Current Strategies for Treatment of Mandibular Fractures With Plate Osteosynthesis: A European Prospective Study.

PURPOSE: The training and preferences of surgeons influence the type of surgical treatment for mandibular fractures. This multicentre prospective study analyzed the current treatment strategies and outcomes for mandibular fractures with open reduction and internal fixation (ORIF). MATERIAL AND METHODS: This prospective study included patients aged ≥16 years who underwent ORIF for mandibular fractures in 12 European maxillofacial centers. Age, sex, pretrauma dental status, fracture cause, site and type, associated facial fractures, surgical approach, plate number and thickness (≤1.4 or ≥1.5 mm), duration of postoperative maxillomandibular fixation, occlusal and infective complications at 6 weeks and 3 months, and revision surgeries were recorded. RESULTS: Between May 1, 2021 and April 30, 2022, 425 patients (194 single, 182 double, and 49 triple mandibular fractures) underwent ORIF for 1 or more fractures. Rigid osteosynthesis was performed for 74% of fractures and was significantly associated with displaced ( P =0.01) and comminuted ( P =0.03) fractures and with the number of nonsurgically treated fracture sites ( P =0.002). The angle was the only site associated with nonrigid osteosynthesis ( P <0.001). Malocclusions (5.6%) and infective complications (5.4%) were not associated with osteosynthesis type. CONCLUSION: Rigid osteosynthesis was the most frequently performed treatment at all fracture sites, except the mandibular angle, and was significantly associated with displaced and comminuted fractures and the number of nonsurgically treated fracture sites. No significant differences were observed regarding postoperative malocclusion or infections among osteosynthesis types.

Streptococcus mitis and Prevotella melaninogenica Influence Gene Expression Changes in Oral Mucosal Lesions in Periodontitis Patients.

Oral microbiome disruptions in periodontitis are related to the chronic inflammatory reactions that could in turn lead to the development of multiple oral diseases. The objective of the study was to assess the frequencies of Streptococcus mitis, Prevotella melaninogenica, and Prevotella intermedia in oral benign lesions, oral potentially malignant disorders (OPMDs), and oral squamous cell carcinomas (OSCCs) and investigate the impact of these bacteria on the expression patterns of the selected (potential) target genes (PI3CA/AKT2/mTOR, DUSP16/MAPK14, and COX2). After sample collection (25 benign lesions, 30 OPMDs, and 35 OSCCs) and DNA/RNA extraction, quantitative real-time polymerase chain reaction (qPCR) was performed to detect bacterial presence and assess relative gene expression levels in different lesion groups. Prevotella melaninogenica was the most prevalent of the three analyzed bacteria, with the frequency being 60% in benign lesions, 87% in OPMDs (p = 0.024), and 77% in OSCC. The OPMD tissues in which Prevotella melaninogenica was present exhibited a higher expression level of AKT2 (p = 0.042). Significantly lower expression of DUSP16 was observed in OSCC tissues containing Streptococcus mitis (p = 0.011). The obtained results indicate a substantial contribution of P. melaninogenica and Str. mitis in the pathogenesis of oral mucosal lesions, possibly via AKT2 upregulation and DUSP16 downregulation.

Immediate placement of extra-short implants in refined scapula tip microvascular free flaps: In house virtual planning and surgical technique - Proof of concept.

