Dental charting in dogs and cats with AVDC abbreviations and indices

Before charting individual teeth

The cat-focused review in the Journal of Feline Medicine and Surgery (JFMS) describes four stages of oral examination:

1. A history.
2. An extraoral examination of the conscious patient.
3. An intraoral examination of the conscious patient.
4. A repeat examination in greater detail under general anaesthesia, with findings recorded on a dental chart [2].

The Ohio State handbook likewise has students evaluate oral and extraoral structures before the tooth-by-tooth portion begins [4]. Items assessed before charting individual teeth include:

• Signalment, diet, medications, prior dental procedures, and home care, which the JFMS authors list as history items [2]
• Facial symmetry, facial palpation, mandibular salivary glands, muscles of mastication, temporomandibular joint movement, nares, and breath odor [2]
• Facial bones, tongue and sublingual area, buccal folds, retropharyngeal area and tonsils, and local lymph nodes [4]
• Occlusion, which Merck notes is easiest to assess while the patient is conscious or sedated, before the endotracheal tube is placed [3]
• Radiographs. Merck reports that the 2019 AAHA Dental Care Guidelines "strongly recommends full-mouth intraoral dental radiography in all dental patients" [3]

The JFMS authors also wrote that "No endodontic examination is complete without dental radiographs" [2].

Tooth identification and numbering

• Numbering system. The AVDC accepts both modified Triadan numbers and anatomical names for recording each tooth. It notes that many leading journals require anatomical names in publications [1].
• Gaps for missing teeth. Under the AVDC convention, gaps are left in the numbering sequence where there are missing teeth. The AVDC's examples are that the first premolar in the feline left maxilla is 206 and that the two lower right premolars are 407 and 408 [1].
• Feline premolars. In the cat, the AVDC states that the tooth immediately distal to the maxillary canine is the second premolar, and the tooth immediately distal to the mandibular canine is the third premolar [1].
• Tooth count. The JFMS authors advise counting the teeth, giving 26 for a kitten and 30 for an adult cat. They also advise watching for supernumerary, persistent deciduous, and missing teeth during the count [2].
• Missing teeth. The Ohio State handbook circles missing teeth on the chart [4]. When no tooth is present and the history does not explain its absence, the JFMS authors advise radiographing the area to confirm the tooth's absence or whether it is retained subgingivally [2].
• Persistent deciduous teeth. The AVDC abbreviation for a persistent deciduous tooth is DT/P. The AVDC calls "persistent deciduous tooth" etymologically correct and notes that "retained deciduous tooth" can be confused with an unerupted deciduous tooth [1].

The AVDC explains that the Triadan system for animals uses three digits because many animals have more than nine teeth in a quadrant [1].

Periodontal findings for each tooth

Merck defines a dental chart as a graphical representation of the mouth that shows each tooth from occlusal, buccal, and/or palatal or lingual views [3]. Periodontal findings recorded for each tooth include:

• Probing depth. Merck lists 1 to 3 mm as normal in the dog and 0.5 to 1 mm in the cat [3]. The JFMS authors give healthy feline sulcus depths of 0 to 0.5 mm and treat anything deeper than 0.5 mm as attachment loss. They measure two or three sites on the buccal surface and two or three on the lingual or palatal surface [2]. These feline figures differ between the two sources.
• Gingival recession (GR). The extent is recorded alongside pocket depth [1][2].
• Bleeding. The JFMS authors use bleeding on probing and spontaneous bleeding as a guide to gingivitis severity and the gingival index [2].
• Stages. Periodontal disease stage, furcation stage, and mobility stage are listed in the table below [1].

