Computed tomography evaluation of risk factors for an undesirable buccal split during sagittal split ramus osteotomy.

Sagittal split ramus osteotomy (SSRO) sometimes induces an irregular split pattern referred to as a bad split. We investigated the risk factors for bad splits in the buccal plate of the ramus during SSRO. Ramus morphology and bad splits in the buccal plate of the ramus were assessed using preoperative and postoperative computed tomography images. Of the 53 rami analyzed, 45 had a successful split, and 8 had a bad split in the buccal plate. Horizontal images at the height of the mandibular foramen showed that there were significant differences in the ratio of the forward thickness to the backward thickness of the ramus between patients with a successful split and those with a bad split. In addition, the distal region of the cortical bone tended to be thicker and the curve of the lateral region of the cortical bone tended to be smaller in the bad split group than in the good split group. These results indicated that a ramus shape in which the width becomes thinner towards the back frequently induces bad splits in the buccal plate of the ramus during SSRO, and more attention should be paid to patients who have rami of these shapes in future surgeries.

The impact of the size of bone substitute granules on macrophage and osteoblast behaviors in vitro.

OBJECTIVE: Bone substitute (BS) size might influence the clinical outcomes of guided bone regeneration (GBR) procedures. The aim of the present study was to investigate the influence of BS size on macrophage (Mφ) and osteoblast behaviors in vitro. MATERIALS AND METHODS: Two different granule sizes (S and M/L) were assessed for four different commercial BSs: deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate type 1 (BCP1), BCP type 2 (BCP2), and carbonate apatite (CO3Ap). The BSs were compared for their impacts on the cell viability and differentiation potential of THP-1-derived Mφs and human osteoblast-like Saos-2 cells. RESULTS: The smaller granules showed higher material volumes and surface areas than the larger granules. Significantly higher viability of Mφs and Saos-2 cells was observed with the DBBM_L-size granules than with the DBBM_S-size granules. Gene expression experiments in Mφs revealed few differences between the two sizes of each BS, although higher CD206 mRNA levels were observed in the BCP1_L group and the CO3Ap_M group than in the respective S-size groups on day 1. Only DBBM showed significantly higher mRNA levels of osteogenic markers, including Runx2 and osteocalcin, in Saos-2 cells in the S-size group than in the L-size group. CONCLUSIONS: The S-size and L-size DBBM granules exhibited clear differences in cell outcomes: cells cultured on the S-size granules exhibited lower cell viability, higher osteopromotive ability, and no noticeable Mφ polarization changes. CLINICAL RELEVANCE: A smaller granule size might be advantageous due to greater bone regeneration potential in the use of DBBM granules to treat defects.

Preoperative transarterial embolization for solitary fibrous tumor of the tongue: A case report.

Solitary fibrous tumors (SFTs) are derived from mesenchymal cells originating mainly from the pleura. Reports of bleeding SFTs in head and neck regions are rare. A number of reports have focused on tongue SFT treatments, but to the best of our knowledge, there are no reports on the usefulness of preoperative arterial embolization. Intraoperative and postoperative bleeding can also lead to airway problems. To avoid unnecessary tracheostomy and ligation of the external carotid artery, preoperative vascular embolism should be considered while removing large tumors or tumors with high blood flow. The current report outlines a case of a 32-year-old woman with a tongue solitary fibrous tumor, who underwent right lingual artery embolization with 300-500 and 500-700 µm embosphere microspheres through a vascular catheter the day before surgical resection. The encapsulated tumor was completely excised under general anesthesia with little to no bleeding during the operation.

Histological comparison of Platelet rich fibrin clots prepared by fixed-angle versus horizontal centrifugation.

