Facial Analysis of Patients with Skeletal Malocclusion Using a Facial 'Phi' Mask

An acoustic analysis on the pronunciation of Korean vowels in patient with class III malocclusion

The purpose of the study was to investigate the characteristics of the pronunciation of Korean vowels in patients with class III malocclusion. 11 adult male patients with class III malocclusion(mean ages 22.3 years) and four adult males with normal occlusion(mean ages 26.5 years) were selected for the analysis of eight Korean monophthongs /i, e, e, a, eo, o, eu, u/. The values and relationships of F1, F2 and F3 were derived from the stable section of target vowel in each sentence, and the analysis using formant plots and vowel triangles' distance and area was conducted to find the features of two groups' vowel distributions. Consequently, it was identified that the pronunciation of males patients with class III malocclusion showed high values of F1 in the low vowels, high values of F2 in the back vowels, and remarkably low position of /a/. The vowel triangle suggested that the triangle areas of male patients with class III malocclusion were shown wider vertically and narrower horizontally than those of males with normal occlusion. These characteristics could reflect the structural features of class III malocclusion such as the prognathic mandible, low tongue position, and advancement of back position of the tongue.

Inferior alveolar nerve injury following removal of mandibular third molar and panoramic radiological risk sign

Correlation of distal caries in the mandibular second molar and eruption state of the mandibular third molar

Distal caries of the second molar is common indication for the mandibular third molar surgery and there are no universally acceptable predictive criteria for distal caries of the second molar. To analyze the correlation of the distal caries of the second molar and the eruption state of the mandibular third molar using panoramic radiographs statistically and propose the acceptable guideline for preventive extraction of the mandibular third molar. 786 patients who were extracted the mandibular third molar from 2002 to 2006 at Samsung medical center were examined. The presence and absence of distal caries of mandibular second molar, age, gender, angulation, impaction degree, distance between distal cementoenamel junction of the second molar and mesial cementoenamel junction of the mandibular third molar were assessed. 79.6% of third molars had a mesial angulation of between 40 degrees and 80 degrees. The mean age of third molar removal for distal caries of second molar was 33.86+/-9.81. The prophylactic removal of a mesio-angular third molar about 40 degrees and 80 degrees could prevent distal cervical caries forming in the mandibular second molar.

Change of lip canting after bimaxillary orthognathic surgery

PURPOSE: The purpose of study was to investigate the correlationship between lip canting change and occlusal canting change after bimaxillary orthognathic surgery, and the ratio of lip canting change and occlusal canting change after the surgery. PATIENTS AND METHODS: The subjects for this study was obtained from a group of 25 patients who took bimaxillary orthognathic surgery for occlusal canting correction at the Department of the Oral and Maxillofacial Surgery, Samsung Medical Center in Seoul, Korea between January 2000 and December 2005 and a patient's chart had to contain a resting frontal facial photograph in natural head position and a corresponding PA cephalogram in occlusion on the same day before the surgery and post-op 6 months later. The lip canting change was assessed with the angle each labial commissure and the bipupilary reference line. And, the occlusal caning change in the frontal plane was assessed with the angle between the each maxillary first molar occulasal surface and the bi-frontozygomatic suture reference line. RESULTS: In angular measurement, average occlusal canting change was 3.09degrees and standard deviation was 1.05degrees, average lip canting change was 1.56degrees and standard deviation was 1.05degrees. In linear measurement, average occlusal canting change was 2.41mm and standard deviation was 2.75mm, average lip canting change was 1.18mm and standard deviation was 0.43mm. Lip canting correction ration to occlusal canting correction was 51.5(+/-8.4)percent in angular measurement and 48.8 (+/-9.1)percent in linear measurement. Under Pearson's correlation analysis, Pearson's correlation coefficient was 0.869 in angular measurement and 0.887 in linear measurement (p-value < 0.01). High correlationship was shown between occlusal canting change and lip canting change. CONCLUSION: First, Bimaxillary orthognathic surgery can correct lip canting as well as occlusal canting. Second, The average amount of lip canting correction is 51.5+/-8.4percent, 48.8+/-9.1percent of occlusal canting correction in the study.

