• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.4
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• pp.323-330
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• 2011

Purpose: The present study examined the reproducibility of an operation plan by comparing the jaw position of STO with the postoperative mandibular set back measurement in sagittal split ramus osteotomy. Methods: Thirty patients with class III dental and skeletal malocclusion and who were treated with BSSRO were reviewed. Three plain radiographs such as the panoramic view, the lateral cephalogram and the submentovertex view were taken before and after operation. Also, paper surgery for STO and model surgery were used to evaluate the amount of mandibular set back. Results: On the panoramic view, the amount of mandibular set back in STO was similar to the postoperative results of model surgery, but the amount of mandibular set back on the lateral cephalogram was smaller than the postoperative result of model surgery and then the amount of set back on submentovertex view was similar to the postoperative result of model surgery. Conclusion: Precise tracing and paper surgery should be performed for a combined expected STO in order to predict the exact amount of preoperative mandibular set back.

• Korean Journal of Cleft Lip And Palate
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• v.10 no.1
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• pp.57-65
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• 2007

It is well known that the main factor which contributes to the relapse of orthognathic surgery for Cleft Lip and Palate (CLP) patients is post-operative scar on hard and soft palate of maxilla. Therefore, to compensate the amount of relapse, though it cannot be the perfect way to prevent orthodontic, orthopedic relapse, the Le-fort I osteotomy of maxilla and set-back osteotomy of mandible are generally carried-out simultaneously. We are to review the factors contribute to the relapse of CLP patients after orthognathic surgery through this clinical case : The relapse of Skeletal Class III tendency immediately after orthognathic surgery for grown up CLP patients.

• The korean journal of orthodontics
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• v.32 no.4 s.93
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• pp.265-274
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• 2002

Among many maturation indicators of growing patients, menarche and skeletal maturity are useful to assess growth and development, and the changes of the first and third finger are relatively important in hand-wrist X-rays. The objective of this study was to evaluate the relationship between menarche and the changes of the phalanx of the first and third finger and compare skeletal maturation among different malocclusion types. The sample used in this study was 29 Class 1,27 Class II and 27 Class III females whose hand-wrist X-rays had been taken with 6 month interval before the appearance of ulnar sesamoid ossification till the phalanges of the fingers were almost fused. The results were as follows. 1. There was no skeletal maturity difference among malocclusion types. 2. There was no difference in the mean chronologic age of menarche among different malocclusion types and that was $12.30\pm0.98$ years. 3. The ulnar sesamoid was observed at $10.35\pm1.01$ years, and on distal phalanx of the first finger, epiphyseal capping appeared at $11.26\pm1.04$ years and fusion at $13.12\pm1.06$ years. The epiphyseal capping on middle phalanx of the third finger was observed at $11.57\pm1.02$ years and fusion at $13.72\pm1.04$ years. 4. The timing of menarche occurred around the same time as the fusion process of distal phalanx of the first finger(p<0.001, r=0.82) and the initiation of fusion of middle phalanx of the third finger(p<0.001, r=0.78). Therefore, we can give the aid when we evaluate the growth and development of growing females seeing the changes at phalanx of the first and third finger.

• The korean journal of orthodontics
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• v.46 no.4
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• pp.199-211
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• 2016

Objective: Given the considerable disagreement between the Peer Assessment Rating (PAR) index and the American Board of Orthodontics Cast-Radiograph Evaluation, we aimed to develop a novel assessment system-the Improvement and Completion of Outcome (ICO) index-to evaluate the outcome of orthodontic treatment. Methods: Sixteen criteria from 4 major categories were established to represent the pretreatment malocclusion status, as well as the degree of improvement and level of completion of outcome during/after treatment: dental relationship (arch length discrepancy, irregularity, U1-SN, and IMPA); anteroposterior relationship (overjet, right and left molar position, ANB); vertical relationship (anterior overbite, anterior open-bite, lateral open-bite, SN-MP); and transverse relationship (dental midline discrepancy, chin point deviation, posterior cross-bite, occlusal plane cant). The score for each criterion was defined from 0 or -1 (worst) to 5 (ideal value or normal occlusion) in gradations of 1. The sum of the scores in each category indicates the area and extent of the problems. Improvement and completion percentages were estimated based on the pre- and post-treatment total scores and the maximum total score. If the completion percentage exceeded 80%, treatment outcome was considered successful. Results: Two cases, Class I malocclusion and skeletal Class III malocclusion, are presented to represent the assessment procedure using the ICO index. The difference in the level of improvement and completion of treatment outcome can be clearly explained by using 2 percentage values. Conclusions: Thus, the ICO index enables the evaluation of the quality of orthodontic treatment objectively and consecutively throughout the entire treatment process.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.185-194
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• 2002

