Efficacy of tracheostomy for respiratory management in patients with advanced oral cancer.

BACKGROUND: Many studies have been reported on tracheostomy to prevent upper airway obstruction after surgery. Among these, the scoring system proposed by Cameron et al. quantifies various factors that influence postoperative respiratory failure. This system provides a basis for surgeons to decide whether to perform an elective tracheostomy. In this study, the authors applied the Cameron scoring system retrospectively to patients undergoing severe oral cancer surgery to reevaluate the indications for elective tracheostomy and to investigate its clinical efficacy in airway management. In this study, a sample of 20 patients who underwent oral cancer surgery was selected and divided into two groups: 10 underwent tracheostomy and 10 did not. The Cameron scoring scores for each patient were extracted, to verify whether elective tracheostomy was performed in accordance with the threshold scores. Differences in scores and significant clinical impact factors between the two groups were analyzed and compared. RESULT: The 10 patients who underwent tracheostomy had an average Cameron score of 6.4, all scoring above the recommended threshold of 5 for tracheostomy. For the 10 patients who did not undergo tracheostomy, the average score was 2.5, with 8 out of these 10 patients scoring below 5. Significant clinical impact factors observed included the location and size of the tumor, the performance of mandibulectomy and neck dissection, and the type of reconstruction surgery. CONCLUSION: In planning surgery for oral cancer patients, it is essential to consider the use of elective tracheostomy based on preoperative assessment of the risk of postoperative airway obstruction using tools like the Cameron scoring system, and patients' condition. Research confirms that elective tracheostomy effectively enhances airway management in patients with severe oral cancer.

Retrospective analysis on prognosis of oral cancer patients according to surgical approaches for effective cancer ablation: swing approach versus visor approach.

BACKGROUND: For the surgical treatment of oral cancer, it is sometimes necessary to expand intraoral access within the oral cavity. The "swing approach" that involves lip splitting of the mandible and temporary mandibular osteotomy and the "visor approach" that does not split the lower lip and mandible are mainly used. This study analyzed postoperative outcomes such as complications, recurrence rate, and survival rate by these two approaches. The goal of this study is to evaluate the surgical outcomes of patients using these two approaches, to propose effective perioperative management for oral cancer surgery, and to compare the prognosis of oral cancer patients. MATERIALS AND METHODS: From 2005 to 2020, 29 patients who underwent surgery at the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital for oral cancer lesions occurred in the mandible, floor of mouth, and tongue were selected for the study. Based on the surgical approach used, a chart review was conducted on various prognostic clinical factors such as the patients' sex and age, primary site, TNM stage, histopathologic grade, recurrence and metastasis, postoperative survival rate, adjuvant chemo-radiation therapy, satisfaction with aesthetics/function/swallowing, length of hospital stay, tracheostomy and its duration, and neck dissection and its type. Statistical analysis was conducted using SPSS 25.0 (SPSS Inc., Chicago, IL) through Fisher's exact t-test. RESULT: There was no statistically significant difference between two groups in terms of clinical and pathological findings, such as survival rate, the need for adjuvant therapies, and the local recurrence rate. Although better outcomes were observed in terms of function, aesthetics, and postoperative complications in the group with visor approach, there was still no statistically significant difference between two groups. However, the duration of hospital stay was shorter in the visor approach group. CONCLUSION: There was no statistically significant difference in clinical prognostic factors between the swing approach and the visor approach. Therefore, when choosing between the two approaches for the ablation of oral cancer, it is considered to select the surgical priority approach that can be easy access based on the size and location of the lesion. The visor approach had advantages of aesthetics and healing period.

Targeting tumor-intrinsic PD-L1 suppresses the progression and aggressiveness of head and neck cancer by inhibiting GSK3ß-dependent Snail degradation.

