• 대한치과교정학회지
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• 제20권2호
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• pp.293-304
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• 1990

The purpose of this study was to describe the morphologic differences between long-face adults and normal-face adults on the lateral and P-A cephalograms. Long-face and normal-face subifects were selected clinically, and then each of them was taken the lateral cephalogram. According to SN-MP angle and ATFH on the lateral cephalogram, long-face group and normal-face group were classified. 2 long-face adults and 18 normal-face adults were collected, and each of them was taken the P-A cephalogram. The results were as follows: 1. The morphologic differences between long-face adults and normal-face adults were closely related to mandibular morphology. 2. Long-face adults, compared with normal-face adults, demonstrated significant increase in ALFH, and significant decrease in ramus height. 3. Long-face adults, compared with normal-face adults, demonstrated significant increase in AUDH and, ALDH, especially in ALDH. 4. On the P-A cephalogram, no measures of transverse dimension demonstrated significant differences between two groups. 5. On the P-A cephalogram, facial height/facial width ratio was significantly larger than normal in the long-face adults, and in the normal-face adults, facial height/facial width ratio was approximately 90%. 6. In the correlation analysis of SN-MP angle and ATFH with all the other variables, the correlation coefficients of SN-MP angle and PTFH/ATFH that of ATFH and ALFH on the lateral cephalogram demonstrated the highest value, and on the P-A cephalogram, SN-MP angle and Cg-GA-Me (Lt.), ATFH and lower facial height demonstrated the highest value of correlation coefficients.

• 대한치과교정학회지
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• 제22권1호
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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.

• 대한치과교정학회지
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• 제45권2호
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• pp.59-65
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• 2015

Objective: To investigate skeletal and dental changes after application of a mandibular setback surgery-first orthodontic treatment approach in cases of skeletal Class III malocclusion. Methods: A retrospective study of 34 patients (23 men, 11 women; mean age, $26.2{\pm}6.6years$) with skeletal Class III deformities, who underwent surgery-first orthodontic treatment, was conducted. Skeletal landmarks in the maxilla and mandible at three time points, pre-treatment (T0), immediate-postoperative (T1), and post-treatment (T2), were analyzed using cone-beam computed tomography (CBCT)-generated half-cephalograms. Results: The significant T0 to T1 mandibular changes occurred $-9.24{\pm}3.97mm$ horizontally. From T1 to T2, the mandible tended to move forward $1.22{\pm}2.02mm$, while the condylar position (Cd to Po-perpendicular plane) shifted backward, and the coronoid process (Cp to FH plane) moved vertically. Between T1 and T2, the vertical dimension changed significantly (p < 0.05). Changes in the vertical dimension were significantly correlated to T1 to T2 changes in the Cd to Po-perpendicular plane (r = -0.671, p = 0.034), and in the Cp to FH plane (r = 0.733, p = 0.016), as well as to T0 to T1 changes in the Cp to Po-perpendicular plane (r = 0.758, p = 0.011). Conclusions: Greater alterations in the vertical dimension caused larger post-treatment (T2) stage skeletal changes. Studying the mandibular position in relation to the post-surgical vertical dimension emphasized the integral importance of vertical dimension control and proximal segment management to the success of surgery-first orthodontic treatment.

• 치과방사선
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• 제1권1호
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• pp.29-37
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• 1971

Modern orthodontics implies not only occlusal excellence, but also the positioning of teeth to produce optimal facial harmony for the individual patients. Several methods have been used in the study of facial height, width and depth were made from living subjects. These methods, however, complicate to control the subjects, therefore many investigators have used profile cephalometric technics. Practically, cephalometric technics were used m orthodontic treatment, maxillo-facial surgery and anthropometric studies. Author was studied to investigate the normal standards of soft tissue profile in Korean adolescences. The subjects consisted of 53 males and 54 females from 17 to 22 years of age and with normal occlusion and acceptable profile. Aluminum filter was designed to obtain both hard and soft tissue structures on a single film. Eight profile landmarks were plotted and drawn on the tracings of all cephalograms and eighteen depth, height and angles were measured from each landmarks of the cephalograms. The following conclusIOns were obtained from this studies; 1. Total facial convexity was 170. 75 in males and females samples and lower facial and: labiomandibular convexity were each of 141.44, 171.05. 2. Maxillary and mandibular sulcus angulations were 137.61, 129.52 and upper and lower lip inclinations were each of 123.26 and 49.56 in male and females. 3. Soft tissue depth of several points were as follows; Subnasale 18.74㎜ in males and 16.65㎜ in females Pogonion 13.40㎜ in males and 13.07㎜ in females upper lip 14.06㎜ in males and 11.91㎜ in females . lower lip 15.46㎜, 13.63㎜ in males and females 4. The protrusion of nose were 16.28㎜ in males and 15.56㎜ in females 5. The vertical length of upper and lower lips were 25.67㎜, 52.96㎜ and the lip posture was indicated 93.43 per cent (closed state) in centric occlusions.

