• The korean journal of orthodontics
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• v.17 no.2
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• pp.311-320
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• 1987

The purpose of this study was to investigate the growth changes of maxilla and mandible and position changes of first permanent molars of growing children The author analyzed the data using cephalometric roentgenogram of 43 boys and 39 girls age of 6 to 11 with normal occlusion The obtained results were as follows 1 The eruption path of maxillary and mandibular first permanent molar superimposed on TM-ANS and mandibular plane shows individual variation 2 There was no correlation between horizontal and vertical changes of maxillary first permanent molar, but positive correlation in mandibular first permanent molar 3 As the eruption, the forward changes of mandibular first permanent molar was significantly greater than that of maxillary first permanent molar 4 As the ages were increased, there were irregular growth changes of maxilla and mandible 5 Growth changes of lower anterior facial height was relatively stable 6 N-S-${\bar{6}}$ was stable after age 7.

• The korean journal of orthodontics
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• v.51 no.6
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• pp.407-418
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• 2021

Objective: To investigate differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and Class II malocclusions. Methods: Forty Korean adult twin pairs were divided into Class I (C-I) group (0° ≤ angle between point A, nasion, and point B [ANB]) ≤ 4°; mean age, 40.7 years) and Class II (C-II) group (ANB > 4°; mean age, 43.0 years). Each group comprised 14 monozygotic and 6 dizygotic twin pairs. Thirty-three cephalometric variables were measured using lateral cephalograms and were categorized as the anteroposterior, vertical, dental, mandible, and cranial base characteristics. The ACE model was used to calculate heritability (A > 0.7, high heritability). Thereafter, principal component analysis (PCA) was performed. Results: Twin pairs in C-I group exhibited high heritability values in the facial anteroposterior characteristics, inclination of the maxillary and mandibular incisors, mandibular body length, and cranial base angles. Twin pairs in C-II group showed high heritability values in vertical facial height, ramus height, effective mandibular length, and cranial base length. PCA extracted eight components with 88.3% in the C-I group and seven components with 91.0% cumulative explanation in the C-II group. Conclusions: Differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and II malocclusions might provide valuable information for growth prediction and treatment planning.

• The korean journal of orthodontics
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• v.53 no.3
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• pp.185-193
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• 2023

Objective: The growth and development of the mandible strongly depend on modeling changes occurring at its ramus. Here, we investigated covariance patterns between the morphology of the ramus and the rest of the face. Methods: Lateral cephalograms of 159 adults (55 males and 104 females) with no history of orthodontic treatment were collected. Geometric morphometrics with sliding semi-landmarks was used. The covariance between the ramus and face was investigated using a two-block partial least squares analysis (PLS). Sexual dimorphism and allometry were also assessed. Results: Differences in the divergence of the face and anteroposterior relationship of the jaws accounted for 24.1% and 21.6% of shape variation in the sample, respectively. Shape variation was greater in the sagittal plane for males than for females (30.7% vs. 17.4%), whereas variation in the vertical plane was similar for both sexes (23.7% for males and 25.4% for females). Size-related allometric differences between the sexes accounted for the shape variation to a maximum of 6% regarding the face. Regarding the covariation between the shapes of the ramus and the rest of the face, wider and shorter rami were associated with a decreased lower anterior facial height as well as a prognathic mandible and maxilla (PLS 1, 45.5% of the covariance). Additionally, a more posteriorly inclined ramus in the lower region was correlated with a Class II pattern and flat mandibular plane. Conclusions: The width, height, and inclination of the ramus were correlated with facial shape changes in the vertical and sagittal planes.

• The Journal of the Korean dental association
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• v.45 no.8 s.459
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• pp.483-490
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• 2007

The aim of this study was to investigate the relationship between the mandibular antegonial notch and the mandibular morphology, and the curve of Spee in anteroposterior skeletal relationship. Pre-treatment lateral cephalograms were obtained from 80(male 34, female 46) adult orthodontic patients and the samples were classified into 3 categories by ANB angle($0^{\circ}$$\leq$ANB< $4^{\circ}$ Class I, $4^{\circ}$$\leq$ANB Class II, ANB< $0^{\circ}$ Class III). The curve of Spee was measured directly from the pre-treatment mandibular study cast of each patient included in this study. Pearson correlation coefficient test and multiple regression analysis in each group revealed the following results; 1. Antegonial notch depth was positively correlated with hoth lower anterior facial height(ANS-Me) in skeletal Class I, II and III groups and Id-Me height in skeletal Class I and II groups. 2. A statistically significant negative correlation was found between the depth of the antegonial notch and the curve of Spee in the Class III group. 3. Significant relationship was not found between the antegonial notch depth and any of the other cephalometric variables such as mandibular body length(Go-Gn) and ramus height(Co-Go). As antegonial notch depth increased, more vertical growth of the mandible was observed. Antegonial notch can be used as a predictor of vertical mandibular growth in the diagnosis and treatment planning of malocclusion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.33 no.5
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• pp.559-566
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• 2007

