• Journal of the korean academy of Pediatric Dentistry
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• v.5 no.1
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• pp.64-75
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• 1978

In order to know cephalometric norms for the preschool children, this roentgeno cephalometric study was undertaken in each 50 Korean male and female children of primary dentition age from 4 to 5 year. The following results were obtained. 1. In the skeletal analysis, there was no significant difference between male and female in angular measurement and the linear measument of the male was generally greater than that of the female. 2. Saddle angle was $122.3^{\circ}$, articular angle was $147.6^{\circ}$, gonial angle was $119.4^{\circ}$ and the sum of each angle was $396.1^{\circ}$ in male and $396.6^{\circ}$ in female. 3. The ratio of mandibular body to anterior cranial base was about 1 : 0.91. 4. In the primary dentition, suggested that the nasion and point A move forward relative to sella turcica in a fashion, pogonion and point B are equal in angular position relative to plan S-N, bony chin and chin button was yet underdeveloped, and the forward growth of mandible was seen rapid than maxilla after 4 years. 5. Suggested that the percentage of anterior facial height to the posterior facial height were 64.4% in male and 64.1% in female. 6. Maxillary primary incisors was more upright than the permanent incisors, mandibular primary incisors was inclined lingually relative to the permanent incisor, and primary incisors was more upright than the permanent incisors. 7. Maxillary primary incisors in female was inclined labially than male. 8. In the the relationship of the upper lip and lower lip to the esthetic line, the upper lip was 2.11mm and the lower lip was 2.33mm front of the esthetic line.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.55-62
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• 2006

Purpose : To find the cause of root curvature by use of panoramic and lateral cephalometric radiograph. Materials and Methods : Twenty six 1st graders whose mandibular 1st molars .just emerged into the mouth were selected. Panoramic and lateral cephalometric radiograph were taken at grade 1 and 6, longitudinally. In cephalometric radio graph, mandibular plane angle, ramus-occlusal plane angle, gonial angle, and gonion-gnathion distance (Go-Gn distance) were measured. In panoramic radio graph, elongated root length and root angle were measured by means of digital subtraction radiography. Occlusal plane-tooth axis angle was measured, too. Pearson correlations were used to evaluate the relationships between root curvature and elongated length and longitudinal variations of all variables. Multiple regression equation using related variables was computed. Results : The Pearson correlation coefficient between curved angle and longitudinal variations of occlusal plane-tooth axis angle and ramus-occlusal plane angle was 0.350 and 0.401, respectively (p<0.05). There was no significant correlation between elongated root length and longitudinal variations of all variables. The resulting regression equation was $Y=10.209+0.208X_1+0.745X_2$ (Y: root angle, $X_1$: variation of occlusal plane-tooth axis angle, $X_2$: variation of ramus-occlusal plane angle). Conclusion : It was suspected that the reasons of root curvature were change of tooth axis caused by contact with 2nd deciduous tooth and amount of mesial and superior movement related to change of occlusal plane.

• The korean journal of orthodontics
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• v.35 no.2 s.109
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• pp.91-105
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• 2005

For af accurate diagnosis and treatment planning of facial asymmetry, the use of 3-dimensional (3-D) image is indispensable. The purpose of this study was to get standard data for the 3-D analysis of facial asymmetry Computerized tomography (CT) was taken in the 60 normal occlusion individuals (30 male. 30 female) who did not have any apparent facial asymmetry. The acquired 2D CT DICOM data were input on a computer, and the reformatted 3-D images were created using a 3-D image software. Twenty three measurements were established in order to evaluate asymmetry; 15 ;omear measurements (6 for ramus length. 1 for condylar neck length, and 8 for mandibular body length) and 8 angular measurements (4 for gonial angle. 2 for frontal ramal inclination. and 2 for lateral ramal inclination) The right aid left difference of each measurement was calculated and analyzed. It is suggested that the right and left differences of the measurements obtained from the study could be used as references for the diagnosis of facial asymmetric patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.2
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• pp.9-20
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• 1990

A series of 19 cases with maxillary hyperplasia and mandibular retrognathia were operated on by simultaneous superior repositioning of the maxilla after Le Fort I osteotomy and anterior repositioning of the mandible after bilateral sagittal split ramus osteotomies with or without osteotomy of the inferior border of the mandible. These were evaluated by retrospective cephalometric and computer analysis for the longitudinal skeletal and dental changes for an average of 17.1 months after surgery. For stabilization of the osteotomized segments, the authors used wire osteosynthesis by means of bilateral infraorbital and zygomatic buttress suspension wire at the maxilla, and direct interosseous wire at the split segments of the mandibular rami. Results show generally good stability after simultaneous maxillary and mandibular surgery with wire osteosynthesis, and a minimal to moderate tendency toward skeletal and dental relapse. This article is a preliminary study to defy the efficiency of the wire osteosynthesis (wo)compared with rigid internal fixation (RIF) for simultaneous maxillary and mandibular surgery. 1. The vertical relapse rate of the A point after superior repositioning of the maxilla is 2.2%. 2. The horizontal relapse rate of the B point after advancement of the mandible is 18.3%. 3. The condyle is distracted inferiorly and slightly posteriorly at the immediate postoperative period. 4. At the long term follow up examination, the condyle presents tendency of return to the preoperative position. 5. Condylar segment angle is decreased at the immediate postoperative period, and at the long term follow up evaluation, the angle is increased. 6. Gonial angle is increased at the immediate postoperative period, and then is decreased at the long term follow up evaluation. 7. The dentition is satisfactory with acceptable movement at the long term follow up evaluation. 8. At the mandibular free body analysis, genioplasty shows good stability. 9. Wire osteosynthesis provides excellent stabilization for the simultaneous maxillary and mandibular surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.3
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• pp.229-237
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• 1993