Incidence of sinus septa and accuracy of panoramic radiograph

PURPOSE: The purpose of this study was to determine the incidence of antral septa and the accuracy of panoramic radiograph in identifying maxillary sinus septa. In addition, when panoramic radiograph led to a false diagnosis of more than majority, we analyzed findings of the panoramic radiograph. PATIENTS AND METHODS: This study included 180 patients who were radiographically examined before the surgery was done using both panoramic and computerized tomographic radiographs(CT scan), Samsung Medical Center from April 2003 to March 2006, and examined the incidence of antral septa, the false diagnosis rate of panoramic radiograph, and radiographic characters in case of false diagnosis. Only those bone lamellae were considered as septa that showed a height of at least 3.0mm. It was thus possible to exclude the alveolar recess. One oral and maxillofacial surgeon(OMFS) determined the presence or absence of sinus septa in CT scan, and five OMFS determined the presence or absence of sinus septa in panoramic radiograph. RESULTS: The septa were observed in 81 of 360 sinuses(22.5%). All septa were oriented in a buccopalatal plane. More or less greater prevalence was observed in the second molar region(38.2%) but no predominant location was found. Panoramic radiograph led to false diagnosed septa in 361 of 1800 cases(20.1%). In case of false diagnosis of more than majority, superimposed image on zygomatic process was 44.1%, faint image in the region not related to sinus lifting 26.5%, faint image in the region related to sinus lifting 17.6%, and misconception for superimposed image 11.8% CONCLUSION: In this study we could get clinico-anatomical information of septum in the maxillary sinus. Compared to CT scan, panoramic radiograph can not clearly differentiate the sinus septa, but we consider that panoramic radiograph may improve its usefulness if we take additional modified panoramic radiograph and clinical exam.

Analysis of prosthodontic and surgical treatment of acquired palatal defect after maxillectomy

One of the treatment methods for maxillary cancers or infections in maxilla is maxillectomy. Palatal defect can be resulted from this operation and it may cause functional problems with swallowing and speech, and psychological problems of patients. After maxillectomy, as rehabilitation, there can be two options. One is a prosthodontic treatment using obturator and the other is surgical reconstruction of defect with graft. As both methods have advantages and disadvantages, in determining treatment method after maxillectomy, various factors have to be considered. The purpose of this study is to compare the prosthodontic group to surgical group after maxillectomy with elapsed days prior to commencement of postoperative oral feeding, and to analyze the results of prosthodontic treatment and surgical treatment. During the period from March of 2000 to June of 2006, 74 patients were treatment by prosthodontic methods for maxillary defect. Among these patients, patients who had only velopharyngeal deficiency after surgery, whose data were incomplete, whose causes of palatal defect were not the treatment of diseases in maxilla, and who already had palatal defect due to previous surgery were excluded in this study. The patients who underwent maxillectomy for the treatment of diseases in the maxilla and were treated immediately after operation using surgical reconstruction or prosthodontic rehabilitation were included in this study. The records of 43 patients were reviewed to compare and to analyze the prosthodontic treatment and surgical reconstruction after maxillectomy. The median of days elapsed prior to commencement of postoperative oral feeding in the prosthodontic group was compared with data of surgical group. The data was analyzed using the Mann-Whitney test (alpha= .05). Days elapsed prior to postoperative oral feeding commencement in the prosthodontic group were less than those in the surgical group.

The study on the bone resorption rate after vertical alveolar ridge augmentation

< 0.05). Also significant difference is on volume resorption on two groups (P < 0.05). CONCLUSION: We found that more bone resorption occurred with iliac(endochondral) bone and when we use intraoral bone, that bone can maintain their vitality for alveolar ridge augmentation.

