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Background/Aim: Idiopathic condylar resorption (ICR) is a morphological change of the condylar head that occurs following orthodontic treatment or orthognathic surgery. This complication is serious, as it can cause relapse after mandible treatment. The aim of this experimental study was to evaluate the mechanism of influence of condylar resorption on compressive mechanical stress in temporomandibular joint following a change in occlusal position by mandible advancement. Materials and Methods: An osteotomy procedure at the midline of mandible was performed in 15 rabbits, with the left side moved forward by 3.5 mm. Advancement of the left side of the mandible resulted in compressive mechanical stress on condylar head on the left side. Samples were subjected to micro-computed tomography, histological staining and immunohistochemistry. Results: The area and depth of anterior condylar resorption at two weeks were significantly different as compared to those at one week (p

The most typical maxillofacial feature of patients with acromegaly is mandibular protrusion. This study aimed to determine differences in maxillofacial morphology between skeletal Class III patients with and without acromegaly using cephalometric analysis. Cephalograms of 37 patients with acromegaly (Acro), 37 age-matched non-acromegalic patients with skeletal Class III malocclusion (C-III), and 37 age-matched Class I malocclusion patients (C-I; control) were retrospectively collected. The skeletal and dental morphology of each group was analyzed using cephalometric analysis, which included linear and angular measurements and facial profilograms. In addition, we analyzed diagnostic performance and cutoff values for discriminating acromegaly from skeletal Class III malocclusion using receiver operating characteristic (ROC) curve analysis. The mandibular ramus height was larger in the Acro group than in the other groups. The increase in L1/MP in the Acro group, which represented labial inclination of the mandibular central incisors, was the most characteristic feature in this study. ROC curve analysis indicated that a cutoff value of 88.4° for L1/MP had the highest diagnostic performance in discriminating acromegaly from non-acromegalic Class III malocclusion. Acromegaly was characterized by a greater degree of bimaxillary prognathism than was non-acromegalic Class III malocclusion. Focusing on labial inclination of the mandibular central incisors would be the most useful way to differentiate acromegaly from non-acromegalic Class III malocclusion.

To ascertain the effects of exposure parameters (tube current and tube voltage) and the gutta-percha cone (GPC) size on root fracture-like artifacts obtained with cone-beam computed tomography (CBCT). Fracture-like artifacts appearing on CBCT images of nine extracted human mandibular premolars filled with GPCs of size #50 or #80 were analyzed using six exposure factors: two tube voltages (80 kV and 110 kV); and three tube currents (4 mA, 7 mA, and 10 mA). On axial images, the gray value (GV) was recorded at three points: the mesiobuccal portion (MBP) as the sound dentin, the mesial portion (MP) as the artifact line, and the water area (WA). The rate of decrease in the GV (RDGV) of the artifact line was calculated using the formula: RDGV (%) = (GV of MBP − GV of MP) × 100/(GV of MBP − GV of WA). Comparison of the #80 group and the #50 group with equal tube voltages and tube currents shows that artifact lines in the #80 group were more obvious than those in the #50 group. The artifact lines with 80 kV were markedly more visible than those with 110 kV for each tube current and GPC size. Tube current changes did not affect the artifact line for any tube voltage or GPC size. For the reduction of artifacts, we recommend selection of higher tube voltages and lower tube currents when taking CBCT images of teeth with each GPC size.

Objective We assessed the aetiology of idiopathic condylar resorption by examining the effects of oestrogen and compressive mechanical stress under a low systemic oestrogen condition in temporomandibular joints (TMJ) caused by an ovariectomy. Materials and methods Female rabbits were divided into non-ovariectomy (non-OVX) and ovariectomy (OVX) groups. A cortical osteotomy was performed with a custom device that was increased in length by 0.25 mm every 12 hr for 1 week after the operation, during which the TMJs in the rabbits received compressive mechanical stress. Samples from both groups were examined with micro-computed tomography and histological staining. Results Area and depth of bone resorption were both greater in the OVX group. Furthermore, a significantly earlier and greater prevalence of sub-condylar bone resorption was noted in that group, while cells positive for tartrate-resistant acid phosphatase were increased in the OVX group. Conclusions The present findings suggest that oestrogen induced a much greater amount of bone resorption on the anterior surface of the condylar head at an earlier stage in the TMJs of the present model rabbits. Thereafter, restoration of TMJ function appeared to occur in a normal manner.

