ABRASION is the mechanical wearing of the crown by non-tooth structures.

ATTRITION is loss of tooth structure caused by tooth-to-tooth contact. Attrition can occur through the normal aging process (physiologic attrition), or through malocclusion (pathologic attrition).

ANTERIOR CROSSBITE is a condition where one or more of the mandibular incisors are positioned rostral to their maxillary counterparts.

APICAL refers to the area of the tooth toward the apex (root tip) or away from the incisal or occlusal surfaces.

ATTACHED GINGIVA covers the external aspect of the gingival sulcus between the marginal gingiva and alveolar mucosa at the mucogingival junction.

ATTACHMENT LOSS (ATTACHMENT LEVEL) is measured from the cementoenamel junction to the depth of the periodontal pocket. Attachment loss is the combination of the probing depth and gingival recession measurements.


BASE NARROW CANINES are lingually displaced mandibular canines caused by a too narrow mandible or persistent primary mandibular canines.

BRACHYCEPHALIC: is a head type typified by a short wide muzzle, e.g., Boxer, Bulldog, Pug, Shih Tzu, etc.

BRACHYGNATHISM (RETROGNATHISM) occurs where one of the jaws is caudal to its normal relationship with the other jaw. Mandibular brachygnathism (retrognathism, Class II occlusion) exists when the mandible is shorter than the maxilla.

BUCCAL pertains to the surface of the premolars and molars facing the cheek.


CALCULUS is mineralized material on the tooth surface.

CALCULUS INDEX (CI#) refers to the amount of calculus on a tooth.

  • CI 0 no observable calculus
  • CI 1 scattered calculus covering less than one third of the buccal tooth surface.
  • CI 2 calculus covering between one and two thirds of the buccal tooth surface with minimal subgingival deposition.
  • CI 3 calculus covering greater than two thirds of the buccal tooth surface and extending subgingivally.

CLEFT is a longitudinal fissure or opening in the marginal gingiva exposing the underlying tooth root.

COMPLICATED FRACTURE involves pulp in the fracture line.

CRAZE LINES are tiny cracks that affect only the outer enamel of the tooth. They do not extend into dentin. Craze lines are the result of “wear and tear” on teeth and need no treatment.


DEVELOPMENTAL DENTAL DISORDERS may be due to abnormalities in the differentiation of the dental lamina and the tooth germs (anomalies in number, size, shape) and/or to abnormalities in the formation of the dental hard tissues (anomalies in structure).

DEHISCENCE is the incomplete coverage by bone over an area of a root that includes the cementoenamel junction.

DENTIN is the main component of teeth. Dentin is normally covered by enamel on the crown and cementum on the tooth's root.

DOLICHOCEPHALIC is a head type: typified by a long, narrow face, e.g., Rough Collie, Borzoi, Doberman or Greyhound.


EMBEDDED tooth is an unerupted tooth covered with bone. ENAMEL is the hard covering of the crown.

ENAMEL is the hard covering of the crown.

ENAMEL DEFECTS are small pits or other malformations on the enamel surface.

ENAMEL HYPOPLASIA occurs when there are areas on the teeth without enamel (enamel is quantitatively defective resulting in enamel thickness variation).

EPULIS is a mass on the gingiva.


FACIAL is the part of the tooth that faces the lips or cheek.

FELINE ODONTOCLASTIC RESORPTION LESIONS There are five recognized stages (based on clinical and radiographic findings). and two types (based on radiographic findings) of feline resorption lesions.

  • Stage 1 (RL 1) extend into cementum only on the root surface. At one time, stage 1 referred to lesions that only involved enamel. The definition is outdated.
  • Stage 2 (RL 2) have destroyed a significant amount of dentin and cementum but has spared the pulp.
  • Stage 3 (RL 3) enter the pulp without extensive crown destruction.
  • Stage 4 (RL 4) have extensive root and crown damage
  • Stage 5 (RL 5) lack a clinical crown but root fragments remain on radiographs.
  • Type I lesions arise in the cervical area of the tooth and extend inward and/or up and down the root. Type I lesions are inflammatory in nature. Radiographically Type I lesions have relatively normal root structure.
  • • The more common Type II lesion begins subgingivally. Radiographically the roots appear to be resorbing. The periodontal ligament will not be readily recognizable due to ankylosis in Type II lesions.

