• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.4
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• pp.350-359
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• 2005

Sagittal split ramus osteotomy(SSRO) has been commonly performed in the mandibular prognathism. The previous studies of the mandibular anatomy for SSRO have mostly been used in dry skull without consideration of age, sex or jaw relationship of patients. This study was performed to evaluate the location of mandibular canal and the anatomy of ramus, such as the location of mandibular lingula and the ramal bone marrow, which were associated with SSRO procedures, in the patients with mandibular prognathism and normal young adults by using computerized tomographs(CT) and 3D images. The young adults at their twenties, who were considered to complete their skeletal growth, and seen in the Department of Orthodontics and Oral and Maxillofacial Surgery in Chonnam National University Hospital between March 2000 and May 2003, were selected. This study was performed in 30 patients (15men, 15women) who were diagnosed as skeletal class I normal relationship, and another 30 patients (15men, 15women) who were diagnosed as skeletal class III relationship upon clinical examination and lateral cephalometric radiographs. The patients were divided into 2 groups : Class I group, the patients who had skeletal class Ⅰ normal relationship(n=30, 15men, 15women), and Class III group, the patients who had skeletal class III relationship(n=30, 15men, 15women). Facial CT was taken in all patients, and pure 3D mandibular model was constructed by V-works version 4.0. The occlusal plane was designed by three points, such as the mesiobuccal cusp of both mandibular 1st molar and the incisal edge of the right mandibular central incisor, and used as a reference plane. Distances between the tip of mandibular lingula and the occlusal plane, the sigmoid notch, the anterior and the posterior borders of ramus were measured. The height of ramal bone marrow from the occlusal plane and the distance between mid-point of mandibular canal and the buccal or lingual cortex of the mandible in the 1st and 2nd molars were measured by V-works version 4.0. Distance(Li-OP) between the occlusal plane and the tip of mandibular lingula of Class III Group was longer than that of Class I Group in men(p<0.01), but there was no significant difference in women between both groups. Distance(Li-SN) between the sigmoid notch and the tip of mandibular ligula of Class III group was longer than that of Class I Group in men(p<0.05), but there was no significant difference in women between both groups. Distance(Li-RA) between the anterior border of ramus and the tip of mandibular lingula of Class III Group was shorter than that of Class I Group in men and women(p<0.01). Distance(Li-RP) between the posterior border of ramus and the tip of mandibular lingula of Class III Group was slightly shorter than that of Class I Group in men(p<0.05), but there was no significant difference in women between both groups. Distance(RA-RP) between the anterior and the posterior borders of ramus of Class III Group was shorter than that of Class I Group in men and women(p<0.01). Longer the distance(SN-AN) between the sigmoid notch and the antegonial notch was, longer the vertical ramal length above occlusal plane, higher the location of mandibular lingula, and shorter the antero-posterior ramal length were observed(p<0.01). Height of ramal bone marrow of Class III Group was higher than that of Class I Group in men and women(p<0.01). Distance between mandibular canal and buccal cortex of Class III Group in 1st and 2nd lower molars was shorter than that of Class I Group in men and women (p<0.05 in 1st lower molar in men, p<0.01 in others). These results indicate that there are some anatomical differences between the normal occlusal patients and the mandibular prognathic patients, such as the anterior-posterior length of ramus, the height of ramal bone marrow, and the location of mandibular canal.

• Journal of Korean society of Dental Hygiene
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• v.10 no.4
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• pp.655-661
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• 2010

Objectives : This study is aimed to prevent the damage to the inferior alveolar nerve during the orthognathic surgery. Methods : The control group consist of 50 patients with class I occlusion. The experimental group consist of 50 patients with class III malocclusion. The cepalometric radiography was used to evaluate the position of the mental foramina. Results : In the first, mental foramen position of class III was more inferior 0.85 mm in the distance between base of mandible and mental foramen. But the distance between occlusal plan and mental foramen had not statistically significant. Secondly, mental foramen location of Mandibular Prognathism was more anterior 0.91 mm in the distance between coronal plane of mandible included pogonion point and mental foramen. Also, the distance of occlusal-coronal plane of mandible included central incisor and mental foramen had statistically significant. The mental foramen location of class III was more anterior 4.81 mm than class I patients. Conclusions : The result of this study could help the clinicians to apprehend fundamental data with various facial skeletal types for any related researches about the location of the mental foramina for other purposes.

