Collaboration with an infection control team promoted appropriate antibiotic use for third molar extraction at a Japanese hospital.

Oral antibiotic therapy is routinely administered when a third molar (M3) is extracted to prevent infectious complications after surgery. Oral third-generation cephalosporins are frequently used after M3 extraction in Japan but at the expense of an increased risk of antimicrobial resistance. Therefore, the infection control team (ICT) at our institution recommended a reduction in use of these agents after M3 extraction. In this study, we compared the types of antibiotic agents prescribed for patients undergoing M3 extraction before and after this recommendation. We investigated the relationship between type of antibiotic used and the likelihood of infectious complications as well as cost savings in patients who underwent M3 extraction in the 6 months before and after the ICT recommendation in July 2018. There was a marked reduction in use of oral third-generation cephalosporins after M3 extraction (P < 0.0001) and increased use of oral penicillins and first-generation cephalosporins after the ICT recommendation. Moreover, surgical site infection (SSIs) were significantly less common after the ICT recommendation (P = 0.0099); however, the SSI rate was higher in patients who received a third-generation cephalosporin than in those who received penicillin (8.8% vs 0.5%). There was also a significant saving in per-patient antibiotic costs after the ICT recommendation (269.5 ± 282.0 JPY vs 454.7 ± 376.6 JPY; P < 0.0001). These findings suggest that collaboration with an ICT promotes appropriate antibiotic use, decreases the risk of an SSI, and improves the cost-benefit ratio in patients undergoing M3 extraction.

Role of sialyl 6-sulfo Lewis X in antitumor immunity against oral squamous cell carcinoma.

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) reportedly play a pivotal role in antitumor immunity against oral squamous cell carcinoma (OSCC); however, mechanisms governing TIL recruitment to OSCC tissues remain to be clarified. This study was undertaken to assess a potential association between TILs and high endothelial venule (HEV)-like vessels that express sialyl 6-sulfo Lewis X (LeX). METHODS: OSCC tissue sections (n=41) were subjected to immunohistochemistry for sialyl 6-sulfo LeX and CD34 to allow quantitation of HEV-like vessels. Triple immunohistochemistry for sialyl 6-sulfo LeX and either CD3 and CD20 or CD4 and CD8 was conducted to determine which lymphocyte subset is more closely associated with HEV-like vessels. RESULTS: HEV-like vessels expressing sialyl 6-sulfo LeX were detected in 27 of 41 (65.9%) OSCC cases, and these vessels were more frequently found in early disease (T1/T2 stages) compared with advanced (T3/T4) stages. The number of T cells attached to the inner surface of these HEV-like vessels was significantly greater than that of B cells, while the number of CD4+ helper T cells and CD8+ cytotoxic T cells did not differ significantly. Interestingly, sialyl 6-sulfo LeX was also expressed on the membrane of a fraction of OSCC cells, and CD8+ cytotoxic T cells were almost exclusively found attached to these carcinoma cells. CONCLUSIONS: Sialyl 6-sulfo LeX is displayed not only on HEV-like vessels but also on OSCC cells and may potentially function in antitumor immunity against OSCC.

Relationship between gustatory function and average number of taste buds per fungiform papilla measured by confocal laser scanning microscopy in humans.

The aim of this study was to elucidate the relationship between the gustatory function and average number of taste buds per fungiform papilla (FP) in humans. Systemically healthy volunteers (n = 211), pre-operative patients with chronic otitis media (n = 79), and postoperative patients, with or without a chorda tympani nerve (CTN) severed during middle ear surgery (n = 63), were included. Confocal laser scanning microscopy was employed to observe fungiform taste buds because it allows many FP to be observed non-invasively in a short period of time. Taste buds in an average of 10 FP in the midlateral region of the tongue were counted. In total, 3,849 FP were observed in 353 subjects. The gustatory function was measured by electrogustometry (EGM). An inverse relationship was found between the gustatory function and average number of fungiform taste buds per papilla. The healthy volunteers showed a lower EGM threshold (better gustatory function) and had more taste buds than did the patients with otitis media, and the patients with otitis media showed a lower EGM threshold and had more taste buds than did postoperative patients, reflecting the severity of damage to the CTN. It was concluded that the confocal laser scanning microscope is a very useful tool for using to observe a large number of taste buds non-invasively.

Post-Traumatic Trigeminal Neuropathy Caused by an Orbital Stab Wound.

