Antimicrobial materials with improved efficacy dedicated to large craniofacial bone defects after tumor resection.

The research was focused on alternative treatment techniques, separating immediate and long-term reconstruction stages. The work involved development of ceramic materials dedicated to reconstruction of the temporomandibular joint area. They were based on alumina (aluminum oxide) and characterized by varying porosities. A broad spectrum of studies was conducted to test the proposed material and determine its suitability for mandibular reconstruction. They compared the effects of substrate properties of ceramic materials in terms of biocompatibility, microbiology and systemic toxicity in in vivo studies. Finally it was concluded that Alumina LithaLox 350D is best suited for jawbone implants.

Bone turnover markers can predict healing time in medication-related osteonecrosis of the jaw.

OBJECTIVES: Medication-related osteonecrosis of the jaw (MRONJ) is a severe and difficult-to-treat adverse event of bone-modifying agents. Therefore predictive strategies determining patients at risk for a prolonged healing duration are needed to optimize treatment. Thus, the present study evaluates whether or not bone turnover markers can be used to predict the healing duration in MRONJ patients. MATERIALS AND METHODS: The present study is a retrospective data analysis of patients suffering from MRONJ and positive histology for Actinomyces spp., who were identified at the General Hospital Vienna from 2014 to 2018. During the first visit, the patients' demographics and levels of bone formation parameters were compiled. Healing times were analysed by Cox regression in dependence on these factors. RESULTS: A total of 52 patients were identified who fulfilled the inclusion criteria. The indication for bone-modifying agents was breast cancer (n = 21), prostate cancer (n = 14), multiple myeloma (n = 6) and other malignant diseases (n = 11). In 43 (82.7%) of our patients, we were able to document complete mucosal healing. Furthermore, patients who responded faster to therapy showed higher levels of C-telopeptide (P < 0.05), osteocalcin (P < 0.05) and bone-specific alkaline phosphatase (P < 0.05), but lower levels of 1.25-dihydroxyvitamin D (P < 0.05) than slower responding patients. No correlation was found regarding parathyroid hormone or calcitonin levels. Interestingly, patients who had a slower response were less likely to report dental procedures, but more likely to report a history of chemotherapy. CONCLUSION: CTX and osteocalcin levels may be used for predicting healing duration for MRONJ.

Patient specific implants for jawbone reconstruction after tumor resection.

In case of benign and malignant tumours affecting the maxillofacial region, the resection of jawbone reflects the standard therapy in more than 5.000 cases per year within the European Union. The resulting large bone defects lead to scarred, mangled facial appearance, loss of mastication and probably speech, requiring aesthetic and functional surgery as a basis for physical and physiological rehabilitation. Although autologous vascularized bone autografts reflect the current golden standard, the portion of bone available for the procedure is limited and subsequent high-dose anti-cancer chemo-/radiotherapy can lead to local tissue necrosis. Autologous vascularized bone from fibular or iliac-crest autografts is current golden standard in jawbone resection post-treatment, however, the portion of transplantable bone is limited and subsequent high-dose anti-cancer chemo-/radiotherapy often results in tissue necrosis Our research focuses on alternative treatment techniques: tissue reconstruction via novel patient-specifically manufactured maxillofacial implant that stimulates bone tissue growth. The planned neoformation of vascularized bone in such implants within the patient's own body as "bioreactor" is the safest approach in tissue engineering. The works described herein included the design of the metallic substrate of the implant with the use of computed tomography basing on real patients scans and then 3D-printing the substrates from the Ti6Al7Nb powder. The metal core was then evaluated in terms of structural characteristic, cytotoxicity and gene expression through the in vitro tests. Further experiments were focused on fabrication of the biocompatible coating for outer surface of the bone implant that would enhance the healing process and accelerate the tissue growth. Functional polymeric granulate dedicated for osteoconductive, osteoinductive and osteogenesis properties were elaborated. Another approach including the coating for the implant surface with two-phase biocompatible layer including polymeric microspheres and hydrogel carrier, which would provide long-time release of bone and cartilage growth factors around the implant were also done. The polymeric granulate containing ßTCP improved bone cells growth, but it some modification has to be done in order to improve structural pores to ensure for better osteoconductivity. The biocompatible coating including PVP hydrogel and polymeric microspheres is still in the development process.

The association of medication-related osteonecrosis of the jaw with Actinomyces spp. infection.