Platelet-rich fibrin (PRF) is prepared from whole blood without any exogenous coagulation factors. Several preparation methods have now been introduced, particularly with differences in centrifugation parameters including g-force and time to improve their regenerative potential. Nevertheless, the centrifugation systems have not yet been clearly investigated for their influences on the PRF clot properties. The aim of the present study was to visually and histologically characterize the cell separation manner and blood cell localization on the whole PRF clots prepared by two different centrifugation system, fixed-angle and horizontal centrifugation. Leukocyte- and platelet-rich fibrin (L-PRF) was prepared on a fixed-angle centrifuge machine (IntraSpin, Intra-Lock, FL, USA) at 2700 rpm (~400 g at the RCF-clot; ~700 g at the RCF-max) for 12 min. The PRF prepared by horizontal centrifugation was prepared on a horizontal centrifugation (H-PRF) (Eppendorf 5702, Eppendorf, Germany) at 700 g at the RCF-max for 8 min. The cell morphology and localization were observed on the surface of PRF clots by scanning electron microscopy (SEM) and histologically by transaxial frozen sections by means of a film method. L-PRF clots demonstrated a sloped separation between the upper plasma and the bottom red blood cell (RBC) layers according to the angle of the rotor. Red dots were often observed on the distal walls of the tubes in the upper layers, consisting of aggregations of RBCs, leukocytes and platelets by SEM and histology. Clots produced on the horizontal centrifuge showed much smoother cell layer distribution/separation along the tube surfaces when compared to L-PRF. Horizontal centrifugation also demonstrated more evenly distributed platelets throughout the PRF clots when compared to L-PRF that gathered the majority of cells along the distal tube surface or within the buffy-coat region. In summary, it was found that horizontal centrifugation resulted in a more uniform blood cell separation of PRF clots when compared to the accumulation of cells gathered along the distal tube surfaces produced prepared by fixed-angle centrifugation. Future research is needed to evaluate the benefit of horizontal centrifugation in clinical practice.

In Vitro Comparison of Macrophage Polarization and Osteoblast Differentiation Potentials between Granules and Block Forms of Deproteinized Bovine Bone Mineral.

Deproteinized bovine bone mineral (DBBM) bone grafts are commonly utilized for guided bone regeneration (GBR) techniques in regenerative dentistry. It has been hypothesized that different forms (blocks versus particulates) might demonstrate the varying properties of cell behavior during the regenerative process. Therefore, the aim of the present study was to investigate DBBM granules and blocks for their effects on osteoblasts and macrophages (Mφs). DBBM granules and blocks were filled to the same size (φ6.4 mm in diameter × 2.0 mm in height) in cell culture wells and assessed for cell viability and cell differentiation of human osteoblast-like Saos-2 cells, and Mφs derived from human monocyte THP-1 cells. The two groups were first characterized by micro-CT analysis, which demonstrated that DBBM granules had a two-fold greater material volume and a four-fold larger surface area than the blocks. DBBM blocks showed superior viability for both osteoblasts and Mφs. Osteoblast experiments were then utilized to better characterize the influence of DBBM shapes/forms on osteoblast differentiation. Alkaline phosphatase (ALP) staining on the undecalcified frozen sections was observed throughout the DBBM granule surface, yet this staining was only observed on the upper portion of the DBBM blocks. Furthermore, DBBM blocks showed M1-Mφ polarization trends with higher IL-1 and IL-6 mRNA expression in Mφs, while the conditioned media from Mφs cultured on DBBM granules promoted osteoblast differentiation with higher mRNA levels of Runx 2, ALP and osteocalcin. In conclusion, the DBBM granules showed more regenerative effects, lower M1 marker expression, and higher osteoblast differentiation potential when compared with the blocks, which might be related to the larger material volume, higher surface area and greater ability for the cells to penetrate through the scaffold.

Improved growth factor delivery and cellular activity using concentrated platelet-rich fibrin (C-PRF) when compared with traditional injectable (i-PRF) protocols.