PURPOSE: PD-L1 is an immune checkpoint protein that allows cells to evade T-cell-mediated immune responses. Herein, we uncover a tumor-intrinsic mechanism of PD-L1 that is responsible for the progression and aggressiveness of HNC and reveal that the extracts of a brown alga can target the tumor-intrinsic signaling pathway of PD-L1. METHODS: The biological functions of PD-L1 in the proliferation and aggressiveness of HNC cells in vitro were examined by metabolic activity, clonogenic, tumorigenicity, wound healing, migration, and invasion assays. The clinical importance of PD-L1 in the prognosis of patients with HNC was analyzed by immunohistochemistry. The relationship between PD-L1 and EMT was confirmed via western blotting, qPCR, and immunocytochemistry. RESULTS: Through our in silico approach, we found that PD-L1 was upregulated in HNC and was correlated with an unfavorable clinical outcome in patients with HNC. PD-L1 was crucial for promoting tumor growth, both in vitro and in vivo. High expression of PD-L1 was closely correlated with LN metastasis in OSCC. PD-L1 facilitated the cytoskeletal reorganization and aggressiveness of HNC cells. Moreover, PD-L1 enhanced the EMT of HNC cells by regulating the Snail/vimentin axis. Consistently, MEIO suppressed the PD-L1/Snail/vimentin axis, thereby inhibiting the aggressiveness of HNC cells. Inhibition of PD-L1 induced by PD-L1 silencing or MEIO treatment caused Snail degradation through a GSK3ß-dependent mechanism. The tumor-intrinsic function of PD-L1 could be attributed to the regulation of the GSK3ß/Snail/vimentin axis. CONCLUSION: The discovery of MEIO targeting the tumor-intrinsic function of PD-L1 may prove particularly valuable for the development of novel and effective anticancer drug candidates for HNCs overexpressing PD-L1.

Non-thermal plasma directly accelerates neuronal proliferation by stimulating axon formation.

Among the various methods, Non Thermal Plasma (NTP) has been recently introduced and is being studied to recover the damaged nerve. In the recent years, several studies have suggested that NTP accelerates nerve cell regeneration, but the mechanism remains unknown. This study evaluated the effect of NTP on neuronal proliferation in SH-SY5Y (Human neuroblastoma cells) cells differentiated by retinoic acid (RA) and investigated the mechanism by which NTP promotes cell proliferation. We analyzed the morphology of differentiated SH-SY5Y cells, and performed western blot analysis and reverse transcription polymerase chain reaction (RT-PCR). Immunofluorescence analysis was performed in an in vivo study by categorizing Wistar A rats into three groups: non-nerve damage (Non-ND), nerve damage (ND), and nerve damage + NTP treatment (ND + NTP). The cell morphology analysis revealed that the number of cells increased and axonal elongation progressed after NTP treatment. In addition, western blots indicated that tau expression increased significantly after NTP treatment. The RT-PCR results revealed that the expression of tau, wnt3a, and ß-catenin increased after NTP treatment. The in vivo immunofluorescence assay showed that NTP increased the markers for tau and S100B while regulating the over-expression of MAP2 and GAP43. NTP treatment accelerated cell proliferation and regeneration of damaged neurons in differentiated SH-SY5Y cells. These results establish the fact of NTP as a noninvasive and effective treatment for nerve injury.

PD-L1 Expression Correlated with Clinicopathological Factors and Akt/Stat3 Pathway in Oral SCC.

Programmed cell death ligand 1 (PD-L1) is an immune checkpoint molecule that inhibits immune responses. The physiological and prognostic role of the PD-L1 signaling pathway in the oral maxillofacial region is unclear. This study aimed to investigate the role of PD-L1 in the progression of oral squamous cell carcinoma (OSCC). Furthermore, clinicopathological factors related to PD-L1 expression were examined in patients with OSCC through immunohistochemistry (IHC) of tissue sections and through an in vitro study in OSCC cells. The medical records, radiographic findings, and mortality referrals of 81 patients obtained from the National Statistical Office were reviewed. IHC was performed on tissue specimens of these patients to determine the expression levels of PD-L1, which showed significant statistical differences based on age, tumor size, TNM stage, cervical lymph node metastasis, and locoregional recurrence. Patients with a high PD-L1 expression had significantly poorer survival rates. Multivariate analysis using the Cox proportional model confirmed the high relative risk ratio for high PD-L1 expression, TNM stage, and neck node metastasis, all of which were significantly associated with a poor prognosis in patients with OSCC. The in vitro study showed that SAS and YD38 cells transfected with PD-L1 siRNA had significantly increased apoptosis, reduced proliferative capacity, and tumorigenicity.

