Evaluation of Long-term Stability of Vertical Control in Hyperdivergent Patients Treated with Temporary Anchorage Devices.

This study aims to evaluate the long-term stability of vertical control in hyperdivergent patients treated with temporary anchorage devices. The sample included 20 hyperdivergent patients without anterior open bite. The temporary anchorage devices were used to intrude the upper incisor and molars for vertical control. Lateral cephalograms were established prior to treatment, immediately after treatment, and during retention. The upper molars and incisors were intruded by 1.33 mm and 1.41 mm after treatment (P<0.05). U6-PP increased by 0.11 mm and 0.23 mm during the first and second stages of retention (P>0.05). U1-PP was found to possess a significant extrusion of 1.2 mm during the first stage (P<0.05), which increased by 0.68 mm during the second stage (P>0.05). The mandibular plane angle (MP-SN) decreased by 2.58 degrees following treatment, and underwent a relapse of 0.51 degree and 0.42 degree during the first and second stages of retention respectively (P>0.05). No significant soft tissue changes occurred, with the exception of increased upper lip length during the second stage (P<0.05). Maxillary anterior and posterior intrusions, counter clockwise rotation of the mandibular plane, and improved profiles can be successfully achieved following treatment with vertical control. During the first stage of retention (less than three years), intruded molars and incisors both exhibited some extrusion, and molars had better long-term stability than incisors. During the second stage of retention (three to six years), the therapeutic effects appeared stable, with the exception of some increase in upper lip length. Rotated mandibular plane remained stable during the entire retention period.

Comparison of skeletal changes between female adolescents and adults with hyperdivergent Class II Division 1 malocclusion after orthodontic treatment.

OBJECTIVE: To compare the skeletal changes between female hyperdivergent adolescents and adults with Class II Division 1 malocclusion after orthodontic treatment. METHODS: Thirty adolescent girls and 30 adult women both with hyperdivergent Class II Division 1 malocclusions were selected. The 2 groups were matched by both treatment period and treatment method. Cephalometric radiographs taken before and after treatment were traced and measured. Data were statistically examined. RESULTS: After treatment, SNA decreased significantly in both groups. SNB remained unchanged in the adolescent group, while it decreased in the adult group. ANB decreased significantly only in the adolescent group and remained unchanged in the adult group. Obvious growth was found in the adolescent group. Ar-Gn, Ar-Go, N-Me and S-Go increased significantly in adolescents. In the adult group, N-Me and ANS'-Me increased after treatment, but with less magnitude than those in the adolescent group. All the angular measures (MP-SN, PP-SN, Ar- Go-Gn and N-S-Ba) remained quite stable in both the adolescent and adult groups. CONCLUSION: Although obvious vertical growth was found in the female hyperdivergent adolescent Class II Division 1 group, no clockwise rotation of the mandible and no mandibular catch-up growth were found. Vertical growth of the mandible was helpful in maintaining the MP-SN angle with conventional orthodontic mechanism in the adolescent group.

[Relationship between craniofacial and airway structure and pediatric obstructive sleep apnea and hyponea syndromes: a case-control study].

OBJECTIVE: The children obstructive sleep apnea and hyponea syndromes has become a global research hot spot, but the research of craniofacial features in obstructive sleep apnea and hyponea syndromes (OSAHS) children was scarce. To evaluate the craniofacial features of obstructive sleep apnea and hyponea syndromes children. METHODS: The subjects involved in this study fell into two groups: the patient group and the control one. The patients and controls were strictly matched by age and sex. Lateral head radiographs and cephalometric measurements were obtained and then compared between the two groups. RESULTS: The findings demonstrated marked differences in terms of SNB, PG-NB, lower facial height, H-C3Me and A&T/P. The SNB angle (75.8±4.3) in the patient group was smaller than that in the control one (78.7±2.6) and the P value was 0.035; the PG/NB value in the patient group (1.3±0.8) mm was higher than that in the control one (0.6±0.6) mm and the P value was 0.02. The anterior face height was (65.1±5.9) mm in the patient group (P=0.04), while the anterior face height in the control group was (61.5±3.2) mm. The position of hyoid was lower in the patient group(5.3±3.7) mm, compared with the control one (2.6±2.6) mm, and the P value was 0.03. Furthermore, the patients of OSAHS had more swelled adenoids and tonsils than the controls. CONCLUSION: The patient group differed from the control group in the length of mandible, lower facial height, position of hyoid and the chin, and the size of the adenoids and tonsils.