FENESTRATION is a window of bone loss which exposes the root surface to the gingival or alveolar mucosa. The fenestration is bordered by alveolar bone on the coronal surface.

FREE GINGIVAL MARGIN is the coronal edge of the marginal gingiva.

FREEWAY SPACE is the space between the maxillary and mandibular premolar teeth cusp tips when the mouth is closed.

FURCATION INVOLVEMENT/EXPOSURE -the furcation is the area where multiple roots diverge from the tooth. Furcation involvement or exposure occurs secondary to periodontal disease. The degree of furcation disease can be recorded as grades:

  • F 1 (furcation involvement) is a depression in the furcation area that extends less than half way under the crown in a multirooted tooth.
  • F 2 (furcation involvement) exists when a depression in the furcation area extends greater than half way under the crown but not through and through.
  • F 3 (furcation exposure) exists when a periodontal probe extends “through and through” from one side of the furcation out the other.

FUSION is the joining of two tooth germs, resulting in a single large tooth. Fusion may involve the entire length of the teeth, or only the roots, depending on the stage of development of the teeth at the time of the union. Usually there will be two separate root canals. With fusion, the tooth count wil reveal a missing tooth when the anomalous tooth is counted as one.


GEMINATION is defined as an attempt to make two teeth from one enamel organ. This results in a structure with two completely or incompletely separated crowns with a single enlarged root and root canal. With germination the tooth count wil be normal when the anomalous tooth is counted as one.

GINGIVAL CLEFT is an area of isolated gingival recession occurring over a dehiscence of the bone covering the root.

GINGIVITIS INDEX (GI#) is the number assigned to designate the degree of gingival inflammation.

  • GI 0 normal healthy gingiva with sharp non inflamed margins.
  • GI 1 marginal gingivitis with minimal inflammation and edema at the free gingiva. No bleeding on probing.
  • GI 2 moderate gingivitis with a wider band of inflammation and bleeding upon probing.
  • GI 3 advanced gingivitis with inflammation clinically reaching the mucogingival junction usually with ulceration. Periodontitis will usually be present.

GINGIVAL RECESSION is a pathological movement of the gingival margin away from the tooth. This causes the root surface to be exposed. Gingival recession is measured from the cementoenamel junction to the gingival margin.

GINGIVAL HYPERPLASIA is the proliferation of the attached gingiva. Gingival hyperplasia is measured from the cementoenamel junction to the gingival margin.

GUM (TONGUE) CHEWERS LESIONS are areas of proliferative granulation tissue below the tongue in small animals that appear to pant frequently. The lesion is caused by the tongue's ventral surface area rubbing against the mandibular cheek teeth. Dogs with these lesions appear to chew gum.


IMPACTED is a dental disorder involving failure of a tooth to fully emerge through the gingiva.


LEVEL BITE exists when the incisor teeth meet edge to edge or premolars occlude cusp to cusp.

LYMPHOCYTIC PLASMATIC STOMATITIS SYNDROME (GINGIVOSTOMATITIS) is characterized by a generalized inflammation of the oral mucosa in cats.


MANDIBLE is the lower jaw bones.

MAXILLA is the upper jaw.

MARGINAL GINGIVA is the most coronal portion of the gingiva which lies passively against the tooth. The marginal gingiva forms the outer wall of the gingival sulcus.

MESATICEPHALIC is a head type of medium length and width of the muzzle e.g., most terriers, hounds, and retrievers.

MOBILITY of teeth exists from trauma, endodontic, and/ or periodontal disease. Mobility can be graded:

  • (M0) indicates no mobility
  • (M 1) indicates the tooth moves less than 1 mm when an instrument is applied to the crown
  • (M2) exists when the tooth is still firmly attached in the alveolus but moves greater than 1 mm laterally
  • (M3) occurs when the tooth freely moves in the alveolus laterally and apically.

