This study presents the radiographic findings of two cases of static bone cavity in the inferior aspect of the condylar neck and mandibular notch of the mandible. On plain CT, a soft tissue mass was observed in each cavity. The submandibular gland and the other glands were not found in each cavity. On contrast-enhanced CT, the soft tissue in the cavity in the inferior aspect of the condylar neck had marked linear enhancement and dilated vasculature structure was observed in the cavity. On the contrast-enhanced MRI, the soft tissue in the cavity of the mandibular notch had marked enhancement and flow void was detected in the cavity. In the inferior aspect of the condylar neck, the cavity size had enlarged radiographically over a period of three years. Vascular lesions were found in the cavity located in the inferior aspect of the condylar neck and mandibular notch of the mandible by both CT and MRI. The vascular lesion might explain the enlargement of the static bone cavity.