Medication-related osteonecrosis of the jaw (MRONJ) represents a complication of bisphosphonate treatment that responds poorly to standard treatment. In a retrospective cohort study we investigated a possible role of Actinomyces spp. in the pathogenesis of MRONJ. Deep biopsies of necrotic bone were collected during surgical treatment of MRONJ and evaluated by histology and microbiology for the presence of Actinomyces spp. Microbiological, demographic and clinicpathological data were analyzed for risk of Actinomyces-associated MRONJ. Between 2005 and 2014, 111 patients suffering from histologically-confirmed MRONJ were identified. Actinomyces spp. were detected in 99 cases (89%) by histology and in six further patients by microbiological culture. A diverse microbial flora was found in all specimens without association with Actinomyces spp. Demographic and clinicopathological characteristics did not separate significantly Actinomyces-positive from Actinomyces-negative cases. Our observations confirm previous reports of a high prevalence of Actinomyces spp. in MRONJ in the single largest cohort available up to now. The high prevalence of Actinomyces spp. and the lack of clinicopathological risk factors underline the prominent role of Actinomyces spp. in MRONJ and may change the current understanding of MRONJ. Established prolonged antimicrobial treatment regimens against Actinomyces spp. infection could therefore be a mainstay of future MRONJ management.

Efficient curing of vinyl carbonates by thiol-ene polymerization.

Vinyl carbonates have recently been identified as a suitable alternative to (meth)acrylates, especially due to the low irritancy and cytotoxicity of these monomers. The drawback of some vinyl carbonates containing abstractable hydrogens arises through their moderate reactivity compared with acrylates. Within this paper, we use the thiol-ene concept to enhance the photoreactivity of vinyl carbonates to a large extent to reach the level of those of similar acrylates. Mechanical properties of the final thiol-ene polymers were determined by nanoindentation. Furthermore, low toxicity of all components was confirmed by osteoblast cell culture experiments.

Manifestation of an ameloblastic carcinoma ten years after follicular cyst enucleation in the mandibular ramus.

Ameloblastic carcinoma (AC) is a rare tumour which can emerge de novo or from an ameloblastoma. To our knowledge, malignant transformation from an odontogenic cyst into an AC has not been documented yet. This case report describes the manifestation of an AC 10 years after enucleation of a histologically confirmed follicular cyst in the angle of the mandible.

Functional outcome after surgical treatment of orbital floor fractures.

In the present article, the authors want to present the results of a retrospectively evaluated consecutive series of patients with surgically treated isolated orbital floor fractures (OFF; "blow-out fractures") concerning the functional outcome after OFF and give detailed recommendations based on the clinical and radiological findings. A series of 60 patients with isolated OFF over a 5-year period needing surgically repair at the same institution were evaluated. Patient data were analysed in terms of preoperative and postoperative clinical parameters and radiological findings. The analysed parameters were type of fracture, diplopia, gaze restriction, enophthalmos, materials used for repair, surgical approach and timing of the surgical intervention. Burst type fractures were more often found than punched-out fractures. The most frequently used surgical approach was a preseptal transconjunctival approach. An overall decrease of gaze restriction (93%), diplopia (89%) and enophthalmos (86%) was observed. According to the fracture size, we used Ethisorb patches in smaller fractures and resorbable or titanium meshes or autologous bone in larger fractures in most cases. Patients who underwent surgery more than 7 days after the trauma showed better results with regard to an improvement of diplopia and motility disturbances than patients who were treated immediately. In indicated cases, the surgical repair of OFF leads to very good results if the anatomical and functional properties of the orbit and its contents are respected. The applied strategy and means presented in our study proved of value and can therefore be recommended.

Impact of elective neck dissection on regional recurrence and survival in cN0 staged oral maxillary squamous cell carcinoma.

To evaluate the impact of elective neck dissection (END) on regional recurrence and survival in cN0 staged patients with maxillary squamous cell carcinoma (SCC). Eighty-six patients with maxillary SCC and clinically staged N0 cervical lymph-nodes were evaluated in this single center retrospective study. Seventy-four of 86 patients were included in this analysis, of which 36 patients were treated with END, 38 without END. Following END, pathohistologically verified regional lymph-nodes in the initially cN0 neck were found in three (8%) patients. In both the +END and non-END group regional recurrences occurred exclusively in patients with T4 primaries. The overall regional recurrence rate was 17% in the +END and 18% in the non-END group, respectively. The 5-year overall survival rate for all tumor stages combined (T1-T4) was 86% in the +END group and 82% in the -END group. Within the patients groups with T4 tumors, 5-year overall survival was 81% for the +END group and 56% for the -END group. Over all tumor stages combined (T1-T4), END did not significantly improve overall survival rates and did not prevent the rate of regional recurrence in cN0 staged patients with maxillary alveolar, gingival and palatal SCC. However, in the subgroup of patients with locally advanced T4 tumors, their seemed to be a clear tendency towards improvement of overall survival in the END group. END can therefore be recommended for these patients.