Comparison of time and cost between conventional surgical planning and virtual surgical planning in orthognathic surgery in Korea.

BACKGROUND: The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost. MATERIAL AND METHOD: This is a retrospective study of the patients who underwent orthognathic surgery at the OOOOO University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and 3-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy+bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using paired t test. RESULTS: Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385±7.8 min, and that for group II was 195±8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction. CONCLUSIONS: The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

The effect of autogenous tooth bone graft material without organic matter and type I collagen treatment on bone regeneration.

OBJECTIVES: The aim of this study is to examine the effect of particulate autogenous tooth graft removed with organic matter and type I collagen addition on bone regeneration and to validate the possibility of useful allograft material for jaw defects. MATERIAL AND METHODS: Autogenous tooth bone maker (Korean Dental Solution® KOREA) made particulate autogenous tooth not including organic matter. We used to the developed tooth grafts for experiment. Cell adhesion test with hemacytometer and energy dispersive X-ray spectroscopy (Supra40 VP®, Carl Zeiss, Germany) analysis about the particulate autogenous tooth and type I collagen were performed. Rabbits were divided into three groups: bone graft with organic matter (OM) removing particulate autogenous tooth group, bone graft with OM removing particulate autogenous tooth and type I collagen group, and a control group. Bone grafting was performed in rabbit's calvaria. The rabbits were sacrificed at different interval at 1, 2, 4, and 6 weeks after bone grafting for the histopathologic observation and observed the effect of bone regeneration by SEM, H-E & Masson stains, osteocalcin IHC staining. RESULT: In vitro cytopathological study showed affinity for cells, cell attachment pattern, and cell proliferation in the order of control group, OM-removed and collagen-treated group, OM-removed particulate autogenous tooth group. The results of the degree of mineralization were opposite to those of the previous cell experimental results, and the OM-removed group, OM-removed group and collagen-treated group were relatively higher than the control group. Histopathologic analysis showed that vascularization and neonatal bone formation were higher in particulate autogenous tooth group with removing OM and with addition of collagen than control group and group of OM removed only. Immunohistochemical analysis showed that osteocalcin (OSC) expression was not observed in the control group, but at 4 weeks groups, OSC expression was observed the OM removed and OM-removed-collagen-treated particulate autogenous tooth, and the degree of expression was somewhat stronger in group of the OM removed and collagen additionally treated particulate autogenous tooth. CONCLUSION: Particles that do not contain organic matter, the saint tooth, was responsible for sufficient bone graft material through the role of space maintenance and bone conduction, and further improved bone formation ability through additional collagen treatment. Therefore, research on various extracellular substrates and autologous bone grafting materials is necessary, and through this, it is possible to lay the foundation for a new type of autologous bone grafting material with excellent academic and technical utility.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer - Case review II: mandibular anterior and the floor of the mouth lesion of basaloid squamous cell carcinoma and clear cell odontogenic carcinoma.

Preoperative patient analysis for oral cancer involves multiple considerations that are based on multiple factors; these include TNM stages, histopathologic findings, and adjacent anatomical structures. Once the decision is made to excise the lesion, the margin of dissection and its extent should be considered along with the best form of reconstruction and airway management. Treatment methods include surgical resection, radiotherapy, and chemotherapy. Although the combined method of treatment is controversial, surgical resection is considered predominantly, and immediate reconstruction after surgical resection follows. The choice of treatment is dictated by the anticipated functional and esthetic results of treatment and also by the availability of a surgeon with the required expertise. Segmental mandibulectomy with primary reconstruction has been shown to have advantages in both functional and esthetic results. A 52-year-old male patient with basaloid squamous cell carcinoma of the floor of the mouth, and the anterior portion of the mandible was treated with surgical procedures that included segmental mandibulectomy with both supraomohyoid neck dissection (SOHND) at Levels I-III and mandible reconstruction with a left fibula free flap. A 55-year-old male patient with clear cell odontogenic carcinoma of the oral cavity underwent segmental mandibulectomy with both SOHND at Levels I-III and mandible reconstruction with a left fibula free flap. The purpose of this study was to review the anatomic and functional results of patients after immediate reconstruction with a fibula free flap following resection of carcinoma in the anterior portion of the mandible and floor of the mouth.

