DNA–DNA hybridization demonstrates multiple bacteria in osteoradionecrosis

Mandibular Osteoradionecrosis: Defining the Microbial Milieu and Antimicrobial Resistance at the Time of Rescue Flap Surgery

OBJECTIVE

To report the microorganisms and their antibiotic sensitivity profile from tissue cultures and stains at the time of anterolateral thigh fascia lata (ALTFL) rescue flap for management of mandibular osteoradionecrosis (ORN).

METHODS

Retrospective chart review of patients who underwent ALTFL rescue flap for native mandibular ORN between 2011 and 2022.

RESULTS

Twenty-six cases comprising 24 patients (mean age 65.4 years, 65.4% male) with mandibular ORN from whom tissue cultures and gram stain were obtained at the time of ALTFL rescue flap. 57.7% grew bacterial species, while 34.6% grew fungal species. Multibacterial speciation was noted in 26.9% of cultures. A combination of bacterial and fungal growth was also seen in 15.4% of cases. All gram-positive cocci (GPC) were pansensitive to antibiotics except for one case of Staphylococcus aureus, which was resistant to levofloxacin. Gram-negative bacilli (GNB) species were isolated in 50.0% of cases. All fungal growth was due to Candida species. No growth was noted in 23.1% of cases. Multidrug resistance was noted in 53.8% of cases when GNB was isolated.

CONCLUSION

We report 76.9% of our cases of mandibular ORN had microbial growth from tissue cultures obtained at the time of the ALTFL rescue flap. Fungal growth was noted in a substantial number of cases and should be obtained as a specimen when pursuing culture-driven antibiotic therapy. Most GPCs were pansensitive to antibiotics, while GNBs were often the harbinger of multidrug resistant mandibular ORN.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:166-169, 2024.

Evaluation of Anterolateral Thigh Fascia Lata Rescue Flap for Mandibular Osteoradionecrosis

Importance

Mandibular osteoradionecrosis (ORN) is a progressive disease that can be difficult to treat. Conservative measures often fail, while conventional definitive management requires a morbid segmental resection with osteocutaneous reconstruction. Evidence of the anterolateral thigh fascia lata (ALTFL) rescue flap technique's safety, effectiveness, and long-term outcomes is needed.

Objective

To determine the long-term outcomes of the ALTFL rescue flap procedure for treating patients with mandibular ORN.

Design, Settings, and Participants

This was a retrospective medical record review performed at a single tertiary-level academic health care institution with patients who were appropriate candidates for the ALTFL procedure to treat mandibular ORN from March 3, 2011, to December 31, 2022. Data analyses were performed from January 1 to March 26, 2023.

Main Outcomes and Measures

Patient characteristics, preoperative radiographic Notani staging, intraoperative defect size, length of stay, complication rates, and clinical and radiographic findings of progression-free intervals.

Results

The study population of 43 patients (mean [SD] age, 66.1 [47-80] years; 24 [55.8%] male individuals) included 52 cases of mandibular ORN. The preoperative Notani staging of the study population was known for 46 of the 52 total cases: 11 cases (23.9%) were stage I; 21 (45.7%), stage II; and 14 (30.4%), stage III. The mean defect area was 20.9 cm2. Successful arrest of ORN disease progression was noted in the clinical and radiographic findings of 50 of the 52 (96.2%) cases, with only 2 (3.8%) cases subsequently requiring fibular free flap reconstruction. The major complication rate was 1.9% (1 case). Clinical and radiographic progression-free intervals were assessed, and no statistically significant differences were noted between Notani staging groups (log-rank P = .43 and P = .43, respectively); ie, patients with stage III disease had no significant difference in risk of clinical (HR, 0.866; 95% CI, 0.054-13.853) or radiographic (HR, 0.959; 95% CI, 0.059-15.474) progression vs those with stage I disease. Weibull profiling revealed 96.9%, 94.6%, and 93.1% successful mandibular ORN arrest at 1, 3, and 5 years, respectively. The major complication rate was 1.9%. Mean (SD) length of stay was 2.7 (0.0-7.0) days. Mean (SD) radiographic follow-up was 29.3 (30.7) months.

Conclusions and Relevance

The findings of this large retrospective patient case series support the continued success of the ALTFL rescue flap technique, a safe and highly effective long-term treatment for mandibular ORN in carefully selected patients.

Oral microbiota may affect osteoradionecrosis following radiotherapy for head and neck cancer

BACKGROUND

Osteoradionecrosis (ORN) is a serious complication of radiotherapy for head and neck cancer (HNC). However, its etiology and pathogenesis have not been completely elucidated. Recent studies suggest the involvement of the oral microbiota in the development of ORN. The aim of this study was to assess the correlation between oral microbiota and the extent of bone resorption in ORN patients.

MATERIALS AND METHODS

Thirty patients who received high-dose radiotherapy for HNC were enrolled. Tissue specimens were collected from the unaffected and affected sides. The diversity, species differences and marker species of the oral microbial community were determined by 16 S rRNA sequencing and bioinformatics analysis.

RESULTS

The ORN group had greater microbial abundance and species diversity. The relative abundance of f_Prevotellaceaeand, f_Fusobacteriaceae, f_Porphyromonadaceae, f_Actinomycetaceae, f_Staphylococcaceae, g_Prevotella, g_Staphylococcus, s_Endodontalis and s_Intermedia were particular;y increased in ORN, suggesting a potential association between the oral microbiota and ORN. Furthermore, g_Prevotella, g_Streptococcus, s_parvula and s_mucilaginosa were identified as potential diagnostic and prognostic biomarkers of ORN. Association network analysis also suggested an overall imbalance in species diversity and ecological diversity in the oral microbiota of ORN patients. In addition, pathway analysis indicated that the dominant microbiota in ORN may disrupt bone regeneration by regulating specific metabolic pathways that increase osteoclastic activity.

