PARANASAL SINUSES

PARANASAL SINUSES

Serve as a resonating chamber for the voice

PARANASAL SINUSES

Decrease the weight of the skull by containing air.

PARANASAL SINUSES

Help to warm and moisten inhaled air

PARANASAL SINUSES

Act as shock absorbers in trauma

PARANASAL SINUSES

Possibly control the immune system

PARANASAL SINUSES

The air containing cavities, formed in the nasal mucosa and continued communication with the nasal fossae, hence it is called

MAXILLARY SINUSES

Are paired and are located in the body of each maxilla.

MAXILLARY SINUSES

Appear rectangular in the lateral image, but they are approximately pyramidal in shape and have only 3 walls

MAXILLARY SINUSES

The apices are directed inferiorly and laterally

MAXILLARY SINUSES

In adult, it is approximately 3.5 cm high & 2.5– 3 cm wide

SPHENOIDAL SINUSES

Paired and occupy the body of the sphenoid bone.

SPHENOIDAL SINUSES

Anatomists state that only one sphenoidal sinus is often present; however, more than 2 sphenoidal sinuses are never present.

SPHENOIDAL SINUSES

Are usually asymmetric.

SPHENOIDAL SINUSES

Lie below the sella turcica and extend between the dorsum sellae and posterior ethmoidal air cells

FRONTAL SINUSES

2nd largest sinuses, paired and are located between the tables of the vertical plate of the frontal bone

FRONTAL SINUSES

One or both may measure approx. 2-2.5 cm in vertical or lateral dimension

ETHMOIDAL SINUSES

Located within the lateral masses of the labyrinths of the ethmoid bone.

Anterior and middle

____ vary in number from 2-8, and opens into the middle nasal meatus.

ETHMOIDAL SINUSES

Divided into 3 groups: (anterior, middle, and posterior)

Posterior cells

___ vary from 2-6 or more

½ to 1 inch posterior to the outer canthus

LATERAL PROJECTION R and L Position

IR: 8X10 CW

Center the cassette approximately

Perpendicular

Entering the patient’s head ½ to 1 inch posterior to the outer canthus farthest from the IR

LATERAL PROJECTION R and L Position

IR: 8X10 CW

CR/RP:?

LATERAL PROJECTION R and L Position

A Lateral projection shows the AP and superoinferior dimensions of the PNS, their relationship to surrounding structures, and the thickness of the outer table of the frontal bone

72-inch

When the lateral projection is to be used for preoperative measurements, it should be made at a ___ SID to minimize magnification and distortion

dorsal decubitus position

If the patient is unable to assume the upright body positions, a lateral projection can be obtained using the

15 degrees

Frontal and (Anterior) Ethmoidal Sinuses Modified Caldwell

IR: 10 X 12 inch LW

Tilt the vertical grid device down so that an angle of

OML forms perpendicular to the plane of the IR

Frontal and (Anterior) Ethmoidal Sinuses Modified Caldwell

IR: 10 X 12 inch LW

LP:?

Perpendicular

to exit the nasion

Frontal and (Anterior) Ethmoidal Sinuses Modified Caldwell

IR: 10 X 12 inch LW

CR/RP:?

OML forms an angle of 15 degrees

Frontal and (Anterior) Ethmoidal Sinuses True Caldwell

IR: 10 X 12 inch LW

LP:

Frontal and (Anterior) Ethmoidal Sinuses Modified Caldwell or True Caldwell

Frontal sinus lying superior to the frontonasal suture Anterior ethmoid cells lying on each side of the nasal fossas and inferior to frontal sinuses; and sphenoidal sinus projected through the nasal fossas just inferior to or in between the ethmoidal air cells

Waters method

is to hyperextend the patient’s neck just enough to place the dense petrosae immediately below the maxillary sinus floors

inferior portions of the maxillary sinuses

When the neck is extended too little, the petrosae are projected over the

maxillary sinuses

antral floors

When the neck is extended too much, the ____ are foreshortened and the ___ are not demonstrated.

OML 37 degrees

MML is approximately perpendicular to the plane of IR.

MAXILLARY SINUSES PARIETOACANTHIAL PROJECTION WATERS METHOD

IR: 8 X 10 inch

LP:?

Perpendicular

Exiting acanthion

MAXILLARY SINUSES PARIETOACANTHIAL PROJECTION WATERS METHOD

IR: 8 X 10 inch

CR/RP:?

