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The results of near infrared spectroscopy in eight patients with osteoradionecrosis of the mandible are presented. These suggest that sites of osteoradionecrosis may be marked by decreased amounts of deoxygenated haemoglobin. The advantages and potential of near infrared spectroscopy are discussed but the technique requires further refinement.
Osteoradionecrosis is a severe complication of radiation therapy for cancer. Prevention of osteoradionecrosis is most important as the condition may be chronic, progressive and lead to pathologic fracture. The clinical experience at the Cancer Control Agency of British Columbia with 26 cases in approximately 1000 patients treated with radical radiation therapy to the head and neck region is presented and discussed. A clinical classification system is proposed to provide a guide for treatment selection, and to allow classification for research purposes.
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.
According to the current concept of osteoradionecrosis such tissue has become hypoxic, hypovascular and hypocellular and it has previously failed to show any bacterial growth. By using a molecular method, i.e., DNA-DNA hybridization, the presence of microorganisms in radionecrotic bone has formerly been demonstrated by us. The aim of the present study was to visualise bacteria in such bone by using scanning and transmission electron microscopy. Fourteen deep medullar specimens from resected radionecrotic mandibles were studied. Microorganisms were detected in 9 of the 14 samples (64%). The bacteria seen included rods, spirochetes and cocci, with rods being the predominant cells. One sample also contained yeasts (blastoconida and pseudohyphae). The data from this study strongly suggest an association between microorganisms and osteoradionecrosis. This may call for a revision of its presumed pathophysiology, including the possibility of an infectious etiology.
INTRODUCTION: Osteoradionecrosis of the mandible is a serious complication following radiotherapy for head and neck cancer. Reconstructive procedures in the head and neck region use a wide range of flaps for defect closure. The methods range from local, mostly myocutaneous flaps and skin grafts to free microsurgical flaps to ensure a satisfactory functional and aesthetic result. Moreover, the donor site defect needs to be closed, with as little as possible functional or aesthetic impairment. PATIENT AND METHOD: A 60-year-old male is presented with a history of squamous cell carcinoma of the left lower lip and chin area in whom the tumour was resected and treated by adjuvant radiotherapy. The follow-up was complicated by chronic inflammation of the left mandibular body as a sequel of radiotherapy; it resulted with partial bone destruction, and soft tissue dehiscence. He was admitted for repair and treatment of the infected mandibular osteoradionecrosis. A supraclavicular artery island flap was used to close the mandibular soft tissue defect. CONCLUSION: The shoulder provides a relatively good skin texture and match to provide cover and lining for defects in the lower part of the face, in combination with minor donor site morbidity.
In this technical approach, we demonstrate that preoperative tetracycline administration helps distinguish between viable and necrotic bone in osteoradionecrosis (ORN) during surgery by exciting tetracycline fluorescence by black light. The difficult aspect of the operative approach lies in the decision of the extent of the debridement in order to prevent an iatrogenic fracture or progression of ORN. With this technique, vital bone, in contrast to necrotic bone, showed detectable fluorescence. Therefore, tetracycline fluorescence labeling may be used in attempts to facilitate the intraoperative decision making in the surgical therapy of osteoradionecrosis.
Osteoradionecrosis of the mandible is a recognised pathological sequel to radiotherapy in the cervico-oro-facial region. Two cases of septic osteoradionecrosis which progressed to pathological fracture are described along with their subsequent clinical management.
PURPOSE: Osteonecrosis of the hyoid bone is an uncommon disease that has only been described occasionally in the literature. MATERIALS AND METHODS: We report 3 cases of osteonecrosis of the hyoid bone after radiation therapy for carcinoma at various sites in the head and neck region. RESULTS: Imaging computed tomography (CT) scans were performed for all 3 cases and did aid in the diagnosis. In 1 case, a 201thallium scintigraphy and a bone scan (99mtechnetium-diphosphonate) were performed and this confirmed the diagnosis of osteoradionecrosis. CONCLUSION: Osteoradionecrosis of the hyoid bone may be misdiagnosed as recurrent neoplasm. Although recurrent or persistent neoplastic disease must initially be ruled out, it is subsequently important to correctly identify osteonecrosis of the hyoid bone, because its surgical treatment is simple and the prognosis is good.
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.
