ABSTRACT
38 molars diagnosed as early cracked teeth and without pulpitis were selected to carry out the clinical observation. All the teeth were prepared and restored by metal crown under local anesthesia. After 1-15 years follow-up, the efficiency was 84.20% and all the tested teeth showed no symptoms of pulpitis and kept good chewing function. The results suggests that for the teeth diagnosed as early cracked molars and without pulp inflammation, making metal crown with less dentin loss is a safe and scientific treatment method.
ABSTRACT
Objective:To evaluate the linearity change of hard tissue of the juvenile of Class II division 1 with mandible functional retrusion by IMGA. Methods: The pre- and post- treatment cephalometric of 12 juvenile patients with IMGA were analyzed in Pancherz analysis to compare the dental position and the skeletal change. Results: After treatment, as far as OLp plane, the statistical changes were significance by pg/OLp,mi/OLp,ii/OLp, co/OLp +pg/OLp,is/OLp -ii/OLp,ms/OLp -mi/OLp,is/OLp-ss/OLp(P0.05), respectively. Conclusion: The IMGA is effective on the treatment of the juvenile patients of Class II division 1 with mandible retrusion of facial hypodivergency.
ABSTRACT
Objective: To study the influence of different inhibition conditions for center of rotation (CR) and regularity variations of CR before and after orthodontic treatment of embedded and inverted impact upper central incisor. Methods:Based on clinical findings a computer model of rolling movement was established,then computer finite element Super DrawnⅡwas applied to establish an analytic analogue computing model for calculation. Results:The deeper the crown embedded by hard tissue,the more the edgewise displacement of CR;while the crown was normally exposed,the moving locus tended toward front and upward. Conclusions: Perpendicular orthodontic force to the long axis of tooth forced point that close to the incisal margin and the partly embedded crown by the alveolar bone,especially the bone of lingual aspect are the main factors for the upward moving and erectness of the root apex. Possible subsidence of CR may be avoided by suitable early stage orthodontic treatment.