When treating borderline cases which have mild crowding, non-extraction treatment may be considered firstly. But crowding may be reappeared by relapse and it may have problems in esthetics and stability. Secondarily four first premolar extraction treatment may be considered. But this may cause dish-in face by overretracting anterior teeth. In this cases, extraction of four second premolar is preferred because this resolves crowding without aggravating profile and has good stability after treatment. So we review cases treated by four second premolar extraction which show good treatment results and stability. The patients had good profile, Class I molar relationship, mild crowding and skeletal discrepancy and their growth had almost completed.

• The korean journal of orthodontics
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• v.52 no.1
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• pp.3-19
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• 2022

Objective: The purpose of this study was to investigate the accuracy of one-step automated orthodontic diagnosis of skeletodental discrepancies using a convolutional neural network (CNN) and lateral cephalogram images with different qualities from nationwide multi-hospitals. Methods: Among 2,174 lateral cephalograms, 1,993 cephalograms from two hospitals were used for training and internal test sets and 181 cephalograms from eight other hospitals were used for an external test set. They were divided into three classification groups according to anteroposterior skeletal discrepancies (Class I, II, and III), vertical skeletal discrepancies (normodivergent, hypodivergent, and hyperdivergent patterns), and vertical dental discrepancies (normal overbite, deep bite, and open bite) as a gold standard. Pre-trained DenseNet-169 was used as a CNN classifier model. Diagnostic performance was evaluated by receiver operating characteristic (ROC) analysis, t-stochastic neighbor embedding (t-SNE), and gradient-weighted class activation mapping (Grad-CAM). Results: In the ROC analysis, the mean area under the curve and the mean accuracy of all classifications were high with both internal and external test sets (all, > 0.89 and > 0.80). In the t-SNE analysis, our model succeeded in creating good separation between three classification groups. Grad-CAM figures showed differences in the location and size of the focus areas between three classification groups in each diagnosis. Conclusions: Since the accuracy of our model was validated with both internal and external test sets, it shows the possible usefulness of a one-step automated orthodontic diagnosis tool using a CNN model. However, it still needs technical improvement in terms of classifying vertical dental discrepancies.

• The korean journal of orthodontics
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• v.32 no.5 s.94
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• pp.301-312
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• 2002

Treatment timing is a very important factor to consider in treating skeletal Class III patients by means of maxillary protraction. According to the literature maxillary Protraction should be carried out at an early age before puberty. However, no scientific data were presented to support this statement and recent studies supported by statistical data showed disagreement concerning the optimum treatment time of maxillary protraction. Therefore, there is no agreement about the optimum treatment time of maxillary protraction. In this study hand-wrist X-rays were taken from 119 patients and subjects were grouped into prepubertal and pubertal group according to their skeletal maturity. Pretreatment and posttreatment lateral cephalometric X-rays were taken and treatment effects were compared. The average treatment time was 6.5 months for the prepubertal group and 6.1 months for the pubertal group. The obtained results were as follows ; 1. The amount of maxillary forward movement was the same for Pretreatment and pubertal group. 2. The amount of maxillary downward movement was the same for prepubertal and pubertal group. 3. The amount of mandibular downward and backward rotational movement was the same for prepubertal and pubertal group. 4. Dental effects were the same for prepubertal and pubertal group.

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.251-265
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• 1999

