Factors associated with an increased risk of SARS-CoV-2 infection in healthcare workers in aerosol-generating disciplines.

BACKGROUND: Healthcare workers (HCWs) are at a high risk of SARS-CoV-2 infection due to exposure to potentially infectious material, especially during aerosol-generating procedures (AGP). We aimed to investigate risk factors for SARS-CoV-2 infection among HCWs in medical disciplines with AGP. METHODS: A nationwide questionnaire-based study in private practices and hospital settings was conducted between 12/16/2020 and 01/24/2021. Data on SARS-CoV-2 infections among HCWs and potential risk factors of infection were investigated. RESULTS: 2070 healthcare facilities with 25113 employees were included in the study. The overall infection rate among HCWs was 4.7%. Multivariate analysis showed that regions with higher incidence rates had a significantly increased risk of infection. Furthermore, hospital setting and HCWs in gastrointestinal endoscopy (GIE) had more than double the risk of infection (OR 2.63; 95% CI 2.50-2.82, p<0.01 and OR 2.35; 95% CI 2.25-2.50, p<0.01). For medical facilities who treated confirmed SARS-CoV-2 cases, there was a tendency towards higher risk of infection (OR 1.39; 95% CI 1.11-1.63, p=0.068). CONCLUSION: Both factors within and outside medical facilities appear to be associated with an increased risk of infection among HCWs. Therefore, GIE and healthcare delivery setting were related to increased infection rates. Regions with higher SARS-CoV-2 incidence rates were also significantly associated with increased risk of infection.

Macrophage polarization differs between apical granulomas, radicular cysts, and dentigerous cysts.

OBJECTIVES: Apical periodontitis can appear clinically as apical granulomas or radicular cysts. There is evidence that immunologic factors are involved in the pathogenesis of both pathologies. In contrast to radicular cysts, the dentigerous cysts have a developmental origin. Macrophage polarization (M1 vs M2) is a main regulator of tissue homeostasis and differentiation. There are no studies comparing macrophage polarization in apical granulomas, radicular cysts, and dentigerous cysts. MATERIALS AND METHODS: Forty-one apical granulomas, 23 radicular cysts, and 23 dentigerous cysts were analyzed in this study. A tissue microarray (TMA) of the 87 consecutive specimens was created, and CD68-, CD11c-, CD163-, and MRC1-positive macrophages were detected by immunohistochemical methods. TMAs were digitized, and the expression of macrophage markers was quantitatively assessed. RESULTS: Radicular cysts are characterized by M1 polarization of macrophages while apical granulomas show a significantly higher degree of M2 polarization. Dentigerous cysts have a significantly lower M1 polarization than both analyzed periapical lesions (apical granulomas and radicular cysts) and accordingly, a significantly higher M2 polarization than radicular cysts. Macrophage cell density in dentigerous cysts is significantly lower than in the periapical lesions. CONCLUSIONS: The development of apical periodontitis towards apical granulomas or radicular cysts might be directed by macrophage polarization. Radicular cyst formation is associated with an increased M1 polarization of infiltrating macrophages. In contrast to radicular cysts, dentigerous cysts are characterized by a low macrophage infiltration and a high degree of M2 polarization, possibly reflecting their developmental rather than inflammatory origin. CLINICAL RELEVANCE: As M1 polarization of macrophages is triggered by bacterial antigens, these results underline the need for sufficient bacterial clearance during endodontic treatment to prevent a possible M1 macrophage-derived stimulus for radicular cyst formation.

Masticatory Rehabilitation of a Patient With Cleft Lip and Palate Malformation Using a Maxillary Full-Arch Reconstruction With a Prefabricated Fibula Flap.

For full-arch reconstruction of an atrophied cleft maxilla with missing premaxilla, a prefabricated microvascular free bony flap is a relevant option. A fibula flap was prefabricated in a cleft patient who received six dental implants and an epithelial layer. Six weeks later, maxillary reconstruction was performed. The inpatient period could be confined to 2 weeks. A fixed provisional prosthesis was delivered after an additional 2 weeks. A prefabricated flap allows for the reduction of the interval without a dental prosthesis to only a few weeks, even when a complex full-arch reconstruction of the maxilla is required.

