The positioning errors in bonding lingual brackets / 대한치과교정학회지

The purpose of this study was to evaluate the positioning errors according to the method of bonding lingual brackets. Dental models of twenty orthodontic patients with malocclusion were selected for this study. The positioning errors were measured on each model that brackets were bonded to. Three different bonding methods were used. For the first method, the bracket was bonded intimately to the lingual surface of the model. For the second method, the bracket was bonded intimately to the lingual surface after setting up using articulator. The passive bracketing, bonding the bracket ligated first to ideal archwire, was used after setting up as the last method. The results were as follows: 1. The brackets bonded without setting up showed greater angulation errors in the upper 1st premolar and the lower canine than those in other bonding methods. The brackets bonded without passive bracketing showed greater positioning errors in upper central incisor, lower 1st and 2nd premolars. 2. The brackets bonded without setting up showed greater torque error in lower 2nd premolar than those in other bonding methods. The brackets bonded without passive bracketing showed greater torque errors in all upper teeth, lower 1st and 2nd premolars. 3. The brackets bonded without passive bracketing showed greater rotation errors between upper central incisors, lower central incisors, lower lateral and central incisor, lower canine and lateral incisor. 4. The brackets bonded without setting up showed greater in-out errors between upper canine and lateral incisor than those in other bonding methods. The brackets bonded without passive bracketing showed greater in-out errors between upper central incisors, upper central and lateral incisors, upper 1st and 2nd premolars, lower lateral and central incisors, lower canine and lateral incisor. These results suggest that there is a large amount of positioning error in lingual brackets even by an indirect bonding technique, and it may be reduced by passive bracketing.

The change of tooth mobility following orthodontic tooth movement ; A short-term study / 대한치과교정학회지

The purpose of the present study was to evaluate the change of tooth mobility following orthodontic tooth movement. Six orthodontic patients which had been treated with edgewise appliance were used. Tooth mobility was measured with Periostest at the time of the removal of orthodontic appliance and 1, 2, 3, 4, 6, 8, 10, 12, 16, 20, 24 weeks after appliance removal. Following results were obtained. 1. Tooth mobility upon the removal of orthodontic appliance showed individual variation while incisor showed greater mobility than the other teeth. 2. Tooth mobility showed continued decrease pattern until 24 weeks after appliance removal. 3. While maxillary incisors showed continued decrease pattern during the study period, the other teeth showed steep decline pattern during the first 12 weeks and gentle slope during the second 12 weeks. 4. The tooth mobility of the maxillary second premolar showed the most typical change in terms of the consistency of the decline. 5. There were no significant differences of tooth mobility between heavy and light-contacted anterior teeth during experimental period. The results of the present study suggested that periodontal reorganization is not completed even in 24 weeks following orthodontic tooth movement.