Chapter 21-- Occlusal Radiography

the occlusal radiographic examination

a type of intraoral radiographic examination that is used to image large ares of the maxilla or mandible on a single film a supplementary technique to bitewing and periapical radiography has applications in the primary, transitional, and/or permanent dentition uses a film packet that is placed between the arches as if the pt were biting a sandwich (adult size 4, pedo size 2)

cross sectional

demonstrates the floor of the mouth commonly exposed on mn (NOTE: can be exposed on either arch; infrequently used for mx)

mx topographical head position

midsagittal plane is perpendicular to the floor ala tragus line is horizontal and parallel to the floor

why use occlusal radiography

there are many situations in which an occlusal radiograph can provide valuable diagnostic information

uses of occlusal radiographs

to evaluate the maxillary sinuses boundaries integrity

types of occlusal radiographs

two basic types topographical cross sectional

topographical

images the anterior tooth regions typically exposed on both mx and mn

types of image and projection techniques

there are different types of projections each projection type can be used with either the mx and mn arch and with either the primary or permanent dentition the different projections uses slightly different angulations or film placements and produce distinctly different images

basic principles of occlusal radiographic technique

film packet placed between arches (as if having a sandwich) white side toward (facing) arch being radiographed stabilized when pt "gently closes" on packet surface

types of occlusal radiographs

film placement for the basic types can be modified to achieve either a standard or lateral view of the arch

uses of occlusal radiographs

for growth and development information in pediatric pts when intraoral periapical radiographs are difficult to obtain questions doctors and parent need answers to.. does this pediatric pt have the perm lateral incisors? where will the left lateral erupt? might an orthodontic evaluation be indicated at this time

mn cross sectional film placement

insert film leaving only 5-6mm extending beyond facial surfaces of mn anterior teeth

mandibular topographical film placement

long edge in a side to side direction white to the bite insert film leaving only 5-6mm extending beyond facial surfaces of mn anterior teeth tell pt to gently close to retain position

mx topographical film placement

long edge in a side to side direction white to the bite insert film leaving only 5-6mm extending beyond facial surfaces of mx anterior teeth tell pt to gently close to retain position

mandibular topographical head position

midsagittal plane is perpendicular to the floor tilt chin up about 3" (so that occlusal plane is 45 degree above horizontal)

mn cross sectional head position

recline pt and positioni mn arch perpendicular to floor

mandibular topographical pediatric modifications

size #2 film tilt chin UP 3" vertical angulation -55 central ray point of entry: midline of chin between central incisors remember this one youll use it often in practice

mx topographical pediatric modifications

size #2 film vertical angulation +60 central ray point of entry: tip of nose between central incisors remember this one you'll need to use it in clinic

uses of occlusal radiographs growth and development information

this pediatric pt has severely affected primary anterior teeth some questions doctor and parent need answers to does the pt have the perm anterior teeth? how long are the primary roots? can the teeth be expected to exfoliate naturally in the near future? or is dental intervention required as soon as possible? have the succedaneous teeth already been affected by the infection in the primary teeth?

uses of occlusal radiographs

to determine the presence and extent of lesions such as cysts

uses of occlusal radiographs

to determine the presence and extent of lesions such as tumors or malignancies

uses of occlusal radiographs

to identify and locate foreign bodies in the soft tissues or bones of the jaws such as sialoliths (aka: salivary stones) int he ducts of the submandibular gland

uses of occlusal radiographs

to identify and locate teeth that are unerupted impacted or supernumerary

uses of occlusal radiographs

to supplement bitewing radiographic examinations when multiple periapicals are not indicated due to pt age and dentition status

uses of occlusal radiographs

to supplement bitewing radiographic examinations when periapicals are impractical due to pt size and ability to cooperate

comparison of mn projection type images

topographical cross sectional

mx topographical image and projection

used to examine the palate the anterior teeth of the maxilla

mandibular cross sectional image and projection

used to examine: floor of the mouth buccal/ lingual of mn

mandibular topographical image and projection

used to: examine the anterior teeth of the mandible

mx topographical lateral view (right or left) image and projection

used to: examine the palatal roots of the posterior teeth locate foreign bodies or lesions in the posterior maxilla

mx topographical PID placement and angulation

vertical angulation +65 central ray point of entry: bridge of nose between central incisors top edge of PID between the eyebrows (adult)

mandibular topographical PID placement and angulation

vertical angulation -55 central ray point of entry tip of chin between central incisors

mn cross sectional PID placement and angulation

vertical angulation 90 degree central ray point of entry: centered over film about 1" below chin