Endodontic pathogens causing deep neck space infections: clinical impact of different sampling techniques and antibiotic susceptibility.

INTRODUCTION: The aims of the present study were to compare microbial populations in patients suffering from deep neck space abscesses caused by primary endodontic infections by sampling the infections with aspiration or swabbing techniques and to determine the susceptibility rates of the isolated bacteria to commonly used antibiotics. METHODS: A total of 89 patients with deep neck space abscesses caused by primary endodontic infections requiring extraoral incision and drainage under general anesthesia were included. Either aspiration or swabbing was used to sample microbial pus specimens. The culture of the microbial specimens and susceptibility testing were performed following standard procedures. RESULTS: A total of 142 strains were recovered from 76 patients. In 13 patients, no bacteria were found. The predominant bacteria observed were streptococci (36%), staphylococci (13%), Prevotella (8%), and Peptostreptococcus (6%). A statistically significant greater number of obligate anaerobes were found in the aspiration group. The majority of patients presented a mixed aerobic-anaerobic population of bacterial flora (62%). The antibiotic resistance rates for the predominant bacteria were 10% for penicillin G, 9% for amoxicillin, 0% for amoxicillin clavulanate, 24% for clindamycin, and 24% for erythromycin. CONCLUSIONS: The results of our study indicated that a greater number of anaerobes were found when sampling using the aspiration technique. Penicillin G and aminopenicillins alone are not always sufficient for the treatment of severe deep neck space abscesses; beta-lactamase inhibitor combinations are more effective. Bacteria showed significant resistant rates to clindamycin. Thus, its single use in penicillin-allergic patients has to be carefully considered.

Staging and grading as prognostic factors in maxillary squamous cell carcinoma.

PURPOSE: This retrospective study was performed to present our long-term results in the treatment of maxillary squamous cell carcinoma and evaluate especially the influence of T staging and grading on patients' survival. PATIENTS AND METHODS: We performed a retrospective analysis of 93 consecutive patients with alveolar, gingival, or palatal maxillary SCC treated at our clinic with surgical resection and/or radiation therapy. Data were obtained from chart review and patients' records and were analyzed statistically using the log-rank test and Kaplan-Meier survival curves. The male:female ratio was 2:1 and the mean age was 63 years (range 35 to 94 yrs). Most patients showed a T4 stage (66%) and the most frequent staging was T4N0M0 (42%). The most common histopathological grading was G2 (57%), followed by G3 (22%) and G1 (21%). The 5-year overall survival rate was 71%, and the recurrence rate was 37%. Advanced T stage (T4) and grading did not significantly influence the cumulative survival rates. CONCLUSIONS: T-stage and grading do not have a significant impact on patients' long-term survival. The most crucial factor for recurrence prevention and therefore survival are free resection margins.

Maxillomandibular advancement for treatment of obstructive sleep apnea syndrome: a systematic review.

PURPOSE: To perform a systematic review of the published data concerning maxillomandibular advancement for the treatment of obstructive sleep apnea syndrome. MATERIALS AND METHODS: A systematic literature search was performed in the PubMed database. Original articles in the English language were reviewed to obtain information about patient data, success rates, and outcome measures. RESULTS: The systematic literature search yielded 1,113 citations, of which 101 articles met our inclusion criteria. After a review of the full text, 39 studies were included in the analysis. Most articles were classified as evidence level 4, and 5 met the inclusion criteria for level 2b. The only prospective randomized controlled study had been published in January 2010 and was assigned level 1b. CONCLUSIONS: A recommendation grade of A to B was achieved with regard to the levels of evidence-based medicine. Our results have shown that maxillomandibular advancement is the most successful surgical therapy, and the postoperative polysomnography results are comparable to those under ventilation therapy.

Single dose granulocyte colony-stimulating factor markedly enhances shear-dependent platelet function in humans.