PURPOSE: Osteoradionecrosis (ORN) of the mandible has long been considered the most destructive complication of head and neck irradiation. Recently, therapeutic irradiation has been implicated as the cause of induced/accelerated atherosclerosis of the cervical carotid artery and subsequent stroke. Panoramic radiography, previously shown to be capable of identifying carotid artery atherosclerosis in nonirradiated individuals, was used to assess the carotid vasculature of patients being treated for ORN. PATIENTS AND METHODS: The panoramic radiographs of 61 men (mean age, 60.5 years; range, 41 to 77 years) who received therapeutic irradiation to the neck 36 months or more previously were assessed for the presence of carotid artery atherosclerotic lesions. Sixty-one control subjects who never received therapeutic irradiation, but who were similarly susceptible to atherosclerosis by virtue of age, were assessed in a like manner. RESULTS: The irradiated individuals sustained a dose of 40 to 72 Gy to the area of the carotid bifurcation. Seventeen individuals (27.9%) with an irradiation dosage to the carotid bifurcation that averaged 59.2 Gy had a panoramic radiograph with a carotid atheroma (11 with unilateral lesions and six with bilateral lesions). The radiographs of the control subjects showed that three individuals (4.9%) had calcified carotid lesions. The mean age of these subjects was 66.1 years; two had unilateral lesions, and one had bilateral lesions. The difference in the proportion of individuals with ORN who manifested carotid artery atherosclerosis on their panoramic radiographs was statistically significant (P = .001) when compared with the nonirradiated control subjects. The lesions seen in both populations had a similar morphologic appearance and were radiographically located within the soft tissues of the neck 1.5 to 4.0 cm inferior-posterior to the angle of the mandible. CONCLUSIONS: Individuals with radiation doses sufficient to cause osteoradionecrosis of the mandible are at significantly higher risk of developing carotid artery atherosclerotic lesions than age-matched, nonirradiated controls.
Mandibular osteoradionecrosis is a serious chronic complication which may follow radiotherapy. Therapeutic ultrasound is a highly effective, inexpensive and readily available means of promoting revascularisation and healing. 'Long wave' ultrasound increases penetration depth and, therefore, seems to be more appropriate than traditional high frequency ultrasound. The aim of this study was to compare a new treatment using 45 kHz with the current standard 1 MHz machine. A traditional 1 MHz machine, pulsed 1:4, at intensities of 0.1, 0.4, 0.7 and 1.0 W/cm2(SAPA) was compared with a long wave machine, 45 kHz, at intensities of 5, 15, 30 and 50 mW/cm2(SA). The ultrasound was applied to human gingival fibroblasts and mandibular osteoblasts in vitro. Cell proliferation (DNA synthesis) and collagen and non-collagenous protein synthesis assays were performed, using radiolabelled thymidine and proline, respectively. Controls were sham-insonated and all readings were given as a percentage of controls. Fibroblast proliferation increased by 47% at 0.7 W/cm2 (1 MHz) and by 43% at 50 mW/cm2 (45 kHz), and osteoblast proliferation increased by 52% at 1.0 W/cm2 (1 MHz), and by 35% at 30 mW/cm2 (45 kHz). Fibroblast collagen production increased by 48% at 0.1 W/cm2 (1 MHz), and by 44% at 15 mW/cm2 (45 kHz) and osteoblast collagen production increased by 55% at 0.1 W/cm2 (1 MHz) and by 112% at 30 mW/cm2 (45 kHz). Long wave ultrasound was, therefore, capable of inducing a comparable or even higher enhancement of bone formation compared with traditional ultrasound, which, with its greater penetration, may accelerate the healing effect of ultrasound on osteoradionecrosis. The suggested intensity for 45 kHz ultrasound is 30 mW/cm2.
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 mandible is a serious complication following radiotherapy of head and neck cancers. A retrospective study of 20 reconstructions of mandibular defects due to osteoradionecrosis was performed. Various osseocutaneous free flaps were used: upper lateral arm (n = 5), radial forearm (n = 1), iliac crest (n = 4) and fibula (n = 7). Four grafts had a condylar prosthesis, and for seven grafts fixation was accomplished with a reconstruction plate. In three patients the mandibular defect was reconstructed using a bridging plate only. We defined a successful reconstruction as a graft or plate that did not need removal. Success was noted in 15 out of 20 patients, giving an overall success rate of 75%. For the free grafts alone (n = 17), successful reconstruction was achieved in 15 patients (88%). Two fibular grafts were lost owing to exposure and infection, as well as all three alloplastic reconstructions. Minor postoperative complications were observed in 11 patients (58%).
