• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.459-474
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• 2005

Making a precise and ideal set-up model is an essential part in the indirect bonding procedure for lingual orthodontic treatment. To evaluate the accuracy of the making a set-up model, 22 adult patients who received lingual orthodontic treatment with 4 bicuspid extractions were selected, and 3 sets of dental models (before, set-up, and after treatment) were measured using the set-up model gauge, an instrument for measuring the inclination and angulation of the clinical crowns on the dental model. Two sets of lateral cephalograms (before and after) from each patient were also evaluated. The mean difference between the before treatment model and the set-up model was $-3.93{\pm}6.98^{\circ}$ for the inclination and $1.87{\pm}5.79^{\circ}$ for the angulation. And the mean difference between the set-up model and the after treatment model was $-4.31{\pm}5.91^{\circ}$ labiolingually and $-2.16{\pm}3.27^{\circ}$ mesiodistally, The after treatment model differed from the before treatment model about $-8.24{\pm}5.39^{\circ}$ in inclination. There were no significant difference between the measured gauge that measured from the dental model using the set-up model gauge and the calculated gauge angle measured from the lateral cephalogram using constructed points and lines. Using the set-up model gauge, it is possible to evaluate the study model 3-dimensionally in relation with the patient's lateral cephalogram and establish whether the doctor's prescription or overcorrection is built in the set-up model precisely.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.1
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• pp.185-194
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• 2001

This study was designed to evaluate the effects of angulation changes of head posture on the enlargement ratios of a lateral headfilm depending on the vortical or horizontal rotation of the objects. A device was constructed to measure regional changes of enlargement ratios. The device was held within the cephalostat and cephalograms recorded at each measured degrees of the device tilting, vertically and horizontally. The enlargement ratios of the horizontal, vertical, and angular measurements on the films taken at each tilted angulations were obtained and compared with those on the films taken without rotation. In summary, the enlargement ratios of the horizontal linear measurements were decreased during horizontal rotations. The enlargement ratios of vortical measurements of the right side on the film were increased and those of the left side were decreased by the horizontal rotations. Enlargement ratios of horizontal measurements were affected further than those of vertical measurements by the same angular changes of the horizontal rotations. Therefore, a disruption of parallelism between the object's midsagittal plane and the film could result in distortion of the image while vertical rotation around the object's porionic axis would not significantly affect the enlargement ratios on the headfilm.

• The korean journal of orthodontics
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• v.39 no.1
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• pp.28-35
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• 2009

Objective: The purpose of this study was to investigate the relationship between menarche and cervical vertebral maturation. Methods: Lateral cephalograms of 67 young korean girls within the range of 1 year before or after their menarche were gathered. The concavity of the cervical vertebrae base and the ratio of the base length to the 3rd and 4th cervical vertebrae anterior height were measured and analyzed. Results: The mean measured values were as follows, concavity of the 3rd cervical vertebrae base: 1.27(${\pm}0.18$) mm, concavity of the 4th cervical vertebrae base: 1.06(${\pm}0.15$) mm, ratio of the base length to the 3rd cervical vertebrae anterior height: 0.73(${\pm}0.06$) and ratio of the base length to the 4th cervical vertebrae anterior height: 0.70(${\pm}0.05$). There was a significant increase in the ratio of the base length to the 3rd vertebrae anterior height and the base concavity of the 3rd and 4th cervical vertebrae during the period of 1 year before to 1 year after their menarche. Conclusions: These characteristics of the 3rd and 4th cervical vertebrae on the lateral cephalogram can provide useful clues on evaluating the growth stage.

• Archives of Plastic Surgery
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• v.34 no.5
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• pp.635-640
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• 2007

Purpose: Mid and lower facial convexity is more common in Oriental people than in Caucasian. Bimaxillary dentoalveolar protrusion is characterized by procumbent teeth, protruding lips, acute nasolabial angle, gummy smile, receding chin, facial convexity. Especially, pure maxillary dentoalveolar protrusion is less frequent than bimaxillary dentoalveolar protrusion. Therefore, it is important to make an accurate decision for the operation throughout the history taking, cephalogram, dental cast to arrive at accurate diagnosis and surgical plan. Methods: From December 2002 to June 2004, ten patients with maxillary dentoalveolar protrusion and microgenia were corrected by maxillary anterior segmental osteotomy and advancement genioplasty. 10 patients were analyzed by preoperative and postoperative clinical photography, posteroanterior and lateral cephalograms. Results: No major complications were occurred throughout the follow-up period except one of the over-recessed, otherwise most of the patients were satisfied with the result. Conclusion: We could correct the occulusal relationship with teeth and improve lower facial profile, asthetically and functionally, by maxillary anterior segmental osteotomy and advancement genioplasty.

• Journal of Korean Dental Science
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• v.3 no.1
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• pp.5-10
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• 2010

This study sought to compare the amounts of posterior anchorage loss during the en masse retraction of the upper anterior teeth between orthodontic mini-implant (OMI) and conventional anchorage reinforcement (CAR) such as headgear and/or transpalatal arch. The subjects were 52 adult female patients treated with sliding mechanics (MBT brackets, .022" slot, .019X.025" stainless steel wire, 3M-Unitek, Monrovia, CA, USA). They were allocated into Group 1 (N=24, Class I malocclusion (CI), upper and lower first premolar (UP1LP1) extraction, and CAR), Group 2 (N=15, Cl, UP1LP1 extraction and OMI), and Group 3 (N=13, Class II division 1 malocclusion, upper first and lower second premolar extraction, and OMI). Lateral cephalograms were taken before (T0) and after treatment (T1). A total of 11 anchorage variables were measured. Analysis of variance was used for statistical analysis. There was no significant difference in treatment duration and anchorage variables at T0 among the three groups. Groups 2 and 3 showed significantly larger retraction of the upper incisor edge (U1E-sag, 9.3mm:7.3mm, P<.05) and less posterior anchorage loss (U6M-sag, 0.7~0.9mm:2mm, P<.05; U6A-sag, 0.5mm:2mm, P<.01) than Group 1. The ratio of retraction amount of the upper incisor edge per 1 of anchorage loss in the upper molar made for the significant difference between Groups 1 and 2 (4.6mm:7.0mm, P<.05). Group 3 showed a relatively distal inclination of the upper molar (P<.05) and the intrusion of the upper incisor and first molar (U1E-ver, P<.05; U6F-ver, P<.05) compared to Groups 1 and 2. Although OMI could not shorten the treatment duration, it could provide better maximum posterior anchorage than CAR.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.193-198
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• 2014

