Long-standing osteomyelitis: a case report and discussion

Osteomyelitis has been a relatively rare condition since the development of antimicrobial therapy.¹ In the oral cavity, the mandibular jawbone is primarily affected owing to its bone density and poorly vascularized cortical plates, with additional vascularization being supplied by the inferior alveolar neurovascular bundle. Maxillary bone is less dense and has an abundant vascular supply from surrounding vessels and is consequently more resistant to developing osteomyelitis.²

Odontogenic micro-organisms are the predominant pathogenic driver in cases of osteomyelitis of the jaws.¹ Host defences can also play a role, however, and systemic diseases such as diabetes mellitus, autoimmune conditions, compromised vascularity (as in osteoporosis and malignancy) can all influence progression of the condition. Additional local factors may also play a part, including bone pathology, the direct effects of radiation to the bone, non-compliance in patients, patient age, nutritional status and the role of certain medications that can affect immunity (eg steroids, chemotherapeutic agents and bisphosphonates).^2,3

Osteomyelitis may arise from the spread of odontogenic infection or as a result of trauma to the jaw bone and teeth, which provides a pathway for pathogens to enter the bone via the pulp or periodontal tissues.¹ Although this bacteria-induced inflammatory process is commonly self-limiting, there is potential for progression to a pathogenic process, and there will be suppuration when bacterial and cellular debris cannot be eliminated by the natural defence mechanisms of the body. When the inflammatory response and suppuration occur within the bone marrow, intramedullary pressure increases and results in a decrease of blood supply to the area. The blood supply is further compromised if the suppuration perforates the cortical plate and collects under the periosteum.^1,3

Case report

A 67-year-old woman presented to the oral surgery department in September 2018, complaining of generalized mandibular pain and a fragment of bone protruding through the gingiva in the left side of her lower jaw. She reported mandibular pain for a number of years, resulting in repeated appointments in the oral surgery department; however, this incident was an acute episode. Her primary concern was that she had not been able to wear a lower complete denture for a number of years due to the intermittent nature of the mandibular jaw pain. This was significantly impacting on her quality of life and day-to-day functioning.

Upon looking into her history further, she had initially been referred in 1999 with ‘non-specific jaw pain’ by her general dental practitioner. Subsequently, her remaining teeth had been removed over a number of years. The jaw pain had persisted and necrotic areas of bone had developed, which had been removed and debrided as they became acutely symptomatic. OPT radiographs taken in 2010, 2011, 2013 and 2017, demonstrated developing areas of necrotic mandibular bone (Figure 1). The clinical diagnosis throughout this time had been osteonecrosis of the jaw, and multiple bone and soft tissue biopsies had been reported as non-specific infection and necrotic bone.

With regard to her medical history, the patient had type II diabetes mellitus, hypertension, hypercholesterolaemia, asthma and glaucoma. Her regular medications were: gliclazide, sitagliptin, metformin, bendroflumethiazide, simvastatin, diltiazem, losartan, fesoterodine, lansoprazole and salbutamol inhaler. The patient had no history of bisphosphonate use, no history of chemotherapy or radiotherapy, and no history of systemic immune suppression.

At the initial examination appointment, a fragment of mobile, necrotic bone was present in the lower left mandible (at the region of the LL4 and LL5). The right mandibular quadrant was extensively swollen and painful to palpate. There was no cervical lymphadenopathy; however, suppuration was evident from two sinuses within the mandibular swelling. An OPT radiograph was taken at this appointment (Figure 2), that showed a loss of trabecular bone architecture and bilateral sequestrum. Following clinical and radiographic examination, a provisional diagnosis of chronic osteomyelitis was made.

Owing to the mobility of the sequestrum in the lower left mandible, and the acute pain that the patient was experiencing, a decision was made to remove it. The sequestrum was removed under local anaesthesia, and specimens were sent to histopathology and microbiology for culture and sensitivity testing. Additionally, swabs were taken of the suppuration from the lower right mandibular swelling and sent to microbiology. The patient was discharged with a course of doxycycline 200 mg for 10 days post-operatively.

