• Korean Journal of Cleft Lip And Palate
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• v.4 no.2
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• pp.45-50
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• 2001

Recents reports have demonstrated that force and direction is important during mandibular distraction osteogenesis. The purpose of this study was to evaluate the resistant force of internal pterygoid muscles and inquire into relationship between internal pte'Ygoid muscles and cephalometric parameters. Eighty four patients with class III malocclusion underwent bilateral sgittal splitting of ramus with intraoral vertico-sagittal ramal osteotomy. A spring scale were used for measuring for resistence of internal pterygoid mescles after splitting of ramus. Skeletal-dental cephalometric analysis was made following statistic package was used for correlation between resistence and cephalometric parameters. The resistant force of right internal pterygoid muscle was greater than left muscle in Korean with class III malocclusion and the force had a linear regression relationship with facial depth (distance between nasion and gonion). The results suggested that facial depth has significant correlation of the resistance of internal pterygoid muscle (p<0.05).

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.2
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• pp.367-378
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• 2005

The purpose of this study was to analyse craniofacial shape by 3D scanner for female adults with age groups. In this study, heads of 452 female adults were measured by 3D scanner. The obtained 25 measurements were analyzed by statistical methods. The results can be summarized as follows; 1. From the basic statistical data analysis, vertex-tragion and the length between the pupils were the longest in their twenties, and grew shorter in elderly groups. The length of nasion-subnasale and the width of mouth increased with an increased in age. 2. According to the analysis of the craniofacial proportions, the head type of female aduls was short-headed. The size of lower face increased with an increase in age. 3. The statistically noticeable differences were found in the measurement of the left and the right sides of face in the age groups of 20, 30, and 40. 4. High correlations were found in two perpendicular lengths, two horizontal lengths and two widths. 5. The order of factor analysis was as follows; the horizontal length, the perpendicular length and the width from highest.

• Archives of Craniofacial Surgery
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• v.12 no.2
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• pp.97-101
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• 2011

Purpose: Nasal bone fracture is the most common type of facial bone fracture. The standard 6-view photography was not adequate to support the evaluation of nasal deformity and the results of closed reduction. The authors have standardized a bird's eye view photography to more effectively evaluate this nasal deformity. Methods: We reviewed the medical records and radiologic studies of 63 nasal bone fracture patients. We had taken clinical photography including bird's eye view that was standardized as nasal tip was aligned to Cupid's bow of upper lip and light was focused on the nasion of all 63 patients. Results: Nasal deviations and reductions were more noticeable on the newly standardized bird's eye view. This clinical photography was very useful to explain the results of reduction. Conclusion: It was concluded that this photography can be more reliable for evaluation of severity of nasal deformity and the result of closed reduction.

• The korean journal of orthodontics
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• v.52 no.6
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• pp.432-438
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• 2022

Objective: To compare crown-root angulations of the permanent maxillary anterior teeth in skeletal Class I, Class II, and Class III Korean malocclusion patients using cone-bean computed tomography (CBCT) images. Methods: Sixty CBCT images were collected from orthodontic patients archive based on skeletal Class I (0˚< A point-nasion-B point angle [ANB] < 4˚), Class II (ANB ≥ 4˚), and Class III (ANB ≤ 0˚) to have 20 samples in each group. Mesiodistal crown-root angulation (MDCRA) and labiolingual crown-root angulation (LLCRA) were evaluated after orientation of images. Crown-root angulations were compared among Class I, Class II, and Class III groups and among the maxillary anterior teeth in each group. Results: LLCRAs of the maxillary central incisor and the lateral incisor were significantly lower in Class III group than those in Class I group. However, those of the canine showed no significant differences among groups. MDCRAs of the maxillary anterior teeth did not significantly differ among groups either. Conclusions: Our results suggest that skeletal Class III malocclusion might affect LLCRA of the maxillary incisors, especially the central incisor.

• Imaging Science in Dentistry
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• v.44 no.3
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• pp.207-212
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• 2014

Purpose: This study aimed to investigate the deviation of landmarks from horizontal or midsagittal reference planes according to the methods of establishing reference planes. Materials and Methods: Computed tomography (CT) scans of 18 patients who received orthodontic and orthognathic surgical treatment were reviewed. Each CT scan was reconstructed by three methods for establishing three orthogonal reference planes (namely, the horizontal, midsagittal, and coronal reference planes). The horizontal (bilateral porions and bilateral orbitales) and midsagittal (crista galli, nasion, prechiasmatic point, opisthion, and anterior nasal spine) landmarks were identified on each CT scan. Vertical deviation of the horizontal landmarks and horizontal deviation of the midsagittal landmarks were measured. Results: The porion and orbitale, which were not involved in establishing the horizontal reference plane, were found to deviate vertically from the horizontal reference plane in the three methods. The midsagittal landmarks, which were not used for the midsagittal reference plane, deviated horizontally from the midsagittal reference plane in the three methods. Conclusion: In a three-dimensional facial analysis, the vertical and horizontal deviations of the landmarks from the horizontal and midsagittal reference planes could vary depending on the methods of establishing reference planes.

• The korean journal of orthodontics
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• v.43 no.6
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• pp.279-287
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• 2013

Objective: To investigate the dentoskeletal factors which may predict soft-tissue chin strain during lip closure. Methods: The pretreatment frontal and lateral facial photographs and lateral cephalograms of 209 women (aged 18-30 years) with Angle's Class I or II malocclusion were examined. The subjects were categorized by three examiners into the no-strain and strain groups according to the soft-tissue chin tension or deformation during lip closure. Relationships of the cephalometric measurements with the group classification were analyzed by logistic regression analysis, and a classification and regression tree (CART) model was used to define the predictive variables for the group classification. Results: The lower the value of the overbite depth indicator (ODI) and the higher the values of upper incisor to Nasion-Pogonion (U1-NPog, mm), overjet, and upper incisor to upper lip (U1-upper lip, mm), the more likely was the subject to be classified into the strain group. The CART showed that U1-NPog was the most prominent predictor of soft-tissue chin strain (cut-off value of 14.2 mm), followed by overjet. Conclusions: To minimize strain of the soft-tissue chin, orthodontic treatment should be oriented toward increasing the ODI value while decreasing the U1-NPog, overjet, and U1 upper lip values.