OBJECTIVES: Several studies have recently demonstrated that only marginal improvements in platelet and leukocyte concentrations are achieved following standard injectable platelet-rich fibrin (i-PRF) protocols. Due to these previous findings, a novel harvesting technique was recently developed to collect higher concentrations of platelets/leukocytes specifically from the buffy coat layer (C-PRF) following faster centrifugation protocols. The aim of this study was to investigate the regenerative properties and effects on growth factor release and cellular activity of PRF collected through this novel harvesting technique compared to standard i-PRF protocols. MATERIALS AND METHODS: The upper 1-ml layer collected through standard i-PRF protocols at low centrifugation speeds was compared with 1 mL of C-PRF collected from the buffy coat layer following high centrifugation protocols (3000×g for 8 min on a horizontal centrifuge) to specifically concentrate cells within the platelet/leukocyte-rich buffy coat layer. Thereafter, the expression of seven different growth factors, including PDGF-AA, PDGF-AB, PDGF-BB, TGF-ß1, VEGF, IGF-1, and EGF, was characterized for up to 10 days. Then, gingival fibroblast biocompatibility was investigated at 24 h (live/dead assay); migration was investigated at 24 h; proliferation was investigated at 1, 3, and 5 days; and the expression of PDGF and TGF-ß was investigated at 3 days. Collagen 1 immunostaining was also quantified at 14 days. RESULTS: At all investigated time periods, a significant increase in growth factor release was observed in C-PRF. In particular, the release of PDGF-AA, TGF-ß1, and EGF exhibited the highest increases when compared with that in i-PRF. While both i-PRF and C-PRF exhibited high biocompatibility and induced significantly higher fibroblast migration and proliferation when compared with that of the control tissue culture plastic group, C-PRF showed the greatest potential for cell migration and proliferation. Furthermore, C-PRF induced significantly higher mRNA levels of TGF-ß and PDGF levels at 3 days and greater collagen 1 staining when compared with induced by i-PRF. CONCLUSIONS: In the present study, it was found that C-PRF collected specifically from the buffy coat layer following higher centrifugation protocols exhibited an up to a threefold increase in growth factor release when compared with that exhibited by standard i-PRF. This significantly promoted higher gingival fibroblast migration, proliferation, gene expression, and collagen I synthesis. CLINICAL RELEVANCE: The findings of the present study demonstrate that a more potent formulation of liquid platelet concentrate than that obtained from the upper plasma layer following a short and slow centrifugation protocol (i-PRF protocol) can be obtained for clinical use by specifically harvesting cells in the platelet- and leukocyte-rich buffy coat layer following an 8-min 3000×g centrifugation protocol (C-PRF protocol).

Correlation between the malignancy and prognosis of oral squamous cell carcinoma in the maximum standardized uptake value.

Positron emission tomography/computed tomography (PET/CT) examinations are indispensable in determining the stage, evaluating the treatment response, and diagnosing recurrence and metastasis during oral cancer treatment. In this study, we examined the correlation between the maximum standardized uptake value (SUVmax) for 18F-FDG PET/CT and the progressive factors, biological characteristics, and prognosis of oral cancer. We included 52 cases of oral squamous cell carcinoma with surgery as the initial treatment. Inclusion criteria included tumor diameter of ≥ 1 cm excluding superficial cancer. We performed 18F-FDG PET/CT examinations before surgery and determined the correlation between SUVmax and clinicopathological factors, such as histological grade, Ki-67 expression, as well as progress factors. SUVmax was significantly correlated with clinical T stage, vascular invasion, lymphatic invasion, Ki-67 expression, and postoperative event (recurrence or metastasis) in Student's t test. Using a cut-off SUVmax of 8.0, clinical T stage, lymph node metastasis, vascular invasion, infiltrative pattern, and Ki-67 expression significantly correlated in chi-squared test. Although observed and expected 3-year overall survival rates were not significantly different, observed and expected 3-year disease-free survival rates were significantly different. Analyzing each clinicopathological factor using various data obtained from 18F-FDG PET/CT scans may be useful to determine prognosis during oral cancer treatment.

Usefulness of Early Plate Removal in Patients With Occlusal Discrepancies After Sagittal Split Ramus Osteotomy.

The aim of this study was to evaluate the effects of early removal of fixed plates in patients with occlusal discrepancies after sagittal split ramus osteotomy (SSRO) with a focus on the positional relationship of the temporomandibular joint (TMJ). Sagittal split ramus osteotomy with/without Le Fort I osteotomy was performed on 98 patients with mandibular prognathism. Of these 98 patients, 15 with occlusal discrepancies and/or TMJ symptoms underwent early plate removal after SSRO. Finally, 12 consecutive patients were evaluated in this study: 7 underwent bilateral SSRO, 1 underwent unilateral SSRO, and 4 underwent bilateral SSRO with maxillary advancement. The axiolateral TMJ Schuller method was used to evaluate the TMJ position. The authors measured 3 spaces (anterior, superior, and posterior joint spaces) between the condyle and glenoid fossa in the sagittal plane. The anterior and superior joint spaces were significantly larger immediately after the operation than before the operation. After early plate removal, these spaces significantly decreased in size. The posterior joint space increased, but with no significant difference. Three months after SSRO, the size of each of the 3 spaces was closely related to its preoperative size. In conclusion, these results suggest that early removal of fixed plates is 1 treatment option for postoperative occlusal discrepancies after SSRO.

