The predictability of dentoskeletal factors for soft-tissue chin strain during lip closure.
10.4041/kjod.2013.43.6.279
- Author:
Yun Hee YU
1
;
Yae Jin KIM
;
Dong Yul LEE
;
Yong Kyu LIM
Author Information
1. Department of Orthodontics, Graduate School of Clinical Dentistry, Korea University, Seoul, Korea. estelle7@korea.ac.kr
- Publication Type:Original Article
- Keywords:
Soft-tissue chin;
Mentalis;
Classification and regression tree
- MeSH:
Chin*;
Classification;
Female;
Humans;
Incisor;
Lip*;
Logistic Models;
Malocclusion;
Overbite
- From:The Korean Journal of Orthodontics
2013;43(6):279-287
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVE: To investigate the dentoskeletal factors which may predict soft-tissue chin strain during lip closure. METHODS: The pretreatment frontal and lateral facial photographs and lateral cephalograms of 209 women (aged 18-30 years) with Angle's Class I or II malocclusion were examined. The subjects were categorized by three examiners into the no-strain and strain groups according to the soft-tissue chin tension or deformation during lip closure. Relationships of the cephalometric measurements with the group classification were analyzed by logistic regression analysis, and a classification and regression tree (CART) model was used to define the predictive variables for the group classification. RESULTS: The lower the value of the overbite depth indicator (ODI) and the higher the values of upper incisor to Nasion-Pogonion (U1-NPog, mm), overjet, and upper incisor to upper lip (U1-upper lip, mm), the more likely was the subject to be classified into the strain group. The CART showed that U1-NPog was the most prominent predictor of soft-tissue chin strain (cut-off value of 14.2 mm), followed by overjet. CONCLUSIONS: To minimize strain of the soft-tissue chin, orthodontic treatment should be oriented toward increasing the ODI value while decreasing the U1-NPog, overjet, and U1 upper lip values.