Sensory and motor neuropathy of the trigeminal nerve due to trauma is quite rare. Furthermore, there have been no detailed reports on occlusal abnormalities and trismus associated with post-traumatic trigeminal motor neuropathy. Here, the authors report a case of trigeminal motor neuropathy and trigeminal sensory neuropathy in all 3 divisions caused by an orbital stab wound. During kendo practice, a 61-year-old man was injured in his right medial canthus with the splinter of a broken bamboo sword. Imaging examinations did not show a brain injury or orbital bone fracture. Intraoral and extraoral examination and needle electromyography revealed trismus, posterior open bite, and denervation of the right masseter. After the injury, the patient strived to use the right molars during mastication and began chewing exercises in the right molar region. A follow-up examination 7 months after the injury revealed an improvement of the functional problems in the masticatory system. Although slight facial numbness in the right ophthalmic division remained, the patient was satisfied with the present status. Further knowledge concerning the natural history of trigeminal neuropathy as well as the treatment of choice should be explored in the future.

Comparison of fungiform taste-bud distribution among age groups using confocal laser scanning microscopy in vivo in combination with gustatory function.

The aim of this study was to compare the distribution of taste buds in fungiform papillae (FP) and gustatory function between young and elderly age groups. Confocal laser scanning microscopy was used because it allows many FP to be observed non-invasively in a short period of time. The age of participants (n = 211) varied from 20 to 83 yr. The tip and midlateral region of the tongue were observed. Taste buds in an average of 10 FP in each area were counted. A total of 2,350 FP at the tongue tip and 2,592 FP in the midlateral region could be observed. The average number of taste buds was similar among all age groups both at the tongue tip and in the midlateral region. The taste function, measured by electrogustometry, among participants 20-29 yr of age was significantly lower than that in the other age groups; however, there was no difference among any other age groups in taste function. These results indicate that the peripheral gustatory system is well maintained anatomically and functionally in elderly people.

A case of retinoblastoma metastasizing to the mandible and review of literature.

OBJECTIVES: The aim of this case report and review was to determine the characteristics of retinoblastoma. METHODS: One case report was introduced along with previous reports on retinoblastoma metastasizing to the mandible. RESULTS: Sixteen cases from 14 reports were included in this study. Including the present case, 11 of 16 patients died within 8 months. DISCUSSION: Retinoblastoma rarely metastasizes to the mandible. However, metastasis to other organs should be considered, and specialists should be consulted if retinoblastoma metastasis to the mandible is observed. Moreover, it is necessary to follow up patients after multidisciplinary therapy is completed, because subsequent complications of the teeth and jawbones associated with therapy could occur.

Keratocystic odontogenic tumor arising at the mandibular ramus with an impacted tooth: a case report and mimic lesions.

OBJECTIVES: To consider the biologic behaviors of keratocystic odontogenic tumors (KCOTs) and ameloblastomas and dentigerous cysts. METHODS: A 63-year-old Japanese man presented with swelling and discomfort in the left cheek during jaw movement. Examination revealed a multilocular lesion within the mandible extending from the left second premolar to the left mandibular ramus and coronoid process; the lesion contained a deviated impacted tooth. The tumor had expanded beyond the bone and was invading the masseter and medial pterygoid muscles. Marginal mandibulectomy with a free iliac bone graft was performed. RESULTS: No recurrence was observed during a 7-year follow-up. DISCUSSION: The histopathological diagnosis of the lesion showed it was a KCOT. These tumors usually grow within the bone, causing bone expansion. However, this tumor had expanded beyond the bone and invaded surrounding muscles. Thus, KCOTs can, in rare cases, manifest themselves as described here. Evaluating preoperative images and histopathological findings is important to determine the optimal treatment strategy.

Effects of Vertical Movement of the Anterior Nasal Spine on the Maxillary Stability After LeFort I Osteotomy for Pitch Correction.

Few reports have so far evaluated the maxillary stability after LeFort I osteotomy (L-1) for pitch correction. In the current study, the authors assessed the SN-PP (palatal plane) to evaluate the skeletal stability after osteotomy with clockwise or counter-clockwise rotation and investigated the effects of anterior nasal spine (ANS) and posterior nasal spine (PNS) movement on the stability of the SN-PP.The SN-PP and the positions of ANS, PNS, and point A were measured on lateral cephalograms before surgery (T1), immediately after surgery (T2), and more than 1 year after surgery (T3).All measured angle and points were stable in 4 cases of counter-clockwise rotation. In the 16 cases of clockwise rotation, T3-T2 of SN-PP, ANS, and point A was -2.05°, -2.56 mm, and -1.64 mm, when the SN-PP increased more than 4° after osteotomy. When the ANS moved downward more than 3 mm, the ANS and point A relapsed significantly by 2.75 and 2.31 mm, while the SN-PP relapsed 1.61° more than 1 year after surgery.When the SN-PP increased by more than 4° or the ANS moved downward by more than 3 mm, the authors suggest shifting the PNS upward instead of moving the ANS downward.

