Actinomyces israelii in osteoradionecrosis of the jaws. Histopathologic and immunocytochemical study of five cases

Histologic analysis of medication-related osteonecrosis of the jaw compared with antiresorptive-exposed bone and other infectious, inflammatory, and necrotic jaw diseases

OBJECTIVE

This study characterized histologic features of medication-related osteonecrosis of the jaw (MRONJ) through analysis of tissues from patients and healthy individuals.

STUDY DESIGN

Bone biopsies were collected from various infectious, inflammatory, and necrotic jaw diseases. Samples were divided into bone exposed to bisphosphonates or denosumab, as well as bisphosphonate-related osteonecrosis of the jaw (BRONJ), denosumab-related osteonecrosis of the jaw (DRONJ), and mixed necrosis, enabling us to identify features of single agent necrosis without influence from previous therapies. Hematoxylin and eosin (H&E), receptor activator of nuclear factor κ-Β ligand (RANKL), tartrate-resistant acid phosphatase (TRAP), osteoprotegerin, toluidine blue, CD14, and CD68 staining and micro-computed tomography (micro-CT) analysis were performed. Groups were compared by using analysis of variance (ANOVA).

RESULTS

In total, 156 bone samples were collected from 105 patients. MRONJ variants exhibited more infectious infiltration. Bisphosphonate (P < .001) and mixed necrosis (P = .002) demonstrated more RANKL- and TRAP-positive osteoclasts. Denosumab necrosis (P = .007), and bone exposed to bisphosphonates (P = .028) in combination with denosumab (P = .022) demonstrated significantly lower numbers of osteocytes per area. CD14 and CD68 positivity was increased for BRONJ (P = .008; P < .001, respectively). MRONJ variants exhibited the widest trabecular width and decreased medullary space to bone. No diminished vascular network in MRONJ samples was observed.

CONCLUSIONS

Histologic features differ among MRONJ variants, with oversuppressed bone turnover, dysfunctional bone resorption, and a disturbed osteocyte network as potential mechanisms of pathogenesis.

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.

Reconstruction with fibular osteocutaneous free flap in patients with mandibular osteoradionecrosis

Background

Osteoradionecrosis is a delayed complication from radiation therapy which causes chronic pain, infection and constant deformity after necrosis. Most of the osteoradionecrosis occurs spontaneously or after the primary oncologic surgery, dental extraction or by trauma of prosthesis. The treatment of osteoradionecrosis relies on both conservative measures and surgical measures. The fibular osteocutaneous free flap has become more popular choice for reconstruction of maxillofacial defects as a treatment of osteoradionecrosis.

Methods

We presented our experiences from 7 patients with osteoradionecrosis who have had reconstruction surgery with fibular osteocutaneous free flap at National Cancer Center during the recent 5 years. We performed segmental mandibular resection with fibular osteocutaneous free flap for all 7 patients of advanced osteoradionecrosis who were not controlled by conservative treatment such as wound irrigation, debridement, and antibiotics.

Results

A wide range of techniques were available for the reconstruction of composite defects resulted from the treatment of advanced mandibular osteoradionecrosis. Significant improvement was noted in relieving pain and treating trismus after the surgery however difficulty in swallowing and xerostomia showed less improvement.

Conclusions

We concluded that fibular osteocutaneous free flap can be performed safely in patients with osteoradionecrosis and yields positive outcomes with significantly increased success rate. The fibular osteocutaneous free flap was our preferred choice for the mandibular reconstruction due to its versatility and predictability.

In vitro bactericidal effect of Nd:YAG laser on Actinomyces israelii

A bactericidal effect has been reported by the use of near-infrared laser light on both Gram-positive and Gram-negative bacteria. The aim of this study was to evaluate the effect of Nd:YAG laser on Actinomyces israelii, filamentous bacteria causing cervicofacial actinomycosis. Experiments were realized on bacterial cells in saline suspension or streaked on Mueller-Hinton (MH) agar plates with or without India ink. Laser application was performed in Eppendorf tubes with different powers and frequencies for 40 s; bacterial suspensions were then streaked on agar plates and incubated at 35 °C in proper conditions for 5 days before colony enumeration. A reduction of colony number variable from 60.13 to 100 % for powers of 2, 4, and 6 W at 25-50 Hz of frequency was observed in comparison with growth control. For agar plates, laser application was performed with different powers at 50 Hz for 60 s. A growth inhibition was observed after 5 days of incubation on MH plates with powers of 6 W and on MH-ink plates with all applied powers. This preliminary study showed a bactericidal effect caused by Nd:YAG laser application worthy to be evaluated in further experiments in vivo.