• Journal of the korean academy of Pediatric Dentistry
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• v.7 no.1
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• pp.53-61
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• 1980

The purpose of this study was to statistically evaluate the spacing of primary dentition according to whether or not a space existed and measurement of amount of space in 205 children (male 114, female 91) from 2 to 6 years of age. The results were as follows; 1. In the incidence of interdental space on each region, spacing between the primary lateral incisors and primary canine in maxilla and between the primary canine and 1st primary molar in mandible showed the highest percentage, on the other hand, spacing between the 1st and 2nd primary molars in both jaw showed the lowest percentage. 2. In the kinds of interdental space, the state of primate space and other space together showed the highest percentage, and in the degree of spacing, $S_2$ showed the highest percentage in both jaw. 3. In the incidence of primate space, maxillary primate space showed higher percentage than mandibular primate space in bilateral case. 4. In the type of arch form, spaced arch showed higher percentage than closed arch and about the half of closed arch showed crowding. 5. In both Jaw, available space showed incisor segments, canine segments, and premolar segments in order of amount, and there were not statistically significant differences of sex or jaws in the amount of available space.

• Archives of Plastic Surgery
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• v.32 no.2
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• pp.168-174
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• 2005

Reconstruction of the lower lip requires consideration of several factors. There should be retained sensation, maintenance of oral sphincter function, and a large enough opening for the mouth. In addition, it is important to achieve an aesthetically acceptable appearance. Webster's modification of Bernard operation is one of good methods which satisfy above mentioned goals. The purpose of this article is to present the results and review the perioperative problems after reconstruction of the lower lip by this operation. We reviewed seven patients after surgical reconstruction by the same method between January of 1996 and December of 2003. Five patients were male and two were female. The mean follow-up period was 15 months. We obtained functionally and cosmetically acceptable appearance after reconstruction. Most of the reconstructed lower lips were large enough for full mouth opening, but one patient required additional commissuroplasty, and one other patient was treated with wound revision for dehiscence resulting from protrusion of mandibular lateral incisor tooth. All other patients accepted their facial appearance. In conclusion, careful planning and consideration for dental problems and proper closure tension may ensure satisfactory outcome & lower lip competence, when using this modified operative method for lower lip reconstruction.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.144-155
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• 1995

It is well known that implants showing no clinical mobility are successfully osseointegrated and have good prognosis. When implants are under load, their mobility begins to increase. It is of necessity to substantiate whether excessive load is on or premature occlusal force is acting prior to desirable osseointegration. Using Periotest unit, we could measure the pattern of mobility change. Consequently, osseointegrated treatment has come to success by intercepting progressive mobility and doing perceptive treatment according to the result of Periotest Value(PTV). In this study, we took records of intangible mobility of 70 osseointegrated implants. And we also measured the mobility of periodontally sound natural teeth as a standard from 30 dental personnel. Conclusions were summarized as followings ; 1. Lower lateral incisor has the highest PTV, whereas lower canine, upper canine, lower premolars and lower 1st molar have the lowest PTV in natural dentition. 2. There are little significant statistical difference of PTV between men and women in both(natural and implant) dentition. 3. In general, lower natural teeth show lower PTV than upper counterpart. 4. Mandibular implants have lower PTV than those of maxillary implants. 5. All of the successfully osseointegrated implants have lower PTV than those of periodontally healthy teeth.

• The korean journal of orthodontics
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• v.38 no.4
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• pp.283-298
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• 2008

Objective: The purpose of this study was to investigate changes in the mandibular dental arch from presurgical orthodontic treatment and orthognathic surgery, and to evaluate the relationships between the pretreatment records and changes of mandibular dental arch in skeletal Class III malocclusion individuals. Methods: Lateral cephalometric radiographs and mandibular study models of 31 adults with skeletal class III malocclusion were taken and measured. All measurements were evaluated statistically by ANOVA, Scheffe's Post Hoc, and paired t-test, and correlation coefficients were evaluated. Results: No significant difference in Mn-LMMC, Mn-LIE, Mn-MnOcc was detected between pretreatment and presurgical groups. Statistically significant but low correlations were demonstrated between the initial arch length discrepancy (ALD) and change in ICW, IPW1 (r = 0.492, 0.615) and change in arch length (r = 0.641). No association was seen between the initial depth of curve of Spee and change in mandibular incisor angle and arch width or arch length. Regression analysis showed that the amount of change for arch length and IPW1 could be explained by 64.0% and 75.8% of the pretreatment variables respectively. Conclusions: This study suggests that orthognathic surgery results can be predictable by measuring the pretreatment records.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.1
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• pp.130-135
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• 2010

Ectopic eruption is caused by an abnormal direction of eruptive path, most common in maxillary first molar, mandibular lateral incisor, and maxillary canine, and sometimes mandibular first molar. Ectopic eruption of first molar leads to abnormal root resorption of second deciduous molar, which, if left untreated, could cause premature loss of second deciduous molar; mesial tilting and rotation of first permanent molar; lack of space for eruption of second premolar; and occlusal problems. Therefore early treatment is advised when diagnosed as ectopic eruption. Treatment of ectopic eruption in the first permanent molar involves providing proper guidance for the direction of eruption using interproximal wedging and distal tipping methods while preserving second deciduous molar. This case report shows satisfactory results of the ectopic eruption of mandibular first molars in young patients who were treated with Humphrey appliance and Halterman appliance.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.69-79
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• 1986

