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

• The korean journal of orthodontics
• /
• v.27 no.1
• /
• pp.65-78
• /
• 1997

This study was carried out in order to determine soft tissue response to incisor movement and mandibular repositioning and to determine feasibility of predicting vertical and horizontal changes in soft tissue with hard tissue movement. For this study, cephalometric records of 41 orthodontically treated adult females who had Angle's Class II division 1 malocclusion were selected and stepwise multiple regression analysis was employed. Following conclusions were obtained by analysing the changes of soft tissue and hard tissue before and after treatment. 1. Hard tissue measurements that showed significant changes before and after treatment were horizontal and angular changes of maxillary incisor, horizontal,vertical and angular changes of mandibular incisor, overjet, overbite, interincisal angle, mandibular repositioning, A,B, skeletal convexity and soft tissue measurements that showed significant changes were horizontal, thickness and angular changes of upper lip, horizontal and angular changes of lower lip, interlabial angle, nasolabial angle labiomental angle, Sri, Ss, Si and soft tissue convexity(P<0.05). 2. All Soft tissue measurements changed significantly before and after treatment had between one and four hard tissue independent variables at statistically significant level, indicating that all soft tissue changes were direct relationship with hard tissue changes 3. Ova jet, horizontal change of maxillary incisor, horizontal change of maxillary root apex and horizontal change of pogonion entered into prediction equations most frequentely indicating that they were more significant variables in prediction of vertical and horizontal changes in the soft tissue with treatment, but vertical changes of mandibular incisor not entered any prediction equations, indicating that it was not considered a good predictor for soft tissue changes with maxillary incisor retraction. 4. Horizontal and vertical changes in subnasale were found to have most independent variables, significant at the 0.05 level in prediction-equations(${\Delta}$Sn(H):Ur, Is(H), Pg(H), UIA,${\Delta}$Sn(V): Is(H), Pg(H), overjet, A), indicating that subnasale changes are influenced by complex hard tissue interaction. 5. Multiple correlation coefficient($R^2$) of the soft tissue prediction equations ranges from 0.2-0.6.

• The korean journal of orthodontics
• /
• v.29 no.2 s.73
• /
• pp.147-156
• /
• 1999

Skeletal Cl III malocclusion is an orthopedic appliance mainly used for growing children with maxillary undergrowth, which largely entails skeletal Cl III malocclusion. It improves anterior crossbite and maxillary position and thus, enables patients to attain favorable Profile but often involves unfavorable profile with protrusive upper and lower lips. Therefore, if orthodontists have knowledge of which condition helps obtain favorable occlusion and profile, they are able to predict the prognosis and limitation of the treatment. This study was done in order to help obtain favorable Profile after treating growing skeletal Cl III children. In the study, we classified childern into two groups, the one with favorable profile(Group 1, n=12) and the other with unfavorable profile(Group 2, n=14) and, with retrospective study using pre- and post-treatment lateral cephalogram, drew the following conclusions. 1. As patients had more serious labioversion of upper incisors, they were more unlikely to have favorable profiles after the treatment. Protrusion of prosthion, which was related with maxillary incisors, also affected profiles. 2. As the NL-ML angle before the treatment was small, it was more likely to get favorable profile. 3. As the degree of lower lip protrusion was high, it was likely to have bialveolar protrusion after the treatment. 4. As the degree of downward and backward rotation of mandible was high, it was likely to get unfavorable profile.

• The korean journal of orthodontics
• /
• v.26 no.5 s.58
• /
• pp.547-556
• /
• 1996

The purpose of this study was to evaluate the skeletal, dental and soft tissue profile changes following the face mask therapy in growing skeletal class III malocclusion patients. The fifteen patients with the good results were selected among the patients who visited the Department of Orthodontics in Seoul National University Hospital. The mean age was 10.63(range 7.25-13.25) years and the mean treatment duration was 9.84(range 2.00-27.00) months. Lateral cephalograms were taken just before and after face mask application. After tracing the cephalograms, thirty five items(twety angular and fifteen linear) were measured. The differences before and after the face mask therapy were compared statistically by the paired t-test(p<0.05). The results were as follows : SNA and Co-A(effective maxillary length) increased significantly after using the face mask(p<0.001), which reflects the orthopedic changes of maxilla. SNB and Co-Gn(effective mandibular length) also showed an increase(p<0.01), which may be a result of the strong growth trends of the samples. FMA, SN-GoGn and Y-axis angle increased significantly(p<0.01), which means the backward and downward rotation of the mandible. This positional change seemed to have compensated an increase of effective mandibular length. There was no statistically significant difference in angulation of upper and lower incisors between pre-treatment and post-treatment(p>0.05). In soft tissue profile, the upper lip was positioned anteriorly(p<0.01) after treatment and approximated to the normal standards.