CONCLUSION

Radiation-induced ORN is associated with significant changes in the oral microbiota, and the latter may play a potential role in the etiopathology of post-radiation ORN. The exact mechanisms through which the oral microbiota influence osteogenesis and osteoclastogenesis remain to be elucidated.

The Progress in Reconstruction of Mandibular Defect Caused by Osteoradionecrosis

Osteoradionecrosis (ORN) is described as a disease with exposed, nonviable bone that fails to heal spontaneously or by means of conservative treatment after radiotherapy in at least 3 months. Though traditional theories in the early stage including hypoxic-hypocellular-hypovascular and fibro-atrophic in addition to new findings such as ferroptosis were put forward to explain the mechanisms of the osteoradionecrosis, the etiology of ORN is still unclear. With the high rate of occurrence in the head and neck area, especially in the mandible, this disease can disrupt the shape and function of the irradiated area, leading to a clinical presentation ranging from stable small areas of asymptomatic exposed bone to severe progressive necrosis. In severe cases, patients may experience pain, xerostomia, dysphagia, facial fistulas, and even a jaw defect. Consequently, sequence therapy and sometimes extensive surgery and reconstructions are needed to manage these sequelae. Treatment options may include pain medication, antibiotics, the removal of sequesters, hyperbaric oxygen therapy, segmental resection of the mandible, and free flap reconstruction. Microanastomosed free-flaps are considered to be promising choice for ORN reconstruction in recent researches, and new methods including three-dimensional (3-D) printing, pentoxifylline, and amifostine are used nowadays in trying increase the success rates and improve quality of the reconstruction. This review summarizes the main research progress in osteoradionecrosis and reconstruction treatment of osteoradionecrosis with mandibular defect.

Osteoradionecrosis of the Hip, a Troublesome Complication of Radiation Therapy: Case Series and Systematic Review

Background

Osteoradionecrosis of the hip is a serious complication of radiotherapy that is easily overlooked by physicians and patients in the early stages. There are relatively few reports on this subject, so there is no clear scientific consensus for the pathogenesis, early diagnosis, and clinical treatment of hip osteoradionecrosis. In this paper, we report two cases of hip osteoradionecrosis and systematically review the related literature.

Case Presentation

We report two cases of hip osteoradionecrosis. One patient successfully underwent total hip arthroplasty in our hospital and recovered well postoperatively. Another patient although we offered a variety of surgical options for this patient, the patient was worried that the bone loss would lead to poor prosthesis fixation, resulting in prosthesis loosening and infection, and therefore ultimately refused surgical treatment.

Conclusion

With the development of radiological techniques, the incidence of hip osteoradionecrosis is decreasing year by year, but early diagnosis and rational treatment remain challenging. The effects of non-surgical treatment are limited. Early prevention, early detection, and early intervention are crucial to delay or prevent the emergence of more serious complications.

Targeted histological evaluation shows high incidence of actinomyces infection in medication-related osteonecrosis of the jaws

Medication-Related Osteonecrosis of the Jaws (MRONJ) is a difficult-to-treat complication of the therapy of osteoporosis and some malignancies cured with bisphosphonates and antiresorptive drugs. The pathomechanism is unclear, but there is increasing observation that Actinomyces infection may play a role in its development and progression. The aim of our study was to demonstrate that histological examination using a validated triple staining procedure for Actinomyces bacteria strains can detect a high rate of Actinomyces infection in patient's samples with MRONJ. 112 previously hematoxylin-eosin (HE) stained samples submitted with the clinical diagnosis of MRONJ were re-evaluated histologically using an appropriate triple special staining validated for the identification of Actinomyces infection. During the first evaluation, when pathologists did not specifically look for Actinomyces, only 8.93% of the samples were reported as positive. In contrast, re-evaluation with triple staining provided a yield of 93.7% positive samples, therefore, we suggest the triple special staining to be standard in MRONJ histology evaluation. These results show that if the clinician suspects Actinomyces infection and brings this to the attention of the pathologist, it could significantly increase the number of correct diagnoses. It serves as an aid for clinicians in therapeutic success of MRONJ by selecting a long-term adequate antibiotic medication which is suitable for the elimination of actinomyces infection.

The Potential Therapeutic Role of Mesenchymal Stem Cells-Derived Exosomes in Osteoradionecrosis

As one of the most serious complications of radiotherapy, osteoradionecrosis (ORN) seriously affects the quality of life of patients and even leads to death. Vascular injury and immune disorders are the main causes of bone lesions. The traditional conservative treatment of ORN has a low cure rate and high recurrent. Exosomes are a type of extracellular bilayer lipid vesicles secreted by almost all cell types. It contains cytokines, proteins, mRNA, miRNA, and other bioactive cargos, which contribute to several distinct processes. The favorable biological functions of mesenchymal stem cells-derived exosomes (MSC exosomes) include angiogenesis, immunomodulation, bone regeneration, and ferroptosis regulation. Exploring the characteristic of ORN and MSC exosomes can promote bone regeneration therapies. In this review, we summarized the current knowledge of ORN and MSC exosomes and highlighted the potential application of MSC exosomes in ORN treatment.

Bacterial spectrum analysis and antimicrobial susceptibility study of osteoradionecrosis of the jaw in Southern China

OBJECTIVE

Osteoradionecrosis of the jaw (ORNJ) is one of the most common and serious complications after radiotherapy of head and neck malignancies due to the high incidence of nasopharyngeal cancer in Southern China. Clinicians lack understanding and consensus on anti-infective treatment in ORNJ lesions. This research aims to provide evidence for rational use of antibiotics by reviewing the bacterial spectrums and antimicrobial susceptibility test of ORNJ patients.

METHODS

We collected patient who was diagnosed with ORNJ from November 2012 to June 2019 in our hospital. Exudate or bone unexposed wound surface sampling, agar plates culturing, and susceptibility testing were analyzed. Descriptive statistics were used for data presentation.

