|Year : 2013 | Volume
| Issue : 1 | Page : 71-73
Diagnosis and management of late onset osteoradionecrosis of the mandible
Thamer M Musbah, Mel Mupparapu
Department of Oral Medicine, Robert Schattner Center, University of Pennsylvania School of Dental Medicine, Philadelphia, PA, USA
|Date of Web Publication||20-Jun-2013|
Thamer M Musbah
Department of Oral Medicine, Robert Schattner Center, University of Pennsylvania School of Dental Medicine, 240 S 40th Street, Philadelphia, PA 19104
Osteoradionecrosis (ORN) is frequently encountered in clinical dental practice. The identification and management of such a lesion is often challenging. This clinical report is based on a patient who had radiation therapy to the head and neck region for a salivary gland malignancy. The patient developed ORN of the mandible 12 years later. This demonstrates the need to understand the pathophysiology of this condition better than we currently know.
Keywords: Hyperbaric oxygen, mandible, osteoradionecrosis, radiation therapy
|How to cite this article:|
Musbah TM, Mupparapu M. Diagnosis and management of late onset osteoradionecrosis of the mandible. J Orofac Sci 2013;5:71-3
|How to cite this URL:|
Musbah TM, Mupparapu M. Diagnosis and management of late onset osteoradionecrosis of the mandible. J Orofac Sci [serial online] 2013 [cited 2014 Sep 3];5:71-3. Available from: http://www.jofs.in/text.asp?2013/5/1/71/113711
| Introduction|| |
Osteoradionecrosis (ORN) is a clinical term used to describe an infection of the bone that was previously necrotic (due to radiation) but aseptic. Most commonly, the infection is secondary and directly extending from either the oral cavity or from a remote systemic site. The condition was described in the medical literature as early as 1930. 
It is known that mandible is often the most common site for ORN due to the inherent dense bone and its sparse vascularity as compared to maxilla. The ORN usually leads to a sequestrum within that region. The sequestrum is both radiographically and clinically evident especially if the area is a former non-healed extraction site.
The diagnosis of ORN in cases of maxillofacial radiation therapy (RT) is sometimes complicated and often undiagnosed until later in the course of the disease when the symptoms become overt. It is important for the dental practitioner to anticipate such situations and be on the alert for an early diagnosis. As is known, the ORN is a condition that can be easily prevented rather than treated.
| Caser Report|| |
A 62-year-old male was referred to admission to the clinic at the University of Pennsylvania School of Dental Medicine with the chief compliant of a recurrent dental infection of 3 months duration. He has been evaluated by an Otorhinolaryngologist, and the patient is currently on oral antibiotics (Penicillin 500 mg) with some relief. A similar episode occurred a year ago when he presented to his Otorhinolaryngologist with the right facial swelling which was managed by an extra-oral incision and drainage and was managed with oral penicillin 500 mg for 7 days.
He reported having a prior history of RT and chemotherapy status post-excision of right submandibular salivary gland malignancy in the year 2001. During and after the radiation therapy, the patient denied having any fluoride treatment that may have led to increase in the radiation caries. Multiple teeth were extracted and eventually full mouth extractions were performed after 15 dives of hyperbaric oxygen (HBO) treatment in 2005. Past medical history was significant for hypertension, hypothyroidism, osteoarthritis, high lipidemia, and history of salivary gland malignancy. Medications: Potassium salts 8 mEq, qd; Levothyroxine 112 mcg, qd; Simvastatin 20 mg, qd and Hydrochlorothiazide 25 mg, qd.
Detailed review of systems was non-contributory. Vital signs were within normal limits at the time of examination.
