Posterior Available Space for Uprighting Horizontally Impacted Mandibular Second Molars Using Orthodontic Microimplant Anchorage.

Treatment of horizontally and deeply impacted mandibular molars is challenging for both orthodontists and oral surgeons because of the limited access and anchorage control. We report on two patients who had horizontally and mesially impacted mandibular second molars (MM2s). Both patients were treated by a surgical orthodontic approach, and the crowns of the impacted teeth were brought into the arches by closed forced eruption. Mesially impacted MM2s were uprighted with orthodontic microimplants, inserted in the retromolar area, and then moved into their ideal position. The first patient was in an active growing stage, while the second patient was beyond the active growing stage. Therefore posterior available space (PAS) should be analyzed before treatment of impacted MM2s to prevent periodontal problems after uprighting of impacted teeth. If PAS is not enough for uprighting impacted MM2s, alternative treatment should be considered based on the stage of growth.

Relationship between maturation indices and morphology of the midpalatal suture obtained using cone-beam computed tomography images.

OBJECTIVE: The purpose of this study was to determine whether predicting maturation of the midpalatal suture is possible by classifying its morphology on cone-beam computed tomography (CBCT) images and to investigate relationships with other developmental age indices. METHODS: The morphology of the midpalatal suture was assessed by using CBCT images of 99 patients. Axial plane images of the midpalatal suture were classified into five stages according to the classification scheme. To make the assessment more accurate, the morphology and fusion of the midpalatal suture were additionally investigated on coronal cross-sectional planar images and volume-rendered images. Bone age was evaluated using the hand and wrist method (HWM) and cervical vertebrae method (CVM); dental age (Hellman's index), sex, and chronological age were also assessed. To evaluate relationships among variables, Spearman's rho rank test was performed along with crosstabs using contingency coefficients. RESULTS: The HWM and CVM showed strong correlations with the maturation stage of the midpalatal suture, while other indices showed relatively weak correlations (p < 0.01). Through crosstabs, the HWM and CVM showed high association values with CBCT stage; the HWM demonstrated slightly higher values (p < 0.0001). Based on the HWM, the midpalatal suture was not fused until stage 6 in both sexes. CONCLUSIONS: Among developmental age indices, the HWM and CVM showed strong correlations and high associations, suggesting that they can be useful in assessing maturation of the midpalatal suture.