Scapula tip flaps have been introduced in the literature as an ideal surgical treatment option for large defects in the horizontal plane of the maxilla. This article aims to present a unique step by step protocol for a near total maxillectomy with a pterygoid bone resection and consecutive microvascular reconstruction with a harvested scapula tip flap. The protocol includes immediate placement of extra-short implants in donor bone with the aid of Virtual Surgical Planning (VSP), and an in-house 3D printing of medical 3D models and surgical guides. So far, there has been no presented surgical technique combining immediate implant placement in the scapula region with simultaneous microvascular repair. This technique allows: tumour resection; flap harvesting; extra-short implant placements and reconstruction to be performed in one simultaneous procedure. The technique is presented with illustrations, VSP (presented on videos), radiographs, and surgical findings. We discovered that this refinement of the scapula tip surgery has enabled reconstructive procedures to be performed at the same time as implant placements, providing expedited functional and aesthetic outcomes in selected cases. Moreover, modification of the surgical technique could enhance the competence of the oropharyngeal edge. In conclusion, this new surgical protocol utilizing VSP, 3D models and simultaneous extra-short implant placement provides indispensable advantages for such a complicated surgical procedures, while significantly shortening the duration of surgery.

Manual versus rigid intraoperative maxillo-mandibular fixation in the surgical management of mandibular fractures: A European prospective analysis.

PURPOSE: Intraoperative stabilisation of bony fragments with maxillo-mandibular fixation (MMF) is an essential step in the surgical treatment of mandibular fractures that are treated with open reduction and internal fixation (ORIF). The MMF can be performed with or without wire-based methods, rigid or manual MMF, respectively. The aim of this study was to compare the use of manual versus rigid MMF, in terms of occlusal outcomes and infective complications. MATERIALS AND METHODS: This multi-centric prospective study involved 12 European maxillofacial centres and included adult patients (age ≥16 years) with mandibular fractures treated with ORIF. The following data were collected: age, gender, pre-trauma dental status (dentate or partially dentate), cause of injury, fracture site, associated facial fractures, surgical approach, modality of intraoperative MMF (manual or rigid), outcome (minor/major malocclusions and infective complications) and revision surgeries. The main outcome was malocclusion at 6 weeks after surgery. RESULTS: Between May 1, 2021 and April 30, 2022, 319 patients-257 males and 62 females (median age, 28 years)-with mandibular fractures (185 single, 116 double and 18 triple fractures) were hospitalised and treated with ORIF. Intraoperative MMF was performed manually on 112 (35%) patients and with rigid MMF on 207 (65%) patients. The study variables did not differ significantly between the two groups, except for age. Minor occlusion disturbances were observed in 4 (3.6%) patients in the manual MMF group and in 10 (4.8%) patients in the rigid MMF group (p > .05). In the rigid MMF group, only one case of major malocclusion required a revision surgery. Infective complications involved 3.6% and 5.8% of patients in the manual and rigid MMF group, respectively (p > .05). CONCLUSION: Intraoperative MMF was performed manually in nearly one third of the patients, with wide variability among the centres and no difference observed in terms of number, site and displacement of fractures. No significant difference was found in terms of postoperative malocclusion among patients treated with manual or rigid MMF. This suggests that both techniques were equally effective in providing intraoperative MMF.

Osteogenic and Adipogenic Differentiation Potential of Oral Cancer Stem Cells May Offer New Treatment Modalities.

