The influence of stabilization splint on condylar position and craniofacial morphology

Yoon, Young Jooh; Kim, Kwang Won

Abstract

The purposes of this study were: 1) to determine the normal range of CR-CO discrepancy in normal occlusion group: 2) to evaluate the changes of condylar position and craniofacial morphology between centric relation and centric occlusion before and after stabilization splint therapy in malocclusion group outside the normal range of CR-CO discrepancy. The normal occlusion group consisted of 80 subjects who had well-balanced faces and good occlusions with acceptable Class I molar relationship. They had not been treated orthodontic ally and had no signs or symptoms of temporomandibular joint dysfunction. 71 malocclusion patients enrolled for orthodontic treatment at the Department of Orthodontics, College of Dentistry, Chosun University comprised the malocclusion group, little variation of growth factor by the second molar eruption. They had CR-CO discrepancy beyond normal range and were subdivided into anterior-posteriorly -[25 Class I (0 or = 4), and 24 Class III (ANB < or = 0)]; vertically - [20 Normodivergentscy (30 or = 34), and 18 Hypodivergency (SNGoMe < or = 30)] ; and sexually - [26 Male and 45 Female]. For malocclusion group, stabilization splint with mutually protected type of occlusal scheme was applied for three months. Panadent articulators, Panadent condylar position indicator (CPl), and lateral headfilm were used to investigate the influence of stabilization splint on condylar position and craniofacial morphology. The results of this study were as follows: 1. The amounts of CR-CO discrepancy in normal occlusion were that the antero-posterior component (delta X) was 0.56 +/- 0.46mm (Male: 0.63 +/- 0.42rnm, Female: 0.49 +/- 0.50mm) ; the supero-inferior component (delta Y) was -0.75 +/- 0.48rnm (Male: -0.76 +/- 0.52rnm, Female: -0.73 +/- 0.43rnm) ; and the transverse component (delta Z) was -0.33 +/- 0.28mrn (Male: -0.38 +/- 0.29mm, Female: -0.31 +/- 0.27mm). 2. The condylar position was in normal range after stabilization splint therapy. 3. The mandible was always rotated infero-posteriorly after stabilization splint therapy. 4. Antero-posteriorly, Class III malocclusion responded very well to the stabilization splint therapy. 5. Vertically, Hyperdivergency responded very well to the stabilization splint therapy. 6. Sexually, Male responded very well to the stabilization splint therapy.