Application of a real-time three-dimensional navigation system to various oral and maxillofacial surgical procedures.

The aim of this study was to confirm the effectiveness of a real-time three-dimensional navigation system for use during various oral and maxillofacial surgeries. Five surgeries were performed with this real-time three-dimensional navigation system. For mandibular surgery, patients wore acrylic surgical splints when they underwent computed tomography examinations and the operation to maintain the mandibular position. The incidence of complications during and after surgery was assessed. No connection with the nasal cavity or maxillary sinus was observed at the maxilla during the operation. The inferior alveolar nerve was not injured directly, and any paresthesia around the lower lip and mental region had disappeared within several days after the surgery. In both maxillary and mandibular cases, there was no abnormal hemorrhage during or after the operation. Real-time three-dimensional computer-navigated surgery allows minimally invasive, safe procedures to be performed with precision. It results in minimal complications and early recovery.

Risk factors for postoperative hemorrhage after minor oral surgery in patients treated with antithrombotic agents.

It has been proposed that minor oral surgery can be performed safely in patients taking antithrombotic therapy without interrupting treatment; however, there is little evidence-based guidance about how to manage postoperative hemorrhage in patients taking antithrombotics, and few randomized trials that help to inform the risk-benefit ratio of continuing or suspending antithrombotic therapy. The aim of this study was to identify risk factors for postoperative hemorrhage to create a protocol for patients undergoing minor oral surgery with antithrombotic therapy. One hundred and two patients were enrolled, who subsequently underwent 142 minor oral surgical procedures while taking antithrombotic therapy. Demographic details including age and sex, laboratory coagulation investigations, and episodes of postoperative hemorrhage were recorded. The prothrombin time-international normalized ratio (PT-INR) of participants taking warfarin was <3.0 in all cases (mean 1.89 ± standard deviation 0.52; range 1.11-2.82). The activated partial thromboplastin time (APTT) was significantly associated with postoperative hemorrhage, which was significantly increased in patients taking warfarin alone or in combination with an antiplatelet agent compared with an antiplatelet agent alone. In 7 cases, postoperative hemorrhage continued for 4 days and more, requiring additional local hemostatic management. Our findings suggest that minor oral surgery can be performed under antithrombotic therapy without the need of discontinuing the antithrombotic agents. Local hemostatic materials did not suppress postoperative hemorrhage. APTT is a possible prediction factor for postoperative hemorrhage in such patients and, therefore, should be determined prior to minor oral surgery in addition to PT-INR value.

Spindle cell carcinoma arising at the buccal mucosa: a case report and review of the literature.

AIMS: Spindle cell carcinoma (SPCC) is a subtype of squamous cell carcinoma, and it mainly occurs in the upper aerodigestive duct. On the other hand, it rarely arises in the head and neck region. The prognosis of this tumor is usually poor because of its highly malignant behavior, such as its high incidence of recurrence or metastasis to cervical lymph nodes. However, the number of accumulated cases is still too low to provide the full details of SPCC. METHODOLOGY: The case of SPCC was counted by using database, PubMed. The authors also present a case of SPCC arising at the left buccal mucosa in a 72-year-old Japanese female in the current study. RESULTS: Only six cases of SPCC arising at the buccal mucosa have been reported previously. The authors' patient died from a recurrent tumor 15 months after the first operation. CONCLUSION: The authors have added this case to the previous knowledge of SPCC arising at the buccal mucosa, and discuss the clinical behavior of SPCC to help suggest a standard treatment strategy for the disease.

Rapid growing myofibroma of the gingiva: report of a case and review of the literature.

PURPOSE: Myofibroma is a rare benign tumor of myofibroblasts that rarely exhibits rapid enlargement and is misinterpreted as a malignant lesion. The aim of this study was to investigate its growth potential and to evaluate the usefulness of preoperative immunohistochemical study for an accurate diagnosis. MATERIALS AND METHODS: A case of rapidly growing myofibroma of the lower gingiva was analyzed using 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography fused with computed tomography (PET/CT) and immunohistochemical study of Ki-67 and p53. The English-language literature from 1981 to 2012 also was reviewed. RESULTS: An 18F-FDG PET/CT image displayed a high accumulation (maximum standardized uptake value, 14.1) in the lesion. A biopsy specimen showed mitotic activity of spindle-shaped cells, but atypia was not present. The MIB-1 labeling index was 10%, and the p53 test result was negative. The preoperative diagnosis of benign tumor of smooth muscle origin was made from the histopathologic and immunohistochemical features. In a review of 94 cases, tumors involved the mandible (33%), gingiva (23%), tongue (15%), cheek or buccal mucosa (12%), palate (8%), lip (4%), and other areas (5%). Nine cases (9.6%) were described as rapidly enlarging, and 8 cases (8.5%) were suspected of malignancy at initial diagnosis. The preoperative biopsy with immunohistochemical study established an accurate diagnosis in 83% of myofibromas, and no recurrences were reported in these patients. CONCLUSIONS: Careful diagnosis is necessary because these lesions sometimes present clinical and radiologic features that resemble those of malignant tumors. Preoperative immunohistochemical analysis should be performed to avoid misdiagnosis or unnecessary aggressive therapy.