(1) Treatment failure of oral squamous cell carcinoma (OSCC) is generally due to the development of therapeutic resistance caused by the existence of cancer stem cells (CSCs), a small cell subpopulation with marked self-renewal and differentiation capacity. Micro RNAs, notably miRNA-21, appear to play an important role in OSCC carcinogenesis. Our objectives were to explore the multipotency of oral CSCs by estimating their differentiation capacity and assessing the effects of differentiation on stemness, apoptosis, and several miRNAs' expression. (2) A commercially available OSCC cell line (SCC25) and five primary OSCC cultures generated from tumor tissues obtained from five OSCC patients were used in the experiments. Cells harboring CD44, a CSC marker, were magnetically separated from the heterogeneous tumor cell populations. The CD44+ cells were then subjected to osteogenic and adipogenic induction, and the specific staining was used for differentiation confirmation. The kinetics of the differentiation process was evaluated by qPCR analysis of osteogenic (Bone Morphogenetic Protein-BMP4, Runt-related Transcription Factor 2-RUNX2, Alkaline Phosphatase-ALP) and adipogenic (Fibroblast Activation Protein Alpha-FAP, LIPIN, Peroxisome Proliferator-activated Receptor Gamma-PPARG) markers on days 0, 7, 14, and 21. Embryonic markers (Octamer-binding Transcription Factor 4-OCT4, Sex Determining Region Y Box 2-SOX2, and NANOG) and micro RNAs (miRNA-21, miRNA-133, and miRNA-491) were also correspondingly evaluated by qPCR. An Annexin V assay was used to assess the potential cytotoxic effects of the differentiation process. (3) Following differentiation, the levels of markers for the osteo/adipo lineages showed a gradual increase from day 0 to day 21 in the CD44+ cultures, while stemness markers and cell viability decreased. The oncogenic miRNA-21 also followed the same pattern of gradual decrease along the differentiation process, while tumor suppressor miRNA-133 and miRNA-491 levels increased. (4) Following induction, the CSCs acquired the characteristics of the differentiated cells. This was accompanied by loss of stemness properties, a decrease of the oncogenic and concomitant, and an increase of tumor suppressor micro RNAs.

European multicenter prospective analysis of the use of maxillomandibular fixation for mandibular fractures treated with open reduction and internal fixation.

INTRODUCTION: The goal of mandibular fracture treatment is to restore static and dynamic occlusal functions. Open reduction and internal fixation (ORIF) of these fractures can be associated with an intraoperative and/or postoperative maxillo-mandibular fixation (MMF). The aim of this study was to analyse the use of perioperative MMF and its effects on occlusal outcomes in the management of mandibular fractures. MATERIAL AND METHODS: This multicentric prospective study included adult patients with mandibular fractures treated with ORIF. The following data were collected: age, gender, pre-trauma dental status (dentate, partially dentate), cause of injury, fracture site, associated facial fractures, surgical approach, type of ORIF (rigid, non-rigid or mixed), thickness and number of plates, modality of intraoperative MMF (arch bars, self-tapping and self-drilling screws [STSDSs], manual, other) and duration of postoperative MMF. The primary outcome was malocclusion at 6 weeks and 3 months. Statistical analyses were performed with Fisher's exact test or chi-square test, as appropriate. RESULTS: Between 1 May 2021 and 30 April 2022, 336 patients, 264 males and 72 females (median age, 28 years) with mandibular fractures (194 single, 124 double and 18 triple fractures) were hospitalized. Intraoperative MMF was performed in all patients. Osteosynthesis was rigid in 75% of single fractures, and rigid or mixed in 85% and 100% of double and triple fractures, respectively. Excluding patients who underwent manual reduction, postoperative MMF (median duration, 3 weeks) was performed in 140 (64%) patients, without differences by type or number of fractures (p > 0.05). No significant difference was found in the incidence of malocclusion in patients with postoperative MMF (5%, 95% confidence interval [CI], 2-10%) compared to those without (4%; 95% IC, 1-11%) (p > 0.05). CONCLUSION: Postoperative MMF was performed in more than half of the patients despite adequate fracture osteosynthesis, with wide variability amongst centers. No evidence of a reduction in the incidence of postoperative malocclusion in patients treated with postoperative MMF was found.

Parental Satisfaction from Telemedicine in the Follow-up of Children Operated for Craniosynostosis during COVID-19 Pandemic.

