• The korean journal of orthodontics
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• v.25 no.6 s.53
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• pp.665-674
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• 1995

The purpose of this study is to investigate the cephalometric characteristics of the open-bite patients with DJD of TMJ. The DJD open-bite cases were compared with normal samples and Class II open-bite cases with normal TMJ respectively. Twenty three open-bite patients with bilateral DJD of TMJ($13.9\~35.3$ yens old, Group I) were selected from the Department of Orthodontics, SNUDH. Group ll consisted of thirteen Class II open-bite cases($13.2\~27.4$ years old) with no TMD signs/symtoms and good condylar shapes. Group III samples were the forty eight healthy dental students who have Class I molar relationships with no history of orthodontic treatment, good facial balance and no TMD symptoms($20.0\~26.8$ years old). First, sixty measurements in the lateral cephalometric radiographs and analysis of variance(P<0.05, Scheffe) were used to compare these three groups. The seven measurements showed significant difference(p<0.05) between Group I and Group II. After analysis of variance, six of them were used for the discriminant analysis(Wilks' stepwise analysis) and the discrminant function for Group I/Group II was obtained. The results and conclusions were as follows : In most of the measurments, Group I and Group II showed the same skeletal and dental characteristics. But seven of the sixty measurements(FH-PP angle, SNB, FH-ArGo angle, articulare angle, genial angle, upper gonial angle and Ar-Go length) were significantly different(p<0.05) between Group I and Group II. These differences may be explained by the fact that in DJD cases the mandible rotated backward due to the shortening of the ramus following the degenerative destruction of condylar head and its surrounding structures. The resulting discriminant function was : $D={-0.120X}_1+{0.066X}_2+{0.144X}_3-{0.058X}_4+2000,\;where\;X_1=ArGo\;length(mm),\;X_2=SArGo\;angle(degree),\;X_3=FH-PP\;angle(degree),\;X_4=Gonial\;angle(degree)$. Mean of the group centroids was -0.555 and percent of the 'grouped' cases correctly classified was $88.89\%$.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.17 no.1
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• pp.89-106
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• 1987

The author obtained individualized lateral cephalometric tomograms from 23 young adults (46 of left and right normal TMJ) with normal occlusion and 20 patients (14 of patient asymptomatic TMJ and 26 of patient symptomatic TMJ) with clicking and painful TMJ after the analysis of submental vertex view. Individualized lateral cephlometric tomogram analysis and TMJ space analysis were performed after tracing each film. All data from these analysis was recorded and statistically processed with CYBER computer system. 1. The results were obtained as follows. In submental vertex view, the mean condylar angulation of Rt. side in normal group was 20.348°±6.358°, Lt. side was 18.870°±7.777° and Rt. side in patient group was 19.350°±7.576° Lt. side was 17.750°±6.146° respectively. The mean condylar angulation of Rt. side was larger than Lt. side in normal and patient group. 2. When the mandible was moved from centric occlusion to centric relation, condylar position relating to the glenoid fossa was placed posteriorly and superiorly in normal TMJ group and patient symptomatic TMJ group. 3. In centric relation position, the proportion of anterior space to posterior space was 1.593 for normal TMJ group, 1.604 for patient asymptomatic TMJ group and 1.671 for patient symptomatic TMJ group. In centric occlusion position, 1.390 for normal TMJ group, 1.539 for patient asymptomatic TMJ group and 1.196 for patient symptomatic group. Normal TMJ group, patient asymptomatic TMJ group and patient symptomatic TMJ group and patient symptomatic TMJ group revealed significant difference in ∠C₂ measurement. (ANOVA-test, p<0.05) 5. Normal group and patient group revealed significant difference in Fh, ∠C₁and ∠C₂ measurement. (T-test, p<0.05) 6. There were strong positive correlation (0.8771) between Fp and Fm, and strong negative correlation (-0.9039) between ∠C₂ and ∠C₁ from the lateral cephalometric tomogram analysis.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.218-230
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• 1999