Distraction osteogenesis(DO) is a surgical method of bone formation that involves an osteotomy and sequential stretching of the healing callus by gradual movement and subsequent remodeling. DO is used to correct facial asymmetry, such as in patients with hemifacial microsomia, maxillary or mandibular retrusion, cleft lip and palate, alveolar defects, and craniofacial deficiency. It is accomplished with the aid of a distraction device, which is secured with screws placed directly into bone, for a predetermined length of time. Hemifacial microsomia is characterized by unilateral facial hypoplasia, often with unilateral shortening of the mandible and subsequent malocclusion. Patients with hemifacial microsomia and facial asymmetry have a vertically short maxilla, tilted occlusal plane, and short mandible. Early treatment is necessary to avoid subsequent impaired midfacial growth. The standard treatment of these malformations consists of the application of bone grafts, which can lead to unpredictable growth. The new bone-lengthening procedure represents a limited surgical intervention and opens up a new perspective for treatment, especially in younger children with severe deformities. This report describes a case of hemifacial microsomia(Type-II left-sided hemifacial microsomia). The patient, a 10-year-old child, visited our clinic for facial asymmetry correction. He had a hypoplastic mandible, displaced ear lobe, 10 mm canting on the right side, and malocclusion. We planned DO to lengthen the left mandible in conjunction with a Le Fort I osteotomy for decanting and then perform a right intraoral vertical ramus osteotomy(IVRO). Progressive distraction at a rate of 0.5 mm/12 hours was initiated 7 days postoperatively. The duration of DO was 17 days. The consolidation period was 3 months. Satisfactory results were obtained in our case, indicating that DO can be used successfully for functional, aesthetic reconstruction of the mandible. We report a case involving DO in conjunction with orthognathic surgery for correcting mandibular hypoplasia with a review of the literature.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.247-257
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• 2003

Various methods have been used on patients with skeletal Class II division 1 malocclusion. The activator, Frankel appliance, headgear, Herbst appliance, and Twin-block appliance are some examples. The ideal treatment effect using these appliances would be to inhibit horizontal and vertical growth of the maxilla while promoting mandibular growth and obtaining optimum dentition. The Teuscher appliance has a simultaneous combined headgear effect with maxillary growth inhibition and an activator effect with mandibular growth promotion. The purpose of this study was to examine how well these effects were clinically obtained and the results are as follows. 1. The forward growth of the maxilla was effectively inhibited. 2. The downward-forward growth of the maxillary dentoalveolar complex was inhibited. 3. Growth promotion of the mandible was not observed. 4. The overjet, overbite, molar key were effectively improved. 5. The protruded upper lip and facial profile were unproved.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.273-286
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• 1995

The purpose of this study was to compare the difference of the growth aspects in three facial growth patterns. The biennial serial cephalometric radiographs of 33 samples(19males, 14females) with normal occlusion from 8.5 years to 18.5 yews of age were used in this study. The facial growth patterrn was categorized in 3 types(Drop type, Neutral type, Forward type) by the total amounts of the Y-axis which changed from 8.5 years to 18.5 years of age. The growth change of the craniofacial area during 10 years in each growth type was analyzed and was compared among the 3 growth types. The results of this study might be summarized as follows. 1. The samples that were classified by total change of the Y-axis during this study period were distributed to 52% of the neutral type, 27% of the forward type, 21% of the drop type. 2. The anterior growth of the maxilla to the cranial base(N per A) showed larger in the forward type than in other 2 types(p<0.05). 3. The palatal plane to the FH plane showed more anterior-superior inclination in the forward type with age during this study period. 4. The anterior growth of the mandible to the cranial base(N per Pog) appeared large in rank order, of largest the forward type, second the neutral type, and third the drop type(p<0.05). 5. During this study period the mandibular plane(SN/MN,FMA) showed more counterclockwise rotation in the forward type than in the drop type(p<0.05), and this tendency was stronger in males than in females(p<0.05). 6. The growth of the mandibular corpus length(Go-Me) showed smaller in the drop type than in the other 2 types(p<0.05). 7. In the forward type and the neutral type, the anterior growth of the mandible was larger than that of the maxilla(p<0.05). 8. In the craniofacial growth distances and angulations turned out to be somewhat variable, but the vertical proportion had a strong tendency whose original relation was maintained consistently during this study period. 9. Through these analyzed data, the profilograms on each growth type were constructed to evaluate individual growth pattern in the orthodontic diagnosis.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.221-230
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• 1997