This study was intended to evaluate a post-operative relapse tendency in mandibular prognathism patients with open-bite. 18 patients with or without open-bite have undergone sagittal split ramus osteotomy and were investigated radiologically with cephalogram. The results were as following 1. The preoperative anterior facial height, mandibular plane angle and mandibular gonial angle were larger in open-bite patients than in nonopen-bite patients.(p>0.05) 2. There was significant correlation between surgical change of SNA, mandibular plane length and long-term relapse.(p<0.01). 3. There was relatively stable postoperative anterior facial height in open bite patients. 4. There was no significant correlation between the surgical change of mandibular plane angle, amount of mandibular setback and long-term relapse.(p>0.01) 5. This study showed that horizontal relapse was more significant than vertical relapse.

• The korean journal of orthodontics
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• v.22 no.1
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• pp.205-227
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• 1992

This study was aimed to investigate the characteristics & the causative areas of the adult skeletal class III malocclusions with different facial divergency. The lateral cephalograms of 80 subjects with skeletal class III malocclusion from 17 to 29 years of age were classified into 3 groups according to SN-MP angle; hypodivergent group $(21.65{\pm}3.52^{\circ})$, neutrodivergent group $(30.50{\pm}2.29^{\circ})$ and hyperdivergent group $(40.02{\pm}3.98^{\circ})$. The data were gathered by digitizing of the traced cephalograms and were statistically analyzed. The results were as follows: 1. The anterior cranial base of the hyperdivergent group was shortest & tipped upwardly to the FH plane. 2. The maxilla of hyperdivergent group was shortest anteroposteriorly and positioned posteriorly to the anterior cranial base. 3. The degree of the mandibular prognathism in hyperdivergent group was less than the hypodivergent group. The hyperdivergent group showed the downward & backward rotated mandible. 4. The mandibular ramus & body was short & slender in the hyperdivergent group and the gonial angle was greatest in the hyperdivergent group. 5. The temporomandibular joint was positioned more superiorly to the anterior cranial base in the hyperdivergent group. 6. The cranial base, palatal plane, occlusal plane and mandibular plane were diverged in the hyperdivergent group. And this group had a great anterior total facial height, especially anterior lower facial height. 7. The craniofacial characteristics of skeletal class III malocclusion were critical in the vertical structure than the horizontal.

• Journal of Oral Medicine and Pain
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• v.17 no.2
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• pp.37-49
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• 1992

80 patients who presented at Wonkwang University Dental Hospital with craniomandibular disorders were collected for this study. To observe the occlusal contact pattern such as contact numbers, contact force and presence or absence of anterior occlusal contact, the author used T-Scan system (Tekscan, Inc, U.S.A.) with are computerized occlusal analysing system. And to study the correlation between craniofacial profile and occlusal contact pattern, cephalogram were also taken, The cephalometric items related to growth pattern, jaw bone relation and denture pattern were measured and analysed according to routine method by computerized program. The obtained data were statistically processed with SPSS/PC+ package about anterior contact pattern and its craniofacial relationship. The obtained results were as follows : 1. In terms of growth pattern, patients without anterior tooth contacts showed a tendency to downward growth of craniofacial profile. The value in this subjects were significantly different from the value of patients with anterior tooth contacts in items of low gonial angle, Jarabak ratio, SN to GoMe angle, FMA, occlusal plane to mandibular plane angle and ramus height. 2. In terms of jaw bone relationship, patients without anterior tooth contacts showed a tendency to backward growth of craniofacial profile. The value of this patients were significantly different from the value of patients with anterior tooth contacts in items of SNB, ANB, mandibular plane to anterior cranial base ratio, SNPo, NAPo and APDI items. 3. But in denture pattern, no statistically significant difference by the presence or absence of anterior tooth contacts were showed between this patients groups. 4. From this study, it could be proposed that anterior open bite in the patients with craniomandibular disorders would be originated from not dental discrepancy but skeletal discrepancy.