Implant-based rehabilitation in oncology patients can be performed with high long-term success.

PURPOSE: Radiotherapy and compromised vital bone and/or surrounding soft tissue can be a challenge to the successful osseointegration of dental implants. We evaluated the long-term results of dental implants in patients with oral cancer. MATERIALS AND METHODS: To address the research purpose, we designed and implemented a retrospective cohort study that included patients with oral cancer who had received dental implants from 2003 to 2011. The data were collected from a clinical oncology database. The predictor variables included a set of heterogeneous variables grouped into logical sets of demographics, surgical treatment, dental rehabilitation, radiotherapy type, and tumor entity. The primary outcome variable was implant survival; the secondary outcome variable was peri-implantitis. The descriptive statistics, survival time analysis, Kaplan-Meier implant survival curves, and Cox hazard proportional modeling were computed. RESULTS: The study sample included 59 patients with oral cancer (20 women [33.9%], 39 men [66.1%]; mean age at tumor diagnosis, 55 years), who had had 272 implants placed during the study period. The mean follow-up period was 30.9 months (range 3 to 82). Of the 272 implants, 269 (98.9%) and 264 (97.1%) had survived for 2 and 5 years, respectively. During the observation period, 10 implants were lost (3.7%). Of the implant failures, 82% occurred in transplanted bone (4 fibula flaps, 4 iliac crests, and 2 native mandibles). We observed peri-implantitis caused by insufficiently attached gingiva and bone loss in 182 of the implants (67%). The factors associated with implant failure were peri-implantitis, insufficient soft and hard tissue, muscle dysfunction, and xerostomia. CONCLUSIONS: Implant-based rehabilitation in oncology patients can achieve a high long-term success rate, although risk factors such as impaired muscle function and a high frequency of peri-implantitis can affect healing.

Skeletal stability and complications in transantral maxillary distraction in patients with cleft lip and palate.

The current prospective study aimed at assessing skeletal stability and complications arising from transantral maxillary distraction adopted for advancements of less than 12 mm in patients with cleft lip, alveolus, and palate malformations.The recruited patients with cleft lip, alveolus, and palate were followed up for 12 months. Lateral skull radiographs were obtained before surgery (T0), at the end of the activation period of the distractors (T1), and after completion of the follow-up interval (T2). Length and height of the maxilla were assessed at the different points of time. The relapse rate of maxillary advancement was calculated. Complications such as infections, distractor breakage and loosening, nonunions, and the need for reoperation were documented.Seven patients were included in this study (mean [SD] age, 19.5 [2.6] y). The length of the maxilla significantly increased by 6.4 ± 1.1 mm at T1 (P = 0.018) but showed a significant relapse by 7.5% at T2 (P = 0.018). As a complication, a case of infection of the cheek occurred during the consolidation period, which could be treated conservatively. In an additional patient, there was a loosening of a distractor at the end of the distraction period, which required reoperation with conventional fixation of the maxilla in the intended position. At the time of removal of the distractors and the conventional osteosynthesis plates, no cases of nonunion could be identified.It seems that the low horizontal relapse rate of transantral maxillary distraction in patients with cleft lip and palate outweighs the possible complications of this procedure in cases of limited distances of advancement of less than 12 mm.

Recurrent adult-type rhabdomyoma: a rare differential diagnosis of "swellings in the masticatory muscle".

Rhabdomyomas are rare benign mesenchymal tumors with skeletal muscle differentiation and a predilection for the head and neck area. A 38-year-old man presented with persistent, slowly growing, painless swelling in the left inner cheek for 2½ years. The lesion was detected during routine dental examination and was considered to represent a mucocele. The mass was removed via a transoral surgical approach, followed by a local recurrence 6 months later that was again surgically removed. The patient is alive and well 2 months after last surgery. Adult-type rhabdomyoma is a rare, occasionally recurring, benign mesenchymal tumor that should be included in the differential diagnosis of submucosal swellings in the oral cavity including the masticatory musculature. Adult-type rhabdomyoma of the cheek and masticatory area are exceptionally rare with no more than 3 cases reported to date.

Geranyl-geraniol addition affects potency of bisphosphonates-a comparison in vitro promising a therapeutic approach for bisphosphonate-associated osteonecrosis of the jaw and oral wound healing.

