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Journal: International journal of oral and maxillofacial surgery

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The actual role of splint therapy in preventing excessive loading of the temporomandibular joint (TMJ) is still debated. Lower intra-articular pressure levels have been measured in patients wearing occlusal splints, which may also reduce oxidative stress in the articular spaces. The aim of this study was to determine whether splint therapy reduces oxidative stress and inflammation in TMJ internal derangement patients by measuring interleukin 6 (IL-6), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) levels in the synovial fluid (SF). Twenty-four patients with a temporomandibular disorder (TMD) were included in the study. TMJ SF samples were obtained prior to arthrocentesis. Twelve patients used a 2-mm hard acrylic, maxillary stabilization-type splint for 3 months after arthrocentesis. Twelve patients had no treatment after the SF aspiration. Second SF samples were obtained from all patients at 3 months post arthrocentesis. IL-6, MDA, and 8-OHdG levels in the samples were evaluated. All patients showed a significant symptomatic improvement after treatment (P < 0.005). No statistical correlation was found between the two groups concerning pre-treatment and 3-month SF levels of MDA, 8-OHdG, and IL-6. Although splint therapy was found to be successful in eliminating clinical symptoms of TMD, the results showed no beneficial effect on inflammation and oxidative stress markers in the synovial fluid.

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Temporomandibular joint (TMJ) ankylosis significantly impacts both physical and psychosocial patient wellbeing. A complete evaluation of treatment outcomes necessitates knowing the extent to which a patient’s quality of life (QoL) is impacted. This study was performed to evaluate the impact of TMJ ankylosis on QoL in 25 TMJ ankylosis patients treated by interpositional arthroplasty. The patients completed OHIP-14 and UWQoL questionnaires once before and then at 3 months after the surgery. There was a significant improvement in mean cumulative scores for both questionnaires. With the exception of functional limitation, all OHIP domains showed significant improvement. Preoperatively, the worst scores were found in the psychological distress domain, followed by the social handicap, physical pain and physical disability domains. More than half of the subjects (56%) reported having suicidal thoughts. Amongst the individual UWQoL domains, appearance, chewing, anxiety (P <  0.01), recreation and mood (P <  0.05) showed improved scores. Appearance and chewing were the top ranked priority domains before and after surgery. No significant change was found in speech, taste, sleep, or breathing. Psychosocial factors were found to play a much bigger role than previously thought. The physical, psychological, and social factors were intricately related and dynamically interacted with each other. Surgical treatment produced a definitive QoL improvement in the patients.

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Segmental defect areas in the mandible can change immediately following osteotomy due to muscular traction, impacting on accurate reconstruction. The purpose of this article is to introduce a new technique based on virtual surgery planning to record the position of the bony parts prior to mandibulectomy, for use in precise mandibular reconstruction after segmental osteotomy. The position information for the bony parts is transferred to a plate with complementary surface contact and locating holes with specific directions and angles. This technique was performed for six patients with segmental defects and the results were compared to those of six previous patients in whom the technique was not utilized. The design of the location holes shortened the average operation time from 406 minutes to 349 minutes (P = 0.033) and decreased the average, maximum, and minimum graft deviation from 1.21 mm to 0.88 mm (P = 0.015), 1.28 mm to 0.99 mm (P = 0.027), and -1.15 mm to -0.77 mm (P = 0.077), respectively. The design of the locating holes in multiple plates shortened the time taken for the bony repositioning step and hence significantly shortened the total operation time. More importantly, it also increased the reconstructive accuracy.

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The purpose of this study was to assess whether genetic variation is a predictor for the development of medication-related osteonecrosis of the jaws (MRONJ) in patients receiving bisphosphonate therapy for various conditions. A systematic review based on the PRISMA guidelines was performed. A search strategy was developed. Comprehensive searches of major databases were conducted for studies published January 2003 through July 2018. The PICOS strategy was used to develop the inclusion criteria. The analysis in each study was performed primarily using single nucleotide polymorphism (SNP) frequency mean values and odds ratios between cases and controls. A total of 3301 patients were enrolled in the 15 included studies (two genome-wide association studies, n = 1877; 10 candidate gene studies, n = 1195; three whole genome/whole exome studies, n = 229). Multiple myeloma was the most prevalent primary disease (54.8%). Zoledronate was prescribed in 68.8% of patients. No one SNP was definitively identified as a risk factor for the development of MRONJ. To date, studies have failed to show a single gene as a risk factor for MRONJ. Heterogeneity of case and control populations may be contributory. Next generation sequencing studies may help elucidate the role and interplay of genetic events in the development of MRONJ.

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Ameloblastoma is a benign odontogenic tumour showing locally aggressive characteristics. This retrospective study was performed to investigate the long-term treatment outcomes of ameloblastoma and to evaluate the risk factors for recurrence. The study was conducted in the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, the University of Hong Kong and covered the years 1990-2017. Patient demographic data, radiographic pattern and findings, clinical findings, tumour site and size, World Health Organization classification, treatment modality, histological pattern, duration of follow-up, and timing of recurrence were recorded and analyzed. The potential risk factors were analyzed by Kaplan-Meier and Cox regression tests. The cases of a total of 128 patients were reviewed; 65 were male and 63 were female. The mean follow-up period was 117 months. The 5-, 10-, and 15-year recurrence rates were 9.3%, 17.6%, and 24.4%, respectively. Kaplan-Meier and Cox regression tests showed that recurrence was significantly associated with radiographic pattern, tumour size, and treatment modality. Multiple regression analysis for these three variables demonstrated that treatment modality was the only independent prognostic factor for recurrence. This study showed that radical resection is the only significant factor for a low recurrence rate of ameloblastoma and patients require long-term follow-up for late-onset recurrence.

