AIM: This study evaluated the new bone formation in the midpalatal suture after surgically assisted rapid maxillary expansion by optical density analysis. METHODS: The sample was comprised by 16 patients (six males and ten females). All patients presented maxillary atresia with posterior crossbite and were submitted to SARME. Maxillary occlusal radiographs were taken at four stages (before SARME, immediately after SARME, three months after SARME and six months after SARME). An aluminium scale (step wedge) with eight steps varying from 1mm to 8mm was adapted at the end of the films. Optical density analysis was performed after digitization of radiographs using the Image ToolTM software (UTHSCSA, San Antonio, Texas, USA). Region A measured 8 x 1mm² and was located 1.2cm from the tangent to the maxillary central incisors at the region of the midpalatal suture. Region B measured 5 x 9mm² and was located 4.3cm from the tangent to the maxillary incisors at the region to the midpalatal suture. RESULTS: Statistical analysis of region A revealed statistically significant differences between phases I and II (p < 0.0001), and phases I and III (p < 0.0001); statistically significant differences between phases I and IV (p = 0.0169), and phases II and III (p = 0.0004); statistically significant differences between phases II and IV (p < 0.0001), and phases III and IV (p = 0.0023). In region B, there was statistically significant differences between phases I and II (p < 0,0001), and phases II and III (p < 0.0001); no statistically significant differences between phases I and IV (p = 0.1152); in phases II and III (p = 0.0002), phases II and IV (p < 0.0001) and phases III and IV (p = 0.0010) statistically significant differences were observed. CONCLUSIONS: Optical density analysis improves post-treatment control of SARME procedures by surgeons and orthodontists. After six months, new bone formation at the midpalatal suture is not complete in region "A" (p < 0.05), but in region"B" no statistically significant differences were observed (p > 0.05) in phases I and IV.
Radiograph; Optical density; New bone formation; Rapid maxillary expansion