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.

Infected osteoradionecrosis of the mandible: follow-up study suggests deterioration in outcome for patients with Actinomyces-positive bone biopsies

Infected osteoradionecrosis (IORN) is one of the major complications of oral cancer radiotherapy. Recent studies showed a high prevalence of Actinomyces in IORN. In this study, the clinical follow up of IORN patients (n=25; 20 male, 5 female) with regard to Actinomyces detection in the mandible was analyzed. Within 1.6-119 months of follow up, disease control was achieved in almost 90% of the patients with Actinomyces-negative bone biopsies, but only in 25% of the Actinomyces-positive group. The presence of Actinomyces was associated with a significantly higher risk of treatment failure (P=0.004; Fisher's exact test). This held true when the data were controlled for 'extent of bone destruction', 'type of surgery' and 'soft-tissue closure' in a logistic regression analysis (P=0.018; Wald test). Since Actinomyces was detected in a significant number of patients with non-healing mucosal defects, this microbe may promote the persistence of chronic non-healing inflammatory processes. Actinomyces positivity defines a subpopulation with a clinically deteriorated course of mandibular IORN.

Increased numbers of osteoclasts expressing cysteine proteinase cathepsin K in patients with infected osteoradionecrosis and bisphosphonate-associated osteonecrosis—a paradoxical observation?

Erosion of the bone is a common problem in patients suffering from infected osteoradionecrosis (IORN) or bisphosphonate-associated osteonecrosis (BON). Besides inflammatory mechanisms and infectious agents, osteoclasts were recently suggested to be specifically involved in the osteolytic mechanisms. We therefore investigated the immunohistochemical labeling of the cysteine proteinase cathepsin K, which plays a central role in osteoclast-mediated bone resorption, in tissue specimens of patients with BON (n=9; four male, five female; mean age=69.2 years) and IORN (n=10; nine male, one female; mean age=60.5 years), and compared the results with control specimens (n=8; six male, two female; mean age=60 years). In all cases, osteoclasts were the predominant cell type expressing cathepsin K. For semiquantitative analysis, we therefore defined osteoclasts as multinuclear giant cells attached to the bone and expressing cathepsin K. Significantly higher numbers of osteoclasts were found for both types of osteonecrosis when compared with the control group (BON+IORN vs controls: P=0.0000036). Within the pathological lesions, IORN cases exhibited significantly less osteoclasts than BON (P=0.00097). Our study verified increased numbers of osteoclasts in patients suffering from BON and IORN. Although it is known that bisphosphonates (and to a lesser extent, irradiation, too) decrease osteoclast function, these findings suggest a critical involvement of osteoclasts in the mechanisms of bone destruction in the respective lesions.

Actinomyces in infected osteoradionecrosis—underestimated?

Infected osteoradionecrosis (IORN) is a severe complication of radiation therapy for head and neck cancer. Infected osteoradionecrosis can lead to fracture and often requires subsequent jaw resection. It is known that irradiated bone is highly susceptible to infections, mainly with Candida species and cariogenic bacteria. Only very few data exist on Actinomyces in IORN. The study population consisted of 31 patients (7 female, 24 male; median age, 58.3 years). All patients exhibited clinical and radiological signs of IORN (infection, mucosa or skin fistula, and sequestrated bone). To detect Actinomyces colonies, histological examination was performed using several staining procedures (hematoxylin-eosin, Gram, Grocott, periodic acid-Schiff). In addition, a semi-nested polymerase chain reaction (PCR) approach was designed targeting the 16S ribosomal RNA gene. We found prominent Actinomyces colonies in 20 (64.5%) of 31 patients. Most of these lesions were localized in the mandible (16/20). Most interestingly, Actinomyces were almost exclusively found attached to the necrotic bone. PCR testing confirmed the presence of Actinomyces-specific DNA sequences (Actinomyces israelii). We show that Actinomyces is considerably more frequent in IORN than previously demonstrated. We suggest that these organisms are involved in the chronic, nonhealing inflammatory processes and the purulent discharge, which are known as characteristics of IORN. It remains to be investigated whether Actinomyces could be involved in the osteolytic mechanisms. From the histopathologic perspective, detection of Actinomyces is important because these bacteria have been shown to be associated with prolonged treatment duration.