• The Journal of Advanced Prosthodontics
• /
• v.15 no.6
• /
• pp.281-289
• /
• 2023

PURPOSE. This study aimed to predict the positional coordinates of incisor points from the scan data of conventional complete dentures and verify their accuracy. MATERIALS AND METHODS. The standard triangulated language (STL) data of the scanned 100 pairs of complete upper and lower dentures were imported into the computer-aided design software from which the position coordinates of the points corresponding to each landmark of the jaw were obtained. The x, y, and z coordinates of the incisor point (X_P, Y_P, and Z_P) were obtained from the maxillary and mandibular landmark coordinates using regression or calculation formulas, and the accuracy was verified to determine the deviation between the measured and predicted coordinate values. Y_P was obtained in two ways using the hamularincisive-papilla plane (HIP) and facial measurements. Multiple regression analysis was used to predict Z_P. The root mean squared error (RMSE) values were used to verify the accuracy of the X_P and Y_P. The RMSE value was obtained after crossvalidation using the remaining 30 cases of denture STL data to verify the accuracy of Z_P. RESULTS. The RMSE was 2.22 for predicting X_P. When predicting Y_P, the RMSE of the method using the HIP plane and facial measurements was 3.18 and 0.73, respectively. Cross-validation revealed the RMSE to be 1.53. CONCLUSION. Y_P and Z_P could be predicted from anatomical landmarks of the maxillary and mandibular edentulous jaw, suggesting that Y_P could be predicted with better accuracy with the addition of the position of the lower border of the upper lip.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.22 no.2
• /
• pp.206-216
• /
• 2000

Predictional study for lateral change between pre- and post-orthognathic surgery has been emphasized mainly on anterior area of lateral profile; upper lip, lower lip and chin et al. So interest for lateral profile change has been less in posterior area of lateral profile and literature analyzing gonial angle change is rare. The purpose of this study is to make prediction for gonial angle change possible and to offer somewhat treatment guidance for gonial angle to be improved by investigating overall gonial angle change between pre- and post-orthognathic surgery and inquiring into factors influencing on pattern of genial angle change. For this study 35 patients were selected retrospectively. Lateral cephalometric radiographs were taken in just pre-op time, pod 1 day, pod 1 year. They were analyzed and genial angles were measured. The results were as follows : 1. Gonial angle at pod 1 day was decreased about $9.3^{\circ}$ than pre-op and gonial angle at pod 1 year was increased about $4.0^{\circ}$ than pod 1 day. So genial angle at pod 1 year was decreased about $5.3^{\circ}$ than pre-op genial angle(p<0.01). 2. Mean pre-op gonial angle was $129.4^{\circ}$, showing significantly high value than normal and mean gonial angle at pod 1 year was $124.1^{\circ}$, showing value near to normal. 3. Mean gonial angle change between pre-op and pod 1 year was decreased about $5.4^{\circ}$ in female and $5.3^{\circ}$ in male. There was no statistically significant difference between male and female(p>0.05). 4. Principal factor influencing on decreased gonial angle in gonial angle change between pre-op and pod 1 year was amount of mandibular setback. 5. Principal factor influencing on increased gonial angle in gonial angle change between pod 1 day and pod 1 year was % horizontal relapse, and it was thought that resorption and bone remodelling on posterior area in mandibular distal segment also were related to increased gonial angle. 6. It is thought that sagittal split ramus osteotomy in mandibular prognathic patients with high value of gonial angle is effective to improvement of gonial angle, and In patients who have normal range of gonial angle and are required with excessive mandibular setback, short lingual cut method, additional resection of posterior margin of distal segment, Obwegeser II method will be considerd. 7. More prudent operation and careful post-op management will be responsible for maintenance of postoperative stable gonial angle.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.28 no.4
• /
• pp.600-612
• /
• 2001

The purpose of this study is concerned with an investigation of the actual condition of traumatic injuries of teeth and supporting structures in children to set up possible criteria for prevention and treatment of injured teeth. The materials consisted of the clinical records of 431 traumatically injured teeth of 212 children, accumulated during two years from the first of April in 1998 to the end of March in 2000, supplied from the Dept. of Pediatric Dentistry, Chonbuk National University Hospital. The incidence of injuries in boys was extremely high for permanent teeth, twice as high as in girls. Accidents to primary teeth were most common from 1 to 2 years of age and to permanent teeth were most from 8 to 9 years of age. The most common cause of trauma was a fall for both primary and permanent teeth, followed by collision. The anterior teeth in maxilla was most frequently affected by trauma in both the primary and permanent teeth. The most common type of trauma were loosening for the primary teeth, followed by luxation types which included the intrusion, displacement and extrusion and complete avulsion types. For the permanent teeth, the most common type of trauma were tooth fracture. The most common trauma of soft tissue was laceration of upper lip, lower lip and gingiva of maxilla Concerning treatment at the first visit, primary teeth with only loosening and concussion were not usually treated. Permanent teeth were often treated by crown restorations for crown fractures and by endodontic procedures for pulpal exposure. Though we could elucidate actual condition of traumatic injuries of teeth in children, we should make a follow-up survey to ensure the prognosis of injured teeth and establish the most desirable criteria for traumatized teeth in children.

