1: intraoral radiographic techniques

types of intraoral radiographs

periapical, bitewing, occlusal

periapical radiography

- more emphasis on the tooth apex and area around tooth apex
- generally, must record entire crown, root, and 2-3mm of periapical area

Bitewing radiography

- used to examine the crowns of both maxillary and mandibular teeth using one image
- ideal for evaluation of alveolar bone loss
- ideal for evaluation of inter-proximal surfaces of teeth for caries (especially in posterior teeth)

Full mouth series

provides a thorough examination of all the teeth and supporting structures
- FMX generally consists of 14-16 PAs and 4BWX

when to do vertical bitewings

for periodontal evaluation if bone loss is significant

types of image receptors

films
sensors
phosphor plates

projection techniques used for periapical radiographs

paralleling technique
bisecting technique

benefits of paralleling technique

minimal distortion

parallel technique

1) Long axis of tooth and film are parallel to eachother
2) The central ray is directed perpendicular to the long axis of the tooth and film

Bisecting angle technique

x rays are directed perpendicular to the imaginary line bisecting the angle formed by the long axis of the tooth and the image receptor

correct vertical angulation results in...

an image identical to the tooth in dimension

indications for use of bisecting angle technique

- difficulty in positioning receptor parallel to teeth
- difficult anatomy
- shallow palate
- edentulous patients
- pediatric patients
- palatal tori/anatomical variations
- shallow floor of mouth
- severe gag reflex
- no sensor holder available

vertical angulation - paralleling technique

central ray is directed perpendicular to receptor and long axis of tooth

horizontal angulation - paralleling technique

central x ray beam must be directed through the interproximal contact areas

Maxillary central incisor PA should include

both central incisors
their periapical areas
open interproximal contacts

Maxillary lateral incisor PA should include

lateral incisor centered over the sensor

Maxillary canine PA should include

entire canine and its perapical area and open interproximal contacts

Maxillary premolar PA should include

distal third of canine, two premolars, and first molar

maxillary molar PA should include

all three molars and part of tuberosity

Mandibular central/lateral PA should include

all central and lateral incisors and their periapical view

mandibular canine PA should include

entire canine centered over the receptor and its periapical area
- open the interproximal contacts

mandibular premolar PA should include

distal third of the canine, two premolars, and first molar

mandibular molar PA should include

all three molars and its periapical area

what should you capture in premolar bitewings?

distal third of canine, premolars, first molar

in vertical angulation, what is acceptable?

positive angulation of 7-10 degrees

"A" error code

missing area due to incorrect sensor position - missing apex, periapical bone, part of the tooth and root, bone level

"B" error code

Beam angulation - incorrect horizontal beam leads to overlap of the interproximal contacts. Incorrect vertical angulation leads to elongation or foreshortening and missing anatomy

"C" error code

Cone cut - incorrect horizontal, vertical angulation. PID is not aligned with XCP ring