OBJECTIVE: The current study aimed to evaluate the satisfaction level of parents from telemedicine use in the long-term follow-up of children operated for craniosynostosis during the COVID-19 pandemic. DESIGN: A cross-sectional 9-question survey analysis using Qualtrics survey software. SETTING: An institutional study carried out at a national, tertiary level academic center in the Slovak Republic. PATIENTS: All patients operated for non-syndromic and syndromic craniosynostosis in our department, who participated in the virtual postoperative follow-up consultations from March 23, 2020, through July 2, 2021, were included in our series. They were enrolled 498 patients, with the parents of 256 children being responding to the survey. INTERVENTIONS: The survey remained open until July 16, 2021, two weeks after the last virtual consultations. It was delivered to the parents by e-mail to generate closed 5-point Likert scale responses. RESULTS: Overall, 72.3% of parents were satisfied with the telemedicine program, and 67.2% found it convenient. Collectively, 89.1% reported that the received instructions were helpful to them. However, only 18.7% of them answered that they would prefer telemedicine consultations in the future. CONCLUSION: The results of this study showed a high satisfaction from the parents during the virtual follow-up of children operated for craniosynostosis. However, despite their positive experience with telemedicine, the vast majority of parents stated that they would prefer in-person visits in the future.

Assesment of radiotherapy effects on the blood flow in gingiva and dental pulp - a laser Doppler flowmetry study.

OBJECTIVE: This study aims to determine and compare the dental pulp and gingival blood flow in patients referred for oropharyngeal radiotherapy (RT) at three different time points: before the start, immediately after, and six months following the completion of RT. The aim is also to evaluate the dependence of the pulp and gingival blood flow on the radiation dose. METHODOLOGY: A prospective study included 10 patients referred for intensity-modulated RT (IMRT) in the oropharyngeal region, with at least one intact tooth surrounded by a healthy gingiva. The dose received by each selected tooth and adjacent gingiva was determined according to the map of treatment planning and computer systems. The blood flow measurements were performed using the laser Doppler flowmetry (LDF) method. RESULTS: Comparing vascular flows at three different time points, the median blood flow in the dental pulp showed no statistically significant difference (p=0.325), contrary to gingiva (p=0.011). Immediately after RT completion, the gingival flow significantly increased compared to its starting point (p=0.012). The pulp flow correlated negatively with the radiation dose, whereas a strong correlation was noted 6 months following the RT completion. CONCLUSIONS: RT caused a significant acute gingival blood flow increase, followed by a long-term (over six months) tendency to return to the starting levels. The dental pulp blood flow is differently affected by higher radiation doses (over 50Gy) in comparison to lower doses (below 50Gy). During RT planning, considering the possibility of protecting the teeth localized near the Gross Tumor Volume as a sensitive organ is recommended.

Assesment of radiotherapy effects on the blood flow in gingiva and dental pulp - a laser Doppler flowmetry study

Abstract Objective This study aims to determine and compare the dental pulp and gingival blood flow in patients referred for oropharyngeal radiotherapy (RT) at three different time points: before the start, immediately after, and six months following the completion of RT. The aim is also to evaluate the dependence of the pulp and gingival blood flow on the radiation dose. Methodology A prospective study included 10 patients referred for intensity-modulated RT (IMRT) in the oropharyngeal region, with at least one intact tooth surrounded by a healthy gingiva. The dose received by each selected tooth and adjacent gingiva was determined according to the map of treatment planning and computer systems. The blood flow measurements were performed using the laser Doppler flowmetry (LDF) method. Results Comparing vascular flows at three different time points, the median blood flow in the dental pulp showed no statistically significant difference (p=0.325), contrary to gingiva (p=0.011). Immediately after RT completion, the gingival flow significantly increased compared to its starting point (p=0.012). The pulp flow correlated negatively with the radiation dose, whereas a strong correlation was noted 6 months following the RT completion. Conclusions RT caused a significant acute gingival blood flow increase, followed by a long-term (over six months) tendency to return to the starting levels. The dental pulp blood flow is differently affected by higher radiation doses (over 50Gy) in comparison to lower doses (below 50Gy). During RT planning, considering the possibility of protecting the teeth localized near the Gross Tumor Volume as a sensitive organ is recommended.

The epidemiology and management of ameloblastomas: A European multicenter study.

