• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.323-335
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• 1998

Clinically, the curve of Spee is widely applied as a determined level of the occlusal curvature when the oral rehabilitation and the reconstruction of the prosthesis is needed at the malalignment dentition due to the missing, extrusion, and the inclination of the teeth. The purpose of this study was to analyze the curve of Spee of the occlusal curvature which influences to the occlusal form and the location three dimensionally, and then was to measure the radius and the degree of curvature of the curve of Spee and also was to investigate the influence to the cuspal inclination according to the change of the inclination of the curve of Spee which was analyzed by AutoCAD R.13 program at the gnathological cast and the cephalometric radiograph. The following results were obtained : 1. The radius of the curve of Spee was the mean of $11.74{\pm}3.64cm$ in the model, $12.75{\pm}4.63cm$ in the radiograph and there was no significant difference statistically between the model and the radiograph(P>0.001). 2. The radius and the degree of curvature of the curve of Spee showed negative correlation(r=-0.80), while the radius and the degree of curvature of the curve of Spee in relation to the length of the curve of Spee did not show correlation. 3. The case of the curve of Spee inclined to the posterior, that is. $Post.M{\theta}$ group showed the mean of $4.73{\pm}3.64$, positive correlation to the P2m, M1mm, M1dm, M2dm, and especially the greatest correlation coefficient to the mesial inclination angle of the mesio-buccal cusp tip of the first molar(r=0.70). 4. The case of the curve of Spee inclined to the anterior, that is, $Ant.M{\theta}$ group showed the mean of $3.28{\pm}3.59$, positive correlation to the P2m, M1mm, and also the greatest correlation coefficient to the mesial inclination angle of the mesio-buccal cusp tip of the first molar(r=0.78

• Journal of Oral Medicine and Pain
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• v.34 no.3
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• pp.247-256
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• 2009

The purpose of this study was to investigate the changes of the pharyngeal space when the following appliances were inserted: the mandibular advancement appliance (MAA), tongue retaining appliance (TRA), and mandibular advancement-tongue retaining appliance (MATRA). Nine male dental students exhibiting Class I occlusion, normal body mass index (BMI), and no signs and symptoms of snoring were selected for this study. The three kinds of snoring appliances (MAA, TRA and MATRA) were fabricated for each subject. The mandibular advancement of the MAA and MATRA was set at a distance of 5 mm, and the TRA and MATRA were made to hold the tongue in front of the maxillary incisors by 10 to 20 mm. Lateral cephalometric radiographs of the following four states - with no appliance, MAA, TRA, and MATRA - were taken to examine any anatomical changes resulting from the application of the appliances. All four radiographs were traced and analyzed for twenty selected variables related to the pharyngeal space, cranio-cervical posture, and position of the soft palate and hyoid bone. According to the results of this study, there were significant increases in both the upper and lower oropharyngeal spaces when the mandible and tongue were protruded simultaneously, although there was a significant increase only in upper oropharyngeal space when the mandible or tongue was advanced separately. In conclusion, it is suggested that the MATRA may result in more positive effect on the control of snoring and OSA compared to a single use of the MAA or TRA, especially for the patients whose upper airway obstruction occurs in the lower oropharynx.

• Journal of Oral Medicine and Pain
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• v.34 no.3
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• pp.277-294
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• 2009

The purpose of this study was to evaluate the soft tissue changes of class II adolescents and adults in respect to extraction or nonextraction. The study included 68 patients from Wonkwang Dental Hospital were categorized to adolescent extraction group, adolescent nonextraction group, adult extraction group, adult nonextraction group. Cephalometric tracing of each patient was done to compare pretreatment and posttreatment of each group, to compare the changes between groups. And among the variables that showed significancy, correlation analysis and simple linear regression were done. The results were as follows. 1. In both adolescents and adults after extraction treatment, nasolabial angle significantly increased and in both subjects after non extraction treatment, nasolabial angle significantly decreased. 2. In extraction subjects, there were positive correlation between the amount of treatment changes of vertical-U1 and E line-upper lip, the changes of vertical-L1 and E line-lower lip, the changes of vertical-L1 and vertical-Li. 3. In extraction subjects, simple regression equations of E line-upper lip, E line-lower lip, Li were calculated by regression analysis. According to the results above, it could be considered that the effect of the extraction or nonextraction treatment was greater than the effect of growth.