• Imaging Science in Dentistry
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• 제50권3호
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• pp.209-216
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• 2020

Purpose: In India, the age of 14 years is the legal age threshold for child labour. Therefore, in suspected instances of child labour, age assessment plays a crucial role in determining whether a violation of the law on the employment of children has occurred. The aim of this retrospective cross-sectional study was to assess the discriminatory ability of stages of cervical vertebral maturation (CVM) in predicting the legal age threshold of 14 years. Materials and Methods: Routinely taken lateral cephalograms from 408 subjects aged 10 to 18 years were evaluated retrospectively using the CVM stages described by Baccetti et al. Descriptive statistics, accuracy, sensitivity, specificity, positive and negative predictive values, and likelihood ratios were calculated for stages 2, 3, and 4 of CVM. Results: Real age increased as the CVM stage gradually increased. The results of 2×2 contingency tables showed that CVM stage 4 produced an accuracy of 71% and 73%, a false positive rate of 7% and 18%, and a post-test probability of 59% and 68% for boys and girls, respectively. Conclusion: Based on these findings, it can be concluded that the stages of CVM are of limited use for predicting the attainment of the legal age threshold of 14 years. Future studies should investigate whether combinations of skeletal and dental methods could achieve better accuracy and post-test probability.

• 대한치과교정학회지
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• 제20권3호
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• pp.427-446
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• 1990

The objective of this study was to understand the major changes of craniofacial dimensions and spatial growth pattern during the late embryonic and fetal period of human fetures. This study was performed with the selective materials of normal fetuses received from the Registry of Congenital Malformation of Seoul National University Hospital. The specimens consisted of nineteen embryos and sixty-six fetuses. The photomicrographs from mid-segittal sections of embryos were used for angular measurement, and the lateral cephalograms taken with soft X-ray were also measured in liners and angular aspects. All of the anatomical landmarks for the tracing of the photomicrographs and cephalograms were referred to the previous reports on literature. The sequential changes of prenatal craniofacial dimensions and agles were analysed statistically and discussed on the focus about the developmental growth directions of human ore-facial structure arised from heterogeneous origins. The results are as follows, 1) Cranial base angle was almost formed at about 6 weeks old embryos with the average angle of $127.4{\pm}6.33^{\circ}$ (n=3) and it was almost constant onwards. 2) The linear increase rates of anterior cranial base length and anterior facial height exceeded those of the posterior cranial base length and posterior facial height, and the maxilla grows more rapidly on the horizontal dimension than the vertical dmension during the fetal period. 3) The angular relationship between the anterior cranial base and palatal plane decreasedslightly during the fetal period, disclosing $11^{\circ}$ at 12th week gestation and $5^{\circ}$ at 41th weeks gestation. 4) Genial angle was maintained almost constantly at about $130^{\circ}$ during the fetal period from 12 weeks to 41 weeks of gestation.

• 대한치과교정학회지
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• 제46권5호
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• pp.331-342
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• 2016

Objective: To evaluate the accuracy and reliability of the diagnostic tools available for assessing maxillary transverse deficiencies. Methods: An electronic search of three databases was performed from their date of establishment to April 2015, with manual searching of reference lists of relevant articles. Articles were considered for inclusion if they reported the accuracy or reliability of a diagnostic method or evaluation technique for maxillary transverse dimensions in mixed or permanent dentitions. Risk of bias was assessed in the included articles, using the Quality Assessment of Diagnostic Accuracy Studies tool-2. Results: Nine articles were selected. The studies were heterogeneous, with moderate to low methodological quality, and all had a high risk of bias. Four suggested that the use of arch width prediction indices with dental cast measurements is unreliable for use in diagnosis. Frontal cephalograms derived from cone-beam computed tomography (CBCT) images were reportedly more reliable for assessing intermaxillary transverse discrepancies than posteroanterior cephalograms. Two studies proposed new three-dimensional transverse analyses with CBCT images that were reportedly reliable, but have not been validated for clinical sensitivity or specificity. No studies reported sensitivity, specificity, positive or negative predictive values or likelihood ratios, or ROC curves of the methods for the diagnosis of transverse deficiencies. Conclusions: Current evidence does not enable solid conclusions to be drawn, owing to a lack of reliable high quality diagnostic studies evaluating maxillary transverse deficiencies. CBCT images are reportedly more reliable for diagnosis, but further validation is required to confirm CBCT's accuracy and diagnostic superiority.

