Radiographic study of the distribution of maxillary intraosseous vascular canal in Koreans / 대한악안면성형재건외과학회지

BACKGROUND: This study aimed to investigate the distribution and prevalence of intraosseous loop (anastomosis between posterior superior alveolar artery and infraorbital artery) in Koreans detected on computed tomography (CT) images taken prior to sinus augmentation surgery. METHODS: From the 177 patients who underwent sinus augmentation with lateral approach at Ewha Womans University Department of Implant Dentistry, 284 CT scans were evaluated. The canal height (CH), ridge height (RH), and canal height from the sinus floor (CHS) were measured on para-axial views at the first premolar, first molar, and second molar. The horizontal positions of the bony canals in the lateral wall were also classified. One-way analysis of variance (ANOVA) and t test were used to estimate the statistical differences (p < 0.05). RESULTS: The intraosseous loops were detected in 92 CT scans (32 %). The mean vertical height of the bony canals from the alveolar crest (CH) was 23.45 +/- 2.81, 15.92 +/- 2.65, and 16.61 +/- 2.92 mm at the second premolar, first molar, and second molar, respectively. In the horizontal positions of the bony canals, intraosseous type was the most predominant. The canal heights more than 15 mm and less than 17 mm were most prevalent (33.7 %) and those under 13 mm were 12.0 %. CONCLUSIONS: The radiographic findings in this study could be used to decide the lateral osteotomy line avoiding potential vascular complication. However, only one third of the canals could be detected in CT scans; a precaution should be taken for the possibility of severe bleeding during lateral osteotomy.

A Multicenter Retrospective Study of Outpatient Intravenous Sedation for Dental Treatments

Four-year survival rate of RBM surface internal connection non-submerged implants and the change of the peri-implant crestal bone

Effect of different sterilization methods on the surface morphology of PPDO-hybrid-PLGA nanofiber scaffold and attachments of PC12 cell

OBJECTIVES: the effect of different sterilization methods on the surface morphology of PPDO-hybrid-PLGA nanofiber scaffold and attachments of PC12 cell were investigated. METHODS: Poly (p-dioxone)-hybrid-Poly (lactide-glycolide) (PPDO-hybrid-PLGA) nanofiber scaffold, fabricated in a tube form with 1.5 mm internal diameter, 0.2 mm thickness and 5 mm length, was prepared using electrospinning method. To study the surface morphology using SEM, The study group and control group in respective were; Control:Non-sterilized scaffold, Group I:scaffold sterilized with 70% Alcohol, Group II: scaffold sterilized with Ethylene Oxide at 65 degrees C, and Group III: scaffold sterilized with Ethylene Oxide at 37 degrees C. To investigate viability of the PC12 cell on the scaffold, The study group and control group in respective were; Control: sterilized with 70% Alcohol, Group I: sterilized with Ethylene Oxide at 65 degrees C, and Group II: sterilized with Ethylene Oxide at 37 degrees C. RESULTS: 1. The surface morphology was slightly changed in Group I, II and GroupIII, compared with control. 2. The attachment of PC12 cells in Group I, II was not higher than in control DISCUSSION: The attachment of PC12 cell is not influenced by different sterilization methods.

Autotransplantation of immature third molars; Pulp healing, periodontal healing and root development

PURPOSES: The aim of this study was to evaluate pulp healing, periodontal healing, root development of autotransplantation of immature third molars and show its viability in treatment of early loss of tooth in young patients MATERIALS AND METHODS: In this article we performed a retrospective study with 41 transplanted teeth in 36 patients. The Mean age at the time of surgery was 17 years(range 13-24 years) and mean postoperative follow up period was 2.4 years(range 1-6 years) We evaluated the survival rate, pulp healing, periodontal healing, root development of the above teeth RESULTS: At the last examination 40 teeth among 41 transplants were still present so survival rate was 97.6%. The pulpal healing was found in 38 teeth of 41 transplants. The periodontal healing was found in 38 transplants. The continuous root development was seen in 38 transplants. CONCLUSIONS: From the above results, the autotransplantation of immature third molars was found to be a useful and reliable treatment method for early loss of teeth in adolescents and young adults.

Mucoepidermoid carcinoma in the mandible : review of a case

the effects of insulin-like growth factor i (igf-i) on expression of vascular endothelial growth factor (vegf) mrna in mg-63 osteoblastlike cells

PURPOSE: To determine the role of Insulin-like Growth Factor-I (IGF-I) in the regulation of Vascular Endothelial Growth Factor (VEGF) expression in MG-63 cells and then to find the mechanism b which this regulation occurs. MATERIALS AND METHODS: MG-63 cells were grown to confluence in 60-mm dishes. To determine the effects of IGF-I on expression of VEGF mRNA according to time and concentration, the cells were treated with 10 nM IGF-I, following isolation of total RNA and Northern blot analysis after 1, 2, 4, 8, 12, 24 hours and after 2 hours of treatment with 0.5, 2, 10, 25, 50 nM IGF-I respectively, isolation of total RNA and Northern blot analysis were followed. To determine the mechanism of action of IGF-I, inhibitors such as hydroxyurea (76.1 microgram/ml), actinomycin D (2.5 microgra/ml), cycloheximide (10 microgram/ml) were added 1 hour after treatment of 10 nM IGF-I. RESULTS: 1. the expression of VEGF mRNA was increased with treatment of IGF-I. 2. The expression of VEGF mRNA was increased according to time- and concentration dependent manner of IGF-I. 3. The effect of IGF-I was decreased by hydroxyuera, actinomycin D, but not by cycloheximide. CONCLUSION: IGF-I regulate the expression of VEGF mRNA in the level of DNA synthesis and transcription. These results could suggest that IGF-I plays an important role in angiogenesis in the process of new bone formation and remodeling.

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.

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.