Oral bacteria may contribute to postoperative infectious complications including postoperative pneumonia or surgical site infection. The aim of this study was to investigate the impact of preoperative dental care on postoperative outcomes among surgical patients under general anesthesia.Retrospective cohort study.We analyzed clinical records of major surgical patients at a university hospital between 2016 and 2018. Subjects were categorized into either the preoperative dental care group, those being referred to dentists by their surgeons based on an individual surgeon's judgment for dental care before surgery, or the control group.The primary outcome was postoperative infectious complications. Secondary outcomes were postoperative inflammation markers (C-reactive protein and fever), and economic outcomes (postoperative length of hospital stay and medical expenses). As the main analysis, the average treatment effects of the preoperative dental care were obtained from the augmented inverse-probability weighting (AIPW) method with consideration of demographics and perioperative risk factors to estimate causal effect of the intervention from the observational data. Then, stratified analyses by age and surgical sites were conducted with the inverse-probability weighting and linear regression methods, respectively.In the AIPW estimation, compared with the control group, the care group saw a significantly lower rate of postoperative infection (average treatment effect -3.02) and shorter fever duration (-2.79 days). The stratified analysis by age revealed significant positive impact of dental care in all age groups, including the highest treatment effects observed among patients younger than 60. Also, treatment effect was observed in wider surgical sites than previously known.This study indicates a significant impact of preoperative dental care on preventing postoperative infection and inflammation. Along with old age or certain types of surgeries in which advantages of dental referral have been already known, preoperative dental referral could be beneficial for broader types of patients.

Objective To evaluate the background factors related to the occurrence of complications in the early stages after dental implant placement. Materials and methods A total of 289 outpatients who received dental implants were retrospectively evaluated for the presence or absence of complications. Background factors, including age, sex, implant width, implant length, implant site, number of implants placed, Periotest values at the time of implant placement, presence/absence of systemic disease (particularly diabetes), and the use of anticoagulation therapy, were compared between patients with and without complications. Logistic regression analysis was performed to identify significant risk factors for the occurrence of complications after dental implant placement. Results Complications in the early stages after dental implant placement occurred in 25 (8.65%) patients. The patients with complications were older than those without complications (P = 0.003). In addition, the incidence of complications was significantly higher in patients with systemic diseases (P = 0.004) and in those receiving anticoagulation therapy (P = 0.005). Logistic regression analysis revealed that age was a significant risk factor (P = 0.025) for early-stage complications, whereas the number of implants, presence of diabetes, and the use of anticoagulation therapy were not significant risk factors. Conclusions Our results show that age is a significant factor influencing the occurrence of complications in the early stages after dental implant placement. Therefore, clinicians should consider this factor when developing their treatment strategies.

Neurofibromatosis type 1 (NF1) is an inherited, autosomal-dominant disorder, also known as von Recklinghausen’s disease. This pathology was first described from a series of patients displaying a combination of nervous system tumors and findings such as cafe-au-lait spots, eye lesions, and bone lesions. Oral mucosal tumors are common in association with NF1, but are relatively rare on the lateral border of the tongue. We describe the case of a 17-year-old boy who presented to the Department of Oral and Maxillofacial Surgery at Tokyo Women’s Medical University Hospital with the chief complaint of swelling and pain involving the right lateral border of the tongue. Medical history included NF1 and developmental disorder. Several cafe-au-lait spots were observed on the back, but cutaneous neurofibromas were not apparent elsewhere on the body. Examination of the oral cavity revealed a lobulated lesion involving the right anterior two-thirds of the tongue. Excisional biopsy was performed for an exophytic portion of the right lingual edge of the lesion. Histopathological analysis of the tongue lesion confirmed the diagnosis of neurofibroma. Because the tongue lesion was widespread on the right side and the patient was 17 years old, we performed conservative treatment comprising surgical resection of only the dysfunctional, painful part of the lesion. Three years have elapsed with no sign of exacerbation.

