• The korean journal of orthodontics
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• v.26 no.4
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• pp.349-358
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• 1996

To extract or not to extract permanent teeth for the correction of malocclusion has been a great debate in the history of orthodontics, and there is a variety of analytic methods and criteria to aid in the diagnosis. Extraction formulas that has been presented are many analytic methods that depend on arch length discrepancy, dental prominence, and skeletal pattern of the each patients. Of these analysis, the most important diagnostic factor is patient's skeletal pattern. Because the behavior of the dentition is closely dependent upon the skeletal pattern of each patient, dentition must be arranged within that person's skeletal frame. EI(Extraction Index) is composed of CF, interincisal angle, and lip position. CF is made of ODI and APDI that differentiate vertical and horizontal component of the skeletal pattern. So, EI not only represents patient's skeletal pattern, but also takes facial appearance into consideration. This study was undertaken to investigate EI and related cephalometric variables on the cephalogram of Korean adolescents which consisted of 153 persons with normal occlusion, harmonious skeleton and pleasing face. The following conclusions were obtained. 1. The mean value of the ODI is $73.5^{\circ}$, APDI $82.5^{\circ}$, CF $156.3^{\circ}$ 2. The mean value of the interincisal angle is $123.6^{\circ}$ 3. The mean distance of upper lip to E-line is 0.0mm, lower lip to E-line is 1.4mm. 4. The mean value of the EI is $153.8^{\circ}$.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.420-426
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• 2009

The purpose of this study was to evaluate skeletal and soft tissue changes that occur after using a facemask for treatment of skeletal class III malocclusion, and to assess the relapse pattern when no retention appliance was used. Fifteen skeletal class III malocclusion patients were treated with a facemask for an average of 12 months. No retention appliance was used during the 1 year follow-up period. Cephalograms were taken during pretreatment, posttreatment, and the 1 year follow-up. Cephalograms were traced, analyzed, and the results were compared between cephalograms. All patients showed significant sagittal skeletal changes after treatment, but they also showed a significant relapse during the 1 year follow-up period when no retention appliance was used. Despite the relapse, the sagittal skeletal changes that remained were still significant. Vertical skeletal change was also significant after treatment, but the total change was not significant after a 1 year follow-up due to relapse. In soft tissue changes, facial convexity and upper lip position improved after treatment and this change remained significant after the 1 year follow-up period. Facemask therapy is therefore an effective method for treatment of skeletal class III malocclusion, however, retention is imperative to maintain the treatment effect.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.317-325
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• 1999

In proper diagnosis of skeletal Class III malocclusion, it was important to know the pattern of three dimensional skeletal & facial disharmony. The purpose of this study was to obtain P-A cephalometric characteristics in skeletal Class III malocclusion comparing with normal occlusion. The samples were consisted of 120 subjects, divided into four groups : Male normal occlusion, Female normal occlusion, Male skeletal Class III malocclusion, Female skeletal Class III malocclusion. Posteroanterior and lateral cephalogram were taken from the subjects with a x-ray apparatus (ASHAI CX90SP, Japan) and traced on acetate paper with routine manner. The transverse and vertical values from posteroanterior cephalometry, the sagittal values from lateral cephalometry and their ratio were obtained. The results were as follows: 1. The anteroposterior discrepancy in skeletal Class III group was not due to short maxillary length(Cd-A), but to longer mandibular length(Cd-Gn) than normal occlusion group. 2. The faces of skeletal Class III group were longer than normal occlusion group. It was not due to increase of upper face height(Cg-ANS) but to increase of the lower face height(ANS-Me) especially mandibular height(Cd-Me). 3. There was no difference in the facial width values between normal occlusion group and skeletal Class III group, except upper molar width(U6-U6), lower molar width(L6-L6) and mandibular width(Ag-Ag) of female skeletal Class III group which were larger than normal occlusion group. 4. The increase of mandibular length of skeletal Class III group was reflected in the increase of lower facial height but did not have an effect on the mandibular width.

