treated by surgical removal of the obstacle. Materials and methods. Following surgical removal of the obstacles to incisor eruption (T1), a group of 34 subjects (mean age 8 years 11 months ±11 months) underwent RME, while a group of 28 subjects (mean age 9 years 1 month ±1 year) was monitored after surgery without further treatment. At T2 (on average 10 months after T1), the prevalence rate of subjects with erupted incisors was recorded. The measurements were taken on the panoramic radiographs at T1 and T2 to assess the vertical position and angulation of delayed unerupted incisors. Results. At T2, impacted incisors erupted in 82.4% of the patients in the RME group versus 39.3% of those in the monitored group (χ2 =8.45, p<0.001). All the patients treated with RME showed an improvement in the vertical and angular position of the unerupted teeth. Logistic regression revealed RME therapy as the only significant predictive variable (p<0.001) for successful eruption of the delayed incisors at T2. Conclusion. RME in early mixed dentition appears to be an effective procedure to increase the prevalence rate of impacted maxillary incisor eruption.