Primary Chronic Osteomyelitis of the Mandible: A 10 -Year Follow- Up

Introduction

Primary chronic osteomyelitis of the jaw (PCO) is a nonsuppurative chronic inflammatory disease of the jawbone affecting mostly the mandible [1]. Its etiology remains unclear. This condition can be either isolated or related to other diseases, such as autoimmune diseases and syndromes, including SAPHO syndrome (synovitis, acne, pus Blister, bone hyperplasia, and osteitis)”, as well as Majeed syndrome or cherubism [1,2]. This condition is mainly seen in young adults, affecting both males and females [3]. Secondary chronic osteomyelitis of the jaw (SCO) is usually caused by bacterial infection of known origin, such as tooth extraction or pulp infection. It is much more common than PCO. However, diagnosis of primary chronic osteomyelitis is often challenging. It is often made based upon the clinical findings, including chronic swelling of the jaw, severe pain, and severe restriction of the mouth opening with no evidence of local infection, trauma or neoplasm [4]. Panoramic radiograph often reveals the presence of osteolytic radiolucent areas, combined with increased thickness of the alveolar lamina dura, and sclerogenic variation of the bone in the affected area and around the mandibular canal [5]. Computed tomography patterns of osteomyelitis can be lytic, mixed or sclerotic. However, sequestrum patterns are rare. Bacterial contamination of bone tissue is best determined by bone biopsy under radiographic guide [6]. The most frequently involved bacteria are Staphylococcus aureus, Gram negatives (Pseudomonas aeruginosa), and anaerobe bacteria (Bacteroides fragilis). Bone scintigraphy is highly sensitive to bone abnormalities. It is a useful method, especially in young patients with suspected inflammatory disease or malignant tumors [7]. Magnetic resonance imaging has many advantages thanks to its ability to detect early changes related to osteomyelitis, to evaluate the true extent of the disease, to depict extraosseous spread of the infection, and to help guide surgical management [8]. Treatment of this condition remains controversial, and it is often based on anti- inflammatory drug therapy such as corticosteroids, nonsteroidal anti- inflammatory drugs (NSAIDs), long term antibiotics, hyperbaric oxygenation (HBO), and more recently Biphosphonates therapy [9]. Surgical management is sometimes required, and it generally consists in decortication. However, in some severe cases, resection of the unhealthy bone remains the only therapeutic solution [10]. Thus, this condition is known as being debilitating and difficult to manage, thus having a severe impact on patient’s quality of life. Recurrence is common and it is reported even many years after the first onset [3]. We herein report the case of a healthy female young patient with a 10-year chronic primitive osteomyelitis of the mandible. The clinical and radiological findings as well as the disease evolution throughout the years are also reported. Treatment modalities are discussed.

Case Presentation

A 24-year-old healthy female patient was referred to the department of oral surgery and oral medicine by her endodontist for a severe limitation of her mouth opening which makes the conservative treatment of the tooth 36 impossible. The patient reported a history of primitive chronic osteomyelitis (PCO) of the left mandible that was diagnosed at the age of 13 years. According to the patient’s medical files, the history of the condition started when the patient was referred by her orthodontist to an oral surgeon for an “abnormal swelling of her left jaw and severe pain”. Panoramic radiograph showed an abnormal bone density of the mandible with small multiple lytic lesions in the left corpus and the area of the germ of the tooth 38 (Figure 1). Computed Tomography showed a heterogeneous pattern with expansion of the left ascending and angulo-mandibular ramus, sclerosis foci, and erosion of the adjacent cortical bone. Surgical curettage of the lesion and extraction of the germ 38 were performed.

Figure 1: The first panoramic radiograph of the patient taken at the age of 13 showing abnormal bone density of the mandible with small multiple lytic lesions in the left corpus and the area of the germ of the tooth 38.

Histological examination predominantly showed chronic inflammatory infiltration and medullary fibrosis. Based on the findings, diagnosis of primary chronic osteomyelitis of the mandible had been made. Complementary scintigraphy was indicated to search any possible extra-oral lesions. No other scintigraphic abnormality of radiotracer fixation on the rest of the osteoarticular system was revealed. Thus, diagnosis of recurrent multifocal osteomyelitis was ruled out (Figure 2). Follow-up was marked with pain, swelling, and mouth opening limitation despite medication including non-steroidal anti-inflammatory drugs: Iboprofen 400mg (twice a day), levofloxacin (Tavanic 500 3 times/day), and paracetamol (Panadol 3g/day). A second surgical intervention was indicated12 months later because of the persistence of symptomatology, especially pain and trismus. The patient underwent decortication of the mandible (the corpus). Pharmaceutical management was based on anti-inflammatory drugs (Iboprofen 500mg), antibiotics: Clindamycin (Dalacine 600mg 2 tab 3 times / day), Levofloxacin (Tavanic 500mg twice a day) and Paracetamol (1g 3 times a day). The patient also received 40 HBO sessions. The patient reported an improvement marked with a decrease in pain and mouth opening restriction despite the persistence of a small and firm swelling of her left mandibular angle and the occasional onset of mild pain that was efficiently relieved with paracetamol. The consultation day, extra-oral examination revealed a firm swelling of the patient’s left jaw extending to the mandibular as well as the temporal areas. Mild pain was present at palpation. The patient had a severe limitation of the mouth opening (1cm). Intra-oral examination revealed a deformation of the corpus in both the vestibular and lingual sides, with gingival fibrosis (Figure 3). Computed tomography showed diffuse sclerosis and an important thickening of the mandibular bone extending to the homolateral condyle. The emergence of the mandibular canal was also involved. Muscular hypertrophy of the masseter muscle and the lateral pterygoidien muscle were evident, too (Figure 4a & 4b). The 3D reconstruction revealed with great precision the extent of the lesion involving the entire left mandible. (Figure 4c). Moreover, periapical radiolucent images were noticeable on the teeth 37 and 36 with evidence of root resorption. Vitality tests on the teeth 36 and 37 were negative.

Given the severity of the condition, steroids injections (prednisone 8mg 1inj/d for five days), Antibiotics (Dalacine 600mg, 2.4g/day) and paracetamol (Doliprane1g, 4g/day) were prescribed. Ten days later, the patient reported a significant improvement in the mouth opening and a decrease of pain; however, the swelling remained unchanged. Endodontic treatment of both teeth 36 and 37 was possible and it was performed under antibiotic therapy: Levofloxacin: Tavanic 500mg (twice a day) in addition to Dalacine 600mg (4tab/d). At the 6-month follow-up, the patient reported an improvement in all the clinical symptoms, especially pain and swelling, and showed no signs of local infection.

Figure 2: Bone scintigraphy revealing No other scintigraphy abnormalities of radiotracer fixation on the rest of the osteoarticular system.

Figure 3: Intra oral examination: severe mouth opening restriction.

Figure 4: Recent CBCT of the patient.
a) Axial slice showing severe bone erosion of the left mandible.
b) Coronal slice showing an important thickening of the mandibular bone extending to the homolateral condyle. Muscular hypertrophy of the
masseter muscle and the lateral pterygoidien muscle.
c) The 3D reconstruction comparing the left and the right side and showing the extend of the lesion to the entire Ramus on the left mandibular side.