PURPOSE: Analysis of the influence of geranyl-geraniol (GG) addition on four bisphosphonate derivatives regarding their influence on cell viability and migration ability of bone metabolism and endothelial cells in vitro. METHODS: Clodronate, pamidronate, ibandronate, and zoledronate were observed with and without GG addition, for their effect on human osteoblasts (HOB), normal human dermal fibroblasts (NHDF), human endothelial progenitor cells (EPC), and endothelial cells of the human umbilical cord (HUVEC) using migration-, MTT-, and colony-forming cell assays. RESULTS: Data pointed to a depressing effect of all bisphosphonates on the migration ability of NHDF, EPC, and HOB. MTT assay demonstrated a decreased cell viability of HUVEC of all bisphosphonates in a 50 µM concentration and of NHDF when treated with 50 µM of clodronate, ibandronate, or zoledronate. Tested drugs showed a depressing effect on colony-forming potential of EPC even in a 5 µM concentration. GG addition demonstrated an attenuate impact on bisphosphonate effect on all primary cell cultures, respectively. CONCLUSION: In vitro comparison showed that the addition of GG weakens the effect of all bisphosphonates examined. It supports investigations that suggest GG to be able to prevent bisphosphonate-associated osteonecrosis of the jaw (BP-ONJ) in vivo. Future clinical trials may discover the local therapeutic use of GG for the prevention of BP-ONJ.

Imaging, histopathological degree of degeneration and clinical findings - Do these correlate in patients with temporomandibular joint disorders.

The gold standard for temporomandibular joint imaging is magnetic resonance imaging, although there are still pathological findings that cannot be seen in MRI but in surgery and the subsequent histological analysis only. The main goal of this investigation was to validate the MRI score used by histopathological findings as well as clinical findings. In this retrospective study 39 patients were included; 38 of which underwent unilateral and 1 underwent bilateral discectomy. MRI findings were graded according to the score by Wurm. Histopathological analysis was performed in hematoxylin-eosin staining and graded in accordance with the scores by Krenn and by Leonardi. For valuation of preoperative pain values of the temporomandibular joint operated on the numeric rating scale was utilized. Correlations were verified by Spearman-Rho. The MRI scores on average showed significantly lower scores for the discs of the operated temporomandibular joint than for the discs of the non-operated side(p<.01). No significant correlations between MRI findings, histopathological findings and pain intensities could be observed. Thus unsuspicious morphology of the TMJ and the articular disc in MRI is no guarantee for the absence of cartilage-degeneration. Further investigations utilizing T2 cartilage mapping could possibly show better correlations between the temporomandibular joint's degree of degeneration and imaging results.

One year of COVID-19 pandemic: Health care workers' infection rates and economical burden in medical facilities for oral and maxillofacial surgery.

The aim of this study was to create an overview on the COVID-associated burdens faced by the oral and maxillofacial surgery (OMS) workforce during 1 year of the pandemic. OMS hospitals and private practices nationwide were surveyed regarding health care worker (HCW) screening, infection status, pre-interventional testing, personal protective equipment (PPE), and economic impact. Participants were recruited via the German Society for Oral and Maxillofacial Surgery. A total of 11 hospitals (416 employees) and 55 private practices (744 employees) participated. The HCW infection rate was significantly higher in private practices than in clinics (4.7% vs. 1.4%, p<0.01), although most infections in HCW occurred in private environment (hospitals 88.2%, private practice 66.7%). Pre-interventional testing was performed significantly less for outpatients in private practices than in hospitals (90.7% vs. 36.4%, p<0.01). Polymerase chain reaction (PCR) was used significantly more for inpatients in hospitals than in private practices (100.0% vs. 27.3%, p<0.01). FFP2/3 use rose significantly in hospitals (0% in second quarter vs. 46% in fourth quarter, p<0.05) and private practices (15% in second quarter vs. 38% in fourth quarter, p<0.01). The decrease in procedures (≤50%) was significantly higher in hospitals than in private practices (90.9% vs. 40.0%, p<0.01). Despite higher infection rates in private practices, declining procedures and revenue affected hospitals more. Future COVID-related measures must adjust the infrastructure especially for hospitals to prevent further straining of staff and finances.

