Facial Mandible

 PA
Indications for imaging
Trauma

 

Anatomy  Demonstrated
 Mandibular rami and the body superimposed on the cervical spine.


Mandible PA Anatomy
Meschan, I. 1955 An Atlas of Normal Radiographic Anatomy Saunders, London

 

Basic Patient Position
Dentures and oral jewellery should be removed.
The patient sits erect facing the bucky, midsagittal plane in the midline of the film, coronal plane parallel to the film interpupillary line parallel to the floor. The chin is lowered to bring the orbital meatal line at 90 degrees to the film.


  Mandible PA Patient Position
Based on Movin & Karlsson 1975 Skeletal projections for Diagnostic Radiology Lippincott  

 
Radiation protection
Direct lead rubber thyroid protection advisable.

 
Central Ray
Dentures and oral jewellery should be removed.
The horizontal central ray is centered in the midline of the posterior neck surface to exit through the closed lips.

 
Exposure Factors
Kv mAS FFD (cm) Grid Focus AEC Cassette
80 12 100 Yes Fine No 18 x 24 cm

 
Evaluation of the Image
 ID and anatomical markers must be present and correct in the appropriate area of the film.
Optimal exposure should penetrate all the bone structures and contrast should be low enough to visualise fully the bone and soft tissue structures.
Limits of the examination, superiorly the TMJs, inferiorly the mandibular symphysis, laterally the skin surfaces of the mandible.
The mandible should be projected symmetrically about the midline, i.e. not rotated. the mastoid air cells should be projected minimally over the TMJs.



 Mandible PA Radiograph
Related Projections
Facial Bones OM
Facial Bones OM 30
Facial Bones Lateral
OPG
Mandible obliques
Additional modalities
CT