The study on ridge preservation for implant site development

PURPOSE: The aim of this study was to investigate healed bovine bone particles (Bio-Oss(R)) and absorbable collagen sponge (CollaPlug(R)) applied extraction socket site at 4-6 months' post-extraction. MATERIAL AND METHODS: From August, 2004 to October, 2005, 17 sockets in 5 adult patients were selected out of the patients whose received ridge preservation using bovine bone particles and absorbable collagen sponges at Department of oral and maxillofacial surgery in Samsung Medical Center. There were 5 male patients, ages 30 to 58 years. Immediate postoperation and 4-6 months after operation study models were compared to evaluate the ridge dimension by measuring vertical height and horizontal width of alveolar ridge. RESULTS: The measurements at 4-6 months revealed, in the ridge dimension, a loss of vertical height of 0.91+/-0.40mm and horizontal width of 1.25+/-0.58mm. There was no adverse reaction. CONCLUSION: This study suggests that treatment of extraction sockets with graft materials and collagen sponges is valuable in preserving alveolar bone in extraction sockets and preventing alveolar ridges defects.

The study on the prognosis of dental implants which has been installed after maxillofacial trauma

PURPOSE: The purpose of this study was to evaluate the success rate of dental implant on post-traumatic region to rehabilitate missing teeth. PATIENTS AND METHODS: 5 patients who had been treated due to maxillofacial trauma during 2000 to 2004 at samsung medical center were selected for this study. 22 dental implants were installed to them for restoring missing teeth. The success rate of these dental implants was evaluated with criteria by T. Albrektsson .We divided installed 22 implants into 2 categories. One category consisted rough surface implants group and smooth surface implants group. And the other category consisted more healing group and less healing group. The healing time was calculated from point of trauma. RESULTS: The success rate of dental implants is 68.2% that is lower than other studies because of poor vascularity of bone bed and mechanical stress according to trauma. Rough surface implants group and More healing group showed superior success rate to others. (P < 0.05) CONCLUSION: We found that to increase success rate, it may need rough surface implants and longer healing period.

Radiographic Study of Peri-Implant Bone Loss and Its Relationship to the Morphology on Maxillary Anterior Alveolar Ridge

PURPOSE: The purpose of this study was to evaluate peri-implant bone loss and implant success on anterior maxillary alveolar ridges and Compare Class III and Class IV ridges in the aspect of peri-implant bone loss. MATERIAL AND METHODS: 14 patients (aged 21 to 68, 6males and 8females), who lacked maxillary anterior teeth and were installed from January 2000 to April 2003 at Samsung Medical Center, were selected. The type of implant used included 30 Branemark implant. They were taken with digital tomographic and conventional intraoral radiographic examinmation, and were treated with implant installaion without bone augmentation. The peri-implant bone resorption was measured at the mesial and distal aspect of implant on the conventional intraoral radiographs. RESULTS: The study classified the anterior maxillary alveolar ridge and measured peri-implant bone resorption from the period of implant installation to the 2nd year after functional loading radiographically. The study revealed no statistically significant difference between two groups, which was classified by its morphology. The average bone resorption on healing period before loading was 0.18mm and 0.18mm, the 1st year of loading period, 0.77 mm and 0.84mm, and on the 2nd year of loading period, 0.07mm and 0.06mm, respectively on both Class III and class IV. CONCLUSION: In the knife edge form of anterior maxillary residual ridges(Class IV), implant placement without ridge augmentation does not have significant difference with that of Class III alveolar ridge in the concern of Implant success after 2 year functional loading period in the aspect of peri-implant bone resorption radiographically.

A study of bone resorption at the posterior border of distal segment after bilateral sagittal split ramus osteotomy of manibular prognathic patients

PURPOSE: This study is to predict the changes of the distal segment by investing the resorption of the excessive distal segment regarding the amount of setback after BSSRO. MATERIAL AND METHODS: 20 patients with Mandible prognathism treated by Obwegeser-Dal Pont method during the years 2000 to 2002 were selected for this study. Group A consisted of 5 males and 5 females with a setback amount of 10mm and above(Mean 10.80mm+/-1.03, n=20) and Group B consisted of 2 males and 8 females with a setback amount of below 10mm.(Mean 6.10mm+/-1.10, n=20) Panorama X-ray was taken at day 1, 1month, 3months, 6months, and 12months after the surgery. Resorption areas of excessive distal segment were measured on these panorama X-rays and compared. RESULTS: There was bone resorption in both groups. Group A showed more bone resorption than Group B. Group B showed slightly higher resorption rate than Group A. However, there was no statistically significant difference between the resorption rates of Group A and Group B. (P>0.05) CONCLUSION: More bone resorption occurred with a larger amount of setback and about one third of the excessive distal segment underwent resorption, irrespective of the amount of setback.