RESULTS

A total of 219 samples were collected in our retrospective study. The most common cultured bacteria were Klebsiella pneumoniae (15.10%), Pseudomonas aeruginosa (13.54%), and Staphylococcus aureus (10.94%). Methicillin-resistant Staphylococcus aureus (MRSA) accounted for 5.21% in the whole positive samples. Ticarcillin, Ofloxacin, Vancomycin, Tigecycline, and Meropenem were more susceptible than other antibiotics to treat uncontrollable infection.

CONCLUSIONS

Our research provided objective evidence for understanding the types of local bacterial flora and drug susceptibility in ORNJ lesions and gave a guiding reference for empirical antibiotics medication.

Surgical Management of Skull Base Osteoradionecrosis in the Cancer Population - Treatment Outcomes and Predictors of Recurrence: A Case Series

BACKGROUND

Skull base osteoradionecrosis (ORN) is a challenging treatment-related complication sometimes seen in patients with cancer. Although ORN management strategies for other anatomic sites have been reported, there is a paucity of data guiding the management of skull base ORN.

OBJECTIVE

To report a single-center tertiary care series of skull base ORN and to better understand the factors affecting ORN recurrence after surgical management.

METHODS

We conducted a retrospective cohort study of patients with skull base ORN treated at our center between 2003 and 2017. Univariate and multivariate binary logistic regressions were performed to identify predictors of recurrence.

RESULTS

A total of 31 patients were included in this study. The median age at ORN diagnosis was 61.1 yr (range, 32.8-84.9 yr). Of these 31 patients, 15 (48.4%) patients were initially treated medically. All 31 patients underwent surgery. Three (14.3%) of 21 patients treated with a free flap and 4 (50.0%) of 8 patients who underwent primary closure experienced recurrence. Cox regression analysis revealed that reconstruction with local tissue closure (P = .044) and ongoing treatment for active primary cancer (P = .022) were significant predictors of recurrence. The median overall survival from index surgery for ORN treatment was 83.9 mo. At 12-mo follow-up, 78.5% of patients were alive.

CONCLUSION

In this study, we assess the outcomes of our treatment approach, surgical debridement with vascularized reconstruction, on recurrence-free survival in patients with skull base ORN. Further studies with larger cohorts are needed to assess current treatment paradigms.

Late radiation effects in survivors of head and neck cancer: State of the science

Head and neck squamous cell carcinoma is one of the most common neoplasms. Radiotherapy (RT) plays an essential role in the management of such cases. Despite advances in the technique, hyposalivation, xerostomia, dysphagia, trismus, radiation caries, and osteoradionecrosis remain significant late complications of RT. The aim of this narrative review was to summarize and update the main findings related to late side effects of radiotherapy in survivors of head and neck cancer (HNC). Such effects limit the ability to speak, ingest food and medications, and breathe and also exert a negative impact on social well-being and quality of life. This review highlights research in the field for both researchers and clinicians, assisting in the prevention and management of these adverse conditions. The findings can contribute to improving preventive management and multidisciplinary interventions for HNC patients.

Is the Risk to Develop Osteoradionecrosis of the Jaws Following IMRT for Head and Neck Cancer Related to Co-Factors?

Background and Objectives: Determine the contribution of coexisting factors to the risk to develop Osteoradionecrosis (ORN) of the jaws among patients who have received radiotherapy by intensity modulated radiation therapy (IMRT) for head and neck cancer (HNC) between 2013 and 2016, in a single medical center. Materials and Methods: The records of all patients treated with IMRT for HNC between 2013 and 2016 in The Davidoff Center for the treatment and Research of Cancer in Rabin Medical Center—Beilinson hospital, Petah-Tikva, Israel were screened. Patients who have received a minimum mean dose of 40 Gy to the oral cavity entered the research and their medical records were retrospectively reviewed. Collected background data included: age, gender, smoking, diabetes mellitus (DM), ASA score, mean and maximal radiation doses (Gy), and diseases characteristics including histological diagnosis, primary tumor site, and disease stage. Results: A total of 1232 patients were surveyed. Out of all screened patients, 93 received a minimum mean dose of 40 Gy to the oral cavity. Out of the 93 patients, 7 (7.52%) developed ORN (ORN+) and 86 did not develop ORN (ORN−). Tumor type in all seven patients in the ORN+ group was Squamous Cell Carcinoma (SCC). In three out of those seven patients (42.9%), the tumor was located in the mandible. Conclusions: within the limits of the relatively small cohort in the current study, we suggest that the development of ORN due to Radiation therapy (RT) with IMRT is related significantly only to the location of a tumor in the mandible. Other co-factors do not significantly increase the risk to develop ORN when RT is delivered via IMRT.

Mycobacterial and Plasmodium ovale-associated destruction of the jaw bones

OBJECTIVES

The project aims were to identify infectious mechanisms responsible for an extreme form of mandibular osteonecrosis and osteomyelitis in West African populations and test the hypothesis that Mycobacterium tuberculosis plays a pivotal role.

MATERIALS AND METHODS

DNA was extracted from mandibular fragments of 9 of 19 patients previously included in a prospective study leading to the mycobacterial hypothesis. Amplified DNAs were used for preparing libraries suitable for next-generation sequencing. For comparison of the whole-genome sequencing data of the 9 patients with DNAs of both microbiota and human tissues, DIAMOND v0.9.26 was used to align sequencing reads to NCBI-nr database and MEGAN 6 for taxonomy binning and identification of Mycobacterium tuberculosis strains.

RESULTS

The data show that mandibular bone fragments of all 9 patients not only contain Homo sapiens and Mycobacterium tuberculosis DNAs; they also contain DNAs of Plasmodium ovale wallikeri, Staphylococcus aureus, Staphylococcus hominis, and Prevotella P3-120/intermedia; as well as large numbers of DNAs from other infectious components.