Objective We experimentally compared the effects of compressive and tractional mechanical stress on the temporomandibular joint (TMJ) of rabbits to assess the etiology of progressive condylar resorption. Materials and methods We performed a cortical osteotomy using custom-made devices that were lengthened by 0.25 mm every 12 h for 1 week after surgery. During this time, the rabbit TMJ was under compressive or tractional mechanical stress. The samples in each group were examined using micro-computed tomography and histological staining. Results Scores for the area of bone resorption were higher in the compressive group than in the tractional group. Moreover, scores for the depth of bone resorption were higher in the compressive group than those in the tractional group. We observed a significantly higher prevalence of resorption in the subcondylar bone in the compressive group than in the tractional group. There were substantially more cells that were positive for tartrate-resistant acid phosphatase in the compressive group than in the control and tractional groups. Conclusions The outcomes here suggest that excessive mechanical stress, particularly compressive mechanical stress, may significantly affect morphological bone change findings in the TMJ.

Background/aim Epidermal growth factor receptor (EGFR) is a target of molecular therapeutics for non-small cell lung cancer. EGFR gene mutations at codons 746-753 promote constitutive EGFR activation and result in worst prognosis. However, these mutations augment the therapeutic effect of EGFR-tyrosine kinase inhibitor. Therefore, the detection of EGFR gene mutations is important for determining treatment planning. The aim of the study was to establish a method to detect EGFR gene mutations at codons 746-753. Materials and methods EGFR gene mutation at codons 746-753 in six cancer cell lines were investigated. A loop-mediated isothermal amplification (LAMP)-based procedure was developed, that employed peptide nucleic acid to suppress amplification of the wild-type allele. Results This mutation-oriented LAMP can amplify the DNA fragment of the EGFR gene with codons 746-753 mutations within 30 min. Moreover, boiled cells can work as template resources. Conclusion Mutation oriented-LAMP assay for EGFR gene mutation is sensitive on extracted DNA. This procedure would be capable of detecting EGFR gene mutation in sputum, pleural effusion, broncho-alveolar lavage fluid or trans-bronchial lung biopsy by chair side.

We report a case of lymphoma that developed on the mandibular gingiva and spontaneously regressed after biopsy was performed. The patient was an 87-year-old man who visited our hospital with a complaint of gingival swelling in the left mandibular molar region. We observed an elastic, soft, well-demarcated, granuloma-like mass measuring 30 × 25 mm in size and comprising partially white pseudomembranous areas. We conducted a biopsy, which confirmed a pathologic diagnosis of a diffuse large B-cell lymphoma. Because of age constraints, the patient was monitored without being administered aggressive therapy, and the mass disappeared 20 days after biopsy. We then performed a follow-up biopsy, which revealed the absence of tumor cells. There was no recurrence of lymphoma during the 2.5-year follow-up period.

Epidermal growth factor receptor (EGFR) is a target of molecular therapeutics for non-small cell lung cancer. EGFR gene mutations at codons 746-753 promote constitutive EGFR activation and result in worst prognosis. However, these mutations augment the therapeutic effect of EGFR-tyrosine kinase inhibitor. Therefore, the detection of EGFR gene mutations is important for determining treatment planning. The aim of the study was to establish a method to detect EGFR gene mutations at codons 746-753.EGFR gene mutation at codons 746-753 in six cancer cell lines were investigated. A loop-mediated isothermal amplification (LAMP)-based procedure was developed, that employed peptide nucleic acid to suppress amplification of the wild-type allele.This mutation-oriented LAMP can amplify the DNA fragment of the EGFR gene with codons 746-753 mutations within 30 min. Moreover, boiled cells can work as template resources.Mutation oriented-LAMP assay for EGFR gene mutation is sensitive on extracted DNA. This procedure would be capable of detecting EGFR gene mutation in sputum, pleural effusion, broncho-alveolar lavage fluid or trans-bronchial lung biopsy by chair side.