Sequential treatment from mandibulectomy to reconstruction on mandibular oral cancer - Case review I: mandibular ramus and angle lesion of primary intraosseous squamous cell carcinoma.

Primary intraosseous squamous cell carcinoma (PIOSCC) is very rare type of squamous cell carcinoma (SCC) that occurs within the jaw and arises from remnants of odontogenic epithelium with no connection to the oral mucosa. This study reports two cases of PIOSCC of the mandible. Reported in this article are two cases of PIOSCC of the mandible that were treated with resection and reconstruction using a fibular free flap. The first case was a 36-year-old male patient who complained of right mandibular pain. Computed tomography (CT) and panoramic radiograph revealed a large radiolucency in the mandibular ramus area. At first, an odontogenic keratocyst was tentatively diagnosed, and an excision procedure was carried out at another clinic. A final biopsy after cyst enucleation revealed well-differentiated SCC, so we proceeded with segmental mandibulectomy and reconstruction using a fibular free flap. The second case was a 48-year-old male patient with left mandibular pain. CT and panoramic radiograph revealed irregular radiolucency in the mandibular angle area near tooth #38. At first, osteomyelitis was tentatively diagnosed, and a curettage was carried out. A later biopsy revealed well-differentiated SCC, so segmental mandibulectomy and reconstruction with a fibular free flap were secondarily performed. Our two cases have had no recurrence. The facial appearance of both patients is satisfactory, and the neo-mandibular body created using a fibular bone transfer displays adequate bony volume.

Gold nanoparticles conjugated with programmed death-ligand 1 antibodies induce apoptosis of SCC-25 oral squamous cell carcinoma cells via programmed death-ligand 1/signal transducer and transcription 3 pathway.

OBJECTIVE: Objective of this study is to test the anti-cancer effect of the gold nanoparticles conjugated with programmed death-ligand 1 (PD-L1) specific antibodies (PDL1-GNP), on oral squamous cell carcinoma. DESIGN: To test the effect of PDL1-GNP on oral squamous cell carcinoma, SCC-25 cells, a type of human oral squamous cell carcinoma which were isolated from human tongue, and HaCaT human keratinocytes as normal cell control, were used. Cell viability was tested by the water-soluble tetrazolium-1 and live/dead assays, while apoptotic cell death of SCC-25 cells were monitored by immunofluorescent staining and flow cytometry. The molecular changes during PDL1-GNP-mediated apoptosis were analyzed using Western blot analysis. RESULTS: PDL1-GNP treatment effectively decreased the growth of SCC-25 cells but not HaCaT cells. The results of the confocal microscopic assay showed that PDL1-GNP specifically bound to the SCC-25 cell membrane. Furthermore, the results of the live/dead, cytochrome c release assays and flow cytometry indicated PDL1-GNP-mediated apoptotic cell death of SCC-25 cells. PDL1-GNP-treated SCC-25 cells showed a phenotype with increased apoptotic proteins, including cleaved form of caspase-3, caspase-9, and poly (ADP-ribose) polymerase 1 (PARP1). PDL1-GNP treatment also effectively decreased B-cell lymphoma 2 (Bcl-2) and PD-L1 protein expression. Phosphorylation of signal transducer and transcription 3 (STAT3) was significantly increased after PDL1-GNP treatment on SCC-25 cells. CONCLUSIONS: PDL1-GNP treatment induced SCC-25 cell apoptosis possibly by inhibiting the function of the PD-L1 protein, since PD-L1 blocks STAT3 phosphorylation, which promotes apoptotic cell death.

Non-thermal plasma application enhances the recovery of transected sciatic nerves in rats.

