• The korean journal of orthodontics
• /
• v.49 no.3
• /
• pp.170-180
• /
• 2019

Objective: The purpose of this study was to investigate the relationship between the facial skeletal patterns and the shape of the mandibular symphysis in adults with malocclusion by using a structural equation model (SEM). Methods: Ninety adults who had malocclusion and had records of facial skeletal measurements performed using cone-beam computed tomography were selected for this study. The skeletal measurements were classified into three groups (vertical, anteroposterior, and transverse). Cross-sectional images of the mandibular symphysis were analyzed using generalized Procrustes and principal component (PC) analyses. A SEM was constructed after the factors were extracted via factor analysis. Results: Two factors were extracted from the transverse, vertical, and anteroposterior skeletal measurements. Latent variables were extracted for each factor. PC1, PC2, and PC3 were selected to analyze the variations of the mandibular symphyseal shape. The SEM was constructed using the skeletal variables, PCs, and latent variables. The SEM showed that the vertical latent variable exerted the most influence on the mandibular symphyseal shape. Conclusions: The relationship between the skeletal pattern and the mandibular symphysis was analyzed using a SEM, which showed that the vertical facial skeletal pattern had the highest effect on the shape of the mandibular symphysis.

• The korean journal of orthodontics
• /
• v.51 no.3
• /
• pp.166-178
• /
• 2021

Objective: To investigate dimensional changes in regional pharyngeal airway spaces after premolar extraction in bimaxillary skeletal protrusion (BSP) patients according to vertical skeletal pattern, and to further identify dentoskeletal risk factors to predict posttreatment pharyngeal changes. Methods: Fifty-five adults showing BSP treated with microimplant anchorage after four premolar extractions were included in this retrospective study. The subjects were divided into two groups according to the mandibular plane steepness: hyperdivergent (Frankfort horizontal plane to mandibular plane [FH-MP] ≥ 30) and nonhyperdivergent groups (FH-MP < 30). The control group consisted of 20 untreated adults with skeletal Class I normodivergent pattern and favorable profile. Treatment changes in cephalometric variables were evaluated and compared. The association between posttreatment changes in the dentoskeletal and upper airway variables were analyzed using linear regression analysis. Results: The BSP patients showed no significant decrease in the pharyngeal dimensions to the lower level in comparison with controls, except for middle airway space (MAS, p < 0.01). The upper airway variable representing greater decrease in the hyperdivergent group than in the nonhyperdivergent group was the MAS (p < 0.01). Posttreatment changes in FH-MP had negative correlation with changes in MAS (β = -0.42, p < 0.01) and inferior airway space (β = -0.52, p < 0.01) as a result of multivariable regression analysis adjusted for sagittal skeletal relationship. Conclusions: Decreased pharyngeal dimensions after treatment in BSP patients showed no significant difference from the normal range of pharyngeal dimensions. However, the glossopharyngeal airway space may be susceptible to treatment when vertical dimension increased in hyperdivergent BSP patients.

• The korean journal of orthodontics
• /
• v.33 no.3 s.98
• /
• pp.141-150
• /
• 2003

The purposes of this study were to classify the anteroposterior and vertical skeletal pattern of normal occlusion samples into specific types with factor and hierarchical cluster analysis, and to evaluate the range and limit of skeletal relationships that permit the establishment of normal occlusion via natural dentoalveolar compensation. Lateral cephalograms of 294 normal occlusion samples were measured, as selected from 15,836 persons through a community dental health survey who cooperated in record taking. Using a factor analysis, two factors representing anteroposterior and vertical skeletal relationships were extracted from 18 skeletal measurements. Then cluster analysis classified the skeletal patterns into nine types. The means and the standard deviations of 8 anteroposterior skeletal measurements and 10 vertical skeletal measurements were determined and comparisons of these measurements among the types were performed. The results obtained in this study showed that the range of normal occlusion included very diverse anteroposterior and vertical skeletal relationships.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.1
• /
• pp.46-52
• /
• 2009

The purpose of this study was to compare the skeletal maturation of cervical vertebrae according to vertical skeletal patterns in the adolescents. Lateral cephalograms of 198 subjects(10 years old), 216 subjects(12 years old), and 138 subjects(14 years old) were reviewed, and subjects were classified according to vertical skeletal patterns. The 30 subjects were selected with the greatest predominance of vertical growth, and the other 30 subjects, with the greatest predominance of horizontal growth; these subjects comprised the vertical and horizontal groups, respectively. For evaluating of skeletal maturation, the concavity of inferior border and verticohorizontal ratio of cervical vertebrae were observed and measured according to age. The measurements were analyzed statistically by SPSS computerized program. The results were as follows : In general, the concavity of the inferior border of the cervical vertebrae was greater in the horizontal group than the vertical group in all of the 10, 12, 14 year olds, but was not statistically significant. The vertico-horizontal ratio of the 3rd and 4th vertebra of the horizontal groups was a significantly larger than the vertical groups in 12 year olds but did not show any statistical significance in 10 and 14 year olds. There were a weak negative correlations between SUM, FMA and the vertico-horizontal ratio for each groups at 12 ages.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.22 no.4
• /
• pp.397-410
• /
• 2000

