Structures observed<unk>  can be used to best visualise a number of structures in the skull. * Maxillary sinuses. * Frontal sinuses, seen with an oblique view. * Ethmoidal cells. * Sphenoid sinus, seen through the open mouth. * Odontoid process, where if it is just below the mentum, it confirms adequate extension of the head. The frontal sinus may not show the frontal sinus in detail. Interpretation of results Pathology Observation None (Normal) * Odontoid process lies exactly below mentum. * Maxillary sinuses are more radiolucent than orbits. Maxillary sinusitis Differentiating pathology in maxillary sinus * Maxillary sinus shows radiopacity. * Mucous membrane shows thickening. * Air-fluid level may be observed if the radiograph is taken in "head-up" position. It is not seen in radiograph taken in lying down position. The concavity of fluid opacity points upwards. Polyp * Maxillary sinus shows radiopacity; which is present despite of the position in which the radiograph is taken. * Usually, the radiopacity has convexity pointing upward. Malignancy Onhgren's line * Sinus is radioopaque. * Sometimes, destruction of walls of sinus is seen and is diagnostic of malignancy * Distance between antero-lateral wall of maxilla and coronoid process of the mandible is measured. If it is increased on one side, it indicates involvement of infratemporal fossa by the malignancy. This is called Handousa's sign. Prognosis of malignancy is determined by position of tumour on basis Onhgren's line.
Waters' view
Caldwell's view
Schuller's view
Fowler's position
De Finetti diagram
Option grid
Talairach coordinates
Stimson line