A study of upper lip profile change after anterior segmental setback osteotomy

PURPOSE: Prediction for soft tissue change after orthognathic surgery is very important for the final esthetics. In this study, we have tried to get the amount of upper lip movement relative to bony segment movement after anterior segmental osteotomy by cephalmetric analysis to predict final upper lip position after surgery. MATERIAL AND METHODS: 20 patients was studied on whom anterior segmental osteotmy as performed by Cupar method during the years 2002 to 2003. Cephalometric radiograph were taken at 1month before surgery and 6 month after surgery. Change of upper lip was measured on landmark Ls and Sto relative to hard tissue (landmark Ia) setback on these X-rays and analyzed. RESULTS: 1. Upper lip setback movement Setback of upper lip showed proportional relation to the hard tissue setback and the ratio was about 84 % (p=0.001). 2. Upper lip downward movement Downward movement of upper lip showed no proportional relation to hard tissue setback And the amount was mean 1.38 mm and SD 1.21mm (p=0.922). CONCLUSION: The posterior movement of upper lip is affected by hard tissue movement and shows good proportional change whereas downward movement is not so much influenced by hard tissue movement. And we think slight downward movement shown in this study could be explained by the V-Y closure performed during surgery.

The study on vertical stability of anterior open bite patients after bssro

PURPOSE: The purpose of this study was to investigate the vertical stability after BSSRO surgery in skeletal class III malocclusion patients with mild anterior open bite and to present a method to increase the stability. MATARIALS AND METHODS: 36 patients, 11 male and 25 female, who received BSSRO surgery with the diagnosis of skeletal class III with anterior open bite at the Department of Oral and Maxillofacial Surgery in Samsung Medical Center, from January 2002 to August 2003, were selected for this study. The patients were between 18 to 45 years of age. Preoperative and postoperative (immediate, 6 months, and 1 year after operation) lateral cephalograms were compared to evaluate the vertical stability by measuring the distance of nasion-menton, mandibular plane angle, and overbite. RESULTS: The nasion-menton distance decreased by 1.65mm immediately after the operation in comparison to the preoperative value. This distance further decreased by 0.60 mm at 6 months and 1.06 mm at 1 year after the operation. The mandibular plane angle increased after the operation and further increased at 6 months and 1 year. The amount of overbite increased by the operation was 2.34mm and an additional increase of 0.70mm at 6 months and 0.94 mm at 1 year were shown. CONCLUSION: Clinically, none of the patients showed relapse of anterior open bite and the vertical stability is highly influenced by orthodontic treatment after the operation. In this study, BSSRO surgery is considered to be a rather reliable procedure that restores stability to skeletal class III malocclusion patients with slight anterior open bite.

Oral granular cell tumor of the palate

Granular cell tumor is a uncommon disease, although head and neck region accounts for approximately 50% of all lesions, 70% are located in oral cavity but can occur at other site of the body. Clinically, it usually presents as a small, slow growing, non-tender, single benign lesion but mutifocal and malignant forms are rarely encountered. The histogenic origin of this tumor was controversial for many years but recent studies using immunohistochemical study support its origin being from neural cell, probably Schwann's cell. In this report, we present a case of benign granular cell tumor occurred on the hard palate studied by histologic and immunohistochemical assay, with review of literatures.

Surgical correction of maxillofacial deformity with fibrous-osseous lesion of mandible using the intraoral vertical ramus osteotomy

A 22-year-old male patient had developed a submasseteric abscess secondary to a mandibular osteomyelitis at the age of 7 years old. The initial presentation at that time seems to be acute suppurative parotitis. The computed tomographic scans taken before surgery demonstrated diffuse deformity, sclerotic change and osteolytic lesion in the mandible. There was no marrow space on both sides of mandibular ramus and thin-walled cortical bone was seen. So, from the results of the computed tomography, the surgery was performed intraoral vertical ramus osteotomy (IVRO) instead of performing the more commonly used bilateral sagittal split ramus osteotomy (BSSRO). In this report, we present a case of surgical correction of mandibular prognathism with fibrous-osseous lesion of mandible with using IVRO.