Quantitative Analysis of Multimodal Skeletal SPECT/CT Reconstructions in Diagnosing Medication-related Osteonecrosis of the Jaw.

AIM: Our goal was to assess visual and quantitative aspects of multimodal skeletal SPECT/CT reconstructions (recon) in differentiating necrotic and healthy bone of patients with suspected MRONJ. METHODS: Prior to surgery, 20 patients with suspected MRONJ underwent SPECT/CT of the jaw 3-4 hours after injection of Tc-99m-DPD (622±112.4 MBq). SPECT/CT data were reconstructed using the multimodal xSPECT Bone and xSPECT Quant algorithms as well as the OSEM-algorithm FLASH 3D. For analysis, we divided the jaw into 12 separate regions. Both xSPECT Bone and FLASH 3D datasets were scored on a four-point scale (VIS xSPECT; VIS F3D), based on the intensity of localized tracer uptake. In F3D and xSPECT Quant datasets, local tracer uptake of each region was recorded as semi-quantitative uptake ratio (SQR F3D) or SUVs, respectively. ROC analysis was performed. Postoperative histologic results served as gold standard. RESULTS: VIS F3D, VIS xSPECT and SQR F3D did not differ significantly in diagnostic accuracy (VIS xSPECT sensitivity=0.64; specificity=0.89). Of the quantitative parameters, SUVpeak yielded the best interobserver reproducibility. SUVpeak was 9.9±7.1 (95%CI: 7.84-11.95) in MRONJ regions, as opposed 3.6±1.8 (95% CI:3.36-3.88) elsewhere, with a cutpoint of 4.5 (sensitivity=0.83; specificity=0.80). Absolute quantitation significantly surpassed VIS and SQR (p<0.05) in accuracy and interobserver agreement (SUVpeak: κ=0.92; VIS xSPECT: κ=0.61; SQR F3D κ=0.66). CONCLUSION: Absolute quantitation proved significantly more accurate than visual and semi-quantitative assessment in diagnosing MRONJ, with higher interobserver agreement.

One Year of the COVID-19 Pandemic in Dental Medical Facilities in Germany: A Questionnaire-Based Analysis.

(1) Background: The COVID-19 pandemic forced healthcare workers to adapt to challenges in both patient care and self-protection. Dental practitioners were confronted with a potentially high possibility of infection transmission due to aerosol-generating procedures. This study aims to present data on healthcare worker (HCW) screening, infection status of HCWs, pre-interventional testing, the use of personal protective equipment (PPE) and the economic impact of the pandemic in dental facilities. (2) Methods: Dental facilities were surveyed nationwide using an online questionnaire. The acquisition of participants took place in cooperation with the German Society for Dentistry, Oral and Maxillofacial Medicine. (3) Results: A total of 1094 private practices participated. Of these, 39.1% treated fewer than 600 patients per quarter and 59.9% treated over 600 patients per quarter. Pre-interventional testing was rarely performed in either small (6.6%) or large practices (6.0%). Large practices had a significantly higher incidence of at least one SARS-CoV-2-positive HCW than small practices (26.2% vs.14.4%, p < 0.01). The main source of infection in small practices was the private environment, and this was even more significant in large practices (81.8% vs. 89.7%, p < 0.01). The procedure count either remained stable (34.0% of small practices vs. 46.2% of large practices) or decreased by up to 50% (52.6% of small practices vs. 44.4% of large practices). Revenue remained stable (24.8% of small practices vs. 34.2% of large practices) or decreased by up to 50% (64.5% of small practices vs. 55.3% of large practices, p = 0.03). Overall, employee numbers remained stable (75.5% of small practices vs. 76.8% of large practices). A vaccination readiness of 60-100% was shown in 60.5% (n = 405) of large practices and 59.9% (n = 251) of small practices. (4) Conclusion: Pre-interventional testing in dental practices should be increased further. Economic challenges affected small practices as well as large practices. Overall, a steady employee count could be maintained. Vaccination readiness is high in dental practices, although with some room for improvement.

The fitting accuracy of pre-bend reconstruction plates and their impact on the temporomandibular joint.