Opportunistic actinomycosis in osteoradionecrosis of the jaws in patients affected by head and neck cancer: incidence and clinical significance

Actinomycosis is occasionally an opportunistic infection occurrence in patients with osteoradionecrosis (ORN). A retrospective study (1992-97) of 50 patients with ORN of the jaws was done to evaluate the incidence and its clinical significance in the management of ORN. Actinomycosis was diagnosed in 12% of ORN cases. In 36 of the 50 patients including five cases of actinomycosis, the ORN was considered to be resolved after treatment. The median treatment duration of ORN was significantly longer (P<0.007) in patients with actinomycosis (29.7 months) than those without the disease (13.4 months). In conclusion, bone biopsy should be considered in cases of ORN with unsatisfactory response to its specific therapies, aiming to identify possible opportunistic actinomycosis infection.

Possibilities of preventing osteoradionecrosis during complex therapy of tumors of the oral cavity

In recent years, there has been a dramatic increase in the number of tumors of the head and neck. Their successful treatment is one of the greatest challenges for physicians dealing with oncotherapy. An organic part of the complex therapy is preoperative or postoperative irradiation. Application of this is accompanied by a lower risk of recurrences, and by a higher proportion of cured patients. Unfortunately, irradiation also has a disadvantage: the development of osteoradionecrosis, a special form of osteomyelitis, in some patients (mainly in those cases where irradiation occurs after bone resection or after partial removal of the periosteum). Once the clinical picture of this irradiation complication has developed, its treatment is very difficult. A significant result or complete freedom from complaints can be attained only rarely. Attention must therefore be focussed primarily on prevention, and the oral surgeon, the oncoradiologist and the patient too can all do much to help prevent the occurrence of osteoradionecrosis. Through coupling of an up-to-date, functional surgical attitude with knowledge relating to modern radiology and radiation physics, the way may be opened to forestall this complication that is so difficult to cure.

Conservative management of osteoradionecrosis

A retrospective records analysis of 32 patients with mandibular osteoradionecrosis seen between August 1960 and September 1995 was undertaken to determine the effectiveness of nonsurgical/nonhyperbaric oxygen conservative management. Two patients died before final analysis. Of those alive, 65.5% of patients were spared resection, having lesions resolve (48.3%), improve (3.4%), or asymptomatically stabilize (13.8%). Sequestrum production allowing "gentle" removal predicted a more favorable clinical course when managed conservatively compared with nonsequestrating lesions (p < 0.05). Criteria to define clinical osteoradionecrosis are proposed.

Osteoradionecrosis of the jaws: a retrospective study of the background factors and treatment in 104 cases

PURPOSE

This study analyzed potential risk factors in patients who received radiation therapy and then developed osteoradionecrosis (ORN).

PATIENTS AND METHODS

A group of 104 patients who developed osteoradionecrosis of the jaws were reviewed treated between 1972 and 1992.

RESULTS

The most common affected site was the mandible (99 cases, 95.2%), followed by the maxilla (5 cases, 4.8%). Among all cases, 93 (89.4%) were induced-trauma ORN, and 11 (10.6%) were spontaneous ORN. The following risk factors were considered as predisposing factors for the appearance of ORN: Anatomic location of the tumor, tumor surgery, total radiation dose, dose rate/day, mode of radiation delivery, time from radiation therapy until the onset of ORN, and dental status. ORN developed more frequently with oral cancer than other head and neck cancers. The size of the tumor seemed not to influence the incidence of ORN except when the tumor invade the adjacent bone. Type of radiation delivery total bone dose, and modes of radiation appeared to influence the risk of ORN occurrence. After conservative treatment, 44 (42.3%) cases had complete healing and resolution 34 (32.6%) cases had a stable, chronic ORN process, and 26 (25.1%) cases had acute and progressive ORN.

CONCLUSION

An understanding of the risk factors is important in preventing ORN after radiation therapy.

The conservative management of osteoradionecrosis of the mandible with ultrasound therapy

A regimen of ultrasound with local debridement and metronidazole has proved to be an effective and practicable treatment for osteoradionecrosis, achieving healing in 10/21 (48%) cases without the need for surgery or sophisticated technology. Nine further patients were successfully treated by covering the preserved mandible with a local intra-oral flap. Only 2 patients required mandibular resection with reconstruction. An ultrasound programme of 1 watt/cm2, 3 mega Hz. pulsed 1:4, 15 min a day for 60 days would seem to be optimum. However, a range of dosage needs to be further explored for inducing neovascularity and neocellularity in the irradiated tissues.

Osteoradionecrosis of the jaws

In 431 patients treated for malignant tumors 21 osteoradionecroses (ORN) were diagnosed in 19 patients. The relation of ORN to radiotherapeutic factors and surgical as well as extraction schemes were studied. There was a clear relation to high dose, high CRE and superfraction. Six ORN developed in connection with tooth extraction. The importance of atraumatic extraction is stressed.

