Evaluation of palate-related factors of the effectiveness of microimplant-assisted rapid palatal expansion in late adolescents and adults.

INTRODUCTION: This study investigated the factors of the effectiveness of microimplant-assisted rapid palatal expansion (MARPE) in late adolescents and adults, such as age, midpalatal suture maturation (MPSM) stage, palate length (PL), palatal index (PI), and midpalatal bone thickness (MBT), and at each microimplant position, the palate bone thickness (PBT), the nasal cortical bone thickness (CoTN), the cancellous bone thickness (CaT), and the palate cortical bone thickness (CoTP) were evaluated. METHODS: Cone-beam computed tomography (CBCT) images of 50 patients (mean, 23.30 ± 7.03 years; range, 16-51 years) treated with MARPE were evaluated. Maxillary expansion ratio (MER) was used to assess the MARPE effectiveness and grouped patients into low and high MER groups according to the mean of MER. MER was the ratio of maxillary expansion width to MARPE screw expansion measured in CBCT images. The t-test was used to analyze the differences between the low and high MER groups. The Pearson correlation test was performed to investigate the correlation between MER and age, MPSM stage, PL, PI, MBT, PBT, CoTN, CaT, and CoTP. RESULTS: Age, MPSM stage, and MBT in regions 18 mm and 21 mm behind the incisor foramen correlated negatively with MER ([Formula: see text], - 0.390, - 0.386, and - 0.335, respectively, all [Formula: see text]), whereas PBT and CoTN of anterior microimplant positions correlated positively with MER ([Formula: see text] and 0.418, respectively, all [Formula: see text]). No correlation was observed between other variables and MER. CONCLUSIONS: MARPE effectiveness decreased as age and midpalatal suture maturation stage increased, respectively. Thinner midpalatal suture bone in regions 18 mm and 21 mm behind the incisor foramen, thicker palate bone, and nasal cortical bone of anterior microimplant positions were related to more effective MARPE. CLINICAL RELEVANCE: In patients with older chronological age and later MPSM stages, MARPE effectiveness might be unsatisfactory. Clinicians should carefully evaluate the palate bone thickness before MARPE treatment.

A CBCT Investigation of the Sella Turcica Dimension and Sella Turcica Bridging in Different Vertical Growth Patterns.

This study aimed to compare the sella turcica dimensions and sella turcica bridging (STB) via cone-beam computed tomography in different vertical patterns and then analyze the link between the sella turcica and vertical growth patterns. The CBCT images of 120 skeletal Class I subjects (an equal proportion of females and males; mean age of 21.46 years) were divided into three vertical growth skeletal groups. Student's t tests and Mann-Whitney U tests were used to assess the possible diversity in genders. The link between sella turcica dimensions and different vertical patterns was explored by one-way analysis of variance, as well as Pearson and Spearman correlation tests. The prevalence of STB was compared using the chi-square test. Sella turcica shapes were not linked to gender, but statistical differences were observed among different vertical patterns. In the low-angle group, a larger posterior clinoid distance and smaller posterior clinoid height, tuberculum sellae height, and dorsum sellae height were determined, and the incidence of STB was higher (p < 0.01). Sella turcica shapes were linked to vertical growth patterns, mainly involving the posterior clinoid process and STB, which could be used as an index to assess vertical growth trends.