The present study aimed at assessing the epidemiology including demographic variables, diagnostic features, and management of ameloblastomas at several European departments of maxillofacial and oral surgery. The following data were recorded for each patient: gender, age, voluptuary habits, comorbidities, site, size, radiographic features, type, histopathological features, kind of treatment, length of hospital stay, complications, recurrence, management and complications of the recurrence. A total of 244 patients, 134 males and 110 females with ameloblastomas were included in the study. Mean age was 47.4 years. In all, 81% of lesions were found in the mandible, whereas 19% were found in the maxilla. Mean size of included ameloblastomas was 38.9 mm. The most frequently performed treatment option was enucleation plus curettage/peripheral ostectomy in 94 ameloblastomas, followed by segmental resection (60 patients), simple enucleation (46 patients), and marginal resection (40 patients). A recurrence (with a mean follow up of 5 years) was observed in 47 cases out of 244 ameloblastomas (19.3%). Segmental resection was associated with a low risk of recurrence (p = 0003), whereas enucleation plus curettage/peripheral ostectomy was associated with a high risk of recurrence (p = 0002). A multilocular radiographic appearance was associated with a high risk of recurrence (p < .05), as well as the benign solid/multicystic histologic type (p < .05). Within the limitations of the study it seems that the management of ameloblastomas will probably remain controversial even in the future. Balancing low surgical morbidity with a low recurrence rate is a difficult aim to reach.

Surgical Management of Bilateral Mandibular Angle Fractures With a Third Molar in Line of Fracture: A European Multicenter Survey.

PURPOSE: The aim of this survey was to investigate the surgical management of bilateral mandibular angle fracture (BMAF) in Europe. METHODS: Data were collected from 2008 to 2018 on patients ≥ 16 years of age who underwent open reduction internal fixation (ORIF) for BMAF with a third molar in the fracture line. The study was conducted at 6 European trauma centers. The following data were recorded: sex, age, cause of the fracture, type of fracture (nondisplaced, displaced, comminuted), type of approach (intraoral, transbuccal, or extraoral), thickness of the plate (≤1.4 mm or ≥1.5 mm), number of plates, cause of plate removal, and third molar extraction status. RESULTS: 25 patients with BMAF (24 males, 1 female, 17 to 83 years old [mean: 28.2 years]) were collected. The main cause of BMAF was assault, and the main surgical approach was intraoral. The most common types of BMAF were displaced + undisplaced (11 patients), displaced + displaced (7 patients), undisplaced + undisplaced (6 patients), and comminuted + comminuted (1 patient). Osteosynthesis was performed with 2 ≤1.4 mm plates on 1 angular fracture and 1 ≤1.4 mm plate on the other fracture in 11 patients, 1 ≤1.4 mm plate on both angular fractures in 6 patients, 1 ≥1.5 mm plate on both fractures in 5 patients, and 2 ≤1.4 mm plates on both fractures in the remaining 3 patients. Out of 25 patients with BMAF, 7 third molars were extracted during ORIF. Among these patients, angular fracture fixation was performed in 3 cases with 1 ≥1.5 mm plate and in 4 patients with 2 ≤1.4 mm plates. CONCLUSIONS: This retrospective multicenter survey indicates a trend of treating with open reduction and rigid internal fixation at least 1 angular fracture of BMAF and those cases requiring extraction of the third molar in the line of fracture.

Endothelial nitric oxide synthase polymorphisms/haplotypes are strong modulators of oral cancer risk in Serbian population.