Aspiration pneumonia associated with a double fracture of the mandible.

Aspiration pneumonia is one of the most life-threatening diseases in the elderly. A 73-year-old woman was diagnosed with aspiration pneumonia after a mandibular fracture. Because her persistent aspiration pneumonia was accompanied by a diminished swallowing function that was believed to be due to a double fracture of the mandible, the patient underwent an open reduction while having pneumonia. Her symptoms of aspiration pneumonia improved immediately after the surgery. The hyoid bone was repositioned to its original position, and the movements of the hyoid bone and mandible were recovered after the surgery. In cases in which the medial bone segment of the mandible moves inside because of a double fracture and the movement of the hyoid bone declines, we strongly suggest that an open reduction should be performed as soon as possible to prevent aspiration pneumonia caused by a swallowing dysfunction.

Long-term follow-up after reimplantation of tumorous mandible bone treated with combination of decalcification and lyophilization.

Mandibular resection requires reconstruction, with often unsatisfactory morphofunctional results. Reimplantation of the resected mandible itself is one of ideal solutions to this problem. However, both devitalization of tumor cells involved in resected bone and preservation of osteoinductive activity are required for successful results. Lyophilization appears to enable devitalization of tumor cells, and decalcified bone implants are likely to have osteoinductive potential. Accordingly, we speculated that decalcification and lyophilization of resected bone would be an appropriate method for mandibular reconstruction. However, there is no study on the reimplantation of mandibles treated with these methods to date. The purpose of this study was to estimate the long-term follow-up of reimplanted mandibles treated with decalcification and lyophilization. Presented here are 2 patients of reimplanted mandibles treated by decalcification and lyophilization who were followed up for 8 and 9 years. We observed a good incorporation of the graft in 1 case, but severe absorption in the other. Our results suggest that treatment with decalcification and lyophilization is 1 strategy for reimplantation of the resected bone in mandibular reconstruction, but further study is needed to prevent absorption of the reimplanted bone over the long term.

Assessment of migrated foreign bodies in the maxillae by x-ray fluorescence spectrometry.

Two cases of foreign bodies that were incidentally observed on orthopantomographs are reported in this study. The foreign bodies were analyzed using an x-ray fluorescence spectrometer to identify what the migrated foreign bodies were and what migration pathways they had taken. The removed metallic foreign bodies from the maxillae of 2 patients, who were referred to the Department of Dentistry and Oral Surgery of the University of Fukui Hospital, were analyzed using an x-ray fluorescence spectrometer in the Department of Dental and Biomedical Materials Science, Nagasaki University. The major component of foreign body in patient 1 was silver, and that in case 2 was iron. On the basis of the imaging results and the patients' clinical history, the foreign bodies were considered to be caused by iatrogenic migration. Understanding the existence of foreign bodies and their migration pathway into the jaw bone can thus make clinicians more aware of such migrations and can thereby contribute to reducing iatrogenic accidents.

Diagnostic role of magnetic resonance imaging in assessing orofacial pain and paresthesia.

The aim of this study was to compare the efficacy of CT and MRI in evaluating orofacial pain and paresthesia. A total of 96 patients with orofacial pain and/or paresthesia were included in this study. The patients who underwent CT and/or MRI examinations were assessed, and the efficacy of CT and/or MRI examinations in detecting the causative disease of the orofacial pain and paresthesia was evaluated. Seventy (72.9%) of 96 patients underwent CT and/or MRI examinations. Whereas CT examinations detected 2 diseases (4.5%) in 44 tests, 13 diseases (37.1%) were detected in 35 MRI examinations. Seven (53.8%) of 13 diseases, which were detected by MRI, were found in elderly patients. A high percentage of patients, who claimed orofacial pain and paresthesia, have other diseases in their brain, especially in elderly patients, and MRI is more useful than CT for evaluating these patients.

Enzyme histochemical adaptive responses of the medial pterygoid muscle and two heads of the lateral pterygoid muscle to long-term soft diet feeding in growing rabbits.