The purpose of this investigation was to know correlation of mean values between centric occlusion and centric relation by the cephalogram in Angle's Class Ⅰ and Ⅲ malocclusion subjects. 22 adults with Angle's Class Ⅰ malocclusion (17 men and 5 women, 21 to 27 years of age) and 14 adults with Angle's Class Ⅲ malocclusion (10 men and 4 women, 21 to 27 years of age) were selected from the dental students in Yonsei University. Each subject was given two lateral cephalometric radiographies and cephalometric analysis was performed. All data from these analyses was recorded and statistically processed with CYBER computer system. 1. The results were obtained as follows: There was a strong positive correlation between centric occlusion and centric relation in all subjects with Angle's Class Ⅰ and Ⅲ malocclusion. 2. In Angle's Class Ⅰ malocclusion, measurements in lower facial height revealed significant difference between centric occlusion and centric relation (P<0.05). In Angle's Class Ⅲmalocclusion, measurements in facial axis angle, mandibular plane angle, convexity of A point, lower incisor protrusion, lower facial height revealed significant difference between centric occlusion and centric relation (P<0.05). 3. When the mandible was moved from centric occlusion to centric relation, the mean distance of mandibular movement was 1.27㎜ (0.2-2.8㎜) in Angle's Class Ⅰ malocclusion, 1.70㎜ (0.55-4.15㎜) in Angle's Class Ⅲ malocclusion, and 1.44㎜ (0.2-4.15㎜) in all subjects.

• The korean journal of orthodontics
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• v.17 no.2
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• pp.165-183
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• 1987

The purpose of this study is to investigate the cephalo-facio-dental relationships in the craniofacial complex and their changes with age, and to use them for diagnostic and treatment purposes in the orthodontics The author studied on the changes of the cephalo-facio-dental relationships, using serial lateral cephalometric roentgenograms of 46 boys and 47 girls aged from 6 to 11 years of normal Korean children Following results were obtained 1 Means and Standard deviation of Korean children were obtained. 2 In the evaluation of the craniofacial vertical proportions, lower anterior face was larger than the upper, and upper posterior face was larger than the lower at all ages 3 The growth change was more prominent in the anterior craniofacial vertical proportion than in the posterior, and growth increment in the upper anterior facial height dimension was larger than m the lower anterior. 4 In the evaluation of the craniofacial horizontal proportion, ANS, Pog, Go and 6 were all situated posterior to their reference ares, and point B was always situated anterior to the arc passing by point A. 5. Anteroposterior growth change was the most prominent in the mandible, and there was no significant difference between the horizontal growth increment in the cranial base and that in the maxilla 6 Growth increment in the horizontal direction was larger in the mandibular apical base than in the maxillary apical base 7 The upper central incisor and the upper first molar were gradually anterior positioned against their reference ares with age increase 8 The length of mandibular corpus was larger than that of cranial base from the seven years old, and the difference was increased as the age increased 9 With age, there was slight difference in the angular relationships formed by craniofacial reference planes and axial inclinations of upper and lower permanent teeth.

• The korean journal of orthodontics
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• v.10 no.1
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• pp.15-27
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• 1980

This study was undertaken to compare the craniofacial morphology of Class II, Division 1 malocclusion with that of normal occlusion in children, and to investigate the incidence of various Class II, Division 1 craniofacial skeletal patterns. The subjects consist of thirty seven boys and fifty three girls with Class II, Division 1 malocclusion, and forty six boys and eighty one girls 10-15 years with normal occlusion. Measurements were recorded, tabulated and analyzed on the lateral cephalograms by the degree of SNA, SNB and ANB. The following characteristics of the Class II, Division 1 skeletal pattern were observed. 1. The anteroposterior relationship of the maxilla to the cranium in the Class II, Division 1 was very similar to that of normal occlusion. 2, Mandible of the Class II, Division 1 malocclusion was in the posterior position in relation to the cranial anatomy when compared to normal. 3. The chin point as measured by SN Pog and NS Gn showed distal positioning in relation to normal occlusion. 4. SN to mandibular plane angle was large in Class II, Division 1 malocclusion. 5. Mandibular incisor inclination was not significantly different between Class II, Division 1 malocclusion and normal occlusion, but maxillary incisors inclined and positioned labially and consequently overjet was large in Class II, Division 1 malocclusion. 6. Class II, Division 1 malocclusion was divided into four types of craniofacial skeletal pattern. The most common Class II, Division 1 pattern was found to be type C in which SN-Mand. Pl. was above mean range of normal occlusion. The next frequent pattern was found to be type A in which maxilla and mandible were within normal range of protrusion while upper incisors were severly labially inclined.