Granulocyte colony-stimulating factor (G-CSF) has been associated with the induction of a hypercoagulable state in patients as well as peripheral blood stem donors. Interestingly, sparse data exist on the kinetics of platelet and coagulation activation in response to G-CSF and it is unknown if G-CSF augments shear-dependent platelet function. These two issues are addressed in the current trial. Thirty-six healthy volunteers were enrolled into this study. All subjects received a single-dose of 5 microg/kg filgrastim intravenously. The effects of recombinant G-CSF on platelet and coagulation function were assessed by the platelet function analyzer PFA-100 (collagen/epinephrine (CEPI-CT), collagen/ADP (CADP-CT) closure times), von Willebrand factor activity (vWF : RiCO) ELISA, tissue factor (TF)-mRNA expression on circulating leukocytes and rotation thrombelastography (ROTEM). G-CSF time-dependently enhanced shear dependent platelet function measured by the PFA-100: CEPI-CT declined by 48% and CADP-CT by 31% with nadir values after 24 h (p < 0.001 as compared to baseline) and returned to near-baseline values after 72 hours. In accordance, VWF : RiCO increased by 59% after 24 h (p < 0.001) and returned to baseline 48 h later. TF-mRNA peaked after 4 hours (>6 fold increase p < 0.001) and reached near-baseline values after 24 hours. Nadir closure times were seen after 24 hours (-15%; p < 0.001). Single-dose administration of 5 microg/kg G-CSF significantly enhances shear-dependent platelet function and strongly induces leukocyte TF-mRNA, which translates into shortened clotting times ex vivo.

Antibiotic susceptibility and resistance of the odontogenic microbiological spectrum and its clinical impact on severe deep space head and neck infections.

OBJECTIVE: The purpose of this retrospective study was to identify the major pathogens responsible for deep space head and neck infections and their current resistance to routinely used antibiotics in a university hospital setting. STUDY DESIGN: A total of 206 patients suffering from odontogenic deep space infections were treated at our department by means of surgical intervention and intravenous administration of antibiotics. RESULTS: The predominant bacteria were viridans group streptococci (VGS), staphylococci, Prevotella, Peptostreptococcus, and Bacteroides. In the aerobic spectrum, resistance against clindamycin was found in 18%, against macrolides in 14%, and against penicillin G in 7%. The anaerobes were resistant to clindamycin in 11%, to metronidazole in 6%, and to penicillin G in 8%. CONCLUSION: The high resistance rate for clindamycin and macrolides was especially striking and may necessitate an adaptation of our antibiotic regime in the future.

Closure of oroantral communications with Bichat's buccal fat pad.

PURPOSE: The aim of the present study was to evaluate the use of the pedicled buccal fat pad for the closure of oroantral communications (OACs) and to describe our experience with this surgical procedure. PATIENTS AND METHODS: A retrospective review of 161 patients treated at the University Hospital for Cranio-Maxillofacial and Oral Surgery in Vienna, Austria, from 2000 to 2005, with the diagnosis of an OAC was performed. All defects were closed by application of a buccal fat pad. Data were obtained from chart review, a compiled database, and clinical follow-up and included the location of the defect, the cause of the OAC, the modality of anesthesia, intraoperative complications, any complications during the process of wound healing, and any late adverse effects. RESULTS: The buccal fat pad for closure of an OAC was successfully used in 161 patients at our department. In 12 patients (7.5%), the closure of the OAC was insufficient, and a second operation was necessary. Excluding all severe and complicating cases such as tumor-related defects or previously treated cases, the overall success rate for closure of the OAC was nearly 98%. No late complications occurred, and all patients were free of pain or any limitations after the 6-month follow-up period. CONCLUSIONS: According to the recommendations and anatomic limitations reported in published studies and discussed in the present report, the application of the buccal fat pad is a safe and reliable procedure for closing an OAC.

Mineral apposition rates provide significant information on long-term effects in BMP-induced bone regeneration.

In this study, a CaP biomaterial was used as a carrier for rhBMP-2. Biomaterials were investigated in calvarial and femoral defects using a rabbit animal model, with unloaded biomaterials serving as control. Fluorochrome labels were administered at days 14 and 70. Specimens were retrieved after 12 weeks for histological analysis. When area fractions were assessed by conventional histomorphometry, no significant effect of rhBMP-2 on the amounts of regenerated bone and residual biomaterial were seen by 12 weeks. After mineral appositional rate (MAR) measurement using double labels, calculation yielded significantly higher MARs for defects at both implantation sites, when compared with surrounding bone, whether or not biomaterials were loaded with rhBMP-2. Analyzing the effect of rhBMP-2, both defect sites showed significantly higher MARs in the rhBMP-2 group. MARs of bone surrounding the defects had also been elevated significantly by rhBMP-2 at calvarial and femoral implantation sites. It is concluded that MAR measurement is suitable to identify long-term effects of rhBMP-2 on bone formation at a time when conventional histomorphometry using fractional area determination is inadequate. Also, by MAR assessment, effects of rhBMP-2 on surrounding bone can be documented.