Dental Radiology

What we’ll be covering today Tooth anatomy Dental formula Nomenclature Number of roots Parallel technique Bisecting angle technique

anatomy Crown supragingival Root subgingival Apex - tip of the root Pulp chamber inner content of tooth from crown to root Dentin surrounds pulp chamber Enamal outer covering of crown Cementum outer covering of root Peridontal ligament

anatomy 4 basic types of teeth Incisors Canine Premolar teeth Molars

Sides of the teeth Every tooth has 5 sides Occlusal - Mesial – Distal – Opposite of mesial Buccal – Lingual or Palatal -

dental formula Illustrate how many of each tooth type the animal has Presented in fractions Maxillary/mandibular

cAnine dental formula Deciduous teeth Permanent teeth 2x(i3c1p3m0)/(i3c1p3m0)=28 total teeth Permanent teeth 2x(i3c1p4m2)/(i3c1p4m3) = 42 total teeth Deciduous teeth fully erupted by 6 weeks of age Permanent teeth all erupted by 6 months Breed differences

When do puppy teeth fall out Incisors first Canines next Premolars last Molars erupt

Feline dental formula Deciduous teeth Permanent teeth 2x (i3c1p3m0)/(i3c1p2m0) = 26 total Permanent teeth 2x (i3c1p3m1)/(i3c1p2m1) = 30 total Missing 1st premolar in maxilla Missing 1st and 2nd premolar in mandible Deciduous teeth erupted by 6 weeks Permanent teeth erupted by 6 months

When do kitten teeth fall out Incisors first Canines next Premolars last Molars erupt Similar to puppies

nomenclature Once learned it is an easy way to identify teeth Makes medical charting easy because many record systems have templates built in Most used system is the triadan system

Triadan system Each tooth is labeled by a code of 3 numbers Can be used in any species However if a species is normally missing teeth you have to know this

Triadan system 1st quadrant upper right 2nd quadrant upper left 3rd quadrant lower left 4th quadrant lower right

Triadan system What about deciduous teeth?????

Why Dental radiology AAHA dental care guidelines for dogs and cats state that preoperative and postoperative dental radiographs are mandated for all extractions Evaluate tooth below gingiva Missing teeth/fractured teeth Proper extraction Follow pathology – oral tumors

Why dental radiology Resorptive lesions Epistaxis Trauma Nasal discharge Non-dental

safety Use positioning devices 6 feet away/lead barrier Ideally wear badges

Film system Film is colored on one side and white on the other Feel a bump This is on the white side and goes towards the tube Bump also goes Chair side processing Different sizes

digital More common Just like in traditional radiology the benefits are huge More costly

Diagnostic dental radiograph 2-3 mm of bone around apex of root Level of alveolar bone

Parallel technique Can ONLY be used on the Tube and film are parallel to one another

Bisecting angle technique Beam is aligned with the bisecting angle between tooth and film Human vs animal

Bisecting angle technique Used on all other teeth 2 things can go wrong with this method

positioning Practice, practice, practice, practice, practice, practice Textbook You tube Informative dvds from company

foreshortening

foreshortening Occurs when the x-ray beam is focused on the film to much

elongation

elongation Occurs when x-ray beam is directed towards the tooth angle too much

errors Root cutoff Cone cutoff Traditional film processing errors Light exposure Processing error Fingerprints Crescents Double exposure

3 simple rules If the image is foreshortened or elongated adjust the tube head If you cut the target off at the edge of the beam (cone cut), simply move the beam over toward the area of cone cut. If you cut the target off at the edge of the film (root cut), move the film over toward the area you cut off

When to take images Prior to cleaning If you clean first take films prior to polishing