• The korean journal of orthodontics
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• v.29 no.1 s.72
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• pp.37-49
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• 1999

Forty-four females with normal temporomandibular joint were compared with fifty-one females with abnormal temporomandibular joint. An orthodontic study model and lateral cephalometric radiographic were used to investigate the relationship between TMD group and non-TMD group in long face patterns. The result were followed that ; 1. There were no significant in overbite and overjet amount. 2. A mandibular 1'st molar inclination and height to the mandibualr plane were more mesial inclined in TMD groups. 3. The functional factors, which were craniocervical posture , tongue posture and hyoid bone position, were no significant.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.4
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• pp.401-406
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• 1999

Secondary deformities of the lip and nose in individuals with repaired unilateral and bilateral clefts may vary in severity, depending on the state of the original defect, the care taken in the initial surgical procedure, the pattern of the patient's facial growth, and the effectiveness of interceptive orthodontic technique. Because each patient has a unique combination of deformities, their surgical reconstruction usually requires the modification and combination of several surgical techniques. Residual lip deformities after primary repair may be esthetic or functional and include scars, skin shortage or excess(vertical and transverse), orbicularis oris muscle malposition or diastasis. The key to accurate repair of secondary cleft lip deformities is a precise diagnosis. This requires observation of the patient in animation and repose. The quality of the scar is not the only factor determining the overall appearance of the lip. Observing the patient in the animated position is critical to assess muscular function. Factors that require precise analysis include lip length, the appearance of the Cupid's bow and philtrum, and nasal symmetry. Only after this detailed analysis can a decision be made as to wether a major or minor deformity exists. We report successful cases using various techniques for the secondary lip deformities.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.3
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• pp.343-350
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• 2000

The goal of this study is the comparison of upper airway size and change of skeletal Class I group and skeletal Class III group (before operation, within 2 weeks after operation, 6 months after operation) respectively. At first, we measured the lines between selected upper air way landmarks on lateral cephalometric x-ray film of skeletal Class I 40 persons whoes age were 23-26 years old, ,and did the same lines of landmarks of skeletal Class III 44 persons who had not been operated yet, were within 2 weeks after operation, were 6 months after operation. And we compared it respectively and analyzed it with paired t-test. We studied the relationship of those on produced data. 1. Skeletal Class III group was narrower in nasopharyngeal air way space than that of skeletal Class I group, and increased in thickness of oropharyngeal, hypopharyngeal wall within 2 weeks after operation, and reduced in nasopharyngeal, oropharyngeal air way space, and did in thickness of nasopharngeal, hypopharyngeal wall 6 months after operation. 2. Skeletal Class III group reduced in nasopharyngeal, oropharyngeal air way space, and increased in thickness of nasopharyngeal, oropharyngeal, hypopharyngeal wall within 2 weeks after operation, restored the thickness of nasopharyngeal, oropharyngeal wall, but did not restored nasopharyngeal, oropharyngeal, hypopharyngeal air way space. 3. Vertical length from hyoid bone to mandibular plane did not have signifacant difference from Class I group but after operation, it increased more than Class I group significantly. 4. The size of airway reduced after operation. Among this, oropharyngeal airway most reduced.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.628-635
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• 2000

The purpose of this study was to evaluate the result after 2-phase surgical-orthodontic treatment without preoperative orthodontic treatment for the skeletal Cl III malocclusion patient and to obtain an adequate protocol on the bases of this result. This retrospective study of ten patients who underwent 2-phase treatment were done to evaluate 1) the surgical stability and relapse pattern 2) the facial esthetics 3) the TMJ problem 4) the total time of the treatment. Results were followed : 1) The horizontal relapse of the mandible was 26.8% and didn't show significant differences compared to the conventional 3-phase treatment. But, it was considered that this amount of relapse was the sum of true relapse and autoratation of mandible due to decreased vertical dimension during orthodontic treatment. 2) It was estimated that there's no difference on the ratio of anterior facial height between the subjects and the normal patients. On the horizontal analysis, the mandible of the subjects was located more anteriorly than that of the normal patients. This result showed that there was a need for the accurate preoperative esthetic evaluation and the additional methods for reducing the relapse due to the occlusal interference. 3) Wide variation was noted on the TMJ symptoms of the subjects, however, it was estimated that there's no significant differencees of symptoms compared to that of the conventional 3-phase treatment on literatures. 4) The average of the overall period of treatment was 20.8 months and we obtained reduction of the treatment time compaired to 3-phase treatment on many literatures. Most of the results of this study were similar to the findings of the 3-phase treatment(preoperative orthodontic-orthognathic surgery-postoperative orthodontic), but total time of the treatment was shorter in patients with 2-phase treatment than in those with the conventional 3-phase treatment. With 2-phase treatment, we experienced many advantages compared to the conventional method considering that it was favarable conditions for the teeth, it had the flexibility for the treatment, and it could be the adequate treatment approach for the stomatognathic system. Although this retrospective pilot study had some limitations, due to small samples, the authors would hope that it could serve as a guide for the future researches, and the clinical applications.