CONCLUSIONS

The data obtained provide direct evidence to support the conclusion that combinations of Mycobacterium tuberculosis, Plasmodium ovale wallikeri, and other oral bacteria are involved in this particular type of mandibular destruction in West African individuals of many ages.

Exosome secreted by human gingival fibroblasts in radiation therapy inhibits osteogenic differentiation of bone mesenchymal stem cells by transferring miR-23a

Radiation-induced fibrosis is recently established as a main reason for osteoradionecrosis of the jaw (ORNJ), anti-eradiation fibrosis drugs achieve satisfactory therapeutic effects. However, the molecular mechanism remain to be fully elucidated. In this study, we found the inhibitory effect of irradiation activated gingival fibroblasts on osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs). Moreover, irradiation-activated-fibroblasts significantly increased miR‑23a expression in hBMSCs. Decreased miR‑23a enhanced osteogenic differentiation of BMSCs, and elevated miR‑23a inhibited this process via directly targeting CXCL12. Finally, exosome released from irradiation-activated-fibroblasts inhibited osteogenic differentiation of BMSCs, and these exosome mediated delivery of miR-23a and further regulated miR-23a/CXCL12 axis in hBMSCs. Therefore, our findings suggest that by transferring miR-23a, exosome secreted by human gingival fibroblasts in radiation therapy serves a vital role in osteogenic differentiation of hBMSCs, which may provide novel clinical treatments for ORNJ.

Chondroradionecrosis of the larynx

PURPOSE OF REVIEW

Purpose of the present review is to revise the literature of the last 18 months, looking for novelties or new trends in diagnosis and therapeutical approaches to a very uncommon complicaton.

RECENT FINDINGS

Some comorbidities as well as prior surgical laryngeal treatment and lifestyle factors are known to increase tissue susceptibility to radiation injury and to complications due to endotracheal intubation.

SUMMARY

Chondroradionecrosis (CRN) of the larynx is a rare and severe complication of radiotherapy and endotracheal intubation which can be fatal if not managed promptly. In recent years, the trend in oncological surgery is organ preservation even in the advanced stage of laryngeal malignancies. However, in certain stages of squamous cell carcinomas, radiotherapy is necessary as a first or second line of treatment. Endotracheal intubation has also been associated with chondronecrosis and it is thought to be secondary to excessive pressure of the endotracheal tube or its cuff on the cartilage itself. Clinical diagnosis of CRN is extremely difficult and should be placed in differential diagnosis with postradiation outcomes and cancer recurrence. PET is useful, but biopsy is still required to confirm the diagnosis. The use of the laryngeal mask airway should prevent this complication and is a reasonable choice through which to administer general anesthesia in selected patients.

Microbiological and Clinical Aspects of Cervicofacial Actinomyces Infections: An Overview

Similarly to other non-spore-forming Gram-positive anaerobes, members of the Actinomyces genus are important saprophytic constituents of the normal microbiota of humans. Actinomyces infections are considered to be rare, with cervicofacial infections (also known as ‘lumpy jaw syndrome’) being the most prevalent type in the clinical practice. Actinomycoses are characterized by a slowly progressing (indolent) infection, with non-specific symptoms, and additionally, the clinical presentation of the signs/symptoms can mimic other pathologies, such as solid tumors, active Mycobacterium tuberculosis infections, nocardiosis, fungal infections, infarctions, and so on. The clinical diagnosis of actinomycosis may be difficult due to its non-specific symptoms and the fastidious, slow-growing nature of the pathogens, requiring an anaerobic atmosphere for primary isolation. Based on 111 references, the aim of this review is to summarize current advances regarding the clinical features, diagnostics, and therapy of cervicofacial Actinomyces infections and act as a paper for dentistry specialists, other physicians, and clinical microbiologists.

Osteoimmunology of tumor necrosis factor-alpha, IL-6, and RANTES/CCL5: a review of known and poorly understood inflammatory patterns in osteonecrosis

Background

The immune and bone systems are closely linked via cytokine cross-talk. This interdisciplinary field of research is referred to as osteoimmunology and pertains to inflammatory and osteoarticular diseases that feature the primary expression of tumor necrosis factor-alpha (TNF-α) and IL-6.

Objective

Are there bone resorptive processes wherein chronic inflammatory conditions are not linked to TNF-α and IL-6 expression, but rather to the expression of other cytokines?

Materials and methods

A comprehensive literature search was performed in PubMed Central.

Discussion

Although all diseases with cytokines involved in bone resorption (TNF-α and IL-6) are at the forefront of destructive inflammatory processes, there is one exception in the literature: fatty oxide osteoporosis/osteolysis in the jawbone (FDOJ), which is associated with significant bone softening. However, it should be noted that TNF-α and IL-6 fall below the levels found in a healthy jawbone in this condition. Another conspicuous finding is that there is a nearly 35-fold overexpression of the chemokine RANTES/CCL5 (R/C) in all FDOJ cases studied thus far in the literature.

Conclusion

FDOJ appears to represent a unique cytokine and inflammatory pattern from osteolysis in the body. R/C can be defined as the dominant carrier of a “maxillomandibular osteoimmunology”.

Preventive effects of tonsil-derived mesenchymal stem cells on osteoradionecrosis in a rat model

BACKGROUND

The purpose of this study was to investigate the effects of tonsil-derived mesenchymal stem cells (MSCs) on osteoradionecrosis (ORN).

METHOD

We generated a mandibular ORN rat model using a combination of 20-Gy single-dose irradiation and tooth extraction. Study groups were negative control (tooth extraction only), ORN group (irradiation, tooth extraction), Matrigel-1 group (Matrigel; BD Biosciences, San Jose, CA; irradiation, Matrigel application immediately after tooth extraction), tonsil-derived MSC-1 group (irradiation, tonsil-derived MSC application immediately after tooth extraction), Matrigel-4 group (irradiation, Matrigel application 4 weeks after tooth extraction), and tonsil-derived MSC-4 group (irradiation, tonsil-derived MSC application 4 weeks after tooth extraction).