Background Alveolar bone is often lost after tooth extraction. Few studies have assessed the longitudinal changes in bone volume that occur within these extraction sites. Purpose To investigate the longitudinal morphological changes in extraction sockets following sustained continuous subcutaneous infusion of human recombinant insulin-like growth factor I (IGF-I). Materials and Methods Fourteen rats were subjected to right mandibular first molar extraction. Experimental rats (n = 7) received a continuous subcutaneous infusion of human recombinant IGF-I (320 mg/day) for 3 weeks by osmotic minipump. Control animals were treated with saline via the same method (n = 7). All rats were then housed for an additional 3 weeks. Micro-CT scanning was performed immediately after tooth extraction and at 1, 2, 3, and 6 weeks after extraction. Results New bone formation was markedly higher in the IGF-I-treated group as compared with the control group. The loss in alveolar ridge height in the IGF-I group was significantly lower than that in the control group at each time point after extraction on the buccal side and at 2, 3, and 6 weeks on the lingual side. Conclusions IGF-I treatment increases the volume of newly formed bone and reduces the loss in alveolar ridge height following tooth extraction.

We studied maxillofacial fractures treated by departments of oral and maxillofacial surgery in Tokyo. A retrospective review of records and radiographs for patients admitted during the 5-year period from 2000 to 2004 was conducted at five departments in Tokyo. Date, age, gender, cause of injury, fracture site, concomitant injury, domestic violence against women, and treatment were reviewed. 674 patients with maxillofacial fractures were admitted. Male-to-female ratio was 3.6 : 1. The most frequent age group was 21–25 years. Fractures of the mandible were most frequent (87%), followed by the maxilla (14%) and the zygomatic bone (12%). Thirty-one percent of fractures were due to traffic accidents, 29% to accidental falls, 23% to violence and 14% to sports. The incidence of maxillofacial fractures caused by traffic accidents was lower, and that caused by falls and violence were higher than in other countries. Seventeen percent of the maxillofacial fracture patients had concomitant injuries. The incidence of domestic violence-related maxillofacial fracture was 1.6% of all cases. These cases were mainly caused by a husband (55%) or a sexual partner (36%). Most patients (67%) were treated by open reduction surgery. However, condylar fracture alone was usually treated by closed reduction surgery.

Epidermal growth factor receptor (EGFR) is a target of molecular therapeutics for colorectal cancer. However, mutation of Kirsten rat sarcoma viral oncogene homolog (KRAS) gene at codons 12 and 13 attenuates the therapeutic effect of anti-EGFR therapies. Therefore, the detection of KRAS gene mutation is important for therapeutic decision-making.KRAS gene mutation at codons 12 (c.34GT, c.35GC, c.35GA) and 13 (c.38GA) in six cancer cell lines were investigated. A loop-mediated isothermal amplification-based procedure was developed that employed peptide nucleic acid to suppress amplification of the wild-type allele.This mutation-oriented gene-amplification procedure can amplify the DNA fragment of the KRAS gene with codon 12 and codon 13 mutation within 30 min. Moreover, boiled cells can work as template resources.This newly developed procedure can be useful for patient stratification for anti-EGFR therapies.

Alveolar bone is often lost after tooth extraction. Few studies have assessed the longitudinal changes in bone volume that occur within these extraction sites.To investigate the longitudinal morphological changes in extraction sockets following sustained continuous subcutaneous infusion of human recombinant insulin-like growth factor I (IGF-I).Fourteen rats were subjected to right mandibular first molar extraction. Experimental rats (n = 7) received a continuous subcutaneous infusion of human recombinant IGF-I (320 mg/day) for 3 weeks by osmotic minipump. Control animals were treated with saline via the same method (n = 7). All rats were then housed for an additional 3 weeks. Micro-CT scanning was performed immediately after tooth extraction and at 1, 2, 3, and 6 weeks after extraction.New bone formation was markedly higher in the IGF-I-treated group as compared with the control group. The loss in alveolar ridge height in the IGF-I group was significantly lower than that in the control group at each time point after extraction on the buccal side and at 2, 3, and 6 weeks on the lingual side.IGF-I treatment increases the volume of newly formed bone and reduces the loss in alveolar ridge height following tooth extraction.

