• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.322-328
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• 2007

The first molar is important for mastication and also it plays roles to formation of vertical occlusion and growth of jaw bone after mixed dentition. Impaction of mandibular first molar can result in a short lower facial height, formation of a follicular cyst, pericoronal inflammation, resorption of the roots of neighboring teeth and malocclusion. The options of treatment plans are as follows; observation, surgical exposure, orthodontic traction, surgical relocation and extraction. Surgical exposure could be considered as a basic treatment plan. For surgical exposure it is important to maintain patent channel between the crown and the normal eruptive path into the oral cavity, many techniques including cementation of a celluloid crown, packing with zinc oxide-eugenol surgical pack are used. In these cases, we could observe spontaneous eruption of mandibular first molar using surgical exposure with or without removal of odontoma. Also we could obtain the main patency effectively and conveniently by using surgical pack and translucent retainer.

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.963-978
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• 1997

Orthodontic patients are individuals that grow and develop ;therefore selection of the proper time for orthodontic treatment Is considered to be one of the most difficult and yet difficult factor.Since the development of cephalometric X-ray, amount and pattern of craniofacial growth change with aging could be predicted and became useful in the process of orthodontic treatment. The relationship between the mean values of cephalometric measurements and body height and weight was studied among the groups(boys and girls) of Korean children from the ages of 3-years to 12-years. 126 boys and 90 girls with no abnormality in growth and development and no history of orthodontic treatment from the ages of 3 years to 12 years were chosen as subjects: Cephalometric X-ray were taken for 2 years and hard tissue analysis based on Burstone's COGS, which was divided into measurements of 6 parts (Cranial base, Maxillar and Mandible, Vertical measurements, Horizontal measurements, Basal bone relationship, Dental measurements). The relationship between craniofacial growth and body height & weight was studied. The following conclusions were obtained : 1. The maximum growth in the measurements of cranial base, N-Ar(FH), N-Ba(FH) corresponded with the age with the maximum increasein body height & weight in both boys and girls. 2. Genial angle gradually decreased with aging in both boys and girls. 3. N-ANS(L) showed greater amount of growth than ANS-Me(L), and this had greater influence on facial profile. 4. $N-A-Pog^{\circ}$ decreased with aging, and mandibular growth exceeded maxillary growth in amount and rate. 5. Length of Y-axis increased, but Y-axis to FH plane remained constant. This show that mandible grows at a constant angulation to cranial base. 6. As Permanent teeth erupt, interincisal angle deceased.

• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.228-236
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• 2006

To evaluate the cephalometric and dental characteristics of obstructive sleep apnea (OSA) patients, 23 OSA patients and 15 control, non-OSA, patients who visited the Sleep Disorder Clinic Center, Keimyung University were investigated. Patients who suffered from apnea-hypopnea episodes over 10times per hour were diagnosed as having OSA after polysomnograph testing, Impressions were taken with alginate. Cephalometric radiographs were taken at maximum intercuspation. The dental cast measurements, including transpalatal width, intercanine width, intermolar width and palatal depth did not differ between the control and OAS groups and did not have a positive correlation with the apnea-hypopnea index (AHI). Upper airway width was statistically narrower than the control group. Upper airway width had a low negative correlation with AHI, but, lower airway width had a low positive correlation, and, the higher the AHI score, the longer the mandibular border to hyoid distance.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.307-313
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• 2018

The respiratory function is relevant to the craniofacial growth and orthodontic diagnosis. The size of the pharyngeal airway was measured in lateral cephalometric view in children visited Kyung Hee University Hospital from January 2015 to August 2017. A total of 74 healthy children (36 boys and 38 girls) aged 7 - 11 years (mean, 8.5 years) with a normodivergent facial pattern were divided into three groups according to anteroposterior jaw relation measuring A point-Nasion-B point (ANB) angle. Lateral cephalometric data were used to measure the airway dimensions. The dimensions of the middle airway were significantly lower, reducing the upper airway space, in large ANB angle group than in other children, suggesting that children with large ANB angle have narrower airway space than others.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.570-593
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• 1996