It has been known that head posture may influence directly and/or indirectly the growth and development of craniofacial morphology and can also be influenced by the funtional demand of physiologic activity. It was reported that facial morphology has close relationships with hyoid bone position and head posture. In many previous studies, Natural Head Posture(NHP) was guided, and also it was shown that NHP has high degree of reproducibility. Otherwise, There was few study about the relationship of head posture, with routine cephalometric film which is used for clinical orthodontic purpose. In this study, according to the Wits and ANB of initial cephalometric film which was taken with vertical pendulum as representative of true vertical reference line. We classified the subjects which is comprised of 60 adult female patients into Class I, II, III (Cl I, II, III)and we tried to find out the correlation of head posture and hyoid bone position according to the classification of malocclusion. As a result of our research, we found the followigs. 1. In comparison of vertical position of hyoid bone relative to the cranial base. the position of hyoid bone of Cl III was lower than that of Cl II. 2. In comparison of anteriorpostes or position of hyoid bone, relative to the cervical column. The position of hyoid bone of Cl III was more anterior than that of a II 3. in comparison of vertical position of hyoid bone relative to mandible. There was no significant correlation aumoug the groups of malocclusion. 4. ANB and Wits showed no significant correlation with hyoid bone position. 5. The relative extension of head, which was noted in Cl II, showed negative with Sum, ANB. 6. In Cl II and Cl III, Post to Ant facial height showed positive correlation with NSL/VER.

• The korean journal of orthodontics
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• v.29 no.1 s.72
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• pp.23-35
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• 1999

Lateral cephalograms or 251 males md 286 females were taken and pubertal growth pattern or cranial base, maxillary and mandible of 7 to 17 years old Korean children was evaluated. 10 landmarks and 16 analytical measurements were evaluated. Analytical measurement and annual difference for each age group was calculated and tested for statistical significance. Analytical measurements were classified into three groups which were cranial base, maxillary and mandibular measurements and also classified into make and female measurements. Following results were achieved. 1. The circumpuberal growth spurt was earlier in Korean females than in males. 2. Cranial base, maxilla and mandible showed circumpuberal growth. The cranial base showed a relatively smaller amount of growth than the facial complex. 3. Middle and posterior cranial base length showed a floater increase than anterior cranial base length and circumpuberal growth spurt was also more definite. 4. the forward and downward growth or maxilla results from maxillary growht itself and transposition or the maxilla due to circumsutural growth aroud the maxilla. Ar-ANS and Ar-Pr which represent maxillary position relative to the cranial base showed more growth than ANS-PNS which represents maxillary bone growth. 5. mandible showed more vertical growth than horizontal growth but without significance. 6. Alveolar gwoth of maxilla and mandible show maximum growth rate of the time of permanent teeth eruption following loss of deciduous teeth . After this period alveolar growth shows a decreasing tendency.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.4
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• pp.324-329
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• 2012

Excessive tooth wear causes loss of tooth structure, disharmony of occlusal plane, functional and esthetic problems. Although the decrease of occlusal vertical dimension may be compensated by growth of alveolar bone, if the length of tooth is not enough for the retention of restoration, minimum increase of occlusal vertical dimension is required without discomfort of the patient. In this case, 33-year-old woman drinks more than 1 liter of soft drinks a day and has bruxism in night time, visited in Seoul National University Dental Hospital with chief complaint of generalized tooth wear and related esthetic and functional problems. It was considered as a loss of occlusal vertical dimension based on the accelerated tooth wear caused by erosion and bruxism and facial appearance, phonetic, esthetic, functional evaluations. It was planned to raise occlusal vertical dimension by provisional restoration two times for patient's adaptation, 3 mm and 2 mm each, total 5 mm. Confirming no discomfort and clinical symptom during total 16 weeks after restoration with provisional fixed restoration, it was restored with porcelain fused to gold crown and bridge. Because the patient was young woman, anterior teeth were restored with collarless porcelain fused to gold crown. This case presents that satisfactory esthetic and functional result by full mouth rehabilitation with increase of occlusal vertical dimension.