• The korean journal of orthodontics
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• v.39 no.1
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• pp.36-42
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• 2009

Objective: The purposes of this study were to provide an epidemiologic data base related to the orthodontic treatment need and to know the changing trends about treatment modality of private orthodontic clinics. Methods: Distribution, trends and orthodontic treatment plan of malocclusion patients were investigated in 1,620 consecutive patients who had been visited and examined in 4 private orthodontic clinics located in Seoul from 2003-2006. Results: Percentage of male and female patients was 26.9% and 73.1% respectively Age distribution had shown that percentage of the patients above 13 years was 78.9%, and above 19 years was 59.0%. Average age of whole patients was 20.5 years. With regard to Angle classification, each percentage of Class I, Class II division 1, Class II division 2 and Class III malocclusion was 38.9%, 34.8%, 2.3% and 24.0%. The percentage of extraction cases(00.9%) outnumbered nonextraction cases(39.1%) and 46% of extraction cases were upper and lower 1st premolar extraction cases. Patients who had chose treatment with fixed appliance and orthognathic surgery was 10.2%. Conclusions: Because the high percentage of adult, Class II malocclusion and orthognathic surgery cases in patients of private orthodontic clinics were shown in this study, orthodontic education program and national health policy in Korea need reformation.

• The korean journal of orthodontics
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• v.26 no.2 s.55
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• pp.219-232
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• 1996

The purpose of this study was to evaluate treatment effects of bionator in Class II division 1 malocclusion by FEM(Finite Element Method). The 73 subjects were classified into good result group and poor result group in reference to posttreatment molar relation, posttreatment overbite and overjet, posttreatment profile, and relapse. Pretreatment and posttreatment lateral cephalograms were taken and FEM was performed. The results were as follow; 1. There was no statistical significance in treatment changes between the sexes, and between the treatment result groups. 2. Treatment changes were not significantly different among the age groups. 3. The effect of treatment period groups on skeletal and dentoalveolar changes were analyzed using ANOVA. Body of maxilla, upper incisor, anterior face, ramus, upper anterior face, lower anterior face and treatment effect were correlated with the treatment period, but correlation coefficients were low. 4. The results of present investigation confirm that Class II bionator can assist in the correction of Class II division 1 malocclusion, mainly due to dentoalveolar changes. 5. There is significant difference in skeletal and dentoalveolar pattern between good result group and poor result group. In poor result group, maxilla was relatively downward and backward rotated, mandible was relatively backward rotated, upper incisor was in relatively lingual position, lower incisor was in relatively labial position.

• The korean journal of orthodontics
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• v.32 no.1 s.90
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• pp.33-42
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• 2002

This study was performed to compare the pattern of dentoalveolar characteristics in different vertical and anteroposterior skeletal types in skeletal Class III malocclusion. The samples selected for this study were consisted of 60 subjects(29 males and 31 females, mean age; 19.7 years) in Class III group, 43 subjects(14males and 29 females, mean age : 20.5 years) in normal group. The findings of this study were as follows : 1. The IMPA of the Class III group was smaller than that of the Class I group(p<0.01). 2. In the Class III groups, SNB and NtoPog had negative correlation with IMPA(p<0.01). The SNB and NtoPog had correlations with SNU1, FHU1 and PalU1(p<0.01) in the male samples, and in the female samples, the SNB and NtoPog had correlations with SNU1(p<0.01). 3. In the Class III male samples, SNMP, FMA, PalMP had negative correlation with IMPA(p<0.01). SNMP, FMA, PalMP had not significant correlation with SNU1, FHU1, PalU1. In the Class III female samples, FMA, PalMP had negative correlation with IMPA(p<0.01). 4. In the high angle group of Class III samples, SNU1, IMPA is smaller than that of low angle group of Class III samples(p<0.05).