• The korean journal of orthodontics
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• v.33 no.6 s.101
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• pp.437-451
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• 2003

The purpose of this study was to measure maximum bite force and to investigate its relationship with anteroposterior, vertical, and transverse facial skeletal measurements. From among the dental students at the College of Dentistry, forty subjects (26 male and 14 female) were selected. With two sets of strain gauge, maximum bite force at the right and left first molars and anterior teeth was measured in the morning and afternoon. After taking lateral and posteroanterior cephalograms, fifty and nineteen variables were evaluated, respectively Paired t-tests and an independent t-test were done and correlation coefficients were obtained. 1. The maximum bite force at the first molars was $68.0\pm13.9kg$. in males and $55.6\pm10.5kg$ in females (p<0.05) while the force at the anterior teeth was $8.4\pm4.9kg\;and\;1.1\pm3.4kg$ respectively (p<0.05). 2. Some tendency for a greater value of maximum bite force at the preferred side was observed but not statistically significant (p>0.05). 3. Significant difference was observed between the strong bite force group and the weak bite force group in some cephalometric and other measurements (p<0.05). N-S-Ar, S-Ar-Go, FH-Hl, IMPA and MMO showed a significant difference in posterior maximum bite force (P). N-S-Ar and FH-H1 also showed a significant difference in anterior maximum bite force (A). 4. Several cephalometric variables showed some correlation with maximum bite force (p<0.05). N-S-Ar, S-Ar-Go, UGA, FH-H6, FH-H1, body weight and MMO were significantly correlated with posterior maximum bite force (P). Go-Me, P-1 and IMPA were significantly correlated with anterior maximum bite force (A).

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.297-306
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• 2000

Lateral cephalometric X-ray films in maximal intercuspation and maximal opening of 68 children were taken and analyzed to examine the pattern of condylar movement and to study the relationship between opening movement and morphologic factors of craniofacial skeleton. The results were as follows : 1. The mean value of maximal opening capacity was 47.1mm, condylar moving distance was 18.1mm, horizontal condyle movement was 17.5mm, vertical condyle movement was 3.8mm and condylar moving angle was $13.1^{\circ}$. 2. The maximal opening capacity had positive relationship with the length of anterior cranial base, mandible and maxillary complex and with posterior facial height and had negative relationship with articular angle, sagittal jaw relationship. 3. Vertical condyle movement and condylar moving angle had positive relationship with articular angle and had negative relationship with gonial angle. 4. Horizontal condyle movement and condylar moving distance had positive relationship with the length of maxillary complex.

• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.491-507
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• 2000

The purpose of this study was to investigate if there were a significant differences in mandibular position between cephalometric measurements from a centric occlusion tracing compared to those of a acquired centric relation by stabilization splint on malocclusion patient with TMD. 60 malocclusion patients, who had TMD and CO-CR discrepancy beyond normal range, were selected and subdivided into Class I, II, III by Angle's classification and also subdivided into clockwise, straight downward, and counterclockwise group by Jarabak's posterior facial height/anterior facial height ratio. Lateral cephaolmetric radiographs with the mandible in centric occlusion were taken and measured, and for each Patient the stabilization splint with mutually protected occlusal scheme was applied for minimum 3months. After each patient's CO-CR discrepancy was in normal range, lateral cephalometric radiographs were retaken and measured. The comparison of the difference between CO-CR cephalometric measurements in all sample, Class I, II, III groups, and Clockwise, Straight downward, Counterclockwise groups were studied. The finding of this study can be summarized as follows: 1 In all sample, the value of cephalometric measurements was significantly different between CO-CR. The mandible rotated to down and posterior position and the vertical change was greater than the horizontal change (overjet-1.3mm increase, overbite-1.9mm decrease). 2. In Class II malocclusion group, most of the mean difference value between CO-CR is higher than that of the other groups and more measurements was statically significant. 3. In clockwise and counterclockwise group, some of the mean difference value is higher than that of straight downward group and more measurements was statically significant. 4. There ware no measurements that explain centric relation measurements from the type of malocclusion, facial pattern and centric occlusion measurements. Henceforth, it is strongly recommended that stabilization splint therapy for orthodontic treatment on TMD patient should be excuted upon overall facial types prior to orthodontic diagnosis and treatment planning.