VTNE Dentistry: Dental Formulas, Triadan Numbering and the COHAT in 10 Scored Items

Dentistry is one of the small VTNE domains, and it's the one many candidates see least in daily work. It rewards exact recall: how many teeth, which number names which tooth, and what comes first in a cleaning. Every clinical statement below comes from the Merck Veterinary Manual, the American Veterinary Dental College (AVDC) or AAHA's 2019 dental guidelines, all read on November 6, 2026; your program's texts may phrase some points differently.

What the VTNE Dentistry domain covers

The 2023 content outline, printed in AAVSB's candidate handbook, gives Dentistry 10 scored items, 7% of the exam, and four task statements, paraphrased:

• A. Apply anatomy, physiology and pathophysiology to dentistry
• B. Prepare and maintain the environment, equipment, instruments and supplies for the dental team and patient
• C. Perform a comprehensive oral health assessment and treatment (COHAT), including scaling and polishing, by hand and by machine
• D. Produce diagnostic dental radiographs

Three of the outline's knowledge statements belong here: dental procedures (it names cleaning, floating, charting, preventive procedures and dental imaging), dental equipment, instruments and supplies, and safety considerations for dental procedures. AAVSB had announced no new outline as of November 6, 2026.

Tooth anatomy and the words the VTNE expects

The Merck Veterinary Manual's page on dentition and dental nomenclature, last reviewed in July 2026, describes a tooth from the inside out:

Two classifications come up in questions about species:

• Crown type. Dogs and cats are brachydont (short crowned). Horses and ruminants are hypsodont: long crowned, with teeth that keep erupting
• Tooth generations. Most mammals are diphyodont, with a deciduous set replaced by a permanent set

The AVDC nomenclature settles the vocabulary. "Deciduous" and "permanent" are the correct terms, and "primary" is acceptable with clients. A deciduous tooth still present when it should have been shed is a persistent deciduous tooth, often called retained. For surfaces and directions:

• Vestibular faces the vestibule or lips; buccal and labial are accepted alternatives
• Lingual faces the tongue; palatal can be used for maxillary teeth
• Mesial is the surface toward the first incisor, and on the first incisor the one next to the midline
• Distal is the opposite surface

AAHA's guidelines add the term that most dental disease questions turn on: the periodontium is the tooth's support, made of the periodontal ligament, gingiva, cementum and alveolar bone. Gingivitis is inflammation of the gingiva; periodontitis is the destructive loss of those supporting structures.

Dental formulas for dogs and cats

A dental formula counts the teeth on one side of the mouth, upper over lower, and doubles the result. From Merck's table of dental formulas:

I is incisor, C canine, P premolar and M molar; the D marks a deciduous tooth. To check a formula, add the top numbers, add the bottom numbers and double the sum. For the adult dog: 3 + 1 + 4 + 2 = 10 upper teeth per side and 3 + 1 + 4 + 3 = 11 lower, so 21 per side and 42 in all. For the adult cat: 8 upper and 7 lower per side, 15 per side, 30 in all.

Points from the same table and page that make good exam material:

• There are no deciduous molars. Neither deciduous formula has an M
• The dog's 42 break down into 12 incisors, 4 canines, 16 premolars and 10 molars
• Cats vary. Merck notes that the maxillary second premolar and the maxillary first molar can be absent in some cats
• Other species. The table also covers the horse, cow, sheep, goat and pig. Its notes say canine teeth usually appear only in male horses, that small first premolars called wolf teeth are often present, and that the canine of domestic ruminants has commonly been counted as a fourth incisor

Formulas and tooth numbers are flashcard material, and the 600 flashcards planned for full VTNE prep include Triadan numbers. Until those open, a handwritten set works just as well.

The modified Triadan system: reading a tooth number

The AVDC calls the modified Triadan system the tooth numbering system of choice in veterinary dentistry, and accepts anatomical names alongside it. Each tooth gets three digits. Merck explains them this way:

The first digit is the quadrant, counted clockwise as you face the animal.

The last two digits are the tooth, counted from the midline. Three anchors are worth memorizing: the central incisor is 01, the canine is 04 and the first molar is 09. In a dog, the premolars fill 05 to 08, the maxillary molars are 09 and 10, and the mandibular molars run to 11.

Missing teeth are skipped, not renumbered. That rule produces the cat's gaps:

• The tooth behind a cat's maxillary canine is the second premolar, 106 or 206; there is no 105 or 205
• The two premolars in a cat's lower jaw are 07 and 08, so 307 and 308 on the left and 407 and 408 on the right
• A cat has one molar in each quadrant: 109, 209, 309 and 409

Worked examples: tooth 304 is the left mandibular canine, 108 is the right maxillary fourth premolar, and 409 is the right mandibular first molar. In a horse, Merck's example is 306, the left mandibular second premolar.

