Normal occlusal anatomy

Maxillary occlusal 
The median palatal suture appears as a thin radiolucent line between the central incisors extending roughly from the alveolar crest to the apices of the central incisors. The incisive foramen is seen as an oval radiolucent area between the apices of the central incisors. The nasal septum is seen as a radiopaque area extending vertically down the center of the image from the posterior of the image to the apices of the central incisors. It is bordered on each side by the nasal fossa which appear as radiolucent lines parallel to the nasal septum. If the maxillary sinus appears in the image it is seen as a radiolucent area in the posterior lateral aspect of the image.

Mandibular occlusal 
The inferior border of the mandible is seen in a mandibular occlusal radiograph. Typically the cortical plate can be seen as a radiopaque line along the border of the mandible. The mental ridge also appears as a radiopaque line parallel to the cortical plate. The genial tubercle appears as a small pointed protrusion extending downward from the cortical plate.