RESULT

Bone mineral density was significantly lower in the ORN group than in the negative control group. The tonsil-derived MSC-1 group showed significantly higher bone mineral density than did the ORN and tonsil-derived MSC-4 groups.

CONCLUSION

A single 20-Gy dose of irradiation combined with tooth extraction successfully generated ORN in the rat model. The tonsil-derived MSCs can be effective for bone regeneration in ORN, particularly when applied immediately after dentoalveolar trauma or surgery.

Risk factors for osteonecrosis of the jaw in oral cancer patients after surgery and eventual adjuvant treatment: The potential role of chemotherapy

BACKGROUND AND PURPOSE

To identify the risk factors for osteonecrosis of the jaw (ONJ) in oral cancer patients after surgery with and without adjuvant therapy in a nationwide, population-based study.

MATERIAL AND METHODS

Using the Taiwan National Health Insurance Research Dataset, we recruited patients with newly diagnosed oral cancer between 1997 and 2011. All of them underwent primary surgery. Data regarding demographic characteristics; tooth extractions; medications; and cancer treatments, including types of mandibular surgery, radiotherapy and platinum-based chemotherapy, were collected for analysis.

RESULTS

We identified 25,858 patients who suffered 2802 ONJ events. The ONJ incidence rate was 3.45 per 100 person-years. Lip cancer was associated with the highest risk of ONJ, followed by buccal mucosa, gum, mouth floor and tongue cancer. Using a time-dependent Cox regression model, multivariable analysis demonstrated that mandibulotomy (hazard ratio (HR), 1.25; 95% confidence interval (CI), 1.01-1.55; p<0.001), radiotherapy (HR, 1.39; 95% CI, 1.26-1.54; p<0.001) and platinum-based chemotherapy (HR, 1.94; 95% CI, 1.56-2.41; p<0.001) were significant risk factors for ONJ. In the subgroup analysis of patients receiving radiotherapy and patients not receiving radiotherapy, platinum-based chemotherapy remained a risk factor for ONJ.

CONCLUSIONS

Mandibulotomy, radiotherapy and platinum-based chemotherapy were associated with an increased ONJ risk. Chemotherapy was a risk factor regardless of whether radiotherapy was administered.

Chondroradionecrosis of the larynx: 24-year University of Wisconsin experience

BACKGROUND

Chondroradionecrosis (CRN) is an uncommon but significant complication of laryngeal radiotherapy that presents a diagnostic challenge to clinicians through its similarity in presentation to cancer recurrence.

METHODS

Two hundred ninety-four patients underwent primary, adjuvant, or salvage radiation for laryngeal cancer from 1991 to 2015 at the University of Wisconsin. Medical records were reviewed to identify and characterize patients with a diagnosis of CRN.

RESULTS

Of the 294 patients, 7 cases (2.4%) of CRN were identified. Development of CRN was associated with the presence of cartilage invasion by tumor (p = .038) and ongoing alcohol use postradiotherapy (p = .036). Additionally, a trend between development of CRN and ongoing smoking postradiotherapy was observed (p = .067).

CONCLUSION

The diagnosis of CRN is challenging, and the likelihood of successful resolution is modest. A high premium should be placed on efforts directed at prevention, such as tobacco and alcohol cessation. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1189-1194, 2017.

Pedicled Temporalis Muscle Flap Stuffing after a Lateral Temporal Bone Resection for Treating Mastoid Osteoradionecrosis

Objective The aim of this study was to compare the outcomes of lateral temporal bone resection and pedicled temporalis muscle flap stuffing with external auditory canal closure with those of canal wall down mastoidectomy for the treatment of mastoid osteoradionecrosis. Study Design Prospective nonrandomized case-control clinical study. Setting Department of Otolaryngology of the First People's Hospital of Foshan. Subjects and Methods Seventy-seven postirradiation nasopharyngeal carcinoma patients with mastoid osteoradionecrosis were included. Forty patients (40 ears) underwent lateral temporal bone resection in the temporalis muscle flap group. Their pedicled temporalis muscle flaps were laid on the surgical cavity, and the external canal opening was simultaneously closed. Thirty-seven patients (37 ears) underwent a canal wall down mastoidectomy in the mastoidectomy group. The surgical wounds and complications following surgery were retrospectively analyzed. Results The patients were followed for 2 years. The percentage of patients with purulent otorrhea and persistent osteoradionecrosis in the temporalis muscle flap group was lower than that in the mastoidectomy group. Conclusion Our preliminary results suggest that lateral temporal bone resection with the pedicled temporalis muscle flap filled into the surgical cavity, followed by closure of the external auditory canal, represents a valuable approach for treating mastoid osteoradionecrosis.

Profile of bacteria colonizing the exposed bone of patients with anti-osteoclastic drug-related osteonecrosis of the jaws

Microbial etiology for anti-osteoclastic drug-related osteonecrosis of the jaw (ARONJ) was suggested. This study investigates any link between bacteria colonizing ARONJ sites and other oral cavity sites. Microbiota samples of 10 ARONJ patients were collected from the exposed bone, adjacent teeth, contralateral teeth, and tongue. DNA checkerboard hybridization was used for microbiota analysis with 43 genomic DNA probes prepared from human oral bacterial (38) and candida (5) species, using Socransky's bacterial complexes as a guide. The frequency and the mean proportion of each bacterial species were used. Eikenella corrodens, Streptococcus constellatus, and Fusobacterium nucleatum were dominant in the ARONJ sites and detected in most teeth samples. Staphylococcus aureus was also dominant in the ARONJ sites and tongue. Significant correlations were found between the mean proportions of bacterial species colonizing adjacent teeth, contralateral teeth, and tongue (p < 0.001, R(2) > 0.69). No significant correlation (p > 0.05, R(2) < 0.025) was found between bacteria colonizing ARONJ sites and other evaluated sites. Within the study limitations, it was concluded that the primary sources of microorganisms colonizing ARONJ sites could be other sites such as teeth and tongue. The microbial profile of the necrotic bone is predominantly colonized with bacteria from Socransky's green and orange complexes, as well as with species associated with bone infections.