This experimental research aimed to investigate the effects of non-thermal plasma on nerve regeneration after transected nerve damage using the sciatic nerve in Wistar albino (A) rats. The experiments were performed on 27 Wistar A rats. The rats underwent surgery for right sciatic nerve exposure and were divided into three groups (each group, n = 9) according to sciatic nerve transected injury (SNTI) and non-thermal plasma application: a non-nerve damage (non-ND) group, a only nerve damage without non-thermal plasma application (ND) group, and a nerve damage with non-thermal plasma application (ND + NTP) group. Subsequent to SNTI and immediate suture, non-thermal plasma was administered three times per week for eight weeks. Evaluation for functional recovery was performed using the static sciatic index measured over the full treatment period of eight weeks. The sciatic nerve specimens were obtained after euthanasia and third day from the last non-thermal plasma application. The sciatic nerve tissues were subjected to histological analysis. Behavior analysis presented that the ND + NTP group showed improved static sciatic index compared with the nerve damage group. Histopathological findings demonstrated that the ND + NTP group had more dense Schwann cells and well-established continuity of nerve fibers, greater than the nerve damage group. Immunohistochemistry showed that the ND + NTP group had increased levels of markers for microtubule-associated protein 2 (MAP2), tau, S100 calcium-binding protein B, and neurofilament-200 and regulated the overexpression of CD68 and MAP2. These results indicated that non-thermal plasma enhanced the motor function and restored the neuronal structure by accelerating myelination and axonal regeneration. Additionally, non-thermal plasma was confirmed to have a positive effect on the recovery of SNTI in rats.

Sports-Related Oral and Maxillofacial Injuries: A 5-Year Retrospective Study, Pusan National University Dental Hospital.

PURPOSE: The incidence of sports trauma is gradually increasing, and its importance is therefore also increasing. The present study was conducted to analyze the types, proportions, and tendencies of sports trauma associated with the oral and maxillofacial regions. PATIENTS AND METHODS: Patients who visited the Emergency Department of Pusan National University Dental Hospital between 2014 and 2018 for more than 5 years were surveyed through retrospective epidemiologic investigations. Type of sports was classified according to American Academy of Pediatrics classification. For statistical analysis, age and gender distribution, cause of trauma, and annual trends data were collected. RESULTS: Of the 517 patients, most of the patients were teenagers (27.9%), followed by those younger than 10 years (23.2%) (χ2 = 22.897; P = .002), and noncontact sports, which is cycling, was the most common (43.5%) cause for trauma in both adult and children groups (χ2 = 91.824; P < .001). The most common sports associated with contact sports, limited-contact sports, and noncontact sports were football (47.7%), baseball (50.0%), and cycling (74.8%), respectively. The causes for trauma injury were as follows: contact sports, other person's body (53.4%); limited-contact sports, other objects (60.9%); and noncontact sports, slip down (77.4%) (χ2 = 298.901; P < .001). The prevalence and incidence of sports injuries increase every year, and the proportion of injured patients in May was the highest (χ2 = 52.360; P = .181). The high percentage of traumatic sports demonstrated statistically significant trends (χ2 = 43.073; P = .002). Kickboard injuries showed a rapid increase recently (P for linear trend = .045), whereas other sports showed no significant trends. CONCLUSIONS: Considering the increasing incidence of sports-related injuries, oral and maxillofacial surgeons should be more concerned with maxillofacial trauma during sports.

Importance in the occurrence rate of shortest buccal bone marrow distance (<1 mm) for sagittal split ramus osteotomy.

BACKGROUND/PURPOSE: The neurosensory disturbance is a common complication following sagittal split ramus osteotomy (SSRO) whereas the shortest buccal bone marrow (SBM) is an important risk factor. The present study aimed to investigate the relationship between the occurrence rates of SBM among three skeletal patterns. METHODS: The cone-beam computed tomography (CBCT) images of 90 participants were divided into skeletal Class I, II, and III. There were six horizontal planes separated apart by a 2 mm interval; it started with plane 0 (original intact mandibular canal) to plane 5 which was 10 mm below. The data of SBM were divided into two groups (SBM ≥ 1 mm and SBM < 1 mm). With an SBM value < 1 mm, we defined a high occurrence rate of postoperative neurosensory abnormality or unfavorable split. RESULTS: The Class III patients had the smallest SBM value (1.31-1.75 mm) whereas the Class II patients had the largest SBM value (1.57-2.09 mm). For the Class III patients, the highest and lowest occurrence rates of SBM were 56.5% and 43.5% respectively. For the Class II patients, the highest and lowest occurrence rates of SBM were 37.1% and 17.7% respectively. The patients with Class III malocclusion had higher occurrence rates of SBM than the patients with Class II malocclusion. CONCLUSION: Class III had a significantly higher occurrence of probability (SBM < 1 mm) than Class II. Therefore, patients with Class III were more likely to experience postoperative neurosensory abnormalities and unfavorable split than patients with Class II.

