Diagnosis of dentofacial deformity needs three dimensional comprehensive understanding of craniofacial skeleton. Eventhough three dimensional computerized tomogram has been developed, the quantified measurement analysis is merely depend on cephalomeric analysis. In our pilot study using the ordinary cephalometric radiogram which is commonly used in clinical basis, we tried to reconstruct three dimensional coordinates from frontal and lateral cephalogram taken from five dry skulls attached with small metal ball. To evaluate the reproducibility of the cephalogram, intra-examiner error was measured and compared with the three dimensional coordinates. Fourteen linear measurement of dry skull and three dimensional value has been compared. The results were as follows: 1. The intra-examiner error of the two dimensional cephalogram showed a similar variation below 1 mm in frontal and lateral cephalogram. The error ranged from 0.11-0.13mm in the case of frontal cephalometrics and 0.12-0.57mm for lateral cephalometrics Three dimensional coordinates showed relatively high reproducibility except 7 coordinates out of 90 (7.8%). The average error of the single measurement of x,y,z point shown to be 0.04+/-0.21mm, 0.01+/-0.01mm. 0.08+/-0.08mm. 2. Compare the 14 linear measurement of dry skull and three dimensional measurement, the mean difference was 0.13+/-1.54mm, ranging from 2.59+/-3.00mm (L-Co, R-Co) to 0.01+/-0.38 (ANS, L-Or). From the result by taking real value percentage rate by 3 dimensional measuring value, the mean value was 100.74+/-3.92% and the measurement which showed the most shortening compared with the real value was the distance between R-Or and ANS (97.75+/-3.11%) and the most enlarged measurement was the distance between L-VMC, L-VIC (106.59+/-20.33%). 3. However, compare the real value and two dimensional cephalometric radiograph, difference between the two is significant degree which hinder the use of two dimensional measurement in clinical situation. This potential pitfall of the cephalogram might be overcome by using our three dimensional coordinate system. If the reproducibility of the frontal and lateral cephalogram is achieved, major concern related to the accuracy of three dimensional measurement is correct detection of anatomical landmark. Further investigation of anatomical investigation of facial skeleton will make this system more accurate and popular in clinical field.
Dentofacial Deformities ; Diagnosis ; Pilot Projects ; Skeleton ; Skull

dentofacial deformities. Patients were devided into two groups. One was impaction and advancement of maxilla with mandibular set-back (Group 1), the other was downward and advancement of maxilla with mandibular set-back (Group 2). Preoperative and postoperative one year cephalometric data were analyzed and compared. Results obtained were as follows: 1. The ratio of horizontal changes of soft tissue to hard tissue at Nt to ANS, Ls to UI, Li to LI, sPog to Pog were 1:0.60, 1:0.79, 1:0.47, 1:0.63 in group 1 respectively, and 1:0.59, 1:0.48, 1:0.83, 1:1.09 in group 2 respectively. Soft tissue changes were highly predictable at the upper lip, lower lip, and chin area. 2. The ratio of vertical changes of soft tissue to hard tissue at Nt to ANS, Li to LI were 1:0.72, 1:0.06 in group 1, and others showed no statistically significant difference. 3. The ratio of horizontal changes of Ls to hard tissue movements at LI(h) was 1:-0.82 in group 1 and at UI(h), LI(h) were 1:0.48, 1:0.01 in group 2. These ratios of group 1 were greater than those of group 2.4. The direction of horizontal change of Li was the same as that of hard tissue change. The ratio of horizontal changes of Li to LI was 1:0.47 in group 1 and others showed no statistically significant difference. 5. The changes of upper lip thickness and length were -1.6mm, -1.4mm in group 1, and -1mm, -2.7mm in group 2. 6. The ratios of thickness of upper lip to ANS, UI, LI were 1:-0.83, 1:-0.37, 1:0.11 in group 1. There was similar trend in group 2, and there were no statistically significant difference. These results suggest that prediction of changes in soft tissue of upper lip, lower lip, and chin were 79%, 47%, and 63% in group 1, and 48%, 83%, and 109% in group 2. There was a tendency to decrease in thickness and increase in length of the upper lip.]]>
Chin ; Dentofacial Deformities ; Humans ; Lip ; Malocclusion ; Maxilla

