• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.14-29
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• 2006

Developments in computer technology have made possible the 3-dimensional (3-D) evaluation of hard and soft tissues in orthodontic diagnosis, treatment planning and post-treatment results. In this study, Korean adults with normal occlusion (male 30, female 30) were scanned by a 3-D laser scanner, then 3-D facial images formed by the Rapidform 2004 program (Inus Technology Inc., Seoul, Korea.). Reference planes in the facial soft tissue 3-D images were established and a 3-D coordinate system (X axis-left/right, Y axis-superior/inferior, Z axis-anterior/posterior) was established by using the soft tissue nasion as the zero point. Twenty-nine measurement points were established on the 3-D image and 43 linear measurements, 8 angular measurements, 29 linear distance ratios were obtained. The results are as follows; there were significant differences between males and females in the nasofrontal angle $(male:\;142^{\circ},\;female:\;147^{\circ})$ and transverse nasal prominence $(male:\;112^{\circ},\;female:\;116^{\circ})$ (p<0.05). The transverse upper lip prominence was $107^{\circ}$ in males, $106^{\circ}$ in females and the transverse mandibular prominence was $76^{\circ}$ in both males and females. Li-Me' was 0.4 times the length of Go-Me'(mandibular body length) and the mouth height was also 0.4 times the width of the mouth width. The linear distance ratio from the coronal reference plane of FT, Zy, Pn, ULPm, Li, Me' was -1/-1/1/0.5/0.5/-0.6 respectively. The 3-D facial model of Korean adults with normal occlusion were be constructed using coordinate values and linear measurement values. These data may be used as a reference in 3-D diagnosis and treatment planning for malocclusion and dentofacial deformity patients and applied for 3-D analysis of facial soft tissue changes before and after orthodontic treatment and orthognathic surgery.

• Archives of Plastic Surgery
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• v.40 no.4
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• pp.433-439
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• 2013

Background Facial beauty depends on the form, proportion, and position of various units of the face. In terms of the frontal view and facial profile, the chin is the most prominent aesthetic element of the lower third of the face. Many methods have been implemented to obtain good proportions of the lower face. In this study, we applied the T-shaped genioplasty method to correcting chin deformities. Methods All of the procedures in 9 cases were performed under general anesthesia. For genioplasty, a horizontal cutting line and 1 or 2 vertical cutting lines were drawn 5 mm below the mental foramen. Osteotomed bone segments of the chin were used for horizontal widening using bone grafts or for horizontal shortening. Likewise, they were used as bone grafts for vertical lengthening or vertical shortening. The bone segments were approximated in the midline and held in place using miniplates. Results The postoperative appearance of the 9 cases showed that the lower third of the face had been naturally changed. At the same time, vertical lengthening or shortening, and horizontal widening or shortening could be implemented during the operation. Satisfactory results were obtained based on reviews of the patients' preoperative and postoperative photographs. The patients were also satisfied with the outcomes. Conclusions Using T-shaped genioplasty, we efficiently adjusted the shape and position of the chin to obtain good proportions of the lower face and change its contour to obtain an aesthetically appealing oval face in accordance with East Asians' aesthetic preferences.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.197-204
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• 1996

This study was performed to mark the criteria of the eathetic smile that was necessary to improve the esthetic problem in oral maxillo-facial region. The facial straight photographs of 62 adults(30 males, 32 females : 19-24 years old) in resting position and during smile were taken. The measurements and proportion of lip-teeth relationship during smile were statistically analyzed with photogrammetry. The following results wow obtained : 1. In the evaluation of the change of lips, smile line ratio was 0.93, buccal corridor ratio was 0.63, and smile symmetry ratio was 0.96. 2. The width of mouth during smile was 1.31 times of the width inthe resting position and 0.48 times of face width. 3. The upper lip height during smile was 0.69 times of the height in the resting position and the lower lip height during smile was 0.93 times of the height in the resting position. 4. The mean exposed lenght of upper central incisor was 9.96mm. Maxillary incisor exposure was significantly correlated with the upper lip change ratio, mouth width change ratio, and buccal corridor ratio.

• The korean journal of orthodontics
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• v.46 no.3
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• pp.137-145
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• 2016