Actinomyces gerencseriae hip prosthesis infection: a case report

Introduction

Actinomyces bacteria are part of the human oropharyngeal microbiota. They have been associated with abdominal, cervicofacial and thoracic infections and a few cases of joint infections have also been described. In particular, Actinomyces gerencseriae, formerly described as Actinomyces israelii serovar II, has rarely been associated with human infections, mostly involving cervicofacial lesions and periodontal diseases. Here, we report one case of hip prosthesis infection due to A. gerencseriae.

Case presentation

A 72-year-old Caucasian male developed an inflammatory collection on the outside of the right thigh where a hip prosthesis had been implanted for 11 years. Culturing a fluid sample from the collection puncture found Staphylococcus hominis and a Gram-positive bacillus unidentified by matrix-assisted laser desorption ionization time-of-flight mass-spectrometry (MALDI-TOF). Sequencing the 16S rRNA gene amplified from both the specimen and the isolate identified A. gerencseriae. Treatment adjusted with amoxicillin and trimethropim-sulfamethoxazole cured the infection.

Conclusion

The recently described A. gerencseriae has rarely been involved in human infections. We report the first case of A. gerencseriae joint infection in a hip prosthesis.

The Effects of Ionizing Radiation on the Oral Cavity

AIM

The aim of this study is to present a literature review on the effects of the ionizing radiation from radiotherapy treatment on dental tissues.

BACKGROUND

Among the effects of increasing global life expectancy and longevity of the teeth in the oral cavity, increasing rates of neoplastic diseases have been observed. One of the important treatment modalities for head and neck neoplastic diseases is radiotherapy, which uses ionizing radiation as the main mechanism of action. Therefore, it is essential for dentists to be aware of the changes in oral and dental tissues caused by ionizing radiation, and to develop treatment and prevention strategies.

RESULTS

In general, there is still controversy about the effects of ionizing radiation on dental structures. However, qualitative and quantitative changes in saliva and oral microbiota, presence of oral mucositis and radiation-related caries are expected, as they represent the well-known side effects of treatment with ionizing radiation. Points that still remain unclear are the effects of radiotherapy on enamel and dentin, and on their mechanisms of bonding to contemporary adhesive materials.

CONCLUSION

Ionizing radiation has shown important interaction with organic tissues, since more deleterious effects have been shown on the oral mucosa, salivary glands and dentin, than on enamel.

CLINICAL SIGNIFICANCE

With the increasing number of patients with cancer seeking dental treatment before and after head and neck radiotherapy, it is important for dentists to be aware of the effects of ionizing radiation on the oral cavity.

Actinomyces and related organisms in human infections

Actinomyces israelii has long been recognized as a causative agent of actinomycosis. During the past 3 decades, a large number of novel Actinomyces species have been described. Their detection and identification in clinical microbiology laboratories and recognition as pathogens in clinical settings can be challenging. With the introduction of advanced molecular methods, knowledge about their clinical relevance is gradually increasing, and the spectrum of diseases associated with Actinomyces and Actinomyces-like organisms is widening accordingly; for example, Actinomyces meyeri, Actinomyces neuii, and Actinomyces turicensis as well as Actinotignum (formerly Actinobaculum) schaalii are emerging as important causes of specific infections at various body sites. In the present review, we have gathered this information to provide a comprehensive and microbiologically consistent overview of the significance of Actinomyces and some closely related taxa in human infections.

Analysis of the factors affecting the formation of the microbiome associated with chronic osteomyelitis of the jaw

Chronic osteomyelitis of the jaw (COMJ) is one of the most intractable diseases among head and neck infections. Antimicrobial agents are routinely administered for COMJ without sufficient bacterial information, resulting in frequent treatment failures. To improve our knowledge of the bacterial aetiology of COMJ and to assist in the development of effective treatments, we performed a comprehensive analysis of the microbiome. Sixteen patients with four clinical types of COMJ (four with suppurative osteomyelitis, three with osteoradionecrosis of the jaw, four with primary chronic osteomyelitis, and five with bisphosphonate-related osteonecrosis of the jaw) were enrolled in this study. Bone samples were subjected to bacterial community comparisons by 16S rRNA gene pyrosequencing. As a result, we clarified that COMJ was caused by a far greater range of bacterial species (12 phyla and 163 genera) than previously reported. Moreover, the bacterial structures in COMJ changed dramatically with disease stage and the condition of the affected bone. Multiple correlation analyses revealed that sequestration and bone exposure could affect the community structure. On the basis of these factors, we reclassified COMJ into three clinical stages: I, inflamed or sclerotic bone without exposure; II, sequestrum without exposure; and III, exposed sequestrum. In stage II, the bacterial diversity was significantly lower, and the anaerobe genera Fusobacterium, Tannerella (formerly Bacteroides) and Porphyromonas were more abundant, than observed during other stages. Because these bacteria habitually reside in any clinical stage, they were considered to constitute the core microbiome of COMJ. Targeting these bacteria should lead to the development of effective preventive measures and cures.

Histological findings on jaw osteonecrosis associated with bisphosphonates (BONJ) or with radiotherapy (ORN) in humans

OBJECTIVE

To describe the histological features of bone tissue harvested from patients affected by jaw osteonecrosis associated with bisphoshponates (BONJ) or with radiotherapy (ORN), in undecalcified ground sections.