BACKGROUND: Various causes for bone defects of the lower jaw have been described. As a result, patients often suffer from compromised aesthetics and a loss of, or reduction in, important physiological functions, such as swallowing, breathing, and speaking. A change in the shape of the lower jaw can impair the natural occlusion and leads to an atypical or modified position of the temporomandibular joint. Titanium reconstruction plates are the standard approach to jaw reconstruction, and are used for temporary bridging of a jaw defect or fixation of a bone graft. Conventionally these plates are intraoperatively adjusted to the mandible by the surgeon. Computer-aided manufacturing, computer-aided design, and rapid prototyping have gained increasing importance in the field of medicine, as they allow the production of individual models of the lower jaw, with the possibility of preoperatively bending the reconstruction plates. In this retrospective study, the accuracy of pre-bent titanium plates and their effect on the temporomandibular joint situation in comparison with intraoperatively curved plates will be discussed. MATERIALS AND METHODS: Patients who attended our department for lower jaw reconstruction between March 2013 and February 2015 were included in this retrospective study. Within that time 20 patients were treated with pre-bent reconstruction plates (group 1). 20 comparable patients were selected with reconstruction and conventional intraoperative bending (group 2). To evaluate the accuracy of the plates and the condylar position, postoperative cone beam computed tomograms and computed tomograms were used to assess the bone-plate distance at 12 defined points and four angles in axial reconstruction. The results were compared, statistically evaluated, and discussed. RESULTS: Regarding the maximum bone-plate distances and the sum of distances, there was a significant difference between the accuracy of the pre-bent and the conventionally bent reconstruction plates (p = 0.022, p = 0.048). Regarding the condylar position, there was no significant difference between both methods (p = 0.867). CONCLUSION: The results of this study show that a better fitting accuracy can be achieved using pre-bent plates. Preparation of the plates proves to be advantageous and meaningful, especially in complex bone defects and deformations of the lower jaw. Nevertheless, concerning the position of the temporomandibular joint, no significant difference could be ascertained between the shown methods, contradicting several studies.

Antiseptic negative pressure instillation therapy for the treatment of septic wound healing deficits in oral and maxillofacial surgery.

INTRODUCTION: Impaired wound healing, chronic wounds and extended soft tissue defects present a crucial problem in reconstructive surgery of the head and neck region, even more after radiation therapy. In such cases the standard is a prolonged open wound treatment. The negative pressure instillation therapy might present an alternative therapy option. MATERIAL AND METHODS: In this study the effects of negative pressure instillation therapy on the healing of chronic wounds in 15 patients diagnosed with impaired wound healing were investigated. These based upon infected osteoradionecrosis and osteomyelitis of the jaw. The parameters investigated as markers of the therapeutic success were serum inflammatory parameters i.e. white blood cell counts, wound smear results and wound surface reduction. RESULTS: The use of negative pressure instillation therapy lead to a reduction of the bacterial load and formation of a stabile granulation tissue in all but one case. The mean inpatient time of the patients was 13.33 ± 4.62 days. Between 2 and 8 dressing changes were needed to reach clinical sufficient wound healing results. Secondary intention wound healing could be obtained in 14 out of 15 cases. The crucial part for the successful application was a watertight enoral suturing as oro-cutaneous fistulae were present in most cases. CONCLUSION: The negative pressure instillation therapy poses a good treatment for wound healing problems and extended size soft tissue defects, even when oro-cutaneous fistulae were present. Especially in cases that contraindicate micro-vascular reconstruction, negative pressure instillation therapy could be a good alternative.

Correlation between pain and MRI findings in TMD patients.