Non-thermal plasma accelerates the healing process of peripheral nerve crush injury in rats.

The objective of this study was to evaluate the effect of non-thermal plasma (NTP) on the healing process of peripheral nerve crush injuries, which can occur during dental implant procedures. For this, a rat model of sciatic nerve crush injury (SNCI) was adopted. The rats were divided into three groups: non-nerve damage (non-ND), nerve damage (ND), and ND+NTP group. To evaluate the sciatic nerve (SN) function, the static sciatic index was calculated, and the muscle and SN tissues were subjected to a histologic analysis. The results showed that NTP effectively accelerated the healing process of SNCI in rats. In contrast to the ND group, which showed approximately 60% recovery in the SN function, the NTP-treated rats showed complete recovery. Histologically, the NTP treatments not only accelerated the muscle healing, but also reduced the edema-like phenotype of the damaged SN tissues. In the ND group, the SN tissues had an accumulation of CD68-positive macrophages, partially destroyed axonal fibers and myelinated Schwann cells. Conversely, in the ND+NTP group, the macrophage accumulation was reduced and an overall regeneration of the damaged axon fibers and the myelin sheath was accomplished. The results of this study indicate that NTP can be used for healing of injured peripheral nerves.

Complications associated with specific characteristics of supernumerary teeth.

OBJECTIVES: The purpose of this study was to identify the characteristics of supernumerary teeth, analyze the associated complications, and to present new clinical knowledge on surgical interventions for supernumerary teeth. STUDY DESIGN: This retrospective cohort study was based on the medical records and radiographic records of patients who underwent surgical extraction of supernumerary teeth. The relationships among the patient's age, gender, anatomic features of supernumerary teeth, and presence and type of complications (i.e., spacing, rotation, delayed eruption of the adjacent tooth, cyst formation.) were investigated. The groups were compared by using the Mann-Whitney U test, the Kolmogorov-Smirnov test, and multiple logistic regression analysis (P < .05). RESULTS: The study population consisted of 705 participants who underwent extraction for 1036 supernumerary teeth. The mean age of the participants was 11.5 years, and 73.5% of the participants were males. The complication rate was 55.6%. Variables associated with an increased risk of complications were the patient's age, dentition, tuberculate shape, and horizontal direction of eruption (P < .05). CONCLUSIONS: An increase in the patient's age or abnormalities in the shape and direction of eruption of supernumerary teeth was associated with complications. These parameters should be considered while formulating the treatment plan.

Whitlockite Granules on Bone Regeneration in Defect of Rat Calvaria.

Whitlockite (WH; Ca18Mg2(HPO4)2(PO4)12) is a calcium phosphate based ceramic that contains magnesium ions. As the second most abundant mineral in living bone, WH occupies 25-35 wt % of the inorganic portion of human bone. Compared to hydroxyapatite (HAp, Ca10(PO4)6(OH)2), WH possesses better mechanical properties, faster resorbability, and promotion behavior on the osteogenesis. In this article, we introduced a fabrication method of interconnected porous WH granules through vacuum filtration, followed by sintering treatment based on the thermal stability of WH synthesized using the tri-solvent system. This study presents a histological, radiological, and immunohistochemical evaluation of the bone healing potential of these WH granules in a 5 mm diameter calvarial bone defect in rats. The histological evaluation shows no inflammation or foreign body reaction in the WH group. The WH group displays newly formed bone at the same thickness as the original bone. On the contrary, bone formation is not observed in the nontreated (NT) group. Besides, immunohistochemistry (IHC) confirmed that WH granules promoted bone regeneration with the significantly higher expression of bone morphogenetic proteins-2 (BMP-2), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN) compared to the NT group without the addition of exogenous cells or growth factors. These results suggest that WH has excellent potential for application in bone tissue regeneration.

