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 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

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

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

Orthognathic surgery of the mandibular prognathism and the retrognathism is tend to be performed on the mandibular ramus to prevent inferor alveolar nerve injuries. The purpose of this study is to find a safe and accurate reference point on mandibular ramus for orthognathic surgery by comparative anatomical study of dentofacial deformity patients. We use 38 Korean Cadavers with normal occlusion(Group 1), 3-dimensional simulation of computerized tomogram of 23 patients with retrognathism (Group 2), 27 patients with mandibular prognathism (Group 3). Following results are obtained : 1. The maximum thickness of the mandibular ramus is 8.78+/-1.15mm for Group 2, 7.61+/-1.26mm for Group 1, 6.95+/-0.82mm for Group3 respectively (P=0001). The minimum thickness is 5.51+/-1.08mm for Group 1 , 5.06+/-0.40mm for Group 2, 4.56+/-0.78mm for Group3, respectively (p=0.0001). But, the thickness at the level of 5mm above the lingular is 0.78+/-0.65mm for Group 2, 5.63 +/-1.28mm for Group 1, 5.32+/-0.91mm for Group 3, respectively. There is no significant difference between these groups(P=0.0510). 2. The horizontal location from the midwaist point to lingular is 0.18+/-1.57mm for Group 1, 0.69+/-1.33mm for Group 2, 0.66+/-1.66mm for Group 3, and there is no significant difference between these groups(p=0.0835). But the vertical location from the midwaist point to lingular is 1.45+/-2.64mm for Group 1, 0.63+/-1.44mm for Group 2, 0.34+/-1.81mm for Group 3, and there is significant difference between these groups(p=0.0030). 3. The horizontal location from the midwaist point to mandibular foramen is 0.29+/-1.75mm for Group 1, 0.63+/-1.44mm for Group 2, 0.34+/-1.81mm for Group 3, and there is no significant difference between these groups(p=0.5403). But the vertical location from the midwaist point to mandibular foramen is -3.33+/-4.43mm for Group1, -4.79+/-2.26mm for Group 2, -6.06+/-2.99mm for Group 3, and there is significant difference between these groups(P=0.0001). 4. The horizontal length from the disto-buccal cusp tip of mandibular second molar to lingula is 30.97+/-4.17mm for Group 3, 28.29+/-2.65mm for Group 1, 25.48+/-0.77mm for Group 2 (p=0.0000), and also vertical length is 7.72+/-3.22mm for Group 3, 6.38+/-1.83mm for Group 1, 5.89+/-2.30mm for Group 2 (P=0.0014). 5. The location of lingular is 0.50 from anterior border of mandibular ramus in all groups, if it assumed the length from anterior border to posterior border is 1. And it is almost 0.33 from the sigmoid notch, if it assumed the length from sigmoid notch to antegonial notch is 1. 6. In Group 1, Antilingular prominence is located on (1.12+/-1.43mm, 4.01+/-2.36mm) from the midwaist point, and there is no correlation between antilingular prominence and lingular, mandibular foramen.
Cadaver ; Colon, Sigmoid ; Dentofacial Deformities* ; Humans ; Molar ; Orthognathic Surgery ; Prognathism ; Retrognathia

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

Orthognathic surgery for the correction of dentofacial deformities is a common elective procedure. That has proven over the years to be a safe operation with minimal long-term morbidity. But, there are many surgical complication including mal-union of the bone, TMJ problem, excessive bleeding, and permanent damage of inferior alveolar nerve. Among them excessive bleeding which focus is not clear is one of the serious complication because that is fatal and so a transfusion is performing for the prevention and management of that. Until the end of the 1980's, homologous blood transfusions were routinely necessary because of the large amounts of blood lost during surgery. Recently several blood-saving measures can be undertaken for orthognathic surgery patients before, during, and after the operation. We made a comparative study of an amount of blood loss, hematologic change and transfusion requirements based on a series of 40 consecutive patients undergoing single-jaw and double-jaw surgery. The purpose of this investigation was to make a comparative analysis of an amount of blood loss, post-operative hematologic change and duration of the procedure under induced hypotensive anesthesia in healthy orthognathic patients.
Anesthesia ; Blood Transfusion ; Dentofacial Deformities ; Hemorrhage ; Humans ; Mandibular Nerve ; Orthognathic Surgery* ; Temporomandibular Joint