Biologigic membrane for guided bone regeneration

The purpose of this study was to evaluate the stability and efficacy of biologic membrane made of freeze-dried cartilage as a barrier to facilitate guided bone regeneration in experimental non-healing bone defects in the rat mandible. Nine adult Sprague-Dawley rats (400-500g) were used in experiment. 5.0mm in diameter were created on the mandibular angle area by means of slow-speed trephine drill. In microscopic examination, dynamic immature bone forming at 2 weeks and its calcification at 4 weeks were observed. The membrane made of lyophilized cartilage taken from human costal cartilage seems to be very effective for guided bone regeneration as a biologic membrane and the scaffold for attachment of cells or local drug delivery system of growth factor, which may meet the ideal requirement of a barrier membrane and graft materials.

Bioassay of human tooth protein blotted polyvinylidene difluoride(PVDF) membrane

PURPOSE: Human tooth proteins are highly heterogeneous, comprising diverse proteins derived from a number of genes. The attempts to identify protein for activity of tooth matrix proteins have been defied by several factors. First, the amount of proteins within teeth is very small relative to many extracellular matrix proteins of other tissues. Second, the bioassay system is tedious and needed for long time. Therefore we tried to find easy techniques, which increase the product rate, and an assay of small proteins, with which amino acid sequence is possible without additional procedures. Materials and METHODS: Total protein were extracted from 300 g enamel removed teeth and 600 g teeth with 4 mol/L guanidine HCl and purified by gel chromatography. Aliquot of proteins was implanted into muscle pouches in Sprague-Dawley rats for bioassay. By SDS-PAGE and membrane blotting, molecular weight of each protein was estimated and a partial amino acid sequence was obtained. Each fraction blotted on the membrane was cut out and inserted in rat ectopic model. RESULTS: In dissociative method, total tooth proteins were obtained 1mg/ml from enamel removed teeth and 3.5 mg/ml from teeth. In SDS-PAGE, four clear bands at the sites corresponding to 66, 40, 20 and 18 kD. Especially The 66 kD band was clearly exhibited. Amino acid sequencing from tooth could be possible using PVDF membrane blotting technique. In amino acid sequencing, 66 kD protein was identified as albumin. CONCLUSION: Compared with conventional method for extraction of teeth protein and bioassay of proteins, the methods in this study were easy, time-saving and more productive technique. The matured tooth proteins omitting additional procedure of mechanical removal of enamel were simply analyzed using blotted PVDF membrane. This method seems to make a contribution as a technique for bioassay and amino acid sequencing of protein.

Measurement and analysis of the resistant muscle force of medial Pterygoid muscle in the mandibular prognathic patients

The purpose of this study was to evaluate the resistant force of medial pterygoid muscles against the mandibular advancement and distraction to anterior, and inquire into the relationship between medial pterygoid muscles and cephalometric variables. Sixty six patients with class III malocclusion underwent bilateral sagittal splitting of ramus with intraoralvertico-sagittal ramus osteotomy for mandibular set-back. The spring scale was used to measure the resistance of medial pterygoid muscles after splitting of ramus. Skeletaldental cephalometric analysis was made and statistic package was used for correlation between resistance and cephalometric variables. The resistant force of the right medial pterygoid muscle was greater than the left one in Koreans with class III malocclusion, and the force had a linear regression relationship with facial depth. The results suggested that facial depth has significant correlation with the resistance of medial pterygoid muscle, which can be acquired from patient's cephalometric analysis.

Malignant ameloblastoma of mandible with lymph node metastasis

Ameloblastomas are generally considered to be benign tumors of odontogenic epithelial origin with high local recurrence. Rarely ameloblastomas exhibit malignant behavior with development of metastases. In this report, we present a 19-year-old woman with ameloblastoma in the right ascending ramus and multiple recurrences. Eleven years after first therapy, ameloblastoma metastasized to ipsilateral submandibular lymph node. We also review literature about cause, treatment and work-up of malignant ameloblastoma.