Clockwise Rotation Of Palatal Plane Research Articles

Three-dimensional cone-beam computed technology evaluation of skeletal and dental changes in growing patients with Class II malocclusion treated with the cervical pull face-bow headgear appliance

This study aimed to 3-dimensionally quantify and compare the outcomes of growing patients with Class II malocclusion treated with the cervical pull face-bow headgear appliance in combination with full fixed orthodontic appliances. The study sample consisted of 22 patients with Class II malocclusion with the following inclusion criteria: ANB>4.75°, Class II molar relationship, and SN-GoGn<37°. The mean age of patients was 12.5 ± 1.1 years at baseline. The average treatment time was 27.7 ± 7.3 months. Cone-beam computed tomography scans were superimposed in the cranial base, maxillary regional, and mandibular regional to evaluate growth, treatment displacements, and bone remodeling. Relevant statistically and clinically significant skeletal changes included average decreases in ANB (2.1 ± 1.1°) and SNA (1.8 ± 1.1°); posterior (1.3 ± 1.4 mm) and inferior (4.6 ± 2.2 mm) displacement of A-point; inferior displacements of B-point (5.4 ± 2.8 mm) and Pogonion (5.8 ± 2.6 mm); superior displacement of Condylion (6.9 ± 2.4 mm); increase in mandibular length (5.4 ± 2.0 mm); and clockwise rotation of palatal plane (1.9 ± 1.9°). Significant proclination of the maxillary incisors (9.8 ± 11.1°) and nonsignificant proclination of the mandibular incisors (4.7 ± 9.6°) were also noted. Class II skeletal correction was primarily achieved by posterior, inferior displacement of the sagittal position of the maxilla. Change in the sagittal position of the mandible/chin (B-point, Pogonion) was not significant; rather, mandibular displacement was significant in an inferior vertical direction without backward rotation, as seen from marked condylar and ramus growth.

Long-term stability of early anterior open bite treatment by magnetic and spring-loaded bite blocks

Introduction The purpose of the present study was to evaluate the long-term stability of open bite correction with spring-loaded and magnetic bite blocks. Materials and Methods A total of 14 patients out of the original sample of 20 were evaluated clinically and cephalometrically at post-treatment, post-retention, and 4.2 years after retention. Of 14 patients, eight were from spring-loaded bite block group, while remaining six were from magnetic bite block group. Normality of data was checked with Shapiro–Wilk test and one-way repeated measures analysis of variance was used to compare the values at different time intervals. Pearson correlation analysis was used to examine the correlations between various cephalometric variables. Results Clinically, decrease in overjet and increase in overbite were evident in 12 patients, while two patients showed non- significant decrease in overbite. Skeletal changes in the form of the closure of mandibular plane angle, clockwise rotation of palatal plane, and significant increase in posterior face height were seen. Molar intrusion relapsed in the follow-up period but was compensated by the incisor extrusion. Overall, the success rate of 85.8% was seen. Conclusion Stability of early treatment with active bite blocks is comparable to any other treatment modality for correction of mild-to-moderate skeletal open bite cases. Importance of retention using the passive bite blocks needs further evaluation.

Comparison of Treatment Outcome and Stability Between Distraction Osteogenesis and LeFort I Osteotomy in Cleft Patients With Maxillary Hypoplasia

The purpose of this study was to compare treatment outcome and relapse between maxillary advancement surgery with LeFort I osteotomy and maxillary distraction osteogenesis in patients with cleft lip and palate with maxillary hypoplasia. The sample consisted of a maxillary advancement surgery with LeFort I osteotomy group (group 1, N= 14, mean age, 21.7 years) and a maxillary distraction osteogenesis group (group 2, N = 11, mean age, 16.3 years). Lateral cephalograms were taken and traced at presurgery (T0), postsurgery (T1), and postretention (T2). Nine hard and four soft tissue cephalometric variables were measured. Differences in measurements at each stage, treatment outcome (T1-T0), and relapse (T2-T1) were compared between groups with independent t test. Because the amount of surgical movement could affect the amount of relapse, a difference in relapse between two groups was compared by analysis of covariance with the amount of surgical movement as a covariant. Although the amounts of forward movements of A point (P < 0.01), upper incisor (P < 0.001), and upper lip (P < 0.001) during T1-T0 were greater in group 2, there were no significant differences in the amounts of relapse (T2-T1) between the two groups. During T1-T0, counterclockwise rotation of the palatal plane was observed in group 2 as a result of downward movement of posterior nasal spine (PNS) at T1, whereas group 1 had clockwise rotation of palatal plane at T1 because of downward movement of anterior nasal spine (ANS). The amounts of relapse (T2-T1) in vertical movements of PNS and upper incisor were significantly different between the two groups (P < 0.05). The amount of required maxillary advancement, vector control of palatal plane, and vertical position of upper incisor would be important factors when planning a surgical treatment in patients with cleft lip and palate with midface hypoplasia.