L. EL ASSASSE, S. BOUTACHALI, F. AMRAOUI, T. AMIL, S. CHAOUIR, A. DARBI Radiology service, Military hospital, Rabat, Morocco

 The mandibular actinomycosis is a rare condition, usually secondary to tooth extraction, mucous wound or mandibular fracture.  We report in this work two cases of mandibular actinomycosis explored by orthopantomogram and facial CT and whose diagnosis is confirmed by histology.

 These two patients aged 26 and 60 years, both having a history as a dental extraction with delayed mucosal healing, having presented a mandibular pain with perimandibular tumefaction.  Radiological aspects were not specific with uni or multigeodic osteolysis.

 A wide excision was indicated for them with empiric antibiotic therapy.  Pathological examination of surgical specimens revealed actinomycotic osteitis.

Case 1: Orthopantomogram showing a left pre-angular osteolytic lesion.

Case 1: Facial CT showing well defined multilocular osteolytic lesion in the horizontal branch of left mandible.

Case 2: Orthopantomogram showing a left parasymphyseal unigeodic osteolytic lesion.

 The cervicofacial actinomycosis is a rare infectious disease whose incidence is estimated at 5 per 100,000 people.  It is most frequent in adults between 20 and 60 years with sex ratio 3 males to 1 female.  It is caused by germs long regarded as intermediate between fungi and bacteria but which proved to be true bacteria: Actinobacteria or actinomycetes.  Involvement of the head and neck region is the most frequent (50 to 75% of cases), thoracic and abdominal locations are rarer.

 Contributing factors sometimes found are poor oral hygiene, oral trauma or surgery, dental procedures and salivary lithiasis.  Chronic tonsillitis, mastoiditis, and otitis are also important risk factors for actinomycosis.

 The radiological signs of actinomycotic osteitis are not specific.  Involvement may be osteolytic (uni or multigeodic) or osteoblastic.  The severe forms of mandibular actinomycosis can develop into the skull base or cervical spine.

 Diagnosis is histological.  Treatment consists of prolonged antibiotic therapy and surgical debridement.  Prognosis depends on early diagnosis and treatment.

 The diagnosis of actinomycosis should be considered in patient with recurrent and chronic suppuration.  The appearance on imaging is not specific and the diagnosis of certainty is histological.

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