X ray of Paranasal Sinus :Water’s View:1, mandible. 2, Upper edge of the orbit. 3, Frontal sinus. 4, Maxillary sinus. 5, Odontoid process.
- Waters’ view (also known as the Occipitomental view) is a radiographic view, where an X-ray beam is angled at 45° to the orbitomeatal line. It is commonly used to get a better view of the maxillary sinuses.
- Odontoid process lies exactly below mentum.
- Maxillary sinuses are more radiolucent than orbits.
- 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.
- Maxillary sinus shows radiopacity; which is present despite of the position in which the radiograph is taken.
- Usually, the radiopacity has convexity pointing upward.
- 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.