Oral carcinoma is the sixth most common malignancy worldwide, with survival rates of approximately 50%. The major type of oral cancer, present in 90% of the cases, is oral squamous cell carcinoma (OSCC). The genetic background predisposing an individual to OSCC is complex and largely unknown. Studies have suggested that endothelial nitric oxide synthase (eNOS) gene polymorphisms modulate the cancer risk, prompting us to assess the impact of three functional eNOS gene polymorphisms on OSCC risk. The present study included 50 patients with OSCC and 110 controls. Polymerase chain reaction and restriction fragment length polymorphism analysis were used for genotyping of single-nucleotide polymorphisms -786 T/C (rs2070744) and 894 G/T (rs1799983) and variable number of tandem repeats (VNTR) intron 4b/a polymorphism. Homozygous carriers of -786 T/C and intron 4b/a VNTR variant alleles paired with a significant increase of oral cancer risk [odds ratio (OR): 3.63, 95% confidence interval (CI): 1.08-12.21; P = 0.045 and OR: 11.29, 95% CI: 2.71-47.11; P < 0.001, respectively]. When combined, CC and 4b4a genotypes together led to a 21-fold OSCC risk increase (OR: 21, 95% CI: 2.07-213.29; P = 0.006). Haplotype analysis showed that the C-G-4b haplotype conferred an 11-fold increase in OSCC risk. In conclusion, eNOS polymorphisms considerably influence levels of OSCC risk in the Serbian population.

Marked epithelial to mesenchymal transition in surgical margins of oral cancer-an in vitro study.

Epithelial to mesenchymal transition (EMT) is a feature of several types of human cancer, including oral squamous cell carcinoma (OSCC). In the present study, tumor and margin cell cultures obtained from patients with OSCC were used to determine the expression patterns of certain EMT-associated markers, including vimentin, α-smooth muscle actin, SLUG and SNAIL. In addition, other EMT-associated features, including clonal, proliferative and migratory potential were compared between the two cell types. Cell cultures were generated from tumor and margin tissue samples from 6 patients and cultured up to the fifth passage. EMT marker expression was assessed by reverse transcription-quantitative PCR. Cell proliferation, colony formation and scratch wound healing assays were conducted to characterize the two cell types in terms of proliferation rates, clonality and motility. All of the studied markers were expressed in tumor and margin cells. Although no significant differences were noted with regard to the aforementioned markers, their expression tended to be higher in margin cultures than in tumor cultures. The expressions of the EMT markers were also higher in the fifth passage compared with those noted at the first with a few exceptions. The rates of proliferation and cell migration were decreased during passages, while the number of colonies was increased in both types of cell culture. Tumor and margin cells indicated certain similarities with regard to EMT transition characteristics.

The "European Mandibular Angle" research project: the analysis of complications after unilateral angle fractures.

OBJECTIVE: The aim of this study was to analyze the complications and outcomes of surgical treatment of angle fractures managed at departments of maxillofacial surgery in several European countries. STUDY DESIGN: Patients hospitalized with unilateral isolated angle fractures between 2013 and 2017 were included. The following data were recorded: gender and age of patients, fracture etiology, presence of the third molar, maxillomandibular fixation, osteosynthesis technique, and complications. RESULTS: In total, 489 patients were included in the study. The Champy technique was found to be the most frequently chosen osteosynthesis technique. Sixty complications were observed, at a rate of 12.3%. Complications were associated with the absence of third molars (P < .05). Instead, the Champy technique was associated with fewer complications (P < .05), in comparison with the other adopted techniques. CONCLUSIONS: The management of angle fractures still represents a challenging task with a significant complication rate. The Champy technique still seems to be a valid option for the treatment of such injuries.

Medication-Related Osteonecrosis of the Jaws: Two Center Retrospective Cohort Studies.