A number of bacterial and fungal species were identified on microbiological and histopathological diagnosis. The commensal organisms were Streptococcus parasanguinis, Streptococcus milleri, Actinomyces sp. and Candida albicans (in hyphae and yeast form). These organisms are considered part of the normal oral flora; however, they are also opportunistic and can become pathogenic in immunocompromised individuals.^4,5,6,7Citrobacter koseri was also isolated, which is a Gram negative bacillus more commonly found in the lower gastrointestinal and urinary tract, but also an opportunistic pathogen.⁸

A 6-week daily intravenous infusion of ciprofloxacin was recommended by the microbiology team, and the Candida colonization was treated with oral fluconazole 200 mg. This was followed by a prolonged course of oral antibiotics.

During treatment with the intravenous ciprofloxacin, the patient was reviewed in the oral surgery department. Following the removal of necrotic bone from the lower left mandible, this area had healed well. The patient had no pain from the lower left region and the mandible was firm to palpate. She continued to experience pain from the lower right mandible and suppuration was evident (Figure 3).

A further decision was made to complete an examination of the swelling in the lower right mandible under local anaesthesia while she was still receiving intravenous antibiotics. Further necrotic bone was removed from the lower right mandible, and the area irrigated with saline (Figure 4).

The patient was reviewed 3 months post-operatively. Her symptoms had resolved and she was pain-free. On clinical examination no exposed bone was present and the right mandibular swelling had resolved. There was no suppuration and the mandible was firm to palpate. A further OPT was taken that showed radiographic resolution, mandibular bone infill and no further bony sequestrum (Figure 5). The patient was continued on oral antibiotics for 1 year, as requested by the microbiology team, and continued to have regular reviews with oral surgery to ensure that she experienced no acute symptoms. As of December 2021, she does not report any further symptoms.

Discussion

Osteomyelitis is a condition that can be difficult to diagnose and challenging to treat successfully because, in many cases, the patient can present with minimal clinical signs of inflammation and the gingiva often appears sound. Tenderness of the periosteum, indicated by pressing on the gingiva in the specific region, can be a local sign of osteomyelitis. The patient's physical symptoms can be significantly debilitating, with pain often described as deep and boring. These symptoms may appear out of proportion to the clinical picture.² Additionally, the incidence of the condition has been decreasing with the availability of antimicrobial therapy; however, treatment of the condition, whether acute or chronic, may only be successful if combined with surgical therapy.^1,9 If surgical therapy is completed, it is important that any specimens are sent for histological and microbiological investigation. In this case, the microbes cultured were particularly virulent and resistant to a number of common antibiotics, and perhaps why previous antibiotic therapy had proved inadequate. In addition, fungal organisms were identified, which were treated with antifungal medication.

In suspected cases of osteomyelitis, it may be advisable to use cone beam computed tomography (CBCT), to identify small bone sequestra because they may not be easily identifiable on routine OPT examination. However, in this case, a CBCT scan was not available at the time of examination and treatment.

This condition significantly impaired the day-to-day life of the patient. She was in continuous discomfort and unable to wear a lower denture, ultimately affecting her quality of life.

This case showed significant radiographic resolution in the mandible after surgical debridement and prolonged treatment with intravenous and oral antibiotics. The improvement can be attributed to elimination of the infectious process using both treatment modalities.^9,10

Conclusion

In this case the patient had been seen in the department for a number of years and had undergone multiple dental extractions, as well as being treated with numerous courses of different antibiotics. Unfortunately, these treatments alone had not resolved her symptoms clinically or radiographically. This case was also discussed at the microbiology multidisciplinary team meeting and, by working with the microbiology department, we were able to identify causative organisms and treat them specifically. The treatment could be considered aggressive and the patient continues to be under close review. However, the improvements that she has seen symptomatically, and that we have seen clinically, are encouraging.