• The korean journal of orthodontics
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• v.49 no.5
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• pp.326-337
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• 2019

Objective: The objective of this study was to develop new parameters based on the foramina of the trigeminal nerve and to compare them with the conventional cephalometric parameters in different facial skeletal types. Methods: Cone-beam computed tomography (CBCT) scans and cephalograms from 147 adult patients (57 males and 90 females; mean age, 26.1 years) were categorized as Class I ($1^{\circ}$ < ANB < $3^{\circ}$), Class II (ANB > $5^{\circ}$), and Class III (ANB < $-1^{\circ}$). Seven foramina in the craniofacial area-foramen rotundum (Rot), foramen ovale (Ov), infraorbital foramen, greater palatine foramen, incisive foramen (IF), mandibular foramen (MDF), and mental foramen (MTF)-were identified in the CBCT images. Various linear, angular, and ratio parameters were compared between the groups by using the foramina, and the relationship between the new parameters and the conventional cephalometric parameters was assessed. Results: The distances between the foramina in the cranial base did not differ among the three groups. However, the Rot-IF length was shorter in female Class III patients, while the Ov-MTF length, MDF-MTF length, and Ov-MDF length were shorter in Class II patients than in Class III patients of both sexes. The MDF-MTF/FH plane angle was larger in Class II patients than in Class III patients of both sexes. Most parameters showed moderate to high correlations, but the Ov-MDF-MTF angle showed a relatively low correlation with the gonial angle. Conclusions: The foramina of the trigeminal nerve can be used to supplement assessments based on the conventional skeletal landmarks on CBCT images.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.865-875
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• 1998

The purpose of this study was to investigate the angle formed by the Sella-Nasion(SN) plane and Frankfort-Horizontal(FH) plane and evaluate the correlation and difference of the FH plane to other horizontal reference planes. Through this study we hope to present a basis for selecting a horizontal reference plae which can be implemented in cephalometric studies and in surgical orthodontic treatment planning. 600 subjects were chosen following a clinical examination md lateral cephlometric X-rays were taken. According to cephalometric analysis the subjects were classified into 3 groups , Skeletal Class I malocclusion or normal occlusion group(male 50, female 50), Skeletal Class II malocclusion group(male 50, female 65) and Skeletal Class III malocclusion group(male 50, female 50). The results were as follows. 1. The angle formed by the SN plane and FH plane showed no difference among the malocclusion groups, but there was a significant sex difference. For males the angle measured was $7.47^{\circ}{\pm}2.40^{\circ}$ whereas for females it was $8.93^{\circ}{\pm}2.72^{\circ}$. 2. The angle formed by the SN plane or FH plane and Mandibular plane was higher in females for all malocclusion groups. This angle in the Skeletal Class I malocclusion group was lower than in the other two groups. 3. There was no difference among the sexes or malocclusion groups considering the angle formed by the FH plane and Palatal plane. 4. The genial angle in the Skeletal Class III malocclusion group was higher than in the Skeletal Class I and Class II malocclusion groups in both sexes.

• Journal of Oral Medicine and Pain
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• v.36 no.1
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• pp.39-51
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• 2011

The aims of this study were to investigate whether the facial skeletal patterns previously reported to be related to temporomandibular disorder (TMD) in other studies could be consistently observed in the TMD patients diagnosed according to Research Diagnostic Criteria for Temporomandibular Disorder (RDC/TMD) Axis I and evaluate its usability in the orthodontic clinics to examine the patients with TMD related symptoms. The clinical records and radiographs of female patients who visited the TMD and Orofacial Pain Clinic of Seoul National University Dental Hospital and were diagnosed as TMD were consecutively filed for this study. Patients were clinically examined and diagnosed according to the revised diagnostic algorithms of RDC/TMD Axis I and the lateral cephalogram, panoramic orthopantomogram, temporomandibular joint (TMJ) orthopantomogram, and transcranial radiograph of each patient were taken and digitalized. The data of patients who were under 18 years of age or had any systemic disease, trauma history involving the TMJ, or skeletal deformity at the time of the first examination were excluded. The remaining data of 96 female patients were finally analyzed. The obtained results were as follows: 1. There are no significant differences of cephalometric measurements between RDC I (muscle disorders) diagnostic groups. 2. Only the articular angle of the RDC group IIc (disk displacement without reduction without limited opening) patients was larger than patients of the no diagnosis of RDC II group (disk displacement). 3. Larger articular angle and smaller facial height ratio were observed in RDC IIIc group (osteoarthrosis) compared to IIIa group (arthralgia). Larger articular angle, larger Bjork sum, smaller posterior facial height, and smaller facial height ratio were observed in RDC group IIIc compared to no diagnosis of RDC III group (arthralgia, arthritis, and arthrosis). 4. According to the results of cephalometric analysis in simplified RDC groups, smaller overjet was observed in muscle disorders (MD) group. Facial height ratio and IMPA were smaller and articular angle was larger in disk displacements (DD) group than in no diagnosis of DD group. In arthrosis (AR) group, posterior facial height, and facial height ratio were smaller, and articular angle, gonial angle, facial convexity, FMA, Bjork sum, and ANB were larger than in no diagnosis of AR group. In joint pain (JP) group, only posterior facial height was smaller than no diagnosis of JP group. In conclusion, Facial morphologic patterns showing posterior-rotated mandible and lower posterior facial height is related to RDC group II and III diagnosis of the TMJ in female TMD patients. RDC/TMD Axis I diagnosis can provide a good clinical diagnostic tool for the standardized examination of the TMJ in orthodontic clinics.