• The korean journal of orthodontics
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• v.38 no.1
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• pp.31-40
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• 2008

Objective: This study investigated the skeletal and dentoalveolar changes after intrusion of maxillary posterior teeth using miniscrew implants during the treatment and posttreatment period. Method: The subjects consisted of 11 adults (1 male, 10 females) whose open bites were treated by posterior teeth intrusion with miniscrew. The lateral cephalometric x-rays of pre-treatment, post-treatment, and the retention period were evaluated. Results: The average intrusion of maxillary posterior teeth at the end of the treatment period was 2.22 mm (p < 0.001) and the average extrusion of maxillary posterior teeth at the end of the 17.4 month retention period was 0.23 mm (p = 0.359). The relapse rate was calculated at 10.36%. A decrease in overbite after the 17.4 month retention period was 0.99 mm (p < 0.05). The relapse rate was calculated at 18.10%. The skeletal changes and vertical height change of maxillary posterior teeth during the retention period was statistically insignificant, but there was a significant decrease in overbite (mean 0.99 mm, p < 0.05). The amount of intrusion and the overbite improvement from treatment significantly correlates to the degree of relapse. Conclusions: The results indicate that intrusion of the maxillary posterior teeth using miniscrews is an effective, non-surgical treatment modality which can reasonably be used to address adult open bite.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.112-122
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• 2001

Background: Cleft lip and palate deformity have unknown patterns of maxillofacial growth and development. The maxillofacial growth can be affected either by congenital or environmental factors such as infection and trauma. Surgical repair of cleft lip and palate may interfere the subsequent growth and development of maxillofacial region. The purpose of this study is to evaluate the characteristics of maxillofacial growth patterns in adult cleft lip and palate patients. Materials and Methods: The material for this study consisted of 17 adult male patients with cleft lip and palate. Cephalometric tracing and measurements were done by one investigator. The relationship between 17 cleft lip and palate patients and Korean norms were evaluated statistically. Results: There were statistically differences in Na. perpendicular to point A, SNA angle, effective maxillary length, maxillofacial differencial. Wit's appraisal and upper incisor to point A(p < 0.01). Pogonion to Na. perpendicular also statistically differed(p < 0.05). Other measurements didn't statistically differ. Conclusion: It was evident that in adult cleft lip and palate patients, maxilla was retruded and short. Careful cleft lip and palate repair and treatment are recommended for facilitating normal growth of maxilla.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.4
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• pp.431-441
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• 2021

Full-mouth rehabilitation with increasing vertical dimension can be used for patients with severely worn teeth. In severely worn teeth also, the alveolar process can be elongated to compensate for the reduced vertical dimension, and the patient's vertical dimension of occlusion can be kept constant. However, full-mouth rehabilitation with increasing vertical dimension must be carefully chosen, because the vertical dimension can be reduced by tooth wear. It is important to establish a treatment plan with the systematic diagnosis of the change in the vertical dimension and gain space for the prosthesis. It is necessary to change the vertical dimension to secure the restoration space and select the minimum vertical dimension elevation for the esthetic and functional goal. In this case report, the patient complained of difficulty during chewing due to a worn dentition and wanted esthetic improvement of the short mandibular anterior teeth. After systematic evaluation and diagnosis, we performed full-mouth rehabilitation with minimum vertical dimension elevation to obtain the space for restoration. This resulted in a stable and harmonious occlusion, and the functional and esthetic problems of the patient were solved after treatment. The patient was satisfied with the results of the treatment and maintained stable occlusion during the follow-up period.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.209-218
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• 2019

This study was aimed to evaluate orofacial morphologies on the cases of developmental disorders of maxillary first molars. Panoramic radiographs, lateral cephalographs, and clinical photos of 2983 children who attended the Pediatric Dental Clinic of Pusan National University Dental Hospital from 2006 to August 2017 were assessed retrospectively. 34 patients were selected whose maxillary first molars were missed or developmentally delayed unilaterally or bilaterally. Demirjian's method was used for estimating dental age, then which was compared to chronologic age of children. Parameters expressing skeletal and dentoalveolar disharmony were checked and compared with control. Additionally, occlusion relationship was evaluated. Maxillary dental age was significantly delayed compared to chronologic age. Several parameters which show skeletal open-bite tendency and skeletal class III malocclusion with maxillary retrusion were statistically significant. Anterior crossbite and edge-bite were expected in most of these cases, but compensation by occlusion and soft tissue was also verified which might mask skeletal class III tendency. Congenital missed or developmentally delayed maxillary first molars might be related with declined growth of maxilla. If developmental disorders of maxillary first molars were verified during clinical examination, careful monitoring of orofacial growth was necessary during puberty and timed orthopedic and orthodontic intervention were considered.