INTRODUCTION: Magnetic resonance imaging has been established as the gold standard for assessment of the temporomandibular joint. Apart from an excellent assessment of the soft tissues it has the advantage not to expose the patient to ionizing radiation. There is a lack of literature concerning the correlation between pain intensity and radiological findings of the temporomandibular joint. Moreover there is the question of whether a progressive degeneration of the cartilaginous components is accompanied by an increasing degeneration of the osseous parts of the mandibular joint and vice versa. Therefore, this study aims at analyzing correlations between pain and radiological findings. Furthermore, the link between osseous and cartilaginous degeneration is studied. MATERIALS AND METHODS: 91 patients who attend our outpatient clinic for temporomandibular disorders are included in this prospective study. Apart from a detailed anamnesis and clinical examination - adapted to the Research Diagnostic Criteria for Temporomandibular Disorders -magnetic resonance imaging of both mandibular joints is performed. Pain intensity is measured using the visual analog scale. To assess and grade the radiological findings a classification system is established. The evaluation of the osseous components is based on the classification of osteoarthritis by Kellgren and Lawrence whereas the rating of the cartilaginous components is adapted to the Research Diagnostic Criteria for Temporomandibular Disorders. Correlations are verified by Spearman-Rho. RESULTS: 83,5% of all patients are female. Most of the time, both sides are affected (47.25%). Women state an average pain of 5.7 (±2.4), men 3.5 (±2.5). 182 discs are examined and assessed with our classification system. Most discs (n = 71) show no pathological changes. The majority of patients show no dislocation (n = 104). The most common forms of dislocation are anterior dislocations (n = 51). The majority of patients show no changes in the osseous component (n = 115). Weak to moderate correlations are found between disc and bone degeneration. Moderate to strong correlations are found between left and right TMJ. CONCLUSIONS: The classification system which is designed and applied during the study proves to be a reliable and practical Instrument. A standardized evaluation of pathologies concerning the temporomandibular joint is possible by using this system. Numerous patients attending our outpatient clinic do not show any signs of degenerative dysfunctions in the mandibular joints. Degenerations of the osseous components tend to be connected with degenerations of the cartilaginous components and vice versa. The question remains if in the future new procedures in imaging will be able to record pathologies not yet detected.

Consultation with a specialized pain clinic reduces pain after oral and maxillofacial surgery.

PURPOSE: Postoperative pain management is important for improved patient care. Our primary objective was to investigate the effect of analgesic treatment adaptation by the pain clinic on postoperative pain relief at an oral and maxillofacial surgery department. Additionally, we aimed to present patients' pain characteristics and the administered analgesic treatment. MATERIALS AND METHODS: A total of 128 patients treated at our clinic in the period 2012-2015 who required analgesic treatment adaptation by our pain clinic were included. They were further divided into 10 groups: tumor, temporomandibular joint disorder, tooth extraction, osteomyelitis, bisphosphonate-related osteonecrosis of the jaw, submandibular abscess, orthognathic surgery, cyst, sinusitis, and fracture. Pain characteristics evaluated were intensity on a numerical rating scale (NRS) before and after intervention of the pain clinic, quality, genesis, and type. RESULTS: Post treatment pain intensity values at rest 1.8 (SD: 1.4) and on exercise (walking and physical therapy) 4 (SD: 2) were statistically significant better compared to pretreatment values (4.2, SD: 2.5, and 6.8 SD: 2, respectively). The highest pain intensities were reported after tooth extractions, orthognathic surgery, cystectomies, and fracture reposition. Pain was mainly continuous and related to a combination of a somatic and a neuropathic pathophysiological mechanism. CONCLUSIONS: Intervention by a specialized pain clinic leads to reduction of postoperative pain.

Assessment of free microvascular flap perfusion by intraoperative fluorescence angiography in craniomaxillofacial surgery.

Microsurgical tissue transfer represents a standard technique for reconstruction in craniomaxillofacial surgery. The transferred tissue is anastomosed to vessels of varying diameters and different physiological conditions. The aim of this study was to evaluate the blood flow in free flaps at their origin and compare this with the flow after reperfusion. In 24 patients undergoing microsurgical procedures (13 radial forearm free flaps (RFFF) and 11 parascapular/scapular free flaps (PSFF)), blood flow was evaluated by intraoperative fluorescence angiography after flap raising and again after reperfusion in the neck area (Flow800, Carl Zeiss AG, Oberkochen, Germany). Flow is expressed by the blood flow index (BFI), maximum intensity (MaxInt) and half-time to MaxInt (t1/2) and was measured in the flap pedicle itself, as well as in the supplying vessels. Following anastomosis of the free flaps in the head and neck area, both the arterial and the venous BFI and MaxInt significantly increased, whereas t1/2 decreased significantly. There was no significant difference in the perfusion parameters between RFFF and PSFF. Intraoperative fluorescence angiography is a reliable method for assessing the perfusion of free microvascular flaps. In the head and neck area, free flaps undergo a significant increase in perfusion but show no differences between varying flap types.