This retrospective cohort study aims to describe characteristics of patients with MRONJ, to identify factors associated with MRONJ development, and to examine variables associated with favourable outcome. Totally 32 patients were followed and observed: 21 females and 11 males, in the age range 35-84 in the period from 2009 to 2018. Clinical, radiological examination (Orthopantomograph and CBCT) and biopsy were performed in order to achieve diagnosis. Demographic and clinical variables were taken into consideration: sex, age, primary disease, medication type, mode of delivery, anatomic location, drug treatment duration, timing of tooth extraction, chemotherapy, presence of bone metastasis, aetiology of MRONJ, disease stage, and treatment modality. MRONJ developed under osteoporosis and malignant disease in 11 and 21 patients, respectively. MRONJ development was triggered by tooth extraction or trauma in 30 out of 32 cases, whereas the two patients developed MRONJ spontaneously. Stages I, II, and III were confirmed in 5 (16%), 18 (58%), and 9 (28%) patients, respectively. Mandible was affected in 23 (72%) patients. MRONJ was treated in our department by conservative and surgical modality. In this study we found that 65% of all patients were classified in the cured/improvement group and 35% in the stable/progression group. The female gender, osteoporosis as primary disease, oral regime intake, shorter period on BPs, earlier stage of disease, and specific anatomic localisation (frontal and premolar maxilla) were factors associated with better response to therapy and favourable clinical outcome. Comprehensive treatment protocol and further randomized studies are necessary for further improvements.

The "European Mandibular Angle" Research Project: The Epidemiologic Results From a Multicenter European Collaboration.

PURPOSE: The aim of this study was to analyze the demographic variables and causes and characteristics of mandibular angle fractures managed at several European departments of maxillofacial surgery. MATERIALS AND METHODS: This study was based on a multicenter systematic database that allowed the recording of data from all patients with mandibular angle fractures between January 1, 2013, and December 31, 2017. The following data were recorded: gender, age, etiology, side of angle fracture, associated mandibular fractures, presence of third molar, intermaxillary fixation, and osteosynthesis. RESULTS: The study included 1,162 patients (1,045 male and 117 female patients). A significant association was found between the presence of a third molar and the diagnosis of an isolated angle fracture (P < .0000005). Furthermore, assaults were associated with the presence of voluptuary habits (P < .00005), a younger mean age (P < .00000005), male gender (P < .00000005), and left-sided angle fractures (P < .00000005). CONCLUSIONS: Assaults and falls actually represent the most frequent causes of angle fractures. The presence of a third molar may let the force completely disperse during the determination of the angle fracture, finding a point of weakness.

Putative cancer stem cells are present in surgical margins of oral squamous cell carcinoma.

PURPOSE: Recent evidence suggests that small subpopulations of stem-like cells are accountable for tumour initiation, progression and metastasis. Until now, studies were focused exclusively on the characterization of these cell populations within the tumour itself, while tumour margins were neglected, although it is known that the histological and molecular status of tumour margins may play a significant role in the course of the disease. Therefore, the aims of the study were to isolate cells from oral squamous cell carcinomas and their respective margins, to characterize these cells using specific markers, to assess their self-renewal potential and determine their chemoresistance. METHODS: Cell cultures were obtained from 12 tissue specimens (6 tumours and 6 margins). Total RNA was extracted and gene expression analysis was done by real-time PCR (RT-PCR). Flow cytometry, immunocytometry, sphere formation and MTT assays were also applied. RESULTS: With minor differences, cells originating from both tumours and tumour margins showed the presence of stem cell markers CD133, Nanog, Sox2, CD44, and Oct4, had the capacity to form spheroids and showed chemoresistance. CONCLUSIONS: Subpopulations of margin cells appeared to have stemness properties which might raise the question of re-evaluation of optimal surgical management.

TNF-α (-308G>A) and TNF-R1 (36A>G) single nucleotide polymorphisms are strong risk factors for odontogenic keratocystic tumor development.

