| Title | First or second premolar extraction effects on facial vertical dimension. | | Author(s) | Kim TK, Kim JT, Mah J, Yang WS, Baek SH | | Institution | Department of Orthodontics, College of Dentistry, Seoul National University, Seoul, South Korea. | | Source | Angle Orthod 2005 Mar; 75(2):177-82. | | MeSH | Adolescent
Bicuspid
Cephalometry
Comparative Study
Face
Female
Humans
Male
Malocclusion, Angle Class I
Mesial Movement of Teeth
Molar
Orthodontics, Corrective
Tooth Extraction
Vertical Dimension
| | Abstract | If the concept of mesial movement of molars to reduce the "wedge effect" and decrease facial vertical dimension (FVD) is valid, it is important to investigate the effect of first (P1) and second premolar (P2) extraction on FVD. This study compares the mesial movement of molars and changes in FVD between P1 and P2 extraction groups in Class I malocclusion with a hyperdivergent facial type. We compared 27 cases with maxillary and mandibular P1 extractions (group 1) and 27 cases with maxillary and mandibular P2 extractions (group 2). To determine FVD changes due to treatment and to compare differences between two groups, paired t-test and independent t-test were performed, respectively. Group 2 showed more mesial movement of the maxillary and mandibular first molars and less retraction of the maxillary and mandibular central incisors than group 1 (P < .05). Both groups showed increased anterior facial height (P < .05), but there were no statistically significant differences in angular and proportional measurements between pre- and posttreatment. There was no significant difference in the amount of FVD change between groups 1 and 2 except in the maxillomandibular plane angle and SN to palatal plane angle (P < .05). These results suggest that there is no decrease in FVD regardless of the maxillary and mandibular P1 or P2 extraction. Therefore, the hypothesis that P2 extraction in hyperdivergent facial types will result in mesial molar movement and decrease FVD by reducing the wedge effect is invalid. | | Language | eng | | Pub Type(s) | Journal Article
| | PubMed ID | 15825779 |
|