Object. Using magnetic resonance (MR) imaging, we studied brain injury from ventricular puncture performed during craniotomy in the acute stage of subarachnoid hemorrhage (SAH). Methods. 80 patients underwent craniotomy for aneurysm obliteration within 48 hr after SAH, ventricular puncture for drainage of cerebrospinal fluid (CSF) was perfomed to reduce intracranial pressure. MR imaging was performed within 3 days following surgery to measure the size of the lesion, and was repeated on postoperative days 14 and 30. Conclusions. Of the 80 patients with ventricular puncture preceding craniotomy, 65 (81%) showed MR evidence of brain injury from the puncture. Overall, 149 lesions were detected. According to coronal images, cortical injuries (54 cases), penetrating injury to tracts along the ventricular tube (55 cases), caudate injury (25 cases), and corpus callosum injury (15 cases). Brain injuries from ventricular puncture did not correlate significantly to patient outcome. While ventricular puncture and drainage of CSF can readily be performed to decrease brain volume at the time of craniotomy in acute-stage SAH, neurosurgeons should be aware of a surprisingly high incidence of brain injury complicating puncture.

Objective The control of bleeding after tooth extraction is a major concern in patients taking warfarin. Light-emitting diode (LED) irradiation with hemostatic gelatin sponge application was investigated. Study Design Patients who took warfarin and required tooth extraction were divided randomly into 3 groups. The first group was irradiated with blue-violet LED after tooth extraction. The second group was treated with a hemostatic gelatin sponge and LED irradiation. The third group was treated with only hemostatic gelatin sponges. Hemostasis was evaluated at 30 seconds after treatment. Results Less than 30% of the patients achieved hemostasis within 30 seconds in the hemostatic sponge group; approximately 50% of the patients in the simple LED irradiation group achieved hemostasis within 30 seconds; and 86.7% of the patients in the LED and hemostatic sponge combined group achieved hemostasis within 30 seconds, indicating that combined treatment with LED and hemostatic sponges provided a significantly higher hemostasis than in the hemostatic sponge group (P Conclusions Blue-violet LED irradiation combined with hemostatic gelatin sponge treatment yielded hemostasis of the extraction socket within 30 seconds without suture in most cases.

OBJECTIVE By use of serial magnetic resonance imaging (MRI), we prospectively investigated the incidence of and the risk factors associated with infarction caused by vasospasm with or without a delayed ischemic neurological deficit (DIND) in patients with subarachnoid hemorrhage (SAH). METHODS In 125 patients who underwent surgery for early aneurysms, postoperative MRI scans were obtained at four time points. We defined an infarct from vasospasm as a new lesion not present on the initial MRI within 3 days after SAH and therefore not attributable to primary brain damage or surgical complications. RESULTS Overall, symptoms of infarction (i.e., DIND) occurred in 38% of patients (48 of 125); DIND with a new infarct on MRI was evident in 34% (43 patients), whereas 4% (5 patients) showed no new lesion but had a DIND. However, 29 patients (23%) showed a new infarct but no DIND on MRI studies (asymptomatic infarction). Asymptomatic ischemic lesions due to vasospasm tended to involve noneloquent brain areas in the territory of intraparenchymal perforators. Multivariate analysis identified variables associated with symptomatic infarction to be of poor SAH grade, advanced age of the patient, angiographic findings of vasospasm, multiple cortical infarcts on MRI studies consistent with vasospasm, and chronic hydrocephalus. CONCLUSION Analysis of the data confirmed the occurrence of asymptomatic infarcts due to vasospasm. These infarcts often developed in noneloquent areas representing perforator territory. MRI investigation of vasospastic lesions referable to intraparenchymal vessels such as perforators complements the study of extraparenchymal major vessel vasospasm in patients with SAH by computed tomographic angiography.

Various kinds of fatty acid esters of L-ascorbic acid were synthesized and their role as chain-breaking antioxidant was studied in the oxidation of methyl linoleate in homogeneous solution. Fatty acid esters of ascorbic acid at either 6- or both 5- and 6-positions were effective as antioxidant and suppressed the oxidation of methyl linoleate, whereas those having ester group at 2-position did not act as antioxidant. 5,6-Erythorbyl dipalmitate was also effective as an antioxidant. Ascorbic acid esters inhibited the oxidation cooperatively with α- and δ-tocopherols as observed for free ascorbic acid. The antioxidant activity was correlated with the reactivity toward galvinoxyl radical.