MATERIALS AND METHODS

Sixteen bone tissue samples from 14 patients with BONJ and two patients with ORN were processed in order to obtain both ground, undecalcified sections and decalcified sections. The sections underwent histometric and morphometric analysis.

RESULTS

Bone tissue samples obtained from patients with BONJ or ORN of the jaws shared some histological characteristics. Common histological features included the loss of bone architecture, the absence of a proper Haversian system and proper marrow spaces, the presence of necrotic spots of non-mineralized tissue, areas of empty osteocytic lacunae next to areas of hypercellularity, the presence of resorption pits with rare osteoclast-like cells and the presence of bacteria and of an inflammatory infiltrate. A violet rib of tissue characterized by large resorption pits facing was frequently observed between the mineralized bone and the inflammatory infiltrate.

CONCLUSIONS

The histological features of BONJ and ORN are similar and resemble those of osteomyelitis. Even though it is not clear whether infection is the cause or consequence of bone exposure, inflammatory cells, bacteria or their products may have a massive, direct lytic effect on bone tissue challenged by bisphosphonates.

Clinical Assessment and Treatment of the Dysfunctional Larynx after Radiation

Objective

To review the pathophysiology of early and late radiation-related tissue changes, methods to differentiate these changes from disease recurrence, and treatment of these changes in the irradiated larynx.

Data Sources

Peer-reviewed publications.

Review Methods

PubMed database search.

Conclusions/Implications for Practice

Early and late radiation-related changes in the larynx manifest variably between individual patients. Severe radiation-related tissue changes in the larynx and recurrent malignancy share many clinical characteristics, and the presence of malignancy must be considered in these patients. Positron emission tomography may help select patients who need operative biopsy to rule out recurrence. In patients with a cancer-free but dysfunctional larynx, both surgical and nonsurgical treatment options, including hyperbaric oxygen, are available for attempted salvage. Further investigation is needed before hyperbaric oxygen can be considered standard-of-care treatment for these patients.

Invasive infections of Aggregatibacter (Actinobacillus) actinomycetemcomitans

BACKGROUND/PURPOSE

Aggregatibacter (Actinobacillus) actinomycetemcomitans, part of the normal flora of the mouth, is frequently found in human periodontal cultures and is an important pathogen causing various invasive infections, particularly infective endocarditis. In this study, we describe the clinical course and outcome of patients with A. actinomycetemcomitans infection.

METHODS

All patients suffering invasive A. actinomycetemcomitans infections at the National Taiwan University Hospital from January 1985 to December 2004 were included in this study. Relevant data regarding clinical presentation, antimicrobial treatment and outcome of these patients were analyzed.

RESULTS

During the study period, there were 11 patients with invasive A. actinomycetemcomitans infections, including eight patients with infective endocarditis, one with osteonecrosis and two with pneumonia and chest wall lesions. Among the patients with infective endocarditis, four had prosthetic valve replacement, four suffered from rheumatic heart disease and one had undergone surgical repair of ventricular septal defect. Lesions in the oral cavity were the probable portals of entry of the microorganism, and included carious teeth, periodontitis or radiotherapy of the ear-nose-throat field, and were noted in nine patients. Transthoracic echocardiography and/or transesophageal echocardiography were performed on the patients with probable infective endocarditis but growth was demonstrated in only four of these patients. Blood culture yielded A. actinomycetemcomitans after prolonged incubation. Three isolates were resistant to penicillin and two of these were also resistant to ampicillin.

CONCLUSION

The diagnosis of invasive A. actinomycetemcomitans infection was delayed due to the indolent clinical course, non-specific presentation and slow growth of the organism. Antibiotic therapy using amoxicillin/clavulanic acid, ampicillin, ampicillin/sulbactam, ceftriaxone, clindamycin, cefotaxime, or levofloxacin was successful in all patients. None of the patients demonstrated recurrence of infection 2-36 months following treatment.

Osteoradionecrosis contains a wide variety of cultivable and non-cultivable bacteria

Background

Direct microscopy, anaerobic culture and DNA–DNA hybridization have previously demonstrated an association between microorganisms and osteoradionecrosis (ORN). The purpose of our study was to use culture independent molecular techniques to detect bacteria in necrotic bone lesions of the mandible after radiation therapy.

Design

Bacterial DNA was extracted from eight deep medullar specimens from resected mandibles (six cases), including one patient with relapse. 16S rRNA genes were PCR amplified, cloned, transformed into Escherichia coli and sequenced to determine species identity and closest relatives.

Results

From the analysis of 438 clones, 59 predominant species were detected, 27% of which have not been cultivated. The predominant species detected from radionecrotic mandibles were Campylobacter gracilis, Streptococcus intermedius, Peptostreptococcus sp. oral clone FG014, uncultured bacterium clone RL178, Fusobacterium nucleatum, and Prevotella spp. The study demonstrated intersubject variability of the bacteria present in ORN. In contrast to the diverse bacterial profile detected in primary infection, only a few members of the oral indigenous flora were identified from the relapse case.

Conclusions

Diverse bacterial profiles in specimens of ORN in marrow spaces of the mandible were detected by culture independent molecular techniques. To better understand the pathogenesis and to improve the therapy of the infection, detection of all members of the complex bacterial flora associated with ORN is necessary.

Osteoradionecrosis: an update

Osteoradionecrosis (ORN) of the mandible is the most serious and severe side effect of combined treatment of head and neck tumors. A new theory for the pathogenesis of ORN has been proposed relating it to a fibro-atrophic mechanism including free radical formation, endothelial dysfunction, inflammation, microvascular thrombosis leading to bone and tissue necrosis. Risk factors mainly include radiation related risk factors, surgery and, tobacco and alcohol abuse. Removing of diseased teeth after and even probably after radiotherapy is generally considered the main risk factor in ORN. Conversely, steroid use before or after radiation may have a protective effect related to the inhibition of the initial inflammatory phase of ORN. Prevention of ORN is still based on the preventive extractions of decayed or periodontally compromised teeth before radiotherapy. Based on the current understanding of ORN pathophysiology, new preventive and therapeutic protocols have been suggested for mild to moderate stages. Free tissue surgical transfers is the treatment of choice of severe, extensive and long established ORN.