Clinical examination revealed paresthesia along the distribution of the right mandibular nerve branch of the Trigeminal nerve. Other cranial nerves were intact. Sub-mentally, there was an active draining fistula with no signs of facial asymmetry or swelling with no lymphadenopathy. Intra-oral examination revealed complete edentulous maxillary and mandibular arches with enlargement of the anterior mandibular alveolar ridge with two discrete draining fistulas and a small ulcer with bony exposure on right mandibular ridge [Figure 1] and [Figure 2].
|Figure 1: Intraoral photograph of the patient's mandibular anterior edentulous ridge showing the swelling|
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|Figure 2: Intraoral photograph of the patient's right mandibular posterior edentulous ridge showing the exposed bone (short-arrow). The fistula is located anterior to the exposed bone (long-arrow)|
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Radiographic examination (Panoramic radiograph) revealed edentulous maxilla and mandible with moderate to severe atrophy of the maxillary edentulous ridges. The mandibular edentulous ridges show mild to moderate bone atrophy. The body of the mandible exhibits dense sclerotic areas both anteriorly and posteriorly. The lower border of the mandible, although well-corticated appears less prominent due to the overall sclerosis. There appears to be an expansion of the alveolar areas superior-inferiorly especially in the left anterior region [Figure 3]. The right canine area shows some irregular alveolar crestal margins corresponding to the area that showed bone exposure clinically. Overall, the radiographic appearance is consistent with chronic sclerosing osteomyelitis. An ORN is a clinical probability due to the exposure of bone and concomitant necrosis.
|Figure 3: Panoramic radiograph showing the diffuse sclerotic alveolar bone changes in the mandible|
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Diagnosis was consistent with ORN of the mandible.
Management of the superinfected ORN will include different modalities starting with conservative treatments such as oral antimicrobials therapy, oral rinses, incision, and drainage and repeated HBO treatments and close monitoring, a less conservative approach would be surgical incision and drainage, surgical debridement, and sequestrectomy. A partial mandibulectomy with fibula free flab reconstruction would be indicated if conservative approaches fail.
| Discussion|| |
Hamilton, et al. concluded that soft-tissue infection paired with classic bone findings such as sub-periosteal abscess formation and cortical bone erosions help distinguish infected ORN from metastatic lesions or aseptic ORN.
Chang et al. hypothesized based on their work that the extraction of teeth prior to RT has in fact, predisposed patients for development of ORN. The authors questioned the "3 week healing period" that was recommended by dental researchers post extractions. Chang et al. believe that this may be insufficient for complete healing of the alveolar bone and hence the irradiation might be precipitating the ORN thereafter. Chang et al. also discuss the implications of HBO and its role in the management of post-irradiation extractions.
Marx's prophylactic HBO recommendation consists of 20 dives of HBO prior to and 10 dives of HBO after the extractions. Marx and co-authors concluded that based on the histopathological evidence obtained from 45 specimens, the physical injury to bone as well as the surrounding soft tissues from high linear energy transfer of RT is the main culprit and the microorganisms play only a secondary opportunistic role in the causation of ORN disproving the original Meyer's hypothesis  about the triad of radiation, trauma and infection. 
Careful evaluation of the patients who undergo external beam radiation therapy or brachytherapy and a cautious follow-up after irradiation is the key in the management of ORN. Once ORN sets in, the options are mostly surgical in combination with HBO. This case demonstrates the need for early detection and management of a late onset HBO. 
Risk assessment studies by Nabil and Samman  related to ORN status post-extractions revealed that mandible has three times higher risk of developing ORN after extractions than the maxilla in patients who were previously irradiated.
The risk of developing ORN seemed to be higher in patients who had extractions for 2-5 years status post-irradiation than those who underwent extractions within the first 2 years as per the data from the systematic review conducted by Nabil and Samman.  It is the opinion  currently that the risk peaks initially within the first 3 months after radiation and the second peak occurs after 2 years and continues to 5 years post-radiation. Further studies are needed to see if there would be a change in the risk after 5 years. Based on this information, it is prudent to say that in clinical dental practice, the patients should be carefully evaluated for needed extractions within the first 5 years after RT and preferably avoid surgical procedures or postpone them until such time that the risk is deemed lower. Further research is needed to shed light on this aspect.
| References|| |
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[Figure 1], [Figure 2], [Figure 3]