• 대한치과교정학회지
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• 제50권3호
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• pp.170-180
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• 2020

Objective: To compare short- and long-term dentoalveolar, skeletal, and rotational changes evaluated by Björk's structural method of superimposition between children with Class II malocclusion treated by functional appliances and untreated matched controls. Methods: Seventy-nine prepubertal or pubertal children (mean age, 11.57 ± 1.40 years) with Class II malocclusion were included. Thirty-four children were treated using an activator with a high-pull headgear (Z-activator), while 28 were treated using an activator without a headgear (E-activator). Seventeen untreated children were included as controls. Lateral cephalograms were obtained before treatment (T1), after functional appliance treatment (T2), and after retention in the postpubertal phase (T3). Changes from T1 to T2 and T1 to T3 were compared between the treated groups and control group using multiple linear regression analysis. Results: Relative to the findings in the control group at T2, the sagittal jaw relationship (subspinale-nasion-pogonion, p < 0.001), maxillary prognathism (sella-nasion-subspinale, p < 0.05), and condylar growth (p < 0.001) exhibited significant improvements in the Z- and E-activator groups, which also showed a significantly increased maxillary incisor retraction (p < 0.001) and decreased overjet (p < 0.001). Only the E-activator group exhibited significant backward rotation of the maxilla at T2 (p < 0.01). The improvements in the sagittal jaw relationship (p < 0.01) and dental relationship (p < 0.001) remained significant at T3. Condylar growth and jaw rotations were not significant at T3. Conclusions: Functional appliance treatment in children with Class II malocclusion can significantly improve the sagittal jaw relationship and dental relationships in the long term.

• 치과방사선
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• 제7권1호
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• pp.31-38
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• 1977

A study was performed to investigate the size of tongue area and intermaxillary space area, and compare the sexual differences between normal Korean children and adults by introducing planimetric and linear analysis of the lateral cephalograms. The cephalograms were composed of 41 child male aged 10.8, 40 child female aged 10.5, 38 adult male aged 21.3 and 40 adult female aged 20.8 respectively. In order to study and measure the intermaxillary space area, the followings were selected, as reference items: occlusal plane, anterior intermaxillary space height, posterior intermaxillary space height, length of intermaxillary space. Among those reference items anterior intermaxillary space height and posterior intermaxillary space height were perpendicular to the maxillary plane. An. index, (equation omitted) While the tongue area was plotted by outline of tongue shadow, above a line extending from the vallecula to the most anterior point on the hyoid body, and above a line from the most anterior point of the hyoid body to the menton. The obtained results were as follows: 1. In general the measurements of male were larger than those of female in intermaxillary space area in childhood and adulthood group. but intermaxillary space area of childhood group showed no significant sexual difference, and that of adulthood group showed significant sexual difference when evaluated statistically. 2. In both groups the measurements of male were larger than those of female in tongue area and there are also statistical significance of sexual differences in both age groups. 3. Considerable growh changes between the childhood and adulthood groups were revealed in intermaxillary space area and tongue area, and the tongue had tendency to become relatively smaller when compared with the intermaxillary space in both sex.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권2호
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• pp.160-163
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• 2005

This study was designed to assess skeletal stabilily after surgical correction of mandibular prognathism by bilateral saggital split ramus osteotomy(BSSRO) and fixation with absorbable screws. From July 2001 to September 2003, 30 patients with Class III malocclusion were treated with BSSRO and mandibular setback. They underwent fixation with Biosorb$^{TM}$ FX screws. Cephalograms were obtained preoperatibely, 2 or 3 days postoperatively, and about 12 months after the operation. Changes in the position of lower incisor tip, B point, and pogonion were examined on lateral cephalograms. The mean mandibular setback just after surgery was 10.6mm. 12 months after surgery, mean relapse at pogonion represented 17.9% and 15.1% at B point. Our results suggest that fixation of the bony segments with absorbable screws after BSSO may be used effectively in properly selected cases.