Case Report

A 59-year-old woman was referred to the authors’ oral and maxillofacial surgery practice with a chief complaint of intermittent pain around the decayed roots of the third molar on her right side for the previous 2 months. The patient’s medical history was remarkable for rheumatoid arthritis (RA) and Crohn’s disease for which treatment included the following medications: azathioprine (Imuran®, GlaxoSmithKline, www.gsk.com): 100 mg once daily for about 5 years; mesalamine (Asacol®, Warner Chilcott Company, LLC, www.wcrx.com): 1600 mg three times daily for the previous 5 years; and prednisone: 12.5 mg daily for about 10 years. In addition, the patient had hypertension, right total hip replacement surgery without complications 3 years prior, and was allergic to penicillin.

On examination, the patient had a decayed remaining lower right third molar root with associated mild swelling and erythema of the surrounding tissue. A panoramic radiograph showed a small portion of the third molar root mainly in the soft tissue above the alveolar bone level (Figure 1). The day after presentation, the patient underwent extraction of the root of the lower right third molar without complications. One hour prior to her surgery, the patient took 600 mg of clindamycin, and she continued on 300 mg of clindamycin three times daily for the next 5 days. The patient returned for follow-up examination 1 week postoperatively and demonstrated normal healing for this timeframe.

One month later, the patient called to report swelling and pain in the area of the extraction site. On examination, swelling was evident in the posterior mandible in the area of extraction, extending to the buccal vestibule and masseteric region, with limited mouth opening to about 15 mm, and purulent discharge behind the second molar. A subsequent panoramic radiograph revealed a mottled, irregular, mixed radiolucent/radiopaque appearance of the posterior mandible around the extracted site, which extended anteriorly to include the adjacent second molar (Figure 2). Given that this condition had existed for 6 to 8 weeks, the preliminary diagnosis of CO was made, and the patient consented to indicated treatment, which consisted of debridement of the wound and extraction of the second molar. The procedure was performed on the same day under local anesthesia; 600 mg of clindamycin was given just prior to the surgery. A buccal full-thickness flap in the second-third molar area was raised, and multiple small bony sequestra with granulations tissue were visualized and removed until fresh bleeding bone was seen; the involved second molar was also removed with copious irrigation after debridement. The patient was placed on clindamycin 300 mg four times daily and was followed weekly.

Four weeks later, the wound remained open with purulent discharge. A second, wider bone debridement procedure was performed, with removal of a few more necrotic bone fragments. Purulent discharge and necrotic bone were sent for culture and sensitivity testing, with later received results of a positive culture showing “mixed oral flora.” An infectious disease (ID) consultation was obtained, and the recommendation was to continue with another course of oral clindamycin and local treatment.

During that time, an important new piece of information was discovered by patient’s primary care physician: the patient had also been on alendronate (Fosamax®, Merck, www.merck.com) 70 mg once a week for the last 3 years due to concerns about potential osteoporosis in this post-menopausal woman on prednisone. “I forgot to mention this Sunday pill,” the patient revealed at the follow-up appointment. Joint consultation between the patient’s ID and primary care physicians resulted in a compromise approach to treating the jaw infection as well as continuing to treat her autoimmune conditions with the immunosuppressive therapy. The agreed upon approach was to discontinue the alendronate and to decrease the dosage of prednisone from 12.5 mg to 10 mg daily. The working diagnosis of the jaw condition at this point was BRONJ.

There was a temporary improvement in her jaw symptoms, but after 5 to 7 days, infection with purulent discharge returned. Follow-up imaging, including a panoramic radiograph (Figure 3), showed persistent mottled, mixed irregular radiolucent-radiopaque appearance, slightly more extensive than that seen on the previous panoramic image. The third debridement of the wound was performed 10 weeks after extraction of the root of the third molar, which was 6 weeks after the first debridement and 3.5 weeks after the second debridement and on day 43 of the oral clindamycin. A large amount of granulation tissue and multiple sequestra of devitalized bone were curetted out down to vital-appearing (bleeding) bone. A second culture and sensitivity test did not reveal the presence of microorganisms. The biopsy was positive for “necrotic sclerotic bone with acute osteomyelitis and colonies of filamentous bacterial organisms consistent with actinomycetes” (Figure 4). As actinomycotic organisms are present in the normal oral flora, the existence of actinomycetes is not an indication of “actinomycosis.” In addition, these features seen under the microscope do not clearly distinguish chronic osteomyelitis from BRONJ.

Because of concerns for mandibular osteomyelitis (and possibly actinomycosis), the ID physician discontinued oral clindamycin, and the patient was placed on a 6-week course of intravenous ceftriaxone (2 gm, once a day) through the peripherally inserted central catheter (PICC line). In 48 to 72 hours, the patient reported much improvement in symptoms. Granulation tissue began to fill the wound, negating the need for further debridement. After 6 weeks of ceftriaxone, complete closure of the wound was occurring, and a panoramic radiograph demonstrated significant remodeling of the bone without a mottled appearance or evidence of sequestration.

Although the patient subsequently developed diabetes mellitus (DM) type 2 and was placed on insulin, it did not complicate the wound healing (Figure 5). Upon discontinuation of ceftriaxone, the ID physician returned the patient back to a 3-week course of oral clindamycin (300 mg, three times a day). The last panoramic radiograph taken on this patient was 5 months after the initial presentation and 3 months after the last debridement. It demonstrated partial fill of the mandibular defect and bone remodeling without evidence of necrosis (Figure 6).

- See more at: https://www.dentalaegis.com/cced/2012/12/odontogenic-osteomyelitis-or-bisphosphonate-related-osteonecrosis-of-mandible-of-patient-with-autoimmune-disease-clinical-dilemma#sthash.FfnECaBv.dpuf

 thank you Singh and Ali for your comments, what would you want a release profile of porous space maintainers used in Odonto Osteo to be like. 

I suggest that in these cases a prolonged course of therapy has to be planned, but this practice may be difficult to apply without an ID consultation. Probably, Clindamycin has the problem of a low genetic barrier to the resistance and an associative regimen with Ampicillin (or similar) may be efficacious.

The choice of antibiotics depends on the type of infection, the severity of the condition. Overall, treatment duration varies between 5 and 10 days. Amoxicillin, amoxicillin/ clavulanate, cephalosporins, doxicycline, metronidazole, clindamycin and macrolides, such as erythromycin, clarithromycin and azithromycin, all stand out amongst the variety of systemic antimicrobials used to treat odontogenic infection.

Dear Dr.Abu-Hassein Muhamad and all  colleagues.

It is true that clindaymicin is an excellent drug against anaerobic gram-positive bacteria, but you must be careful not to give the drug over 5 days, and you have to ask your patient to inform you if is observing any blood in his stool during the treatment and up to 4 weeks after finishing the treat treatment. Since the patient might develop later Clostridium difficile associated diarrhea which can be serious and the patient should be treated with metronidazol to stop the diarrhea.