dentofacial deformities. Patients were devided into three groups. One was advancement group of maxilla(Group I, N=14), another was impaction group of maxilla(Group II, N=12) and the other was combination group(advancement & impaction)(Group III, N=12). Preop. and 1 month postop.(T1), preop. and 6 months postop.(T2) were analyzed and compared. The results obtained were as follows; 1. The upper lip thickness(UL-VP) moved anteriorly approximately 62% of the horizontal maxillary change and this was significant in the advancement group(Group I) 2. The upper lip length(Stm-Sn) and the lower border of upper lip(Stm) moved superiorly 25%, 40% of the maxillary impaction group(Group II) (P<0.05) 3. There was significancy in the upper lip thicness(UL-VP) approximately 56% of the combination group(Group III) (P<0.05) 4. The nasolabial angle decreased in all groups, but there were no significancy.]]>
Dentofacial Deformities ; Humans ; Lip ; Nose ; Osteotomy

BACKGROUND: The Le Fort I osteotomy is one of the most widely used and useful procedure to correct the dentofacial deformities of the midface. The changes of the maxilla position affect to overlying soft tissue including the nasal structure. Postoperative nasal septum deviation is a rare and unpredicted outcome after the surgery. There are only a few reports reporting the management of this complication. CASE PRESENTATION: In our department, three cases of the postoperative nasal septum deviation after the Le Fort I osteotomy had been experienced. Via limited intraoral circumvestibular incision, anterior maxilla, the nasal floor, and the anterior aspect of the septum were exposed. The cartilaginous part of the nasal septum was resected and repositioned to the midline and the anterior nasal spine was recontoured. Alar cinch suture performed again to prevent the sides of nostrils from flaring outwards. After the procedure, nasal septum deviation was corrected and the esthetic outcomes were favorable. CONCLUSION: Careful extubation, intraoperative management of nasal septum, and meticulous examination of pre-existing nasal septum deviation is important to avoid postoperative nasal septum deviation. If it existed after the maxillary osteotomy, septum repositioning technique of the current report can successfully correct the postoperative septal deviation.
Dentofacial Deformities ; Maxilla ; Maxillary Osteotomy ; Nasal Septum ; Osteotomy* ; Spine ; Sutures

dentofacial abnormality.]]>
Adolescent ; Dentistry ; Dentofacial Deformities ; Humans ; Osteotomy ; Root Resorption ; Tooth

dentofacial deformity patients.]]>
Cheek ; Dentofacial Deformities ; Female ; Humans ; Male ; Orbit ; Smiling

dentofacial deformity patients. 1. Conventional nasion relator in cephalostat was used to reproduce the same head position for the same dry skull. The mean difference of the three dimensional cephalogram for the same dry skull was 0.34+/-0.33mm. Closeness of repeated measures to each skull reveals the precision of this method for the three dimensional cephalogram. 2. Concerning the accuracy, the mean difference between the three dimensional reconstruction data and actual lineal measurements was 1.47+/-1.45mm and the mean magnification ratio was 100.24+/-4.68%. This Diffrerence is attributed mainly to the ill defined cephalometric landmarks, not to the positional change of the dry skull. 3. Cephalometric measurement of lateral and frontal radiographs had no consecutive magnification ratio because of the different focus-object distance. The mean difference between the frontal and lateral cephalogram to the actual lineal measurements was 4.72+/-2.01mm and -5.22+/-3.36mm. Vertical measurements were slightly more accurate than horizontal measurements. 4. Applying to the actual patient analysis, it is recommendable to use this program for analyzing the asymmetry or spatial change after operation. The orthodontic bracket would be a favorable cephalometric landmark for constructing the three dimensional images.]]>
Dentofacial Deformities ; Head ; Humans ; Imaging, Three-Dimensional ; Orthodontic Brackets ; Skull