Toll-like receptor 2 activation implicated in oral squamous cell carcinoma development.

Recent studies have revealed that Toll-like receptors (TLRs) are highly expressed and activated in many types of cancer. Physiologically, TLR2 recognizes bacteria and other microorganisms in the oral cavity; however, the role of TLR2 in oral squamous cell carcinoma (OSCC) is unclear. In this study, we demonstrated that TLR2 is highly expressed in OSCC in comparison with adjacent non-malignant tissue. TLR2 was also expressed in OSCC-derived cell lines, and its expression was activated by ligands derived from bacteria and mycoplasma. Furthermore, to elucidate the mechanism of OSCC progression via TLR2 signal transduction, we focused on microRNAs (miRNAs) that are induced by TLR2 activation. Interestingly, ligand activation of TLR2 induced the expression of miR-146a and we found that downregulation of caspase recruitment domain-containing protein 10 (CARD10) mRNA in OSCC-derived cell lines. Moreover, knockdown of CARD10 induced resistance to cisplatin-induced apoptosis in OSCC cells. These findings suggest that the activation of TLR2 by bacterial components can enhance the progression of OSCC and may be implicated in acquired resistance to cisplatin-induced apoptosis through regulation of the miR-146a pathway.

Indications of Potassium Titanyl Phosphate Laser Therapy for Slow-Flow Vascular Malformations in Oral Region.

BACKGROUND: Indications for laser therapy for slow-flow vascular malformations in the oral and maxillofacial regions have not been clearly documented. The authors aimed to estimate the frequency of resolution of slow-flow vascular malformations and to identify risk and prognostic factors associated with resolution in potassium titanyl phosphate (KTP) laser treatment. METHODS: This study was designed as a prospective cohort study. Patients who had diagnosed slow-flow vascular malformations were continuously assigned to receive KTP laser therapy. All patients had intralesional laser photocoagulation performed under local anesthesia. Administered power of the KTP laser was fixed at 2 watts throughout the procedure in all patients. The primary endpoint was to understand the frequency of resolution of slow-flow vascular malformations in KTP laser treatment. Secondary endpoints were: treatment outcomes based on lesion size; treatment outcomes based on location; treatment outcomes based on total energy in joules; types of complications. Treatment outcomes were judged by a clinical assessment as well as reduction in lesion size on magnetic resonance imaging. RESULTS: Data were obtained from 26 patients (9 men, 17 women) with 38 lesions. The average lesion size was 13.5 ±â€Š7.7 mm. Treatment outcomes based on lesion size showed that cure and regression were obtained in lesions less than 30 mm in size. However, lesions larger than 30 mm showed no response. Lesions in the tongue and lips showed higher cure rates than in other areas. Treatment outcomes based on administered total energy in joules showed that 68% of lesions were treated and responded well at less than 400 joules. Complication rate was relatively high in the buccal mucosal lesions. Immediate postoperative complications such as necrosis were more common in high-energy administration than in low-energy administration. CONCLUSION: Our results indicated that KTP laser therapy was effective for slow-flow vascular malformations less than 30 mm in size without significant side effects.

Intravenous Dexamethasone Administration Before Orthognathic Surgery Reduces the Postoperative Edema of the Masseter Muscle: A Randomized Controlled Trial.

