• Imaging Science in Dentistry
• /
• v.46 no.2
• /
• pp.117-125
• /
• 2016

Purpose: This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Materials and Methods: Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Results: Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. Conclusion: In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

• The korean journal of orthodontics
• /
• v.10 no.1
• /
• pp.15-27
• /
• 1980

This study was undertaken to compare the craniofacial morphology of Class II, Division 1 malocclusion with that of normal occlusion in children, and to investigate the incidence of various Class II, Division 1 craniofacial skeletal patterns. The subjects consist of thirty seven boys and fifty three girls with Class II, Division 1 malocclusion, and forty six boys and eighty one girls 10-15 years with normal occlusion. Measurements were recorded, tabulated and analyzed on the lateral cephalograms by the degree of SNA, SNB and ANB. The following characteristics of the Class II, Division 1 skeletal pattern were observed. 1. The anteroposterior relationship of the maxilla to the cranium in the Class II, Division 1 was very similar to that of normal occlusion. 2, Mandible of the Class II, Division 1 malocclusion was in the posterior position in relation to the cranial anatomy when compared to normal. 3. The chin point as measured by SN Pog and NS Gn showed distal positioning in relation to normal occlusion. 4. SN to mandibular plane angle was large in Class II, Division 1 malocclusion. 5. Mandibular incisor inclination was not significantly different between Class II, Division 1 malocclusion and normal occlusion, but maxillary incisors inclined and positioned labially and consequently overjet was large in Class II, Division 1 malocclusion. 6. Class II, Division 1 malocclusion was divided into four types of craniofacial skeletal pattern. The most common Class II, Division 1 pattern was found to be type C in which SN-Mand. Pl. was above mean range of normal occlusion. The next frequent pattern was found to be type A in which maxilla and mandible were within normal range of protrusion while upper incisors were severly labially inclined.

• Korean Journal of Cleft Lip And Palate
• /
• v.14 no.1_2
• /
• pp.1-18
• /
• 2011

Skeletal malocclusion is the result of abnormal dimension and alignment of each skeletal component. Understanding on these mechanisms may help to elucidate the etiology of skeletal malocclusion and to establish population-oriented treatment plans. Attempts to subdivide the Angle's classification have been performed for Class III malocclusion, while few studies have been conducted for Class II malocclusion despite recent growing interests in Class II malocclusion. 200 adults (88 male, 112 female) with skeletal Class II malocclusion were collected and subdivided using cluster analysis, using the measurements representing the dimension and the alignment of each facial skeletal component. The properties of each cluster was grouped within the subjects and a comparison between the subjects and the control group (38 male, 35 female) with normal occlusion was performed. Six clusters were finally recognized in each male and female groups. The clusters in both genders were mainly characterized by the cranial base alignment, dimension of the posterior cranial base, dimension of the mandibular ramus and the degree of mandibular rotation. The results implicate that active treatment of mandible rather than the nasomaxillary complex may be primarily considered for the correction of Korean Class II skeletal pattern.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.48 no.2
• /
• pp.140-150
• /
• 2021

A total of 580 patients, who visited and received an orthodontic diagnosis in the Department of Pediatric Dentistry, Seoul National University Dental Hospital from 2017 to 2019, were investigated in this study. The aim of this study was to evaluate skeletal patterns of pediatric orthodontic patients determined with lateral cephalometric analysis and to analyze the relationship between skeletal pattern and probable associated clinical features. Also, the modality of orthodontic treatment for each skeletal classification was investigated to aid in therapeutic decisions. Patients aged 7 year accounted for the largest age group; 54.2% of patients showed a skeletal class I pattern, 22.2% showed a skeletal class II pattern, and 23.6% showed a skeletal class III pattern. Bi-maxillary retrusion for skeletal class I, retruded mandible with normal positioning of the maxilla for skeletal class II, and retrusion of the maxilla with protrusion of the mandible for skeletal class III were the largest subgroups by skeletal pattern. Brachyfacial type accounted for 55.0% of patients, followed by 31.9% of mesofacial type and 13.1% of dolichofacial type. The prevalence of anterior crossbite in the study was 43.3%, higher than that in previous studies.

• The korean journal of orthodontics
• /
• v.27 no.2
• /
• pp.209-219
• /
• 1997

This investigation was designed to analyze the degree of dental compensation according to horizontal components of craniofacial skeleton and to investigate correlation between dental compensation and craniofacial pattern in skeletal class III malocclusion. The material selected for this study consisted of standard lateral cephalogram of 59 subjects in normal occlusion group, 91 subjects in mild skeletal class III malocclusion group and 58 subjects in severe skeletal class III malocclusion group. The mild skeletal class III malocclusion group was divided into two groups, one was class III malocclusion without anterior crossbite group and the other was class III malocclusion with anterior crossbite group. The data were analyzed by Quick-ceph image program. The results were as follows. 1. Mild skeletal class III malocclusion without anterior crossbite group showed the most labial inclination of upper incisors, followed by severe skeletal class III malocclusion group and mild skeletal class III malocclusion with anterior crossbite group, the Latter showing the least. The amount of lingual inclination of lower incisors was the largest in severe skeletal class III malocclusion group, and there was no statistically significant difference between mild skeletal claw III malocclusion without anterior crossbite group and mild skeletal class III malocclusion with anterior crossbite group. 2. There were little differences in vertical skeletal structure between mild skeletal class III malocclusion without anterior crossbite group and mild skeletal class III malocclusion with anterior cwssbite group, they showed statistically significant differences in the upper incisors measurements. 3. The measurements of lower incisors in mild skeletal class III malocclusion without anterior crossbite group and upper incisors in mild skeletal class III malocclusion with anterior crossbite group represented a high correlation with skeletal structure. Especially, ∠IMPA and ∠FMIA of lower incisor measurements, and ∠U1-FH ∠U1-SN of upper incisor measurements showed high correlation with skeletal structure in each group. 4. ∠IMPA and ∠FMIA of lower incisor measurements showed high correlation with skeletal structure in all groups. ∠U1-FH, ∠U1-SN and U1-facial plane(mm) of upper incisor measurements represented higher correlation with skeletal structure than any other upper incisor measurements.