Sagittal split ramus osteotomy (SSRO) is widely used in treatment of dentofacial deformities. But, many complications can occur including unfavorable fractures during osteotomy. To prevent these complications, it is necessary to understand comprehensively the anatomy of the mandiular ramus. The purpose of this study was to evaluate the morphology of the madibular ramus in manibular prognathism patients by computed tomography comparing with normal control group. The study group consisted of 33 skeletal class III patients (20 males, 13 females) and the control group consisted of the 52 patients without dentofacial deformities (32 males, 20 females). The mean age of study group was 22.0-year old, and that of control group was 37.1-year. For the CT examination, following scan parameters was used: 1mm slice thickness, 0.5 second scan time, 120kV and 100mA/s. The axial scans of the head were made parallel to the mandibular occlusal plane. The anteroposterior length of the ramus, the distance from anterior border of the ramus to lingula, the relative distance from the anterior border of the ramus to lingula compared to the anteroposterior length of the ramus, the thickness of anterior and posterior cortical plate, the thickness of medial cortical plate of the ramus at lingula level, the thickness of cancellous bone of the ramus at lingula level were measured. The skeletal class III mandibular prognathism patients exhibited shorter anteroposterior length of the ramus, thicker anterior and posterior cortical plate, thinner mediolateral cancellous bone thickness. The lingula has a relative stable anteroposterior position in ramus in all groups. There was higher possibility of fusion of medial and lateral cortical plate at lingula level in the mandibular prognathism group. In conclusion, the mandibular prognathism patients have narrow rami with scanty cancellous bone, which means that careful preoperative examination including CT scan can prevent undesirable fractures during osteotomy.
Dental Occlusion ; Dentofacial Deformities ; Head ; Humans ; Male ; Osteotomy ; Osteotomy, Sagittal Split Ramus ; Prognathism

As the most of dentofacial deformity patients indicated to orthognathic surgery have strong desire for esthetic improvement as well as functional improvement, ideal esthetic evaluation should be made at surgical prediction. Lateral cephalographs has been commonly used for surgical prediction, however, remarkable discrepancy between esthetic viewpoint by simple looking and analysis on lateral cephalographs often found on evaluation of sagittal position of the upper and lower jaws especially in cases of mandibular prognathism of Koreans. In these cases, we have been employed Esthetic NaP(ENaP)-line for corrective evaluation and ideal surgical pre-diction on lateral cephalographs, but the efficacy of ENaP-line has not been evaluated. This is a study on efficacy of ENaP-line for orthognathic surgery of Korean mandibular prognathism. 170 Korean patients who had been diagnosed as mandibular prognathism and planned for orthognathic surgery at Department of Oral and Maxillofacial Surgery, College of Dentistry, Yonsei University during last 10 years are studied. The obtained results are as followings; among 170 patients of mandibular prognathism, 132 patients(77.6%) had not discrepancy in evaluation of sagittal position of the maxilla between cephalometric and esthetic evaluation(they are classified as Group I), however, 38 patients(22.4%) had definite discrepancy(they are classified as Group II). ENaP-line was employed in all cephalometric analysis of Group II. The proportions of male and female were similar in both Groups. Sixteen vertical reference lines perpendicular to 16 horizontal reference lines were obtained as followings; Each of the representative degree of SN/AFH, SN/CFH and AFH/CFH obtained at Group I was applied to SN plane, AFH plane and CFH plane of Group II each other, and so 16 horizontal reference lines could be obtained individually according to each of the applied degree to each plane. And then their reliability to coincide with ENaP-line of Group II was evaluated. A vertical reference line perpendicular to a horizontal line made by application of the representative degree of AFH/CFH in Group I to AFH line in Group II had the most highest coincidence with ENaP-line of Group II, however, its agreement was 42% in male and 47% in female. From this results, the rest of them should be determined their corrective jaw position definitely depend on
Dentistry ; Dentofacial Deformities ; Female ; Humans ; Jaw ; Male ; Maxilla ; Orthognathic Surgery* ; Prognathism* ; Surgery, Oral

OBJECTIVE: The aim of this study was to assess artifacts induced by metallic restorations in three-dimensional (3D) dental surface models derived by cone-beam computed tomography (CBCT). METHODS: Fifteen specimens, each with four extracted human premolars and molars embedded in a plaster block, were scanned by CBCT before and after the cavitated second premolars were restored with dental amalgam. Five consecutive surface models of each specimen were created according to increasing restoration size: no restoration (control) and small occlusal, large occlusal, disto-occlusal, and mesio-occluso-distal restorations. After registering each restored model with the control model, maximum linear discrepancy, area, and intensity of the artifacts were measured and compared. RESULTS: Artifacts developed mostly on the buccal and lingual surfaces. They occurred not only on the second premolar but also on the first premolar and first molar. The parametric values increased significantly with increasing restoration size. CONCLUSIONS: Metallic restorations induce considerable artifacts in 3D dental surface models. Artifact reduction should be taken into consideration for a proper diagnosis and treatment planning when using 3D surface model derived by CBCT in dentofacial deformity patients.
Artifacts* ; Bicuspid ; Cone-Beam Computed Tomography* ; Dental Amalgam ; Dentofacial Deformities ; Diagnosis ; Humans ; Molar