Positron emission tomography-computed tomography versus positron emission tomography-magnetic resonance imaging for diagnosis of oral squamous cell carcinoma: A pilot study.

Diagnostic imaging of head and neck cancer has made enormous progress during recent years. Next to morphological imaging modalities (computed tomography [CT] and magnetic resonance imaging [MRI]), there are also hybrid imaging systems that combine functional and morphological information (positron emission tomography [PET]/CT and PET/MRI). The aim of this study was to compare the diagnostic accuracy of PET/MRI in the diagnosis of head and neck cancer with other imaging modalities (MRI, CT, PET/CT). Ten patients (nine male and one female) with histologically proven oral squamous cell carcinoma participated in an 18 F-FDG-PET/CT scan and an additional 18 F-FDG PET/MRI scan prior to surgery. The morphological and functional results were compared with the histological results. Inclusion criteria were histologically proven oral squamous cell carcinoma and no prior surgical intervention, medical therapy, or local external radiation. There was no significant correlation between tumor differentiation and maximum standard uptake values. Functional imaging showed a slightly better correlation with the measurement of the maximal tumor diameter, whereas pure morphological imaging showed a better correlation with the measurement of infiltration depth. Only with PET/MRI could correct lymph node staging be reached; the other imaging tools showed false-negative or false-positive results. In conclusion, we showed in our limited patient cohort that PET/MRI is superior to the morphological imaging modalities, especially for lymph node staging.

Major histocompatibility complex class II polymorphisms are associated with the development of anti-resorptive agent-induced osteonecrosis of the jaw.

The aetiology of anti-resorptive agent-induced osteonecrosis of the jaw (ARONJ) is still under debate. Clinical and genetic risk factors are currently being investigated to help understand its pathogenesis. This case-control study analysed a large number of cancer patients (n = 230) under therapy with intravenous bisphosphonates, half of which were diagnosed with ARONJ. Multiple myeloma, greater patient age and the use of more than one bisphosphonate were identified as clinical risk factors on logistic regression analysis. In addition, 204 patients were genotyped for HLA-DRB1 and DQB1 and the allele frequencies were compared between ARONJ (n = 94) and unaffected cancer patients (n = 110). For the HLA class II alleles, a strong increase in the frequency of DRB1*15, DQB1*06:02, DRB1*01 and DQB1*05:01 was observed in the ARONJ group. These results were reinforced on analysis of the respective haplotypes, with DRB1*15-DQB1*06:02 being significantly associated with the development of ARONJ (odds ratio [OR] 2.5; 95% confidence interval [CI] 1.3-5.0). The presence of at least one of the haplotypes DRB1*15-DQB1*06:02 and DRB1*01-DQB1*05:01 was highly associated with the development of ARONJ (OR 3.0; 95% CI 1.7-5.5). The data in this study of a large number of cancer patients receiving intravenous bisphosphonates suggest that MHC class II polymorphisms represent genetic risk factors for the development of ARONJ. This result supports recent findings that inflammation and infection might play an important role in the pathogenesis of ARONJ.

Oncocytic lipoadenoma of the parotid gland: a report of a new case and review of the literature.

Oncocytic lipoadenoma is a rare salivary gland tumour composed of adipose tissue and oncocytic epithelial cells in varied proportions. This tumour is still not included in the current WHO classification of salivary gland neoplasms. We herein report a further case of oncocytic lipoadenoma originating in the parotid gland of a 55-year-old woman. The tumour presented as a slowly growing asymptomatic left-sided parotid gland mass. The resected tumour measured 2.7 cm in maximum diameter and was composed of oncocytoma-like epithelial component admixed with mature adipocytes that made up 10% of the whole mass. Foci of sebaceous differentiation were seen. This rare variant of lipomatous salivary gland tumours is in need of more recognition and should be distinguished from other fat-containing salivary gland lesions, particularly lipomatous pleomorphic adenoma and myoepithelioma.