Genome-wide association study of sensory disturbances in the inferior alveolar nerve after bilateral sagittal split ramus osteotomy.

BACKGROUND: Bilateral sagittal split ramus osteotomy (BSSRO) is a common orthognatic surgical procedure. Sensory disturbances in the inferior alveolar nerve, including hypoesthesia and dysesthesia, are frequently observed after BSSRO, even without distinct nerve injury. The mechanisms that underlie individual differences in the vulnerability to sensory disturbances have not yet been elucidated. METHODS: The present study investigated the relationships between genetic polymorphisms and the vulnerability to sensory disturbances after BSSRO in a genome-wide association study (GWAS). A total of 304 and 303 patients who underwent BSSRO were included in the analyses of hypoesthesia and dysesthesia, respectively. Hypoesthesia was evaluated using the tactile test 1 week after surgery. Dysesthesia was evaluated by interview 4 weeks after surgery. Whole-genome genotyping was conducted using Illumina BeadChips including approximately 300,000 polymorphism markers. RESULTS: Hypoesthesia and dysesthesia occurred in 51 (16.8%) and 149 (49.2%) subjects, respectively. Significant associations were not observed between the clinical data (i.e., age, sex, body weight, body height, loss of blood volume, migration length of bone fragments, nerve exposure, duration of anesthesia, and duration of surgery) and the frequencies of hypoesthesia and dysesthesia. Significant associations were found between hypoesthesia and the rs502281 polymorphism (recessive model: combined χ² = 24.72, nominal P = 6.633 × 10⁻7), between hypoesthesia and the rs2063640 polymorphism (recessive model: combined χ² = 23.07, nominal P = 1.563 × 10⁻6), and between dysesthesia and the nonsynonymous rs2677879 polymorphism (trend model: combined χ² = 16.56, nominal P = 4.722 × 10⁻5; dominant model: combined χ² = 16.31, nominal P = 5.369 × 10⁻5). The rs502281 and rs2063640 polymorphisms were located in the flanking region of the ARID1B and ZPLD1 genes on chromosomes 6 and 3, whose official names are "AT rich interactive domain 1B (SWI1-like)" and "zona pellucida-like domain containing 1", respectively. The rs2677879 polymorphism is located in the METTL4 gene on chromosome 18, whose official name is "methyltransferase like 4". CONCLUSIONS: The GWAS of sensory disturbances after BSSRO revealed associations between genetic polymorphisms located in the flanking region of the ARID1B and ZPLD1 genes and hypoesthesia and between a nonsynonymous genetic polymorphism in the METTL4 gene and dysesthesia.

Intravenous sedation and hemodynamic changes during dental implant surgery.

PURPOSE: The purpose of the present study was to determine whether intravenous sedation during dental implant surgery contributed to stabilization of hemodynamics. MATERIALS AND METHODS: Two hundred fifty-five consecutive patients treated with dental implants were randomly assigned to receive either intravenous sedation with local anesthesia (sedation group, n = 123) or local anesthesia only (nonsedation group, n = 132). Midazolam and propofol were used synergistically as sedative agents. Systolic blood pressure, diastolic blood pressure, and pulse rate were measured every 2.5 minutes during dental implant surgery. On the basis of these data, the coefficient of variation, percentage of change, maximum values, and incidences of a larger increase were analyzed and expressed as cardiovascular changes. RESULTS: A comparison of percentages of change, maximum values, and incidences of a greater increase showed that systolic and/or diastolic blood pressure were significantly higher in the nonsedation group than in the sedation group. The combination of midazolam and propofol sedation prevented excessive increases in blood pressure. The circulatory suppression induced by the intravenous sedation regimen not only reduced mental stress arising from the state of sedation but also exerted a pharmacologic effect. The application of this intravenous sedation regimen stabilized hemodynamics and contributed to the safety of the patient in dental implant surgery. CONCLUSION: The application of intravenous sedation had a beneficial effect for hemodynamic changes during dental implant surgery.

Automatic segmentation of teeth from dentomaxillofacial 3D-CT images.

CT is an effective tool for image diagnosis because it enables noninvasive observation of internal organs. In the course of CT, 3D-CT, such as a helical scanning CT and a multi-detector row CT, has been developed. With the use of 3D-CT, organs can be observed from several viewing directions. Even now, however, 3D-CT images are generated by manual procedures to extract objective organs using the threshold method. These procedures waste time and effort. Therefore, development of highly automated and effective extracting techniques has been desired. The region growing (RG) method is one of the effective techniques of extracting internal organs. The conventional RG method, however, has some defects. Extracted regions are strongly affected by the threshold value for segmentation. A break point on a region contour yields a leakage of region. To overcome these defects, we formulated a modified region growing method with edge detection (MRGWED) which combines a three-dimensional region growing technique and an edge detection technique. Using the MRGWED, we tried to extract teeth from dentomaxillofacial 3D-CT image data.