Objective: The purpose of this study was to investigate the characteristics of orthodontic patients at Yonsei Dental Hospital from 2008 to 2012. Methods: We evaluated Angle's classification from molar relationships, classification of skeletal malocclusion from the A point-nasion-B point angle, facial asymmetry, and temporomandibular joint disorders (TMDs) from the records of 7,476 patients who received an orthodontic diagnosis. The orthognathic surgery rate, extraction rate, and extraction sites were determined from the records of 4,861 treated patients. Results: The patient number increased until 2010 and gradually decreased thereafter. Most patients were aged 19-39 years, with a gradual increase in patients aged ${\geq}40years$. Angle's Class I, Class II divisions 1 and 2, and Class III malocclusions were observed in 27.7%, 25.6%, 10.6%, and 36.1% patients, respectively, with a gradual decrease in the frequency of Class I malocclusion. The proportion of patients with skeletal Class I, Class II, and Class III malocclusions was 34.3%, 34.3%, and 31.4%, respectively, while the prevalence of facial asymmetry and TMDs was 11.0% and 24.9%, respectively. The orthognathic surgery rate was 18.5%, with 70% surgical patients exhibiting skeletal Class III malocclusion. The overall extraction rate among nonsurgical patients was 35.4%, and the maxillary and mandibular first premolars were the most commonly extracted teeth. Conclusions: The most noticeable changes over time included a decrease in the patient number after 2010, an increase in the average patient age, and a decrease in the frequency of Angle's Class I malocclusion. Our results suggest that periodic characterization is necessary to meet the changing demands of orthodontic patients.

• Journal of Dental Rehabilitation and Applied Science
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• v.19 no.3
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• pp.247-256
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• 2003

The patient had bruxism and epilepsy tendency. Inadequate or unstable posterior support was identified due to severe anterior attrition and decreased occlusal vertical dimension. Prematurities of posterior occlusal and wear facets increased the function of anterior teeth, resulting in severe wear. Wear facets displayed sharply defined peripheries, which are matched on articulated diagnostic casts. Also the patient showed C III malocclusion tendency, and lost some facial contour with drooping corners on the mouth. In this case, the alteration of OVD (Occlusal Vertical Dimention) may provide a biologically compatible adjunct to the treatment such as dentofacial esthetics, improved visual proportion in facial heightand mechanical solutions to the force-management of the masticatory system. The patient requires extensive restorative treatment to regain appropriate function, esthetics and comfort. According to the report by Farhad Fays, the average vertical distance from the maxillary to the mandibular mucolabial reflection in the region of the central incisors is approximately 34mm. However, the vertical distance of this patient was found to be 32mm, which was necessary to add gauge 20-sheets to apply vertical dimension. A removable occlusal overlay splint, which restores OVD to the estimated optimalposition, is the general first trial. The patient was observed periodically for 6 weeks, while appropriate adjustments were made vertical dimension to function. When patient felt comfortable with the splint, the teeth were prepared, and provisional restorations are placed for 3 months. The provisional restoration was fabricated by a diagnostic wax-up. When the patient felt comfortable with the provisional restoration, the final restoration mimics OVD, function, and esthetics that have been developed in the treatment restorations. Restoration of the extremely worn dentition presents a substantial challenge to thedentists. Therefore, careful evaluation of the etiology, history, and factors associated with occlusal vertical dimension should be preceded prior to the appropriate treatment planning.

• Archives of Craniofacial Surgery
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• v.22 no.2
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• pp.99-104
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• 2021

Background: To fight the coronavirus disease 2019 (COVID-19) pandemic, many countries have implemented social distancing and lockdowns. We investigated the changes in the trauma patterns of emergency plastic surgeries in the midst of a pandemic. Methods: A retrospective review of the medical records of all patients treated for emergency plastic surgeries was performed at our hospital in Seoul. We conducted the analysis between March 1 and June 30, 2020, and compared the data obtained with that of the same period in 2019. We also investigated changes in trauma patterns according to the social distancing level from July 2020 to February 2021. Results: There was a total of 800 emergency plastic surgery patients from March to June 2020, which was less than the 981 in the corresponding period in 2019. The proportion of patients aged 7-17 years and ≥ 80 in 2020 showed a significant decrease. In 2020, patients presenting with facial trauma decreased and hand trauma, markedly laceration, increased significantly. In 2020, more injuries happened at home, whereas significantly fewer injuries happened on the streets. In 2020, slipping and sports injury decreased, whereas penetrating injury increased significantly. In the changes observed according to the social distancing level, there were significant differences in age classification, facial open wound, and the mechanism of injury. Conclusion: Social distancing has caused a change in emergency plastic surgeries. To ensure safe and appropriate treatment, strict epidemiologic workup and protective equipment are required.