In patients with tumors of the head and neck, ionizing radiation delivered in dosages that will kill cancer cells induces unavoidable changes in normal tissue. Bone cells and vascularity may be irreversibly injured, leaving devitalized bone susceptible to the development of osteoradionecrosis. This clinical report describes the fabrication of an acrylic/rubber prosthesis retained by an orthodontic headgear. The prosthesis was used to improve the mastication, speech, and saliva control of a patient treated for osteoradionecrosis of the mandible.
We undertook a microradiographic study in osteoradionecrotic mandibular bone to estimate the number of vascular channels in the compact bone, number of resorption areas, and number of regeneration areas. Normal mandibles had a similar number of vascular channels/vision field compared with compact bone in other parts of the body. Irradiation itself did not significantly alter this number. After osteoradionecrosis had developed in the mandible, the number of vascular channels increased (p = 0.02). Treatment with hyperbaric oxygen further increased the number of vascular channels/vision field (p < 0.003). The normal mandible had no resorptive or regenerative areas, either before or after radiotherapy. The osteoradionecrotic mandible, however, had an increased number of resorptive as well as regenerative areas/vision field. Fluorescence as an indication of incorporation of tetracycline was seen in the regenerative areas of all osteoradionecrotic specimens treated with doxycycline. The process started from the vascular channels, periosteum, and endosteum. We conclude that the compact bone of mandibular osteoradionecrosis has high metabolic activity with active resorption and regeneration of bone and the limitation of the blood supply through cortical vascular channels, seems to be only one of many important factors.
Osteoradionecrosis of the mandible poses formidable problems for treatment. In the last 6 years, the fibula osteoseptocutaneous free flap was used in 12 cases to replace mandibles with radionecrotic damage. The presence of a pathologic fracture, exposed necrotic bone, or a persistent fistula not responding to conservative treatment were the indications for such a radical approach. Mandible defects after resection were around 8.0 cm long, and in all cases intraoral mucosa, skin, or both were included with the bone excision. All vascularized fibula osteoseptocutaneous flaps transplanted were successful with good primary bone healing. Adequate facial symmetry and improvement in oral function was achieved. No evidence of osteoradionecrosis recurrence was observed after a mean follow-up period of 3 years and 9 months. The advantages of using the fibula osteoseptocutaneous flap for mandible reconstruction are numerous, and good aesthetic and functional results can be obtained when it is used for reconstruction after radical excision of osteoradionecrotic lesions.
Spontaneous osteoradionecrosis of the mandible is an oral complication of radiation therapy. Bone necrosis, unrelated to trauma or infection, is more common when high doses of radiation, including interstitial implants, are delivered to a large bone volume. Management provides a challenge for the dentist and patient. When conservative, non-surgical treatment is unsuccessful, surgical debridement with adjunctive hyperbaric oxygen therapy and eventual mandibular resection may result. A case of spontaneous osteoradionecrosis is described which underscores the clinical course of the disease and treatment outcomes.
Osteoradionecrosis (ORN) is a late terminal sequela of irradiation that does not resolve spontaneously. In a preliminary study, a combination of pentoxifylline (PTX), tocopherol (Vit-E) and clodonate has been shown to be of clinical benefit with more than 50% regression of progressive ORN observed at 6 months in 12 patients. A 68-year-old woman presenting with severe exteriorized osteoradionecrosis had received radiotherapy for breast cancer 29 years previously. She had palpable breast fibrosis, including the sternum (15 cm x 11 cm) and a painful fistulous track in the upper part of the bone (orifice diameter 10 mm) surrounded by local inflammatory signs, and chronic osteitis with sequestra extrusion. MRI showed deep radiation-induced fibrosis below this area without cancer recurrence, and complete bone destruction over an area of 7 cm x 4 cm. Oral PTX (800 mg day(-1)), Vit.E (1000 IU day(-1)) and clodronate (1600 mg day(-1)) were administered daily for 3 years and were well tolerated. The patient exhibited regular clinical improvement until complete closure of the fistula and total regression of the clinical fibrosis. MRI confirmed the good response and showed heterogeneous restoration of the sternum, which was filled with new tissue. This is the first time that antifibrotic treatment with combined PTX-Vit.E plus clodronate has been shown to have a significant effect on necrosis, by completely reversing severe progressive ORN and the associated radiation-induced fibrosis.