MAXILLARY SINUSES PARIETOACANTHIAL PROJECTION WATERS METHOD

The image shows a parietoacanthial projection of the maxillary sinuses, with the petrous ridges lying inferior to the floor of the sinuses. The frontal and ethmoidal air cells are distorted

foramen rotundum

The Waters method is also used to demonstrate the

open-mouth Waters method and lateral projections

may be the only techniques for demonstrating the sphenoidal sinuses

Perpendicular

Exiting acanthion

MAXILLARY & SPHENOIDAL SINUSES OPEN-MOUTH WATERS METHOD

IR: 8 X 10 inch

CR/RP:?

MAXILLARY & SPHENOIDAL SINUSES OPEN-MOUTH WATERS METHOD

demonstrates the sphenoidal sinuses projected through the open mouth along with the maxillary sinuses

Perpendicular

through the sella turcica, ¾ inch anterior to the level of the EAM

ETHMOIDAL& SPHENOIDAL Sinuses SUBMENTOVERTICAL PROJECTION

IR: 8 X 10 inch

CR/RP:?

ETHMOIDAL& SPHENOIDAL Sinuses SUBMENTOVERTICAL PROJECTION

demonstrates a symmetric image of the anterior portion of the base of the skull. The sphenoidal sinus and ethmoidal air cells are shown

Perpendicular

Exiting nasion

ETHMOIDAl, SPHENOIDAL AND MAXILLARY SINUSES PA PROJECTION

IR: 8 X 10 inch

CR/RP:?

Perpendicular

Intersection of MSP and MCP passing through sella turcica and the angles of the mandible.

SPHENOIDAL Sinuses VERTICOSUBMENTAL PROJECTION SCHULLER METHOD (obsolete)

IR : 8 x 10 inch CW

CR/RP:?

SPHENOIDAL Sinuses VERTICOSUBMENTAL PROJECTION SCHULLER METHOD(obsolete)

shows an axial image primarily of the sphenoidal sinus and also the posterior ethmoidal air cells, the maxillary sinus and the nasal fossae

Direct the CR to the MSP along a line extending from the sella turcica to the center of the open mouth. The caudal angulation of the CR depends on the shape of the face.

SPHENOIDAL Sinus AXIAL TRANSORAL POSITION PIRIE METHOD (obsolete)

IR: 8 x 10 inch CW 1 in 1 Bucky

CR/RP:?

SPHENOIDAL Sinus AXIAL TRANSORAL POSITION PIRIE METHOD (obsolete)

An axial image of the sphenoidal sinuses is projected through the open mouth. The maxillary sinuses and the nasal fossae are also demonstrated.

53 degrees

Ethmoidal, Frontal, and Sphenoidal PARIETO-ORBITAL PROJECTION SCHULLER METHOD(obsolete)

IR : 8 x 10 inch CW

LP: MSP forms ____

Perpendicular

Entering the upper parietal region and emerging at the midorbit resting on the grid device.

Ethmoidal, Frontal, and Sphenoidal PARIETO-ORBITAL PROJECTION SCHULLER METHOD(obsolete)

IR : 8 x 10 inch CW

CR/RP:?

Ethmoidal, Frontal, and Sphenoidal PARIETO-ORBITAL PROJECTION SCHULLER METHOD(obsolete)

This method shows a parieto-orbital projection of the ethmoidal aircells (posterior and anterior) and the frontal and sphenoidal sinuses and the optic canal. Both sides are examined for comparison.

AML forms approximately 20 degrees

MSP is rotated approximately 35 degrees.

Head is tilted so that the MSP is angled 20 degrees

Relationship of the Teeth to Maxillary Sinuses’ Floor PA AXIAL OBLIQUE PROJECTION LAW METHOD(obsolete)

IR : 8 x 10 inch CW

LP:

25 to 30 degrees cephalad

Enters posterior to the uppermost angle of the mandible and emerges from the opposite maxillary sinus

Relationship of the Teeth to Maxillary Sinuses’ Floor PA AXIAL OBLIQUE PROJECTION LAW METHOD(obsolete)

IR : 8 x 10 inch CW

CR/RP:?

Relationship of the Teeth to Maxillary Sinuses’ Floor PA AXIAL OBLIQUE PROJECTION LAW METHOD(obsolete)

PA Axial oblique projection of the floor of the maxillary sinus (antrum) is seen, showing its relationship to the teeth, from the molars to the canine. Both sides are examined for comparison.