Various types of horizontal reference planes are used for diagnosis, treatment planning and evaluation of treatment results. But these reference Planes lack accuracy and repro-ducibility, and are mainly for Caucasian. Unlike the adult patients who have completed growth, the horizontal reference planes for growing children may change continuously during growth. Therefore this must be considered in selecting the horizontal reference plane. 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 angle formed by FH plane and other horizontal reference planes in relation to different skeletal maturity and malocclusion types. 540 subjects with no orthodontic treatment history were chosen, and hand -wrist X-rays and lateral cephalometric X-rays were taken. According to SMA(Skeletal Maturity Assessment) of hand-wrist X-rays, the subjects were classified into 3 skeletal maturity groups : SMI 1-4 for group A, SMI 5-7 for group B and SMI 8-11 for group C. A second classification was made according to cephalometric analysis of lateral cephalograms. The subjects were classified into 3 malocclusion groups : Skeletal Class I, II and III malocclusion group. 10 measurements were evaluated. The results were as follows. 1. The angle formed by the SN plane and FH plane showed no difference among skeletal maturity groups, malocclusion groups, and between .sexes. 2. The angles formed by the SN plane and FH plane were $8.27^{\circ}{\pm}2.31^{\circ}$ for males and $8.59^{\circ}{\pm}2.24^{\circ}$ for females. The average value for females and males was $8.42^{\circ}{\pm}2.28^{\circ}$. 3. The angle formed by the FH plane and palatal plane was almost constant showing no difference among skeletal maturity groups, malocclusion groups, and between sexes($1.09^{\circ}{\pm}3.21^{\circ}$).

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.657-668
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• 2000

The purpose of this study was to evaluate the amount and interrelationship of the soft tissue of nose and maxillary changes and to identify the nasal morphologic features that indicate susceptibility to nasal deflection in such a manner that they would be useful in presurgical prediction of nasal changes after maxillary advancement surgery in skeletal Class III malocclusion. The sample consisted of 25 adult patients (13 males and 12 females) who had severe anteroposterior skeletal discrepancy. The patients had received presurgical orthodontic treatment. They underwent a Le Fort I advancement osteotomy, rigid internal fixation, alar cinch suture and V-Y advancement lip closure. The presurgical and postsurgical lateral cephalograms and lateral and frontal facial photographs were evaluated. The computerized statistical analysis was carried out. Soft tissue of nose change to h point change ratios were calculated by regression equations. The results were as follows 1. The correlation of maxillary hard tissue horizontal changes and nasal soft tissue vortical changes were high and the ${\beta}_0$ for soft tissue to ADV were 0.228 at ANt, 0.257 at SNt. 2. The correlation of maxillary hard tissue and nasal soft tissue horizontal changes were high and the ${\beta}_0$ for soft tissue to ADV were 0.484 at ANt, 0.431 at SNt, 0.806 at Sn. 3. The correlation of maxillary hard tissue horizontal changes and width changes of ala of nose were high and the ${\beta}_0$ lot alar base width ratio to ADV were 0.002. 4. The DRI, Prominence of nose, Pre-Op CA is not a quantitative measure that can be used clinically to improve the predictability of vertical and horizontal nasal tip deflection. In this study, increases in nasal tip projection and anterosuperior rotation occur when there is an anterior vector of maxillary movement. These nasal changes were Quantitatively correlated to magnitude of maxillary(A point) movement.

• The korean journal of orthodontics
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• v.28 no.2 s.67
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• pp.237-253
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• 1998

Surgical-orthodontic treatment is performed for the skeletal Class III patients with no remaining growth and too big a skeletal discrepancy (or camouflage treatment, and two jaw surgery is needed in order to have maximum effect in such patients. In two jaw surgery cases, surgical alteration of the occlusal plane is necessary to establish optimal function, esthetics and postoperative sability, therefore the establishment of the occlusal plane is essential in diagnosis and treatment. The object of this study is to evaluate the stability of the indiviual ideal occlusal plane bsaed on the architectural and structural craniofacial analysis of Delaires. Thus, the subjects of this study were 48 patients who underwent two jaw surgery, and divided in two groups. Each group were composed of 24patients, A group were operated with ideal occlusal plane and B group were not. Two groups were compared at the preoperative, immediate postoperative (average 4.3days), and long-term postoperative (average 1.3years) lateral cephalometric radiographs. The following results were obtained: 1. There was no significance in occlusal plane angulation between $T_2\;and\;T_3$. Average long term follow-up changes of occlusal Plane angle were $0.24^{\circ}{\pm}2.43$, with FH plane and $0.15{\circ}{\pm}2.16{\circ}$ with SN plane in all 48 patients. These results demonstrated that the occlusal plane after two jaw surgery in skeletal Class III malocclusion was stable. 2. There was no significance in postoperative stability of occlusal plane between A and B group. 3. There was no significance in postoperative stability of occlusal plane depending on surgeon and operative method within each group. 4. The postoperative changes of occlusal plane were correlated to the postoperative changes of jaw rather than tooth position. 5. There was no correlation between the postoperative changes of occlusal plane and maxillary impaction and mandibular setback with surgery.