The aim of the present study was to investigate the histochemical effects of long-term soft diet in the medial pterygoid muscle as well as the two heads of the lateral pterygoid muscles in growing rabbits. Eleven young rabbits were divided into two groups as solid diet (control group; n = 6) or soft diet (soft-diet group; n = 5) groups. After 6 months, muscle fibers from the medial and the two heads of the lateral pterygoid muscles were histochemically defined. In the medial pterygoid muscle, the percentage of the type 1 fiber cross-sectional area to total area was 10.1 ± 2.4% in the control group and 8.3 ± 3.0% in the soft-diet group, respectively. In the soft-diet group, there was a trend toward an increase in the number of type 2A fibers, and toward a decrease in the numbers of type 2B fibers in comparison with the controls. In the two heads of the lateral pterygoid muscle, the percentage of the type 1 fiber cross-sectional area to total area was 8.4 ± 7.5 and 3.3 ± 2.7%, respectively. Compared to that of the control group, the two heads in the soft-diet group showed a trend toward a decrease in the number of type 2A fibers. In addition, type 2B had a tendency to decrease in the number in the inferior head. In conclusion, this study suggests that long-term soft diet leads to adaptations of the pterygoid muscles. Two heads of the lateral pterygoid muscle revealed different adaptation from jaw-closing muscles under soft-diet conditions.

Mandibular reconstruction using iliac bone and great auricular nerve grafts and oral rehabilitation using osseointegrated implants in a patient with a large ossifying fibroma: a 10-year follow-up study.

Ossifying fibromas are bone-related benign neoplasms that are characterized by well-demarcated lesions composed of fibrocellular tissue and mineralized material with varying appearances. Although small lesions are asymptomatic, they may cause enlargement of the affected jaw and rarely require reconstructive or restorative treatments for aesthetic and functional problems. In this study, we report a 35-year-old woman who underwent multidisciplinary treatment for a large ossifying fibroma of the mandible. A segmental mandibular resection was performed, and immediate reconstruction was performed using iliac bone and great auricular nerve grafts. After consolidation of the grafted bone, oral rehabilitation was fulfilled using osseointegrated implants and a fixed prosthesis. There was no evidence of recurrence ten years after the resection of the tumor. The range of mouth opening and motion of the temporomandibular joint provided a functional mandible. The neurosensory examination revealed the recovery of sensibility of the mental region and pulpal sensitivity of the teeth. The prosthesis was stable, and no clinical or radiographic signs of implant failure were observed. Our results demonstrate that the proper combination of reconstructive and restorative treatments could result in appropriate aesthetic and functional outcomes for a period of ten years.

Frontal meningioma incidentally detected in the routine preoperative assessment of tongue cancer: a case report and literature review.

Recent advances in diagnostic tools, such as computed tomography and magnetic resonance imaging (MRI), have provided clinicians with the opportunity to detect asymptomatic meningiomas. This report describes a case of frontal convexity meningioma detected incidentally at MRI during the preoperative assessment of tongue cancer. To the best of the authors' knowledge, this case report is the first regarding the successful treatment of tongue cancer in a patient with incidental meningioma. The incidence, perioperative management, and various imaging tests to detect meningiomas are discussed, with a review of the literature.

BMP signaling is responsible for serum-induced Id2 expression.

Ids function as negative regulators of basic helix-loop-helix transcription factors and their expression is rapidly induced by serum stimulation in various cell types. In this study, we investigated the molecular basis of serum-induced expression of the mouse Id2 gene in NIH3T3 cells. A small-molecule inhibitor of bone morphogenetic protein (BMP) type I receptor kinases blocked the serum induction of Id2 mRNA. The chemical compound and several inhibitory proteins specific for BMP signaling suppressed the serum-induced activation of the luciferase construct with the mouse Id2 4.6-kb promoter region. Importantly, serum stimulation evoked rapid phosphorylation of Smad1/5/8 and significant activation of the reporter plasmid containing the recently identified BMP-responsive element (BRE) of the mouse Id2. Mutation analysis demonstrated that the binding sites for Smad proteins in the Id2 BRE were critical for serum response of the 4.6-kb whole construct. Gel shift and chromatin immunoprecipitation (ChIP) assays confirmed the serum-inducible binding of Smad1/5/8 and Smad4 to the Id2 BRE in vitro and in vivo. Finally, a knockdown experiment revealed the functional importance of Smad1 in the serum induction of Id2 expression. Thus, we concluded that BMP signaling is primarily responsible for the serum-induced Id2 expression. Our results also suggest that some of the cellular effects caused by serum are mediated through BMP signaling.