Merck's dog dentition figure also gives root counts, which matter when you read a radiograph:

The COHAT, in AAHA's order

AAHA's 2019 Dental Care Guidelines for Dogs and Cats spell out COHAT as comprehensive oral health assessment and treatment, and define a professional dental cleaning as scaling above and below the gum line, polishing and an oral examination under general anesthesia. Their list of essential steps starts like this, paraphrased:

1. Examine the conscious patient before anesthesia, for a first read of periodontal disease.
2. Radiograph the whole mouth of the anesthetized patient with intraoral film or an intraoral digital system.
3. Scale above and below the gum line. Use a hand scaler above it and a curette below it, or a powered ultrasonic scaler followed by a curette. AAHA says not to use a rotary scaler, which roughens enamel.
4. Polish the crowns with a low-speed handpiece, prophy angle and cup at no more than 3,000 rpm, using prophy paste or fine-grit pumice. Disposable prophy angles and single-use paste prevent cross contamination.
5. Probe and chart after scaling and radiographs. Each tooth is probed in at least six places, and AAHA gives normal depths of no more than 2–3 mm in a midsized dog and 1 mm in a midsized cat.
6. Irrigate below the gum line to clear debris and paste, then inspect for calculus that was missed.

The later steps are the veterinarian's treatment decisions. AAHA stages periodontal disease from PD1 (gingivitis) through PD2 (less than 25% attachment loss) and PD3 (25–50%) to PD4 (more than 50%).

Four points from the same guidelines fit the outline's safety and scope statements:

• Why a curette goes below the gum line. Its heel and toe are rounded, which makes it less traumatic to soft tissue than a sickle scaler
• Why anesthesia is required. AAHA says that without general anesthesia the disease can't be accurately diagnosed or treated, pain can't be addressed and the airway can't be protected; removing only the calculus above the gum line is cosmetic
• What a technician does. In AAHA's description, a credentialed technician examines the mouth, dictates charting, takes the radiographs and performs the cleaning. Extractions are oral surgery and aren't a technician's task, and supervision follows each state's practice act
• Mouth gags. AAHA says spring-loaded mouth gags must be avoided because they may compromise blood flow, and that a mouth prop, if one is needed, shouldn't open the mouth fully

AAHA also says every anesthetized patient should be intubated to protect the airway, which is where this domain meets the next: the VTNE anesthesia guide covers the cuff check and extubation after a dental procedure. To test the sequence rather than reread it, 105 Dentistry practice questions, each with an explanation, are planned for full VTNE prep; none of it is on sale yet.

Dental radiographs, instruments and operator safety

Task D is producing diagnostic dental radiographs, and AAHA's guidelines recommend full-mouth intraoral radiographs for dental patients. Their radiation safety points are specific:

• Wear protection. A lead shield or apron, a thyroid shield and a radiation dosimeter
• Know the three sources. The primary beam, scatter radiation and leakage from the tube head
• Stay out of the primary beam, and don't touch the tube head or housing during an exposure
• Reduce scatter by standing at least 6 feet from the source, at a 90–135 degree angle from the path of the primary beam
• Have leakage tested on a regular schedule by a licensed professional

For task B, the environment and instruments, AAHA's requirements are:

• A dedicated space. Dental work contaminates its surroundings, so it belongs in a low-traffic area separate from the sterile surgical suite, with ventilation, anesthetic scavenging, good lighting and a table that drains
• Clean instruments every time. Dental instruments are cleaned and autoclaved between uses and stored sterile, and single-use items are discarded after each patient. The VTNE surgical nursing guide covers sterilization itself
• Protect the operator. Scaling and drilling aerosolize bacteria and debris, so AAHA calls for mouth, respiratory, skin, eye and ear protection, and notes that rinsing the mouth with a chlorhexidine solution before scaling reduces bacterial aerosol
• Mind ergonomics. Proper seating, and instruments placed within easy reach at working height

What this guide leaves out: radiographic positioning techniques, dental charting abbreviations, tooth resorption and other pathology, and floating and the rest of large-animal dentistry. None of the sources opened for this guide teaches them in a form that could be checked here. AAVSB's study page links its textbook reference list for those topics.

Two VTNE-style dentistry questions, written by Passy

These are original practice questions, not VTNE items.

1. A dog's dental chart records a fracture of tooth 208. Which tooth is it?

• A. The right maxillary fourth premolar
• B. The left maxillary fourth premolar
• C. The left mandibular first molar
• D. The left maxillary first molar

Answer: B. The 200 quadrant is the left maxilla. Counting from the midline, the canine is 04 and the four premolars are 05 to 08, so 08 is the fourth premolar. Option A is 108, C is 309 and D is 209.

2. In AAHA's sequence for a dental cleaning, when is each tooth probed?

• A. On the conscious patient, before anesthesia
• B. Under anesthesia, before any scaling, so calculus marks the pockets
• C. Under anesthesia, after scaling and full-mouth radiographs
• D. Only on teeth that look abnormal on radiographs

Answer: C. AAHA places the periodontal probe after scaling and radiographs, with each tooth probed in at least six places and abnormal findings charted. The conscious exam in option A is a visual first step, not probing.

Studying the VTNE Dentistry domain

As a Passy suggestion, give Dentistry about its share of your hours and spend them on recall. Write the four formulas from memory, then number a blank dog and cat chart quadrant by quadrant until the cat's gaps stop catching you. Learn the cleaning steps in order, with the reason for each. The VTNE study plan guide puts the domain in week 6 of an 8-week schedule, next to Laboratory Procedures and Diagnostic Imaging.

Ten items is 7% of the score, the same weight as Emergency Medicine/Critical Care or Pain Management/Analgesia, so it's worth more than a skim. The VTNE format guide shows how all 10 domains are weighted. When checkout opens, full VTNE prep planned for launch lets you practice one domain at a time or mix all ten, and the free VTNE practice questions are a mixed set you can try now.