[Os odontoideum: clinical and radiological aspects].

Few reports of os odontoideum have been made. We report two cases where this affection was revealed by cervical pain and hemiparesis in one case and acute tetraparesis in the other. Patients with os odontoideum usually present with neurological signs, but some have only cervical pain and some others remain asymptomatic. Radiological exams, including radiograms, cervical scanner and MRI lead to the diagnosis. Different surgical treatment can be proposed to symptomatic patients. Prophylactic surgical treatment is not indicated.