Background: Craniofacial anatomic abnormalities related to structural narrowing of the upper airway have been reported in patients with obstructive sleep apnea syndrome. In this study, we evaluated the craniofacial anatomic characteristics of Korean patients with obstructive sleep apnea syndrome, and the role of cephalometric analysis in the prediction of abnormal breathing during sleep. Methods: Thirty-nine patients with obstructive sleep apnea syndrome(OSAS), 39 simple snorers(simple snorers) and 20 controls(control) had cephalometric analysis using the technique of Riley et al, and underwent standardized polysomnographic recordings. Different variables, including sex, body mass index, cephalometric and polysomnographic data, were statistically analyzed. Results: Pm-UPW and V-LPW distances were significantly shorter in OSAS when compared with simple snorers or control. PAS in simple snorers was shorter than in control. ANS-Gn distance in OSAS was significantly longer than in control. PNS-P distance in OSAS or simple snorers was significantly longer than in control. MP-H distance in OSAS was significantly longer than in simple snorers or control and MP-H distance in simple snorers was also longer than in control. NL/Pm-P angle in OSAS was lesser than in control. MP-H distance in OSAS or in the combined groups of OSAS and simple snorers was significantly correlated with apneahypopnea index(AHI). PNS-P distance in the combined groups of OSAS and simple snorers was correlated with AHI. In male of all subjects, body mass index was significantly correlated with PNS-P or MP-H distance. Conclusion: Cephalometric analysis can be useful tool in determining the craniofacial anatomic abnormalities in patients with obstructive sleep apnea syndrome. Cephalometric parameters, especially MP-H distance, can be useful for predicting frequency of narrowing or obstruction of upper airway during sleep.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.327-340
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• 1985

This study was performed to establish the Cephalometric standards and growths change of Korean Teen aged group by McNamara's Analysis. The data from Cephalometric films of 161 male and 205 female subject aged from 10 to 18 years of Normal Korean were used for this study. The following results were obtained: 1. Means, standard deviation from measured values in each age group and sexual values were obtained. 2. Greater measurement stowed in male than female in Condylion to point A, Condylion to Gnathion, MaxilloMandible differential and ANS to mouton in linear measurement of 18 age group. 3. Condylion to point A, Condylion to gnathion, MaxilloMandible differential and ANS to Menton are increased as the age increased. 4. Facial axis angle and Mandible plane angle of 15 and 18 aged group showed less value than that of 10,11,12 age group. 5. There was no significant value changes of Lower incisor to A-Po, SNA angle and Lower pharynx by the increasing of age.

• The korean journal of orthodontics
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• v.18 no.1 s.25
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• pp.127-139
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• 1988

Esthetic is one of the prime goal of the orthodontic treatment. It is represented by the word of harmony or balance. There is no absolute esthetic norm but it is important to study about it in orthodontic and orthognatic surgical treatment planning. The purpose of this study is to obtain the norm of Korean female adolescents who were candidates of 1986, 1987 Miss Korea Beauty Contest. The 77 individual samples were selected and studied by cephalometric analysis. Obtained results were as follows: 1 Korean esthetic norm was obtained. 2. Simple correlation coefficient was obtained between each measurements. 3. Holdaway ratio of Korean beauty was 3.3 : 1. 4. To compare with caucasian, profile of Korean beauty had less prominant nose, more prominant lip and deeper sulcus depth.

• The korean journal of orthodontics
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• v.41 no.1
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• pp.42-50
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• 2011

Objective: The purposes of this study were to establish cephalometric norms of Mongolian adults, which have not previously been reported in orthodontic journals, and to compare them with cephalometric norms of Korean adults. Methods: Lateral cephalometric radiographs of 74 Mongolian adults (35 men, 39 women) and 95 Korean adults (52 men, 43 women) with normal occlusions and well-balanced lateral profiles were obtained. The subjects were chosen by orthodontists of the same ethnic background. Forty craniofacial variables were measured, and groups were compared by analysis of covariance. Results: The cephalometric norms for male and female Mongolian and Korean adults with normal occlusions and well-balanced lateral profiles were established. Sexual dimorphism was found in linear skeletal measurements and vertical skeletal relationships. Compared with Korean adults, Mongolian adults had shorter anterior facial height, more prominent chins, and more upright upper incisors. There were few differences in soft tissue measurements. The differences were statistically significant, but their clinical importance may be limited. Conclusions: Cephalometric differences can be considered, but little difference may exist in the orthodontic diagnosis and treatment planning of Mongolian and Korean adults.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.2
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• pp.184-199
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• 1996