Antimicrobial activity of super-oxidised water against oral microorganisms.

OBJECTIVE: The radical anion of oxygen (O(-)) is extremely oxidative and shows high reactivity. In this study, the antibacterial activity of water super-oxidised water containing high concentration of O(-) (O(-)-water) was tested against cultured planktonic cells of cariogenic bacteria, periodontopathic bacteria and Candida albicans. METHODS: O(-)-water was prepared using the AOE-750 (Oxy Japan Corporation, Japan) and its antibacterial activity against pure culture of Streptococcus sobrinus, Porphyromonas gingivalis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and C. albicans evaluated. Each oral microorganism (10(4) to 10(8)CFU/ml) was exposed to three concentrations of O(-)-water at room temperature or 37 degrees C for 15s to 24h. RESULTS: Exposure to O(-)-water resulted in a bactericidal effect against all cariogenic and periodontopathic bacteria tested. No significant fungicidal effect was observed on C. albicans, however. CONCLUSION: The results demonstrate that O(-)-water exerts an antibacterial effect on cariogenic and periodontopathic bacteria.

Systemic Inflammatory Response Syndrome and postoperative complications after orthognathic surgery.

Symptoms of Systemic Inflammatory Response Syndrome (SIRS) presenting immediately after surgery have lately been regarded as potential warnings of impending postoperative complications and multiple organ failure. Reports discussing the relationship between operative stress and SIRS are found in the field of digestive surgery, but not in that of oral surgery. Sixty-five patients with jaw deformity who had undergone maxillary and mandibular orthognathic surgery (Le Fort I osteotomy and sagittal splitting ramus osteotomy) between September 2003 and October 2006 were involved in this study. A search based on the SIRS diagnostic criteria resulted in assignment of 33 cases to the SIRS group and 32 cases to the non-SIRS group. Postoperative complications occurred in 27.3% of the SIRS group and 0.0% of the non-SIRS group (p<0.01). In four cases, a postoperative fluctuation in IL-6 level evaluated. These results suggest the importance of careful management of postoperative SIRS patients in preventing complications.

Patient in whom surgery was selected to improve mandible position after changing doctors.

A patient who visited our department after job relocation was reexamined, and a marked discrepancy was found in mandibular position between centric occlusion and centric relation. Although the patient was originally scheduled to undergo orthodontic treatment only, the results of comprehensive tests indicated that surgery would be needed to resolve this discrepancy. Surgery was performed with the patient's consent, yielding favorable results. Although the entire orthodontic treatment lasted 3 years and 11 months, including treatment prior to transfer, it was clear that long-term use of intermaxillary elastics would not have corrected the discrepancy and that surgery was the right decision.

Dental implant treatment with different techniques for sinus floor elevation--a case report.

A 60-year-old man with missing maxillary molar teeth received dental implant therapy for reconstruction of occlusion. Sinus floor elevation with autogenous bone graft consisting of iliac bone block and particulate cancellous bone and marrow (PCBM) was performed in the bilateral maxillary sinuses for implant placement. On the right side, bone height in the molar region was less than 2mm. Therefore, a delayed protocol was applied, and 2 implants were placed 4 months after bone grafting. Bone graft resorption occurred during the healing period of 4 months. On the left side, 3 implants were placed simultaneously with sinus floor elevation, as bone height in the molar region was more than 4-5mm. The bone graft was carried out at the same time as implant placement. After implant placement, resorption of the bone graft stopped, and the superstructures were delivered on both sides. The tissues around the implants were clinically healthy at one year after examination. Sinus floor elevation with autogenous bone graft is an acceptable option for implant treatment in the maxillary molar region where there is adequate height of existing bone. In postoperative care, it is important to undertake adequate follow-up to ascertain occurrence of bone graft resorption.

Adenomatoid odontogenic tumor arising from the mandibular molar region: a case report and review of the literature.

This case report describes a rare case of an adenomatoid odontogenic tumor (AOT) arising in the mandibular third molar region of a 20-year-old female. The tumor was a well-circumscribed intraosseous lesion with an embedded tooth. Histologically, the induction of extensive globular calcification was evident in addition to the characteristic histological features of AOT. The present case lends support to the categorization of AOT as an odontogenic tumor consisting of a disorderly mixture of odontogenic epithelium and odontogenic ectomesenchyme with calcification.

Oral cancer research with an emphasis on genomic analysis.

Ablative surgery has been a standard procedure for many years, but during the past few years there has been a significant improvement in our understanding of invasion and metastasis in oral cancer. Each procedure has to be planned individually. Before surgery, every attempt must have been made to arrive at a proper diagnosis, including the exact nature and aggressiveness of the tumor and an analysis of the patient's genetic background. These procedures and the prognosis will be discussed.