MANDIBLE, SINUSES, TEMPORAL BONE

Wynn Harrison, MEd

NEW WORDS

• Sinusitis: Inflammation of the sinuses

• Mucocele: Enlargement of the lacrimal sac. Cystic disease of the air cavities – causes erosion of the bone

• Retention Cyst: A cyst retaining the secretion of a gland, ie: mucosal or sebaceous cyst

Mastoiditis: Inflammation of the mastoid sinus

• Otitis: Inflammation of the ear: ie: otitis media; can be internal or external

• Acoustic Neuroma: benign tumor of the eighth cranial nerve. Symptoms = hearing loss, pain, headache, balance problems.

Mandible

AP Axial (Townes)

• OML = 30 degrees• IOML = 37

degrees

• Center mid-ramus

PA Mandible

• OML perpendicular to IR

• Center mid-mandible

Axiolateral Mandible

• Head tilt 15 degrees

• CR 15 degrees cephalic

SMV Mandible

• IOML parallel to IR and perpendicular to CR.

• Image mentum skimming frontal bone

• Merrill’s p. 389-390

Temporomandibular joints

Cone-Down of TMJ

• Relaxed Lateral with 15 degree caudal angulation

Merrill’s p. 396

Schullers Projection

• The Schullers Projection can be used to evaluate the temporal mandibular joints and mastoid air cells and inner ear.

Schullers Protection for TMJ• Open and closed

mouth view are taken of both TM joints.

• The TMJ closest to the Bucky will be the one seen at the center or top of the film.

• Accurate positioning is essential to being able to compare joints.

TMJ Syndrome

• Clicking, pain in TMJ• May indicate dysfunction of the

TMJ• Caused by inflammation, stress,

muscle spasm, etc.

Paranasal Sinuses

Lateral Sinus

Sinuses: Caldwell

Frontal

Ethmoid

Maxillary

Water’s view (sinuses)

Maxillary Sinus

Petrous Pyramids

What sinuses can you see?

Waters Projection

• Waters projection demonstrates:• Cloudy maxillary

sinuses worse on left.

• Sinus infection that needed antibiotics.

SMV - Sinuses

• Demonstrates sphenoid sinus

• Merrill’s p. 418

Temporal Mandibular Bone

• Law Method• Shuller Method• Stenver’s Method• Arcelin Method• Mayer Method• Hickey Method

• These projections will not be on your boards … but review Merrill’s p 430-452

PATHOLOGY

Fracture to Mandible and Zygomatic Arches

Mandibular Ramus Fracture

Bilateral Fractures of the Mandible

Film critique

Critical thinking