BACKGROUND: Polymorphisms in genes encoding tumor necrosis factor-α (TNF-α) and its receptor TNF-R1 have been shown to affect one person's susceptibility to develop certain neoplastic diseases. The aim of the present association study was to investigate whether single nucleotide polymorphisms (SNPs) in TNF-α (-308G>A) and TNF-R1 (36A>G) genes modulate the susceptibility for keratocystic odontogenic tumors (KCOTs) development in Serbian patients. METHODS: Genotyping was performed in 60 KCOT patients and 125 healthy individuals, using polymerase chain reaction/restriction fragment length polymorphism analysis. RESULTS: A significant difference in genotype and allele frequencies was found between patients and controls for both SNPs (P < 0.05). Carriers of the TNF-α A variant had an eightfold increase of KCOT risk (OR = 8.12, 95% CI = 3.98-16.56, P < 0.0001), while carriers of the TNF-R1 G variant had approximately a fourfold increase of KCOT risk (OR=3.65, CI: 1.60-8.40, P = 0.001). CONCLUSIONS: Our findings suggest that the two polymorphisms are strong risk factors for KCOT development in Serbian population.

Malignant ameloblastoma metastasis to the neck--radiological and pathohistological dilemma.

INTRODUCTION: Ameloblastomas are odontogenic epithelial, locally invasive tumors of slow growth and mostly of benign behavior. Their frequency is low (they account for 1% of all head and neck tumors and about 11% of tumors of dental origin). Malignant variations of ameloblastoma are malignant ameloblastoma and ameloblastic carcinoma. They constitute less than 1% of all ameloblastomas. We presented a case of malignant ameloblastoma of the mandible with neck metastasis. CASE REPORT: A patient, aged 72, presented with the following symptoms: pain in the lower jaw, swelling in the left submandibular area and difficult mouth opening. The patient was admitted to the Department of Oral and Maxillofacial Surgery, Clinical Center of Montenegro, two months after he had noticed the symptoms. Panoramic radiography (OPG) showed that both jaws were partially toothless with terminal stage of periodontitis of the remaining teeth. Also, OPG showed sharply limited semicircular defect in the retromolar region and along the front edge of the mandible rami. Conventional histopathologic examination of the neck masses showed malignant ameloblastoma which contained central fields of squamous differentiation. Immunoreactivity of several markers was determined using immunohistochemical analyses. After these diagnostic methods a definite histopathology diagnosis was made: Ameloblastoma metastaticum in textus fibroadiposus regio colli (typus acanthomatosus). CONCLUSION: It is not possible to distinguish conventional, ie intraosseous, ameloblastoma from malignant ameloblastoma according to histopathologic features. It is necessary to pay special attention, especially in elderly patients, and to carry out further clinical, radiological and pathohistological diagnostic procedures, such as immunohistochemical analysis. A timely and correct diagnosis and treatment of malignant ameloblastoma require a multidisciplinary approach.

Oral squamous cell carcinoma detection by salivary biomarkers in a Serbian population.

Early detection of oral squamous cell cancer (OSCC) is the key to improve the low 5-year survival rate. Using proteomic and genomic technologies we have previously discovered and validated salivary OSCC markers in American patients. The question arises whether these biomarkers are discriminatory in cohorts of different ethnic background. Six transcriptome (DUSP1, IL8, IL1B, OAZ1, SAT1, and S100P) and three proteome (IL1B, IL8, and M2BP) biomarkers were tested on 18 early and 17 late stage OSCC patients and 51 healthy controls with quantitative PCR and ELISA. Four transcriptome (IL8, IL1B, SAT1, and S100P) and all proteome biomarkers were significantly elevated (p<0.05) in OSCC patients. The combination of markers yielded an AUC of 0.86, 0.85 and 0.88 for OSCC total, T1-T2, and T3-T4, respectively. The sensitivity/specificity for OSCC total was 0.89/0.78, for T1-T2 0.67/0.96, and for T3-T4 0.82/0.84. In conclusion, seven of the nine salivary biomarkers (three proteins and four mRNAs) were validated and performed strongest in late stage cancer. Patient-based salivary diagnostics is a highly promising approach for OSCC detection. This study shows that previously discovered and validated salivary OSCC biomarkers are discriminatory and reproducible in a different ethnic cohort. These findings support the feasibility to implement multi-center, multi-ethnicity clinical trials towards the pivotal validation of salivary biomarkers for OSCC detection.