Purpose: The present study was aimed to investigate the variation of soft palate morphology in different age and gender groups. The correlations of radiographic velar length (VL), velar width (VW), pharyngeal depth (PD), and Need's ratio with soft palate variants were also studied in the North Indian subpopulation. Materials and Methods: The study sample consisted of 300 subjects aged between 15 and 45 (mean: 31.32) years. The velar morphology on lateral cephalograms was examined and grouped into six types. The results obtained were subjected to a statistical analysis to find the correlation between variants of the soft palate with gender and different age groups. Results: The most frequent type of soft palate was leaf shaped (48.7%), and the least common was crook shaped (3.0%) among both the genders and various age groups, showing a significant correlation. The mean VL, VW, and PD values were significantly higher in males and significantly correlated with the types of soft palate. A significant correlation was observed between the mean VL, VW, PD, and Need's ratio with various age groups, showing an inconsistent pattern with an increase in age. The types of soft palate, gender, and Need's ratio were also significantly correlated, with an overall higher mean value of the Need's ratio among female subjects and the S-shaped soft palate. Conclusion: The knowledge of a varied spectrum of velar morphology and the variants of the soft palate help in a better understanding of the velopharyngeal closure and craniofacial anomalies.

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

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.5
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• pp.407-412
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• 2011

Purpose: The purpose of the present study was to evaluate the postoperative skeletal stability of two-jaw surgery (Le Fort I osteotomy and bilateral sagittal split ramus osteotomy) via surgery first orthodontic treatment (SFOT) in class III malocclusion. Methods: Thirty-two patients who had two-jaw surgery via SFOT were included in this study. Serial lateral cephalograms were obtained before (T0), immediately after (T1), and six months after (T2) surgery. Twelve variables were measured for horizontal and vertical skeletal stability as well as for dental change. All measurements were evaluated statistically by a paired t-test ($P$ <0.05). Results: The mean skeletal changes were $0.1{\pm}2.5$ mm at point A and $-12.0{\pm}7.4$ mm at the pogonion. The mean horizontal relapse was 11.6% at the pogonion, and the mean vertical surgical changes included an upward displacement of $2.1{\pm}7.1$ mm and a forward displacement of $1.4{\pm}4.6$ mm at the pogonion. Upper incisor inclination decreased after surgery and was maintained at T2, and lower incisors were proclined from T1 to T2 by postsurgical orthodontic treatment. Conclusion: Postoperative skeletal stability of two-jaw surgery via surgery first orthodontic treatment in class III malocclusion was clinically acceptable.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.101-114
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• 2000

The purpose of this study was to evaluate the soft-tissue profile changes from 24 to 32 yews of age in Korean adults. The subjects used in this study consisted of 17 males and 8 females. The data obtained from the lateral cephalograms taken at age 24 and 32, were analyzed statistically. The obtained results were as follows : 1. During the observation period, there were no significant changes in the hard-tissue measurements in both sexes (p>0.05). 2. In the anteroposterior measurements of soft-tissue, the males had significant increase in chin area (Pog', Gn'), and the females had significant decrease in lower lip (LI) (p<0.05). 3. In the vertical measurements of soft-tissue, both sexes showed the increased tendency in upper lip length (Sn-Sto) where the males showed significant increase (p<0.05). The lower facial height (Sn-Gn') turned out significant increase in both sexes (p<0.05). 4. In general, the females and males had the increased tendency in soft-tissue thickness, especially significant increase in chin area (Pog', Gn') (p<0.05).

• The korean journal of orthodontics
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• v.47 no.6
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• pp.344-352
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• 2017

Objective: The purpose of this study was to compare the changes induced in the pharyngeal airway space by orthodontic treatment with bodily retraction of the mandibular incisors and mandibular setback surgery without extraction. Methods: This retrospective study included 63 adult patients (32 men and 31 women). Thirty-three patients who had been treated via four-bicuspid extraction and bodily retraction of the mandibular incisors (incisor retraction, IR group) were compared with 30 patients who had been treated via mandibular setback surgery (MS group) without extraction. Lateral cephalograms were acquired and analyzed before (T1) and after treatment (T2). Results: The superior pharyngeal airway space did not change significantly in either group during treatment. The middle pharyngeal airway space decreased by $1.15{\pm}1.17mm$ and $1.25{\pm}1.35mm$ after treatment in the IR and MS groups, respectively, and the decrease was comparable between the two groups. In the MS group, the inferior pharyngeal airway space (E-IPW) decreased by $0.88{\pm}1.67mm$ after treatment (p < 0.01). The E-IPW was larger in the MS group than in IR group at T1, but it did not differ significantly between the two groups at T2. No significant correlation was observed between changes in the pharyngeal airway space and the skeletal and dental variables in each group. Conclusions: The middle pharyngeal airway space decreased because of the posterior displacement of the mandibular incisors and/or the mandibular body. The E-IPW decreased only in the MS group because of the posterior displacement of only the mandibular body.