• The korean journal of orthodontics
• /
• v.47 no.6
• /
• pp.375-383
• /
• 2017

Objective: The purpose of this study was to evaluate the dental and skeletal effects of the modified C-palatal plate (MCPP) for total arch distalization in adult patients with Class II malocclusion and compare the findings with those of cervical pull headgear. Methods: The study sample consisted of the lateral cephalograms of 44 adult patients with Class II Division 1 malocclusion, including 22 who received treatment with MCPP (age, $24.7{\pm}7.7years$) and 22 who received treatment with cervical pull headgear (age, $23.0{\pm}7.7years$). Pre- (T1) and post-treatment (T2) cephalograms were analyzed for 24 linear and angular measurements. Multivariate analysis of variance was performed to evaluate the changes after treatment in each group and differences in treatment effects between the two groups. Results: The mean amount of distalization at the crown and root levels of the maxillary first molar and the amount of distal tipping was 4.2 mm, 3.5 mm, and $3.9^{\circ}$ in the MCPP group, and 2.3 mm, 0.6 mm, and $8.6^{\circ}$ in the headgear group, respectively. In addition, intrusion by 2.5 mm was observed in the MCPP group. In both groups, the distal movement of the upper lip and the increase in the nasolabial angle were statistically significant (p < 0.001). However, none of the skeletal and soft tissue variables exhibited significant differences between the two groups. Conclusions: The results of this study suggest that MCPP is an effective treatment modality for total arch distalization in adults.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.32 no.6
• /
• pp.544-550
• /
• 2010

Purpose: The result of all malignant neoplasms including oral cancer is decided by long-term prognosis. However, until now, there are only a few reports about long-term prognosis of cancer secluded in the oral cavity. So, we investigated all patients that visited our clinic for oral squamous cell carcinoma (SCCa) for the last 10 years. From this survey, we hope to find important factors that influence prognosis of the disease. Patients and Methods: A retrospective study was performed for patients that visited the oral oncology clinic for oral cancers from Jan. 2001 to Feb. 2010. We selected the patients that were diagnosed with SCCa and received curative treatment. In these patients, we investigated basic epidemiology, smoking history, body mass index, recurrence rate, treatment methods, pathologic data and 5-yr survival rate. Results: There was a total of 185 patients (115 males, 70 females and mean age: 57.3 years) that visited the oral oncology clinic for oral SCCa. Areas of primary lesion were tongue (105 cases, 57%), lower gum (19 cases, 10%), floor of mouth (16 caess, 8%), retromolar trigone (12 cases, 6.5%), and buccal cheek (11 cases, 6%). Other involved areas were upper gum, palate, lip, and salivary glands-of 1 case each. The overall 5-year survival rate was 63.7%. The factors that influenced prognosis of the disease were stage of the disease, status of differentiation, recurrence, metastasis of cervical lymph node and age. Conclusion: The factors that influence prognosis of disease are stage of the disease, status of differentiation, recurrence, metastasis of cervical lymph node and age. To point out a current trend, the mean age of patients that developed oral cancer was lower than that of before. Secondly, the prevalence of oral cancer in non-smoker are on the rise. Thus, further studies on etiology and epidemiology should be done.

• Journal of Yeungnam Medical Science
• /
• v.10 no.1
• /
• pp.37-47
• /
• 1993

It is commonly assumed that nasorespiratory function can exert a dramatic effect upon the development of the dentofacial complex. Specially, it has been stated that chronic nasal obstruction leads to mouth breathing, which causes altered tongue and mandibular positions. If this occurs during a period of active growth, the outcome is development of the "adenoid facies". Such patients characteristically manifest a vertically long lower third facial height, narrow alar bases, lip incompetence, a long and narrow maxillary arch and a greater than normal mandibular plane angle. But several authors have reported that so-called adenoid facies is not always associated with adenoids and mouth breathing, and that a particular type of dentition is not always found in mouth breathers with or without adenoids. Some authors have believed adenoids lead to mouth breathing in cases with particular facial characteristics and types of dentition. We assumed that the ability to adapt to individual's neuromuscular complex is various. So, we compared the difference of influence of mouth breathing between childrens who have different facial types. This study included 60 patients and they were divided into three groups by Rickett's facial type. Their dentition and tongue position were compared. The results are as follows. 1. There is a significant difference in arch width of upper molars between different facial types. Especially dolichofacial type patients have narrowest arch width. 2. There is a significant difference in tongue position between different facial types. Especially dolichofacial type patients have lowest positioned tongue.