Versatility of the pedicled buccal fat pad flap for the management of oroantral fistula: a retrospective study of 25 cases.

PURPOSE: Maxillary bone grafts and implantations have increased over recent years despite a lack of maxillary bone quality and quantity. The number of patients referred for oroantral fistula (OAF) due to implant or bone graft failure has increased, and in patients with an oroantral fistula, the pedicled buccal fat pad is viewed as a robust, reliable option. This study was conducted to document the usefulness of buccal fat pad grafts for oroantral fistula closure. MATERIALS AND METHODS: We retrospectively studied 25 patients with OAF treated with a buccal fat pad graft from 2015 to 2018. Sex, age, OAF location, cause, duration, presence of systemic disease, smoking, previous dental surgery, and side effects were investigated. RESULTS: A total of 25 patients were studied. Mean patient age was 54.8 years, and the male to female ratio was 19:6. Causes of oroantral fistula were cyst enucleation, tumor resection, implant removal, bone graft failure, and extraction. Excellent results were obtained in 23 (92%) of the 25 patients. In the other two patients that both smoked, a small fistula was observed during follow-up. No recurrence of oroantral fistula was observed after 2 months to 1 year of follow-up. CONCLUSIONS: The incidence of oroantral fistula is increasing due to implant and bone graft failures. Oroantral fistula closure using a pedicled buccal fat pad was found to have a high success rate.

A retrospective analysis of risk factors of oromaxillofacial infection in patients presenting to a hospital emergency ward.

BACKGROUND: The purpose of this study was to review the clinical features of oromaxillofacial infections in patients presenting to a hospital emergency ward, to identify the key factors affecting the requirement for hospitalization, and the potential risk factors predisposing to a prolonged length of hospital stay. METHODS: A retrospective medical record review of the 598 patients treated for oromaxillofacial infection from 2013 to 2017 at the oral and maxillofacial surgery department, Yangsan Pusan National University Hospital, was conducted. The following information was collected from each patient: sex, age, past medical history, site of infection, etiology, admission or outpatient care, level of C-reactive protein (mg/dL), fascial spaces involved, treatment method, and duration of hospitalization. Chi-squared tests were used to identify risk factors, which were further analyzed using multivariable logistic regression. RESULTS: A total of 606 patients were eligible for inclusion in the study, of which eight were excluded due to having incomplete charts; thus, 598 patients were included: 55% were male, mean patient age was 47.1 ± 19.9 years, and 12.9% of patients were diabetic. Furthermore, 71.2% of patients had infection originating in the mandible; the most common tooth of origin was lower posterior, and 29.8% of patients were hospitalized. Risk factors for hospital admission were elderly patients with concurrent disease, elevated C-reactive protein level, and multiple-space infection in the oromaxillofacial area. The duration of hospitalization was correlated with both diabetes and age. CONCLUSIONS: The requirement for hospital admission is determined by the severity of the infection; even severe infections, once treated with appropriate surgery, have no relation to the length of hospital stay. The important risk factors for increased duration of hospitalization are diabetes mellitus and older age. The understanding of risk factors associated with a prolonged hospital stay during the treatment of oromaxillofacial infection will aid in treatment planning as well as highlight the importance of adequate diabetes control in patients at risk of such infection.

Comparison of time and cost between conventional surgical planning and virtual surgical planning in orthognathic surgery in Korea.

BACKGROUND: The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost. MATERIAL AND METHOD: This is a retrospective study of the patients who underwent orthognathic surgery at the Pusan National University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and three-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy + bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using the paired t test. RESULTS: Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385 ± 7.8 min, and that for group II was 195 ± 8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction. CONCLUSIONS: The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

Langerhans cell histiocytosis of the mandible: two case reports and literature review.

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the proliferation of dendritic cells resulting in local or systemic symptoms. The clinical symptoms of patients with Langerhans cell histiocytosis depend on the site and the degree of involvement. This article describes two case histories of unifocal bony Langerhans cell histiocytosis with mandibular involvement and further discusses the appropriate management of such via a review of the literature.