Effects of bracket slot size during en-masse retraction of the six maxillary anterior teeth using an induction-heating typodont simulation system.
10.4041/kjod.2017.47.3.158
- Author:
Ji Yong KIM
1
;
Won Jae YU
;
Prasad N K KOTESWARACC
;
Hee Moon KYUNG
Author Information
1. Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu, Korea. hmkyung@knu.ac.kr
- Publication Type:Original Article
- Keywords:
Tooth movement;
Appliances;
Heat induction typodont;
Bracket slot size
- MeSH:
Crowns;
Incisor;
Mechanics;
Tooth Movement;
Tooth*
- From:The Korean Journal of Orthodontics
2017;47(3):158-166
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To investigate how bracket slot size affects the direction of maxillary anterior tooth movement when en-masse retraction is performed in sliding mechanics using an induction-heating typodont simulation system. METHODS: An induction-heating typodont simulation system was designed based on the Calorific Machine system. The typodont included metal anterior and resin posterior teeth embedded in a sticky wax arch. Three bracket slot groups (0.018, 0.020, and 0.022 inch [in]) were tested. A retraction force of 250 g was applied in the posterior-superior direction. RESULTS: In the anteroposterior direction, the cusp tip of the canine in the 0.020-in slot group moved more distally than in the 0.018-in slot group. In the vertical direction, all six anterior teeth were intruded in the 0.018-in slot group and extruded in the 0.020- and 0.022-in slot groups. The lateral incisor was significantly extruded in the 0.020- and 0.022-in slot groups. Significant differences in the crown linguoversion were found between the 0.018- and 0.020-in slot groups and 0.018- and 0.022-in slot groups for the central incisor and between the 0.018- and 0.022-in slot groups and 0.020- and 0.022-in slot groups for the canine. In the 0.018-in slot group, all anterior teeth showed crown mesial angulation. Significant differences were found between the 0.018- and 0.022-in slot groups for the lateral incisor and between the 0.018- and 0.020-in slot groups and 0.018- and 0.022-in slot groups for the canine. CONCLUSIONS: Use of 0.018-in slot brackets was effective for preventing extrusion and crown linguoversion of anterior teeth in sliding mechanics.