MUCOGINGIVAL DEFECTS are deviations from the normal anatomic relationship between the gingival margin and the mucogingival junction (MGJ). Common mucogingival conditions are recession, absence or reduction of keratinized tissue, and probing depths extending beyond the MGJ.


OCCLUSAL is the articulating or biting surface of the tooth.

OPEN BITE occurs when part or all of the incisor teeth are prevented from contacting normally when the mouth is fully closed.


PARTIALLY ERUPTED TOOTH is a tooth that has failed to erupt fully into a normal position. The term implies that the tooth is partly visible.

PERIODONTAL DISEASE is graded or staged on the dental chart. Healthy gingiva can be graded as PD 0.

  • Stage 1 (PD 1) (gingivitis) appears as a redness of the gingiva and no attachment loss.
  • Stage 2 (PD 2) (early periodontitis) shows an increase in inflammation and edema. In stage 2 there will be less than 25% of support loss when probed.
  • Stage 3 (PD 3) (moderate periodontitis) occurs when there is a moderate loss of attachment or moderate pocket formation with between 25-50% support loss. Furcation exposure and mobility may be present. The gingiva will bleed upon gentle probing at this stage.
  • Stage 4 (PD 4) (advanced periodontitis) occurs when there is breakdown of the support tissues with severe (>50% support loss) pocket depth or recession of the gingiva.

PERIODONTAL POCKET is a gingival sulcus that has experienced an apical extension of the epithelial attachment.

PALATOGLOSSITIS (“faucitis”, caudal stomatitis) inflammation of caudal oral mucosa lateral to glosso-palatine folds (isthmus of the fauces) and tongue which occurs in some cases of LPGS.

PLAQUE is a mass of bacteria that are adherent to the enamel surface of the tooth.


  • PI 0 no observable plaque
  • PI 1 scattered plaque covering less than one third of the buccal tooth surface
  • PI 2 plaque covering between one and two thirds of the buccal tooth surface
  • PI 3 plaque covering >two thirds of the buccal tooth surface

POSTERIOR CROSSBITE occurs when one or more permanent maxillary posterior teeth occlude palatally rather than buccally with their mandibular counterparts.

PROBING DEPTH (POCKET DEPTH) is the measurement of the gingival sulcus or pocket as measured from the gingival margin to the apical limit of the sulcus or pocket. Depending on the tooth, probing depths greater than 4 mm in large dogs, 2 mm in small dogs, and 1 mm in cats are abnormal and should be charted.

PROGNATHISM is a forward relationship of one jaw relative to the other jaw. Prognathism should be qualified by the adjectives “maxillary” and “mandibular”. Mandibular prognathism (Class 3) has maxillary incisors occluding lingual or caudal to the mandibular incisors.

PULPITIS is the inflammation of the pulpal tissue, often discoloring the tooth.


SUPERNUMERARY tooth is any tooth in addition to the normal dentition primary or secondary.


UNERUPTED TEETH have not perforated the oral mucosa. Refers to a normal developing tooth, an embedded tooth, or an impacted tooth entirely covered by soft tissue and partially or completely covered by bone.

UNDER ERUPTED TEETH erupt far enough to break through the gingiva but a significant portion of the crown remains under the gingiva.


WEAR FACET is a localized worn area on a tooth often associated with malocclusion.

WRY BITE is a condition where one or more of the jaw quadrants are out of proportion to the other three, causing a deviation from the midline.

Table of Contents
Smile Book IV
Small Animal Dental Anatomy, Pathology, and Charting
Jan Bellows, D.V.M. Diplomate, American Veterinary Dental College
About The Author
Dental Charting
Normal Canine Dental Anatomy
Normal Feline Dental Anatomy
Congenital Dental Pathology
Periodontal Disease
Periodontal Examination
The Traumatized Tooth
Fractured Tooth Classification
Odontoclastic Resorption
Benign Oral Masses
Malignant Oral Masses
Drug Inserts

Check out the entire
Smile Book Series


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Jan Bellows, DVM
All Pets Dental Clinic
17100 Arvida Parkway
Weston, FL 33326
(954) 349-5800