Index	AVDC criterion [1]
PD0	No clinically evident gingivitis or periodontitis
PD1	Gingivitis only, no attachment loss, normal alveolar margin
PD2	Less than 25% attachment loss, or at most F1
PD3	25 to 50% attachment loss, or F2
PD4	More than 50% attachment loss, or F3
F1	Probe goes less than halfway under the crown
F2	Probe goes more than halfway under the crown, not through and through
F3	Probe passes through and through
M0	Physiologic mobility up to 0.2 mm
M1	Non-axial mobility over 0.2 mm and up to 0.5 mm
M2	Non-axial mobility over 0.5 mm and up to 1.0 mm
M3	Over 1.0 mm, or any axial movement

Merck describes F2 as the probe extending "approximately halfway" under the crown [3], while the AVDC wording is "greater than half way" [1]. The AVDC measures attachment loss in either of two ways [1]:

• By probing the clinical attachment level.
• Radiographically, as the distance from the cementoenamel junction to the alveolar margin relative to root length.

Whole-mouth indices

The AVDC separates three terms [1]:

• A stage tracks the extent of a likely progressive disease.
• A grade measures severity at diagnosis.
• An index is "a quantitative expression of predefined diagnostic criteria."

The whole-mouth indices described in the sources are:

• Calculus grade 0 to 3, per Merck. Grade 0 is no supragingival calculus, and grade 3 is heavy supragingival calculus with substantial subgingival deposition [3].
• Gingivitis grade 0 to 3, per Merck. Grade 2 includes bleeding on probing, and grade 3 includes spontaneous bleeding [3].
• Plaque index. The JFMS authors name the Logan and Boyce modification of the Turesky index as the most accepted method and describe it as using a disclosing solution [2].
• Calculus index. The JFMS authors name the Warrick Gorrel method, which scores the surface area covered by calculus [2].

The fetched JFMS text does not reproduce the numeric scales for the plaque or Warrick Gorrel indices. The authors note that plaque scoring is used in research and can also gauge how well home care is working [2].

Tooth lesions and their abbreviations

The Ohio State handbook links each lesion to its tooth with a line and an abbreviation [4]. To tell complicated from uncomplicated crown fractures, the handbook drags the explorer across the fractured surface. If the explorer tip goes into the pulp cavity or gets "stuck" or "catches" in the fractured surface, the fracture is charted as complicated [4].

Code	AVDC meaning [1]
T/FX/EI	Enamel infraction (crack with no loss of tooth substance)
T/FX/EF	Enamel fracture
T/FX/UCF	Uncomplicated crown fracture, pulp not exposed
T/FX/CCF	Complicated crown fracture, pulp exposed
T/FX/UCRF, T/FX/CCRF	Crown-root fracture without or with pulp exposure
T/FX/RF	Root fracture
RTR	Retained root or reserve crown
AB / AT	Abrasion (contact with a non-dental object) / attrition (tooth-to-tooth contact)
CA	Caries
E/H	Enamel hypoplasia
T/NV	Nonvital tooth
TR 1 to TR 5; T1 to T3	Tooth resorption stage; radiographic type
T/SN	Supernumerary tooth

• Tooth resorption. The AVDC stages run from mild hard tissue loss at TR 1 to TR 5, where only irregular radiopacities remain under complete gingival covering. The fetched AVDC page lists TR4a and TR4c as substages [1]. The JFMS authors state that treatment requires whole-dentition radiography to confidently classify the resorption lesions and to define whether an absent tooth has retained roots [2].
• Crowding. The Ohio State handbook charts this as CWD when two teeth share one gingival collar or there is no gingiva between two adjacent teeth [4]. CWD does not appear in the fetched AVDC text.
• Oral masses. The handbook notes OM with directional terms such as mesial buccal. It instructs that a mass not be touched with the probe and that a new sterile probe be used if it is [4]. The AVDC uses OM followed by a suffix for specific tumor types, such as OM/SCC [1].

Occlusion

• Abbreviation format. The AVDC abbreviates a malocclusion diagnosis as MAL plus the class number, then the specific abbreviation and tooth numbers. Its example is MAL1/CB/R202, and teeth sharing one finding are separated by commas [1].
• Classes. Class 1 is neutroclusion with malpositioned teeth. Class 2 is mandibular distoclusion, class 3 is mandibular mesioclusion, and class 4 is maxillomandibular asymmetry [1][3].
• "Wry bite." The AVDC calls "wry bite" non-specific and says "its use is not recommended" [1]. Merck still lists it as an alternative term for class 4 [3].