This study was intended to perform the influence of condyle positional change after surgical correction of skeletal Class III malocclusion after BSSRO in 20 patients(males 9, females 11) using computed tomogram that were taken in centric occlusion before, immediate, and long term after surgery and lateral cephalogram that were taken in centric occlusion before, 7 days within the period intermaxillary fixation, 24hour after removing intermaxillary fixation and long term after surgery. 1. Mean intercondylar distance was $84.45{\pm}4.01mm$ and horizontal long axis of condylar angle was $11.89{\pm}5.19^{\circ}$on right, $11.65{\pm}2.09^{\circ}$on left side and condylar lateral poles were located about 12mm and medial poles about 7mm from reference line(AA') on the axial tomograph. Mean intercondylar distance was $84.43{\pm}3.96mm$ and vertical axis angle of condylar angle was $78.72{\pm}3.43^{\circ}$on right, $78.09{\pm}6.12^{\circ}$on left. 2. No statistical significance was found on the condylar change(T2C-T1C) but it had definitive increasing tendency. There was significant decreasing of the distance between both condylar pole and the AA'(p<0.05) during the long term(TLC-T2C). 3. On the lateral cephalogram, no statistical significance was found between immediate after surgery and 24 hours after the removing of intermaxillary fixation but only the lower incisor tip moved forward about 0.33mm(p<0.05). Considering individual relapse rate, mean relapse rate was 1.2% on L1, 5.0% on B, 2.0% on Pog, 9.1% on Gn, 10.3% on Me(p<0.05). 4. There was statistical significance on the influence of the mandibular set-back to the total mandibular relapse(p<0.05). 5. There was no statistical significance on the influence of the mandibular set-back(T2-T1) to the condylar change(T2C-T1C), the condylar change(T2C-T1C, TLC-T2C) to the mandibular total relapse, the pre-operative condylar position to the condylar change(T2C-T1C, TLC-T2C), the pre-operative mandibular posture to the condylar change(T2C-T1C, TLC-T2C)(p>0.05). 6. The result of multiple regression analysis on the influence of the pre-operative condylar position to the total mandibular relapse revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condyalr head long axis angle, the more increasing of mandibular horizontal relapse(L1,B,Pog,Gn,Me) on the right side condyle. The same result was founded in the case of horizontal relapse(L1,Me) on the left side condyle.(p<0.05). 7. The result of multiple regression analysis on the influence of the pre-operative condylar position to the pre-operative mandibular posture revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condylar head long axis angle, the more increasing of mandibular vertical length on the right side condyle. and increasing of vertical lengh & prognathism on the left side condyle(p<0.05). 8. The result of simple regression analysis on the influence of the pre-operative mandibular posture to the mandibular total relapse revealed that the more increasing of prognathism, the more increasing of mandibular total relapse in B and the more increasing of over-jet the more increasing of mandibular total relapse(p<0.05). Consequently, surgical mandibular repositioning was not significantly influenced to the change of condylar position with condylar reposition method.

• The korean journal of orthodontics
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• v.30 no.1 s.78
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• pp.91-99
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• 2000

This study was done to identify the changes of bite force and occlusal contact between before and after stabilization splint therapy. 16 female patients, accepted for orthodontic treatment at the Department of Orthodontics, College of Dentistry, Chosun University, were selected as the sample of this investigation. For comparisons, the samples of 16 were divided into just before stabilization splint, 1 month after stabilization splint, 2 months after stabilization splint, and 3 months after stabilization splint and used the T-scan system to identify the bite force and occlusal contact changes for each group. Statistical analysis of the data was carried out ANOVA tests, and Turkey tests using $SPSS/PC^+$. The results were as follows : 1. Bite force change from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 2. Bite force changes from 1 to 3 months after stabilization splint therapy showed no statistical significance (p>0.05). 3. The changes of anterior occlusal contacts showed no statistical significance regardless of the wearing periods of stabilization splint (P>0.05). 4. The changes of posterior occlusal contacts from just before treatment to 1 month after stabilization splint therapy was statistical significantly decreased (P<0.05). 5. The changes of posterior occlusal contacts Outing 1 to 3 months after stabilization splint therapy showed no statistical significance (P>0.05). 6. Posterior teeth rather than anterior teeth were more influenced by the changes of the number of occlusal contacts. To sum up above results, we may respect to capturing and stabilizing centric relation Position just 1 month after stabilization splint therapy.

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.3
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• pp.359-371
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• 2010

Facial asymmetry has been found with a higher frequency (70~84%) in skeletal class III malocclusion patients. Anticipating the poor prognosis of prosthesis due to malocclusion, occlusal stability must be obtained by orthodontic treatment. Moreover, orthodontic surgery would be needed in some severe cases for better functional and esthetic results. The orthognathic surgery is performed on one jaw or two jaw depending on the results of facial diagnosis. Genioplasty may change the vertical, horizontal, sagittal position of chin by osteotomy or augmentation using implants, also. This case is about a 24 year-old male patient who visited our clinic to solve the facial asymmetry and mandibular prognathism. Skeletal class III malocclusion, maxillary canting and menton deviation to left by 13 mm were detected. Multiple ill-fitting prostheses, unesthetic maxillary anterior prostheses, and several dental caries were found. After pre-operative orthodontic treatment, Le-Fort I osteotomy, sagittal split ramus osteotomy, genioplasty, right mandibular angle augmentation were done for the correction of jaw relation and asymmetry. By diagnostic wax-up after post-operative orthodontic treatment, maxillary full mouth rehabilitation and mandibular posterior restorations were planned out. For better result, clinical crown lengthening procedure was done on #11, 12 and implant was placed on left mandibular first molar area. The patient was satisfied with the final prostheses. Because of his high caries risk, long-term prognosis will depend on the consistent maintenance of oral hygiene and periodic follow-up.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.74-83
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• 2006