Bilateral mixed density lesions in the body of the mandible

A patient with actinomycosis involving the right and left body of the mandible is reported. Such a diagnosis, although not common, should be considered when formulating a differential diagnosis of such mixed radiopaque-radiolucent lesions. Proper collection of a specimen, transplant, and culture under anaerobic conditions is imperative if a laboratory diagnosis is to be made. A biopsy, yielding the characteristic histopathological features of actinomycosis infection, is frequently adequate for diagnosis and treatment.

Comparison of polyclonal and monoclonal antibodies to Actinomyces and Arachnia species

Polyclonal (PoAbs) and monoclonal (MoAbs) antibodies were produced to Actinomyces israelii serotypes 1 and 2, to Actinomyces naeslundii, and to Arachnia propionica, and their specificities were studied by an enzyme immunoassay (EIA). All PoAbs except those to A. propionica reacted also with at least one other Actinomyces species. Only the MoAb to A. naeslundii proved to be more specific than the corresponding PoAbs. This MoAb did not crossreact with other Actinomyces or Arachnia species, nor with any other anaerobic or aerobic bacteria studied by inhibition EIA. Immunoblotting studies indicated that the antibody specific to A. naeslundii is directed against a large molecular weight antigen (greater than 150 kd), probably polysaccharide in nature. The produced PoAbs and MoAbs can be used for further analyses of the antigenic determinants of different Actinomyces and Arachnia species.

Late effects of radiation treatment of tongue and floor-of-mouth cancer on the dentition, saliva secretion, mucous membranes and the lower jaw

The purpose of this study was to determine retrospectively any changes in the dentition, saliva secretion, mucous membranes and the lower jaw resulting from the radiation treatment given to patients with cancer of the tongue or floor of the mouth. The study covers 29 patients treated at the Department of Radiotherapy and Oncology of Helsinki University Central Hospital between 1972 and 1981. 23 of the patients were treated for cancer of the tongue and the remaining 6 for cancer of the floor of the mouth. The radiation doses ranged from 5300 to 6700 rad. Clinical examination revealed that the number of carious teeth doubled as a result of radiotherapy, while the incidence of cervical lesions increased by a factor of 10, both compared with the controls. About 70% of the patients studied were found to have either moderate or extensive fungal growth. Stimulated saliva secretion had fallen to about 20% and resting saliva secretion to about 30% of the values for the control group. Radiography revealed pathological changes in the mandible in 34% of the patients. Clinically, 2 patients were found to have extra-oral fistulae. In 1 of these, the spontaneously fractured end of the mandible was visible for several cms. 3 of the patients had undergone hemimandibulectomy because of osteoradionecrosis.

Immunocytochemical demonstration of Actinomyces species and Arachnia propionica in periapical infections

Immunocytochemical methods were used for the demonstration of Actinomyces israelii, Actinomyces naeslundii and Arachnia propionica in bacterial colonies found in 7 routine biopsies from periapical inflammatory lesions. All 3 species were found in one specimen, both A. israelii and A. propionica in 3 specimens, and one of each species in the remaining 3 biopsies. Specificity controls by enzyme immunoassay showed that antiserum to A. israelii reacted also with A. odontolyticus, and that to A. naeslundii with A. viscosus, while antiserum to A. propionica did not show any cross-reactions with Actinomyces species. The results indicate that immunocytochemical methods can be used for the diagnosis of periapical actinomycosis at the species level. Actinomyces and Arachnia species seem to have an important role in the pathogenesis of complicated periapical infections.

Immunoelectron microscopic study of Actinomyces colony in odontogenic periapical infection

A periapical Actinomyces colony was studied by immunoelectron microscopy with a specific antiserum against Actinomyces israelii. Positive as well as some negative micro-organisms were seen within the colony. Reacting antigens were localized in the cytoplasm and the cell wall of the bacteria, which suggests that more than one antigen is involved in the reactions with the present antiserum. The ultrastructural results confirmed the applicability of the peroxidase method with Actinomyces antiserum in paraffin sections for diagnostic purposes.

Draining fistulas associated with an endodontically treated tooth

A case of periapical actinomycosis is presented. Although apparently uncommon, actinomycosis should be considered when a chronic periapical lesion, often in the maxilla, is associated with an endodontically treated tooth or a previous history of trauma. Histologic examination of the tissue or the presence of "sulfur granules" in the exudate will usually establish the diagnosis. Treatment consists of local curettage and antibiotic therapy.