PURPOSE: Dexamethasone seems to suppress postoperative swelling. However, the standard administration dose of dexamethasone for bilateral sagittal split osteotomy (BSSO) has not been reported. This study focused on clarifying the most effective dose of dexamethasone for BSSO. MATERIALS AND METHODS: This research was planned as a prospective, randomized controlled, double-blind study. Patients undergoing BSSO were randomly assigned to receive intravenous preoperative dexamethasone under 3 different dose conditions: 16 mg, 8 mg, and 0 mg (control). The endpoints of this study were 1) postoperative changes in masseter muscle thickness and buccal soft tissue thickness; 2) postoperative changes in maximum incisal opening; 3) postoperative changes in sensation of the chin and lower lip region; 4) postoperative changes in blood examination findings (white blood cell count, neutrophil count, C-reactive protein level, and lymphocyte count); and 5) types of complications. Data were recorded at 2 to 4 time intervals: before surgery, postoperative day 1, postoperative day 2, and postoperative day 3. Average age, gender, average body mass index, average surgery time, and average blood loss also were examined. Data were analyzed by 1-way analysis of variance (Bonferroni multiple-comparisons test) after the Bartlett test. RESULTS: We enrolled 24 patients, including 5 men and 19 women, in this study. The rate of increase in the thickness of the masseter muscle 24 hours after BSSO was 38.4% in the 16-mg group (n = 8), 57.7% in the 8-mg group (n = 8), and 56.1% in the 0-mg group (n = 8). The rate of increase in masseter muscle thickness in the 16-mg group was significantly lower than that in the 0-mg group (P < .05). Regarding the number of lymphocytes after surgery, the 16-mg and 8-mg groups maintained preoperative levels whereas there was a reduced number of lymphocytes in the control group. No statistically significant results were obtained for the following study endpoints: postoperative changes in maximum incisal opening and postoperative changes in sensation of the chin and lower lip region. CONCLUSIONS: This investigation showed that the most effective dose of dexamethasone for BSSO is 16 mg.

Evaluation of OK-432 Injection Therapy as Possible Primary Treatment of Intraoral Ranula.

PURPOSE: A ranula is a pseudocyst caused by mucous extravasation from the sublingual gland. Recently, a sclerosing agent, OK-432 (picibanil), has been reported to be highly effective for treating lymphangioma and cervical cystic lesions. The present study assessed the effectiveness of OK-432 injection therapy for intraoral ranula to clarify whether it can be used as the primary treatment. PATIENTS AND METHODS: The present study was a retrospective clinical study of patients with intraoral ranula who received OK-432 injection therapy from 2005 to 2015. The ranula size was measured on computed tomography or magnetic resonance imaging studies. We dissolved 1 Klinische Einheit (KE) unit of OK-432 powder in normal saline equal to the aspiration volume. The primary endpoint was the treatment results. The secondary endpoints were the relation between the treatment results and the lesion length and aspiration volume. RESULTS: A total of 23 patients received OK-432 injection therapy for an intraoral ranula. The mean lesion size was 19.96 mm. The mean aspiration volume was 2.14 mL. The number of injections was 1 to 4 (mean 1.70). The treatment results were complete regression (CR) in 18 (78.2%), partial regression (PR) in 3 (13.0%), and no response (NR) in 2 (8%) patients after the last injection. The overall efficacy rate was 91.2% (21 of 23). No serious complications were observed. The lesion length and aspiration volume of the CR group was 17.38 mm and 1.40 mL, respectively. The lesion length and aspiration volume of the PR/NR group was 29.20 mm and 4.80 mL, respectively. The PR/NR group lesions were significantly larger than the CR group lesions. CONCLUSIONS: OK-432 injection therapy for intraoral ranula is safe and effective compared with other surgical therapies. This therapy could potentially become a primary treatment of intraoral ranula.

A randomized trial to identify the most effective dose of remifentanil during Le Fort I osteotomy.

