09 Occlusal radiograph exam

Question 1

occlusal radiographs

Answer 1

ancillary radiographs through the occlusal plane, supplement to periapicals, made on #4 film (3”x2.25”)

Question 2

occlusal radiograph selection criteria

Answer 2

precise location of roots or impacted teeth, localize foreign materials or soft tissue calcifications, patients with trismus (only opens few mm), evaluate maxillary sinus, examine cortical bone (thinning, cysts, neoplasms, etc.)

Question 3

anterior maxillary occlusal radiograph

Answer 3

patient sitting upright with ala-tragus line parallel with floor, film slid back in mouth until leading edge touches raphe bilaterally, +65degrees through bridge of nose, canine to canine of anterior palate with nasal fossa (+45degrees - elongation, +90degrees - foreshortened)

Question 4

posterior maxillary occlusal radiograph

Answer 4

patient sitting upright with ala-tragus line parallel with floor, film with emulsion (white) side up centered over arch of interest, back to raphe on that side, +60degrees through infraorbital foramen, visualize nasolacrimal canal, zygomatic process, maxillary sinus, cortices on side of interest

Question 5

anterior mandibular occlusal radiograph

Answer 5

patient upright with headrest tipped back, emulsion (white) side down centered over anterior mandible, -55degrees through chin tip, canine to canine, inferior cortex of mandible and genial tubercles

Question 6

posterior mandibular occlusal radiograph

Answer 6

patient laying back with headrest back, emulsion (white) side towards mandible, 0degrees perpendicular to film, visualize floor of mouth and posterior ridge on side of interest to 3cm of chin