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The aim of this study was to systematically review the aetiology, in particular histopathological and microbiological factors, of retrograde peri-implantitis of endodontic origin. The review is registered in the PROSPERO database (CRD42017063898). An electronic search for publications was performed in two databases, from their inception up to October 2018. Subsequently a hand search of the reference lists was conducted. Articles in English and other languages using Latin characters were included. Two independent reviewers selected the studies, extracted and synthesized the data, and assessed the quality. The methodology of the included articles was evaluated using the relevant Joanna Briggs Institute tools. Six studies fulfilled the eligibility criteria and were included in the systematic review. Histopathological examination in the component studies reflected that the presentation of retrograde peri-implantitis involves cyst formation or chronic inflammation. Bacteria found in these lesions included Porphyromonas gingivalis, Corynebacterium, Streptococcus, and Klebsiella pneumoniae. Two studies were judged as having a low possibility of bias and four were judged as having a moderate possibility of bias. This review determined that endodontic complications associated with adjacent teeth, residual infection at the extraction site due to previous apical periodontitis, or refractory apical periodontitis might be considered likely aetiological factors, although the evidence is limited.

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This study was performed to evaluate the linear and volumetric effects of a technique for reconstruction of the posterior atrophic mandible, including the final bone gain of the graft, by three-dimensional assessment. Thirteen individuals were recruited into the study and submitted to a total of 15 mandibular autogenous bone block surgeries. Cone beam computed tomography images were obtained at three different times. Bone graft length and thickness, and the volume, height, and width of the graft were measured. Data were compared statistically among the time points using the Friedman test, and cluster analysis was performed to identify the association between the study variables and the resorption rate (α = 0.05). Linear analysis of the width and height of the recipient area at the different time points revealed a statistically significant difference. The final average increase in height was 1.6 mm; all subjects showed an average volume gain of 3.412mm3, and 77% of the subjects showed an average graft resorption of 0.688mm3 construction of three-dimensional vertical defects of the posterior mandible resulted in good healing with minimal complications and minimal bone graft resorption, favouring vertical bone gain.

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Rehabilitation of the atrophic posterior mandible is a challenge in dental practice. Conventional treatments include the segmental sandwich osteotomy or inlay bone grafting (IBG), onlay bone grafting (OBG), short implants, distraction osteogenesis, and inferior alveolar nerve transposition (IANT), each with its downsides. This case series is reported to introduce a modification of IBG - pedicled segmental rotation (PSR) for the reconstruction of co-existing vertical and horizontal defects in the posterior mandible. Ten healthy patients with vertical-horizontal defects (no vertical bone walls and basal bone width <5 mm) were included. Posterior mandibular defects were treated with PSR, PSR + IANT, or PSR + OBG. In PSR, a pedicle-preserved segment is up-fractured superiorly and then flipped 90° to a vertical position. The segment is then supported with inorganic bovine bone and autogenous bone particulates. Cone beam computed tomography was performed preoperatively and at the 4-month follow-up, in addition to clinical examinations. Soft tissue healing was uneventful. Radiomorphometric analysis showed a mean new bone volume of 647.79 ± 81.31 mm3 (ΔH = 7.13 mm), 836.99 ± 119.14 mm3 (ΔH = 7.8 mm), and 640.20 ± 50.13 mm3 (ΔH = 6.59) in the PSR, PSR + OBG, and PSR + IANT groups, respectively. The proposed PSR technique used in this case series showed promising results for vertical and horizontal augmentation of the atrophic posterior mandible before placement of dental implants.

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The aim of this systematic review and meta-analysis was to determine whether there are clinically effective reductions in postoperative pain, oedema, and trismus following submucosal dexamethasone administration during impacted mandibular third molar surgery. An electronic database search was conducted up to and including June 2018. Randomized and quasi-randomized trials assessing the effects of submucosal dexamethasone in adult patients undergoing mandibular third molar surgery were included. The mean differences or standardized mean differences were extracted and pooled using the fixed-effects or random-effects model. Seventeen trials were included and independently assessed for risk of bias. There was low quality evidence that submucosal dexamethasone reduces early postoperative pain, early and late postoperative trismus, and late postoperative oedema after mandibular third molar extraction. Moderate quality evidence was found for the reduction of late postoperative pain and early postoperative oedema. The greatest clinical effect of submucosal dexamethasone injection during impacted mandibular third molar surgery was a reduction of early postoperative pain (number needed to treat (NNT) = 4) and early postoperative oedema (NNT = 5). The reduction in trismus was not clinically significant (<5 mm). Further research focusing on strengthening the quality of evidence, investigating potential harms and a definitive protocol for submucosal administration during mandibular third molar surgery is required.

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The aim of this study was to evaluate the outcomes of temporomandibular joint (TMJ) anterior disc displacement and condylar remodelling for sagittal fracture of the mandibular condyle (SFMC) in children. Disc displacement was observed in 20 patients with 24 SFMCs (age 4-12 years) via magnetic resonance imaging. After 6 months of closed treatment (T1), the joints were categorized based on the displaced disc status as complete reduction (DCR) or incomplete reduction (DICR). Moreover, condylar remodelling was compared between the groups using cone beam computed tomography images of the TMJ obtained at T1 and at the 1-year follow-up (T2; 15 patients with 18 displaced SFMCs). At T1, 17 of 24 joints with SFMC were assigned to the DCR group and six to the DICR group; one unilateral SFMC case developed ankylosis. Condylar depth and height differed significantly between the groups at T1, but not at T2. Intra-group comparison exhibited significant changes in the condylar depth and height over time in the DICR group. Thus, most of the anteriorly displaced discs (17/24, 70.8%) achieved reduction following closed treatment. Although sustained anterior disc displacement was associated with an increased depth and reduced height of the condyle, no clinical impairment was noted unless ankylosis developed.