• Imaging Science in Dentistry
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• v.50 no.2
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• pp.105-115
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• 2020

Purpose: This study investigated the position of the hyoid bone and its relationship with airway dimensions in different skeletal malocclusion classes using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 180 participants were categorized based on the A point-nasion-B point angle into class I, class II, and class III malocclusions. Eight linear and 2 angular hyoid parameters(H-C3, H-EB, H-PNS, H-Me, H-X, H-Y, H-[C3-Me], C3-Me, H-S-Ba, and H-N-S) were measured. A 3-dimensional airway model was designed to measure the minimum cross-sectional area, volume, and total and upper airway length. The mean crosssectional area, morphology, and location of the airway were also evaluated. Data were analyzed using analysis of variance and the Pearson correlation test, with P values <0.05 indicating statistical significance. Results: The mean airway volume differed significantly among the malocclusion classes(P<0.05). The smallest and largest volumes were noted in class II (2107.8±844.7 ㎣) and class III (2826.6±2505.3 ㎣), respectively. The means of most hyoid parameters (C3-Me, C3-H, H-Eb, H-Me, H-S-Ba, H-N-S, and H-PNS) differed significantly among the malocclusion classes. In all classes, H-Eb was correlated with the minimum cross-sectional area and airway morphology, and H-PNS was correlated with total airway length. A significant correlation was also noted between H-Y and total airway length in class II and III malocclusions and between H-Y and upper airway length in class I malocclusions. Conclusion: The position of the hyoid bone was associated with airway dimensions and should be considered during orthognathic surgery due to the risk of airway obstruction.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.8 no.1
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• pp.49-61
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• 1978

A study was made to investigate a relationship existing in the dentoskeletal framework and the soft tissue profile around the face, and compare the sexual differences between boys and girls having the normal occlusion in the mixed dentition. The lateral cephalograms were composed of 67 boys aged 10.3 years and 68 girls aged 10.4 years, respectively. By means of the lateral cephalograms, both the hard-and soft tissue structures were simultaneously analyzed, measured and evaluated by introducing the several reference items: S-N plane, palatal plane, mandibular plane, N-A line and A-P line for the dentoskeletal structures and N’-P’line for the soft tissue, and the 21 measuring points for the both structures. The significant findings were as follows: 1. In general the boys showed the larger nasal component dimension than did the girls, but the length and height of nose(N’-Prn and NA-Prn) showed the significant sexual difference among those when evaluated statistically. 2. The lip-thickness was found to be minimal in the region of nasion, greater in the region of pogonion, and much greater in the region of point A in the both sexes, but the only thickness over point A(A-A’) showed the significant sexual difference statistically. 3. The upper and lower lip position were found to be located anteriorly to the esthetic line in the both sexes, but upper lip position showed the significant sexual difference when evaluated statistically. 4. The regions of nose and upper lip had a tendency not to be following the underlying skeletal profile.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.7-14
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• 2001

Purpose : The lateral cephalometric Korean norms of the skeletal and pharyngeal dimension were analyzed for the diagnosis of obstructive sleep apnea syndrome(OSAS). Materials and Methods : The lateral cephalometric radiographies were taken in male(n=53) and female(n=50), who had a normal profile, class I occlusion, normal ANB $(0{\sim}4^{\circ})$ and normal Wits $Appraisal(-4{\sim}0mm)$. The X-rays were traced by two oral and maxillofacial surgeons twice. The significant differences between male-female and examiners were tested. Results : The angle of mandibular line to Nasion-Sella line was $31.12^{\circ}/33.79^{\circ}$ (in male/in female, p=0.0018). The lower Gonion angle was $73.74^{\circ}/73.74^{\circ}(p=0.9978)$. The length of the soft palate was 36.93mm/34.35mm(p=0.0002). The pharyngeal airway space was 13.42mm/11.55mm at mandibular plane level(PAS(ML))(p=0.0025). The hyoid was placed inferiorly to mandibular plane 10.18mm/7.72mm(p=0.0051). The results from this study are to be used for the diagnosis of OSAS.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.58.1-58.8
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• 2019

Background: The aim of this study is to investigate the relationship between gender-specific and obesity-related airway anatomy in patients with obstructive sleep apnea (OSA) by using cephalometric analyses. Methods: We retrospectively evaluated 206 patients with suspected OSA undergoing polysomnography and anthropometric measurements such as body mass index, neck circumference, and waist-hip ratio. We checked lateral cephalometry to measure tissue landmarks including angle from A point to nasion to B point (ANB), soft palate length (SPL), soft palate thickness (SPT), retropalatal space (RPS), retrolingual space (RLS), and mandibular plane to hyoid (MPH). Results: Male with OSA showed significantly increased SPL (P = .006) compared with controls. SPL and MPH had significant correlation with apnea-hypopnea index (AHI) and central obesity. Female with OSA showed significantly increased ANB (P = .013) and SPT (P = .004) compared with controls. The receiver operating characteristic curves revealed that SPT in male and ANB and SPT in female were significant in model 1 (AHI ≥ 5) and model 2 (AHI ≥ 15). MPH was also significant for male in model 2. Conclusion: Male and female with OSA had distinct anatomic features of the upper airway and different interactions among soft palate, mandible, and hyoid bone.