Osteoradionecrosis of the jaws--a current overview--part 1: Physiopathology and risk and predisposing factors

PURPOSE

The aim of this paper is to explore the current theories about definition, classification, incidence and physiopathology of osteoradionecrosis (ORN) of the jaws. Moreover, it is discussed the predisposing and risk factors for the development of osteoradionecrosis based on the literature review.

DISCUSSION

Osteoradionecrosis is one of the most serious oral complications of head and neck cancer treatment. Osteoradionecrosis is a severe delayed radiation-induced injury, characterised by bone tissue necrosis and failure to heal. Osteoradionecrosis either stabilises or gradually worsens and is notoriously difficult to manage. The most widely accepted theory to explain its cause until recently was the theory of hypoxia, hypovascularity and hypocellularity. A new theory for the pathogenesis of osteoradionecrosis was proposed. The clinical presentations of osteoradionecrosis are pain, drainage and fistulation of the mucosa or skin that is related to exposed bone in an area that has been irradiated. The tumour size and location, radiation dose, local trauma, dental extractions, infection, immune defects and malnutrition can predispose its development.

CONCLUSIONS

A better understanding of risk factors for the development ORN and of the underlying pathophysiology may improve our ability to prevent this complication and help to improve the prognosis for those being treated for osteoradionecrosis.

Multimodality surgical and hyperbaric management of mandibular osteoradionecrosis

PURPOSE

To elucidate long-term outcomes in 65 consecutive patients meeting a uniform definition of mandibular osteoradionecrosis (ORN) treated with multimodality therapy including hyperbaric oxygen (HBO).

METHODS AND MATERIALS

Pretreatment, post-treatment and long-term follow-up of mandibular lesions with exposed bone were ranked by a systematic review of medical records and patient telephone calls. The ranking system was based on lesion diameter and number plus disease progression. Changes from pretreatment to post-treatment and follow-up were analyzed by Wilcoxon signed-rank tests. Improved wound survival, measured by time to relapse, defined as any less favorable rank after HBO treatment, was assessed by Kaplan-Meier analysis.

RESULTS

In all, 57 cases (88%) resolved or improved by lesion grade or progression and evolution criteria after HBO (p < 0.001). Four patients healed before surgery after HBO alone. Of 57 patients who experienced improvement, 41 had failed previous nonmultimodality therapy for 3 months and 26 for 6 months or more. A total of 43 patients were eligible for time-to-relapse survival analysis. Healing or improvement lasted a mean duration of 86.1 months (95% confidence interval [95% CI], 64.0-108.2) in nonsmokers (n = 20) vs. 15.8 months (95% CI, 8.4-23.2) in smokers (n = 14) versus 24.2 months (95% CI, 15.2-33.2) in patients with recurrent cancer (n = 9) (p = 0.002 by the log-rank method).

CONCLUSIONS

Multimodality therapy using HBO is effective for ORN when less intensive therapies have failed. Although the healing rate in similarly affected patients not treated with HBO is unknown, the improvements seen with peri-operative HBO were durable provided that the patients remained cancer free and abstained from smoking.

Osteonecrosis of the jaw and the role of bisphosphonates: a critical review

Osteonecrosis of the jaw (ONJ), a condition characterized by necrotic exposed bone in the maxillofacial region, has been reported in patients with cancer receiving bisphosphonate therapy, and rarely in patients with postmenopausal osteoporosis or Paget disease of bone receiving such therapy. In the absence of a uniform definition, the American Academy of Oral and Maxillofacial Surgeons (AAOMS), the American Society for Bone and Mineral Research (ASBMR), and other groups have established similar diagnostic criteria for bisphosphonate-related ONJ, which is more commonly reported in patients with advanced malignancies with skeletal metastases who receive higher doses, and is more rarely reported in patients with osteoporosis and Paget disease who receive lower doses. However, a critical review of the literature reveals that the etiology of ONJ remains unknown, and to date no direct causal link to bisphosphonates has been established. Despite an increased awareness of ONJ and recent improvements in preventive strategies, patients and physicians alike continue to express concern about the potential risks of bisphosphonate treatment in both oncologic and nononcologic settings. Although much remains to be learned about this condition, including its true incidence in various patient populations, its pathophysiology, and optimal clinical management, evidence to date suggests that the positive benefits of bisphosphonates in patients with malignant bone disease, osteoporosis, or Paget disease outweigh the relatively small risk of ONJ.

Actinomyces--gathering evidence of human colonization and infection

The roles of the 'classical'Actinomyces spp. as colonizers of oral cavities of man and animals, in development of intra-oral infections and as agents of actinomycosis have been well documented. This mini-review focuses on perceptions of human colonization and infection that have emerged in the past decade, largely as a result of advances in classification, identification and direct detection from clinical material. Arguably, of the greatest importance is the recognition of actinomycosis as a major factor and indicator of poor prognosis in both infected osteoradionecrosis and bisphosphonate-associated osteonecrosis of the jaws. Among recently described species, Actinomyces graevenitzii has been isolated almost exclusively from oral and respiratory sites and may be a causative agent of actinomycosis. Conversely, several other Actinomyces spp. are isolated commonly from superficial soft tissue infections. Members of the genus Actinobaculum, which is closely related to Actinomyces, are strongly associated with urosepsis. Isolation and identification of Actinomyces and related genera by conventional methods remain difficult. Diagnosis is commonly belated and based solely upon histological findings. Development of direct detection methods may aid patient management and further elucidate clinical associations.