PURPOSE: The Le Fort I osteotomy (L-I) requires extensive dissection and manipulation of tissue, causing hemodynamic instability and an undesirable postoperative stress response. This study aimed to clarify the most effective dose of remifentanil during L-I. MATERIALS AND METHODS: This study was designed as a prospective, randomized, controlled double-blinded study. Patients (American Society of Anesthesiologists physical status I to II) undergoing L-I were randomly assigned to receive anesthesia with propofol and remifentanil under 3 remifentanil dose conditions: 0.25 µg/kg/minute (group 1), 0.5 µg/kg/minute (group 2), and 0.75 µg/kg/minute (group 3). All patients underwent L-I with propofol and remifentanil target-controlled anesthesia. The study endpoints were mean arterial pressure (MAP) and heart rate. Data were recorded before L-I (20-minute period before surgery), during L-I (from the beginning of surgery to downfracture), and after L-I (20-minute period after downfracture). Average age, gender, average body mass index, aimed maxillary position, average bispectral index, average surgery time, and average blood loss also were examined. Data were analyzed using the Bartlett test and then 1-way analysis of variance with the Bonferroni multiple comparison test. RESULTS: Data were obtained from 20 patients (9 men, 11 women). The average operating times for groups 1, 2, and 3 were 53.1, 46.7, and 49 minutes, respectively. The age range was 18 to 46 years (average, 26.05 yr). The rate of MAP increase from before to during L-I in group 1 was 10.8% (n = 7). The rate of MAP increase from before to during L-I in group 3 was 2.1% (n = 6). Group 3 showed a significantly lower rate of MAP increase during and after L-I compared with group 1 (P < .05). CONCLUSION: Remifentanil administration at 0.75 µg/kg/minute stabilized hemodynamics during L-I without major side effects. Results indicated that the standard index of remifentanil administration during L-I should be 0.75 µg/kg/minute when using oxygen, propofol, and remifentanil for general anesthesia.

Cyclo-oxygenase-2 expression is associated with vascular endothelial growth factor C expression and lymph node metastasis in oral squamous cell carcinoma.

PURPOSE: Cervical lymph node metastasis in oral squamous cell carcinoma (OSCC) is recognized as a poor prognostic factor, although its mechanism remains unclear. Recently, cyclo-oxygenase-2 (COX-2) level has been found to correlate highly with vascular endothelial growth factor C (VEGF-C) and lymph node metastasis, as in other solid tumors. However, there has been no report of this correlation in OSCC. Therefore, the aim of this study was to investigate whether COX-2 immunohistochemical expression in OSCC was associated with VEGF-C expression, histopathologic parameters, and lymph node metastasis. MATERIALS AND METHODS: Lymphatic vessel density, VEGF-C, and COX-2 immunohistochemical expression were examined pathologically in 60 specimens of invasive OSCC. Relations of histopathologic parameters to lymph node metastasis were analyzed. RESULTS: Expression levels of VEGF-C and COX-2 and lymphatic vessel density in the lymph node metastatic group were significantly higher than in the nonmetastatic group (P < .01). A significant correlation was found between the expression levels of VEGF-C and COX-2 (r = 0.512; P < .001). COX-2 expression was significantly related to lymph node metastasis (P = .004) and VEGF-C expression (P = .005). Univariate analysis showed that survival time was impaired by higher COX-2 and VEGF-C expression levels. Multivariate survival analysis showed that COX-2 expression was an independent prognostic factor. CONCLUSION: This study showed that VEGF-C expression was upregulated by COX-2 in OSCC. High VEGF-C expression appears to promote peritumoral lymphangiogenesis. These data indicated that lymph node metastasis is promoted by COX-2 and VEGF-C in OSCC.

Navigation surgery for Le Fort 1 osteotomy in a fibrous dysplasia patient.

Orthognathic surgery is sometimes performed for fibrous dysplasia to correct malocclusion or facial asymmetry. However, Le Fort 1 osteotomy for this disease is difficult because of severe anatomical abnormality. Computer-assisted surgery is a rapidly developing technique in oral and maxillofacial surgery that is helping to ensure the safety of the surgery. We report a case of polyostotic craniofacial fibrous dysplasia in which two-jaw orthognathic surgery was performed using a navigation system with the Le Fort 1 osteotomy procedure. A 29-year-old woman presented with swelling and asymmetry on the right side of her face. Craniofacial fibrous dysplasia on the right side had been previously diagnosed, and she had undergone conservative surgery several times before. The disease extended to the right mandible, maxilla, and zygomatic, temporal frontal, and orbital areas, including the skull base. We first performed conservative contouring around the frontal and orbital areas, and then Le Fort I osteotomy and sagittal split ramus osteotomy to correct the asymmetry and cant of the occlusal plane. A passive infrared navigation system (Vector Vision surgical navigation system) was used for the Le Fort I osteotomy. The postoperative course was stable, and the facial asymmetry and cant of the occlusal plane improved and remained suitable 2 years after surgery. Thus, Le Fort 1 osteotomy can be performed safely in fibrous dysplasia with the aid of a passive infrared navigation system.