Analysis of lateral cephalometric radiograph (cephalogram) has been used routinely to evaluate skeletal and dental relationships, but analysis of the lateral facial photograph has not been used frequently for evaluation of skeletal relationships. As concerns about harm of X-ray irradiation increases, this study was planned to evaluate the possibility of substituting analysis of the lateral cephalogram with analysis of the lateral facial photograph by comparing these two analyses. According to the ANB values from cephalometric analysis, subjects were divided into three groups: Class I malocclusion group (n=32). Class II malocclusion group (n=32), and Class III malocclusion group (n=31). After measurements of angles indicating horizontal and vertical relationships of the maxilla and mandible on the lateral cephalograms and photographs, differences between Class I, II and III groups were evaluated. To evaluate the similarity between two similar values in the cephalograms and photographs, t-test using standardized variable Z and correlation analysis were performed in the Class I malocclusion group. The results showed that 1) SnN'Pg' on the photograph can be used to evaluate the antero-posterior relationship of the maxilla and mandible (ANB), 2) N'-Sn/Sn-Pg' on the photograph can be used to evaluate facial convexity (NA/APg), 3) Sn-Tra-Me' on the photograph can be used as a measurement similar to FMA. In conclusion, partly substituting lateral cephalogram analysis with lateral facial photograph analysis was possible in the evaluation of the maxilla and mandible.

• The korean journal of orthodontics
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• v.30 no.5 s.82
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• pp.591-598
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• 2000

This study was designed to analysis the airway which affects to breathing, speech and facial growth pattern in unilateral cleft lip and palate patients. Upper airway and the position of hyoid bone pattern were analyzed on the lateral cephalometric radiographs of the 78 subjects of complete unilateral cleft lip and palate group and each group was divided two sub-groups by circumpubertal growth peak and gender. These data were statistically analyzed to examine the difference between pre-circumpubertal growth peak group and post-circumpubertal growth peak one, and between male and female group. The results of this study were as follows: 1. After circumpubertal growth peak stage, the position of hyoid bone was lower than before in both male and female group. 2. After circumpubertal growth peak stage, the measurement were increased in CV3ia-APH, PNS-ad which related to the volume of pharyngeal space. This was due to the decrease of adenoid and anteroiferior growth of mandible and affected to breathing and speech after circumpubertal growth peak. 3. During circumpubertal growth peak stage, all measurements increased more in male than female group, which due to the different amount of growth in different gender. 4. The position of hyoid bone was lower in male than female group in all age group. 5. After circumpubertal growth peak stage, CV3ia-APH increased more in male. This was due to the more growth in madible of male which resulted in the activation of digastric muscle.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.255-265
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• 1996

The purpose of this study was to investigate if there were a significant difference between cephalometric measurements of mandibular position derived from a centric occlusion tracing compared to those of a converted centric relation tracing in the Class III malocclusion. The sample consisted of 25 Class III malocclusion and 25 normal occlusion persons who had no orthodontic treatment. The records included an lateral cephalometrics in centric occlusion, centric relation and centric occlusion bite registration and diagnostic casts mounted on the SAM II articulator in CR. The amount of CR-CO discrepancy of condyle was recorded using a MPI(Mandibular Position Indicator, MPI $200^{(R)}$, Great Lakes Orthodontics, USA). The conversion of the CO cephalogram to CR using the MPI readings was performed on the Conversion work sheet. Measures of mandibular position were chosen for the purpose of this study. The comparison of the difference between CO and CR cephalometric measurements in the normal occlusion and Class III malocclusion group were studied. The results were as follows: 1. In the features of CR-CO discrepancy of the condyle, the condyle was displaced posterior and inferior when the teeth were in centric occlusion. The horizontal component(${\Delta}X$) in Class HI malocclusion group was greater than the vertical component(${\Delta}Z$) and also greater than the horizontal component(${\Delta}X$) in normal occlusion group. There was no statistically significant correlation between MPI measurements and the groups of normal occlusion and Class III malocclusion group. 2. In the comparison of the cephalometric measurements in each group, Normal occlusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity and ODI. Class HI malocclusion group showed significant difference in measurements such as ANB, Facial angle, Facial convexity, ODI, SNB, APDI, L1-FP and it had more significance than the normal occlusion group. 3. The Value of cephalometric measurements was significantly different between CO and CR but there were no differences between the groups of normal occlusion and Class III malocclusion. The results of this study suggest that if the discrepancies are greater than the amount of normal displacement from clinically captured centric relation, centric relation should be considered as the starting point for proper diagnosis and treatment planning.