Skeletal class III had been classified by the position of the maxilla, the mandible, the maxillary alveolus, the mandibular alveolus and vertical development. This morphologic approach is simple and useful for clinical use, but it is insufficient to permit understanding of the pathophysiology of dysmorphoses. The author hypothesizes that there are different patterns of mutual relation of the skeletal components which have contributed pathologic equilibrium of skeletal class III. The purpose of this study are threefold: 1) to classify skeletal class III in subgroups, which can show the architectural characteristics of the deformity, 2) to analyse the craniofacial architecture of each subgroup on etio-pathogenic basis, and 3) to characterize and visualize the pattern as a prototype. Materials used in this study were lateral cephalograms of 106 skeletal class III adults, which were analysed with modified Delaire's architectural and structural analysis. Linear and angular measurements of the individual subject were obtained and cluster analysis was used for the subgrouping. Data were evaluated for verification of the statistical significances. The following results were obtained. 1. By the modified Delaire's architectural and structural analysis and cluster analysis, skeletal class III adults were classified into 7 clusters and presented as prototypes, which could show the pathophysiology of the skeletal architecture 2. There was significant relationship in measurement variables of each cluster, which could reflect characteristics of the skeletal pattern of growth. 3. The flexure of cranial base had a close relationship to the anterior rotational growth of the maxilla and contributes to understand the etio-pathology of skeletal class III. 4. The proportion of craniospinal area in cranial depth, craniocervical angle and vertical position of point Om had a close relationship to rotational growth of the mandible and direction of condylar growth. They contribute to understand the etio-pathology of skeletal class III. In summary, the cranium and the craniocervical area must be considered in diagnosis and treatment planning of dentofacial deformity. And the occlusal plane can be considered as a representative which shows the mutual relationships of the skeletal components.

• The korean journal of orthodontics
• /
• v.29 no.3 s.74
• /
• pp.303-315
• /
• 1999

The aim of this study was to evaluate the morphology of the mandibular symphysis and anterior alveolar and skeletal relationship under the influence of the rotational growth pattern of mandible in skeletal Class III malocclusion. A total of U untreated adult subjects were divided into two groups-forward rotational growth pattern group, backward rotational growth pattern group-according to the suggestion of Skieller et al.. The antero-posterior position, vertical relationship, mandibular symphysis and anterior alveolar and skeletal relationship were assessed on lateral cephalometric radiographs. Mandibular symphysis and anterior alveolar and skeletal relationship in each subject were studied and the following conclusions were drawn : 1. Concerning the antero-posterior position, forward rotational growth pattern group showed significantly larger SNA, SNB. Conceming the vertical relationship, all measurements showed statistically significant differences. 2. Forward rotatioal growth pattern group showed significantly larger IMPA, MnAD, backward rotational growth pattern group showed significantly larger MxABH. 3. There was no statistically significant difference in symphysis ratio to mandibular plane between forward and backward rotational growth pattern group. 4. In the correlative analysis of rotational growth pattern of mandible and mandibular symphysis, anterior alveolar and skeletal relationship, statistically significant correlations in overbite, IMPA, MnAD, symphysis width were showed.

• 대한치과교정학회:학술대회논문집
• /
• 1998.10a
• /
• pp.28-30
• /
• 1998

• The korean journal of orthodontics
• /
• v.42 no.5
• /
• pp.227-234
• /
• 2012

Objective: To evaluate the presurgical orthodontic tooth movement of mandibular teeth after dental decompensation for skeletal Class III deformities on the basis of vertical skeletal patterns. Methods: This cohort was comprised of 62 patients who received presurgical orthodontic treatment. These patients were divided into 3 groups according to their vertical skeletal patterns. Changes in the positions of the mandibular central incisor, canine, premolar, and 1st molar after presurgical orthodontic treatment were measured using a cone-beam computed tomography (CBCT) superimposition method. Results: The incisors moved forward after dental decompensation in all 3 groups. The canines in group I and the 1st premolars in groups I and III also moved forward. The incisors and canines were extruded in groups I and II. The 1st and 2nd premolars were also extruded in all groups. Vertical changes in the 1st premolars differed significantly between the groups. We also observed lateral movement of the canines in group III and of the 1st premolar, 2nd premolar, and 1st molar in all 3 groups (p < 0.05). Conclusions: Movement of the mandibular incisors and premolars resolved the dental compensation. The skeletal facial pattern did not affect the dental decompensation, except in the case of vertical changes of the 1st premolars.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.34 no.1
• /
• pp.10-16
• /
• 2018

Purpose: The purpose of this study was to evaluate distalizing effects from the Pendulum appliance on vertical component of craniofacial structures. Materials and Methods: 20 Patients who visited for orthodontic treatments are assigned to two groups. Group I, SN-MP > 37 degrees are showing hyperdivergent pattern. Group II, 29 < SN-MP < 37 degrees are showing mesocephalic pattern. Each group are consisted of 10 people. Results and Conclusions: Differences between skeletal classifications result in significant differences at labioversion of lower incisors and distalized amount, which is larger at Group I (P <.05). Group II has only shown significant distalized molars (P < .05). Labioversion of lower incisors has not shown significant change. Skeletal anchorage-assisted Pendulum appliance doesn't deteriorate vertical component nor significantly improve.

• The korean journal of orthodontics
• /
• v.45 no.2
• /
• pp.66-73
• /
• 2015

Objective: To compare condylar position and morphology among different vertical skeletal patterns. Methods: Diagnostic cone-beam computed tomography images of 60 adult patients (120 temporomandibular joints) who visited the orthodontic clinic of Hallym University Sacred Heart Hospital were reviewed. The subjects were divided into three equal groups according to the mandibular plane angle: hypodivergent, normodivergent, and hyperdivergent groups. Morphology of the condyle and mandibular fossa and condylar position were compared among the groups. Results: The hypodivergent and hyperdivergent groups showed significant differences in superior joint spaces, antero-posterior condyle width, medio-lateral condyle width, condyle head angle, and condylar shapes. Conclusions: Condylar position and morphology vary according to vertical facial morphology. This relationship should be considered for predicting and establishing a proper treatment plan for temporomandibular diseases during orthodontic treatment.