• Archives of Craniofacial Surgery
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• v.19 no.4
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• pp.270-274
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• 2018

Background: Nasal bone fractures occur frequently because the nasal bone is located at the forefront of the face. The goal of this study was to examine the cause, change in severity, change in incidence, and demographics of nasal bone fracture according to today's lifestyle. Methods: A total of 2,092 patients diagnosed as having nasal bone fractures at our department between 2002 and 2017 were included in this study. We retrospectively examined patients' medical records to extract information regarding age, sex, cause of injury, combined facial bone fractures, and related injuries such as skull base fracture, spinal cord injury, brain hemorrhage, and other bone fractures. Fracture severity was classified by nasal bone fracture type. Results: No statistically significant difference was found in annual number of patients treated for nasal bone fracture. The proportion of patients who underwent closed reduction was significantly decreased over time for those with nasal bone fractures caused by traffic accidents. However, it was not significantly changed for those with nasal bone fractures due to other causes. The number of patients with combined facial bone fractures increased over time. Incidences of severe nasal bone fracture also increased over time. Conclusion: The study suggested that there is a decrease in the frequency and increase in the severity of nasal bone fracture due to traffic accident. Many protective devices prevent nasal bone fractures caused by a small amount of external force; however, these devices are not effective against higher amounts of external force. This study highlights the importance of preoperative thorough evaluation to manage patients with nasal bone fractures due to traffic accident.

• Korean Journal of Cognitive Science
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• v.20 no.1
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• pp.51-77
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• 2009

Using a modified Posner's cue-target paradigm, we investigated whether negative cues attract more attention than neutral cues in anxious people. Previous studies used commonly an unbalanced proportion of valid and invalid trials(75% vs. 25% respectively). But in the present study, an equivalent proportion of valid and invalids trials was used for measuring detection speed of cues without participant's expectancy caused by the unbalanced proportion. Emotional words(Experiment 1) and facial expressions(Experiment 2) were used as cues for target locations. The result of Experiment 1 and 2 showed that threatening cues facilitated target detection in valid trials and interfered with it in invalid trials in anxious participants and a, reverse response patterns were found in non-anxious participants. This indicates that threatening cues attract more attention to the cued location in anxious people and in contrast, non-anxious people avoid threatening stimuli. In Experiment 3, we investigated the difference of validity effect across anxiety levels. The results showed that anxious participants gave less attention to cued location when the cues were non-informative whereas non-anxious participants gave more attention to cued locations in the same condition. We discussed two kinds of cognitive bias caused by anxiety levels: attentional bias and proportion related bias.

• The korean journal of orthodontics
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• v.17 no.2
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• pp.165-183
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• 1987

The purpose of this study is to investigate the cephalo-facio-dental relationships in the craniofacial complex and their changes with age, and to use them for diagnostic and treatment purposes in the orthodontics The author studied on the changes of the cephalo-facio-dental relationships, using serial lateral cephalometric roentgenograms of 46 boys and 47 girls aged from 6 to 11 years of normal Korean children Following results were obtained 1 Means and Standard deviation of Korean children were obtained. 2 In the evaluation of the craniofacial vertical proportions, lower anterior face was larger than the upper, and upper posterior face was larger than the lower at all ages 3 The growth change was more prominent in the anterior craniofacial vertical proportion than in the posterior, and growth increment in the upper anterior facial height dimension was larger than m the lower anterior. 4 In the evaluation of the craniofacial horizontal proportion, ANS, Pog, Go and 6 were all situated posterior to their reference ares, and point B was always situated anterior to the arc passing by point A. 5. Anteroposterior growth change was the most prominent in the mandible, and there was no significant difference between the horizontal growth increment in the cranial base and that in the maxilla 6 Growth increment in the horizontal direction was larger in the mandibular apical base than in the maxillary apical base 7 The upper central incisor and the upper first molar were gradually anterior positioned against their reference ares with age increase 8 The length of mandibular corpus was larger than that of cranial base from the seven years old, and the difference was increased as the age increased 9 With age, there was slight difference in the angular relationships formed by craniofacial reference planes and axial inclinations of upper and lower permanent teeth.

• The korean journal of orthodontics
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• v.49 no.4
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• pp.222-234
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• 2019

Objective: To investigate the three-dimensional lip vermilion changes after extraction and non-extraction orthodontic treatment in female adult patients and explore the correlation between lip vermilion changes and incisor changes. Methods: Forty-seven young female adult patients were enrolled in this study (skeletal Class III patients were excluded), including 34 lip-protruding patients treated by extraction of four first premolars (18 patients requiring mini-implants for maximum anchorage control and 16 patients without mini-implants) and 13 patients requiring non-extraction treatment. Nine angles, seven distances, and the surface area of the lip vermilion were measured by using pre- and post-treatment three-dimensional facial scans. Linear and angular measurements of incisors were performed on lateral cephalograms. Results: There were no significant changes in the vermilion measurements in the non-extraction group. The vermilion angle, vermilion height, central bow angle, height/width ratio, and vermilion surface area decreased significantly after the orthodontic treatment in the extraction groups, but the upper/lower vermilion proportion remained unchanged. Significant correlations were found between the changes in incisor position and those in vermilion angles, vermilion height, and surface area. Conclusions: Extraction of the four first premolars probably produced an aesthetic improvement in lip vermilion morphology. However, the upper/lower vermilion proportion remained unchanged. The variations in the vermilion were closely related to incisor changes, especially the upper incisor inclination changes.