The challenges to achieve three dimensional facial proportionality and occusal stability in many patients with complex dentofacial deformity have been met by the development and use of the maxilla, mandible, and chin surgery techniques in combination with efficient orthodontic treatment. There is a clinical, biological, and biomechanical foundation for simultaneous surgical repositioning of the maxilla, mandible, and chin in a significant proportion of adult and adolescent patients. A combination of the surgical and orthodontic approach may provide increased treatment efficiencies and optimal esthetic results. Art and science to determine the treatment objectives, specifically, the desired soft tissue changes are firstly established by using the clinician's "esthetic sense" of the facial beauty and proportion aided to a few cephalometric guidelines. In this sense, the dependence on the clinician's "esthetic eye" by Dr. Bell is more important in analyzing the facial proportion than the satisfaction of rigid cephalometric norms. The purpose of this article was to elucidate the indication for simultaneous surgical repositioning of the maxilla, mandible, and chin, and to describe the clinical cephalometric analysis for orthognathic surgery. Representative 6 case reports were presented and discussed to illustrate the esthetic, orthodontic, and surgical treatment objectives with long-term follow-up.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.3
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• pp.463-469
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• 1996

Sonoring is caused by the repeated obstructions of versatile upper air way structure during sleep and is known as a kind of disease entity varing from simple snoring to obstructive sleep apnea syndrome(OSAS) which can cause serious cardiopulmonary complications due to its hypoxic pathophysiology. It has been reported that over 30% of middle-aged person have the problems of snoring and its accompanied symptomes and signs. Cephalometric measurements, frequently used to measure sella-nasion-subspinale(SNA) and sella-nasion-supramentale(SNB) angles, can provide the informations about the posterior airway space(PAS), the mandibular plane(MP) and the position of hyoid bone. These informations are useful in determining the therapeutic modalities of the snoring and OSAS patients. However, with conventional routine upright position, it does not represent the actual images of obstructive mechanism during sleep but only show the images of awaken normal upper airway anatomy. Therefore we have taken dual images of a routine upright lateral and a supine cephalometric view to compare both.

• Imaging Science in Dentistry
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• v.37 no.1
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• pp.19-26
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• 2007

Purpose : To examine whether the maxillofacial skeletal morphology correlates with the condylar position and the anatomic characteristics of articular eminence using measurements of lateral cephalometric radiographs and individualized sagittal temporomandibular joint (TMJ) tomographs. Materials and Methods : I compared measurements of 202 TMJs of 101 orthodontic patients of Kangnung National University Dental Hospital. 1 used Pearson's correlation for comparison of the measuring values in lateral cephalometric radiographs and individualized sagittal TMJ tomographs. Results : Large occlusal plane angle tendency showed decreased width of posterior eminence slope, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large mandibular plane angle tendency showed decreased superior joint space, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large genial angle tendency showed decreased depth of articular fossa, decreased posterior slope angle of eminence and anterior position of condylar head. Large anterior facial height and large posterior facial height tendency showed increased width of posterior slope of eminence, increased depth of articular fossa, increased posterior slope angle of eminence and posterior position of condylar head. Conclusion : Maxillofacial skeletal morphology has correlation with the anatomic characteristics of TMJ. Individualized sagittal TMJ tomographs can provide useful information for anatomical analysis of TMJ.

• Imaging Science in Dentistry
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• v.52 no.3
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• pp.239-244
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• 2022

Purpose: Despite the proliferation of numerous morphometric and anthropometric methods for sex identification based on linear, angular, and regional measurements of various parts of the body, these methods are subject to error due to the observer's knowledge and expertise. This study aimed to explore the possibility of automated sex determination using convolutional neural networks(CNNs) based on lateral cephalometric radiographs. Materials and Methods: Lateral cephalometric radiographs of 1,476 Iranian subjects (794 women and 682 men) from 18 to 49 years of age were included. Lateral cephalometric radiographs were considered as a network input and output layer including 2 classes(male and female). Eighty percent of the data was used as a training set and the rest as a test set. Hyperparameter tuning of each network was done after preprocessing and data augmentation steps. The predictive performance of different architectures (DenseNet, ResNet, and VGG) was evaluated based on their accuracy in test sets. Results: The CNN based on the DenseNet121 architecture, with an overall accuracy of 90%, had the best predictive power in sex determination. The prediction accuracy of this model was almost equal for men and women. Furthermore, with all architectures, the use of transfer learning improved predictive performance. Conclusion: The results confirmed that a CNN could predict a person's sex with high accuracy. This prediction was independent of human bias because feature extraction was done automatically. However, for more accurate sex determination on a wider scale, further studies with larger sample sizes are desirable.