• The korean journal of orthodontics
• /
• v.37 no.1 s.120
• /
• pp.29-43
• /
• 2007

Objective: To establish proper diagnosis and treatment plan for skeletal Class II malocclusions, some important factors to consider are the patient's skeletal morphology, prognosis as well as the treatment effects. Therefore, the present study analyzed the effects of activator treatment on different skeletal patterns in growing Class II malocclusion patients. Methods: A total of 116 patients (53 boys & 63 girls) in the experimental group were treated with the activator appliance. The experimental group was classified into either hyperdivergent or hypodivergent groups according to articular and genial angles. Results: Patients with hypodivergent growth patterns showed good effects of activator treatment. Conclusion: It seems conceivable that through classifying adolescent Class II malocclusion patients into different skeletal patterns, activator treatment effects may be predicted during the diagnosis and treatment planning stage.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.45 no.1
• /
• pp.98-108
• /
• 2018

This study aimed to evaluate the nasopharyngeal and oropharyngeal dimensions of the patients with skeletal class II division 1 or division 2 patterns during the pre-peak, peak, and post-peak growth periods for comparison with a skeletal class I control group (79 for pre-peak, 40 for peak, 40 for post-peak). Total 159 lateral cephalograms (70 for skeletal class I, 51 for skeletal class II, division 1, and 38 for skeletal class II, division 2) were selected. The growth of anteroposterior dimension of the pharyngeal airway were statistically significant among growth periods. The dimension for the nasopharyngeal and oropharyngeal airway space was the smallest in the division 1 skeletal class II group followed by class II division 2 and skeletal class I.

• The korean journal of orthodontics
• /
• v.47 no.4
• /
• pp.248-255
• /
• 2017

Objective: The purpose of this study was to investigate whether the craniofacial patterns of Korean children with snoring and adenotonsillar hypertrophy (ATH) could be categorized into characteristic clusters according to age. Methods: We enrolled 236 children with snoring and ATH (age range, 5-12 years) in this study. They were subdivided into four age groups: 5-6, 7-8, 9-10, and 11-12 years. Based on cephalometric analysis, the sagittal and vertical skeletal patterns of each individual were divided into Class I, II, and III, as well as the normodivergent, hypodivergent, and hyperdivergent patterns, respectively. Cluster analysis was performed using cephalometric principal components in addition to the age factor. Results: Three heterogeneous clusters of craniofacial patterns were obtained in relation to age: cluster 1 (41.9%) included patients aged 5-8 years with a skeletal Class I or mild Class II and hyperdivergent pattern; cluster 2 (45.3%) included patients aged 9-12 years with a Class II and hyperdivergent pattern; and cluster 3 (12.8%) included patients aged 7-8 years with a Class III and hyperdivergent pattern. Conclusions: This study found that the craniofacial patterns of Korean children with snoring and ATH could be categorized into three characteristic clusters according to age groups. Although no significantly dominant sagittal skeletal discrepancy was observed, hyperdivergent vertical discrepancy was consistently evident in all clusters.

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

• The korean journal of orthodontics
• /
• v.27 no.5 s.64
• /
• pp.801-813
• /
• 1997

A comparative study was made on the chewing movements of normal occlusion and skeletal class m malocclusion. Thirty normal occlusion subjects and twenty skeletal class III malocclusion patients were given chewing gums for the study : using BioPAK system, the chewing movement on the frontal plane was recorded and analyzed. With a typical chewing path chosen representing each subject, chewing width, opening distance, opening and closing angles, maximum opening and closing velocities were observed. Seven characteristic patterns were classified based on the types of chewing paths. The followings are the results : 1. Compared with the normal occlusion group, the skeletal class III malocclusion group showed more varied and vertical chewing patterns. 2. In comparision of chewing widths, skeletal class m malocclusion group showed narrower path than the normal occlusion group(p<0.01). 3. In opening distance, skeletal class III malocclusion group appeared shorter than the normal occlusion group without statistical significance(p>0.05). 4. In opening and closing angles, skeletal class III malocclusion group showed more acute angles than the normal occlusion group(p<0.01). 5. In maximum opening and closing velocities, skeletal class III malocclusion group was slower than the normal occlusion group but with no statistical significance(P>0.05). 6. In the classification of chewing movement pattern, the normal occlusion group had Type II as the highest rate at 73.4% ; in skeletal class III malocclusion group, the highest rate was Type III at 35.0%, followed by Type II at 30.0% 7. In the classification of chewing movement pattern, Type IV(chopping type)of skeletal class III malocclusion group showed a higher rate with 25.0% over 3.3% of normal occlusion group.