Summary. In this retrospective cephalometric study, the lateral skull radiographs of 12 children with Class III malocclusions of skeletal origin were examined. An analysis ofthe changes produced during treatment revealed that whilst changes in apical base relationship were small, and were mainly limited to a reduction in angle SNB, the effects on the soft tissue profile were surprisingly effective.

A patient with skeletal Class Ⅲ malocclusion was treated in 2 phases during the early permanent dentition. In phase 1, maxillary protraction was combined with rapid palatal expansion; in phase 2, fixed appliances were placed. The results were good posttreatment, and, 1 year later, a favorable growth tendency could be observed. This report shows that treatment for a patient with skeletal Class Ⅲ malocclusion can be started in the early permanent dentition, with very good final results.

The purpose of this study was to evaluate dentoskeletal and soft-tissue profile changes after extraction of lower second molars and treatment using the Tip-Edge technique in severe Class Ⅲ subjects. Thirteen patients with severe skeletal Class Ⅲ malocclusion (four males, nine females), diagnosed as requiring orthognathic surgery, but who rejected surgical therapy, were included in the study. The average age was 13.2±0.8 years. Lateral cephalometric films taken at the beginning and the end of treatment were analyzed using the Pancherz analysis and a traditional cephalometric analysis. The arithmetic mean and standard deviation were calculated for each variable. Paired ttest was performed to evaluate significant treatment change. After active treatment, dramatic overjet change was noted, with an average value of 5.5mm (P>001). Inclination of lower incisors was decreased 12.08 when measured to the mandibular plane (P>001). Inclination of upper incisors was increased by 2.18 to the SN plane (P<05). A negative value of the distance between upper and lower lip position to Sn-Pg9 at the beginning of treatment changed to a positive value (P<001). The results of this preliminary study suggest that success in the treatment of some severe Class Ⅲ deformity in the permanent dentition can be achieved with fixed appliances and extraction of lower second molars. A remarkable soft-tissue change was noted after the treatment, and concave facial profiles changed to straight profiles.

SUMMARY Class Ⅱ elastics are usually employed in the treatment of excessive overbite and overjet with the Begg technique. The effect of Class Ⅱ elastics on bite opening and the extent of such an effect is uncertain. This article, based on measurements of 30 cases, illustrates that the effect of the vertical component of force from Class Ⅱ elastics in reducing the intrusive force generated by the anchor bands in the upper archwire is less than previously believed. The position of the circles in the archwire for intermaxillary elastics has the greatest influence on theanterior intrusive force of the upper archwire. The direction of the Class Ⅱ elastics and the lengthof the dental arch (a negative correlation) came second, while the force actually exerted by theelastics had the smallest influence. It is, therefore, suggested that the position of the intermaxillary elastic circles should be located according to the differing clinical objectives.

We have previously demonstrated that all-trans retinoic (atRA) induced growth inhibition and apoptosis in mouse embryonic palate mesenchymal cells (MEPM). In the present study, we investigated the molecular mechanisms of atRA-induced apoptosis and its putative action pathway. atRA-induced apoptosis is associated with activation of the initiator caspase-9 and the effector caspase-3, but not of the effector caspase-8. A broad caspase inhibitor (z-VAD-fmk), caspase-9 inhibitor z-LEHD-fmk and caspase-3 inhibitor (z-DEVD-fmk) blocked atRA-induced DNA fragmentation and sub-G1 fraction, but not caspase-8 inhibitor z-IETD-fmk. We further showed that atRA dosedependently promoted mRNA expression of retinoic acid receptor b (RAR-b) and g. A weaker increase in RAR-a mRNA was seen only at the highest concentration of atRA (5mM). The pan RAR antagonist, BMS493, completely abrogated atRA-induced DNA fragmentation, Sub-G1 fraction, and caspase-3 activation. Taken together, these findings show that caspase-mediated induction of apoptosis by atRA is an RAR-dependent signaling pathway.