10 - Canine and Feline dental disease Flashcards
Know your tooth surfaces!
Buccal / labial / vestibular
Lingual
Palatal
Mesial
Distal
See pic!!!
Describe the “labial orientation / mounting” system
- Embossed dot on corner of image: Convex towards tube, concave away from tube. ALWAYS POSITIONED ROSTRALLY
- Maxillary teeth face ventrally; mandibular teeth face dorsally
- Present as if patient facing you: If caudal (distal) structures are to the left = right arcade (and vice versa)
- NEVER MIRROR OR FLIP AN INTRAORAL RADIOGRAPH, not true when using near parallel technique.
Which teeth in the dog and cat have three roots?
Dog: Maxillary fourth premolar; maxillary first and second molars = 108/208; 109/209; 210/310
Cat: Maxillary fourth premolar = 108/208
What is the main constituent of the opaque structures of the mature crown?
Dentin
How thick is enamel typically in the dog / cat?
Dog: <0.5mm
Cat: <0.2mm
Dental anatomy: learn picture!
Name one place where enamel is more prevalent in canine teeth
Low rounded cusps of the maxillary first molar
Which component of teeth comprises 20-30% tubules?
Dentin
What does cervical burnout describe?
Artefact: Diffuse lucent area in cervical region. Due to overexposure on mesial / distal aspects between edge of enamel cap and alveolar ridge
=> Incorrect dx of resoptive lesions or caries
What does cementum look like radiographically?
Not normally visualised due to low contrast with dentin
How frequently are apical delta identified in canine teeth? And non apical root canals?
Apical delta: Approximately 70% of teeth
Non apical (lateral) canals: 2.5%
=> between 5-20 ramifications within a given delta
Where / what is the lamina dura?
Opaque line around alveolus / tooth socket.
=> not more mineralised, just relates to projection
What may cause a double periodontal ligament space and lamina dura?
Convexity on the surface of the root
Name the bones of the skull / face!
Where are the following structures identified?
1) Palatine fissures
2) Incisive canal
3) Infraorbital foramen
4) Infraorbital canal
1) Palatine fissure: Large opeingns caudal to 3rd incisor
2) Incisive canal: Small opening lcoated at palatel suture linecaudal to central incisors
3) Intraorbital foremen: Infraorbital nerve and vessels. Junction where zygomatic arch joints maxilla
4) Canal: Extends caudally from foramen (short in cats, can have double canal)
Know the anatomy of the mandible!
How many processes does the mandibular ramus have?
What inserts on each process?
1) Coronoid process: Temporal muscle
2) Condyloid process: Forms TMJ
3) Angular process: Massester and medial pterygoid
Desscribe normal variants of the mandibular symphysis
1) Narrow in larger breed dogs
2) Wider with advanced age
3) Wider with smaller breeds, especially with brachys
4) Geriatric felines; Can be ossified
Where are the. mental foramen found?
1) Rostral: smallest, vetnral to area between 1st and 2nd mandibular incisors
2) Middle: Largest, ventral to area between 1st and 2nd premolars
3) Caudal: Between roots of third premolar or absent.
What type of teeth do the cat, dog and horse have?
Diphyodont - permanent and deciduous pairs
When is a tooth considered “persistent deciduous tooth”?
If a permanent tooth is fully erupted and deciduous counterpart still present
Deciduous dental formulas (dog /cat):
Remember:
- No deciduous molars in dog or cat
- No deciduous first premolars in dog
- Deciduous teeth have same appearance as tooth erupting distal to it
- Deciduous premolars erupt buccal
- Deciduous max canines are distal, mand canines are labial to permanent
Permanent dental formulas:
At what age does apex closure of teeth occur?
What features can be used to age teeth?
Dog: 7-10mo
Cat 7-11mo
=> Canines close later, molars close earlier
Aging:
- Secondary dentin laid down progressively, so narrowing of pulp cavity.
- Increased opactiy and coarseness of trabecular bone of alveolus and less distinct lamina dura
What is hypercementosis?
- Cemental dysplasia (adaptive change) in periodontal ligament -> inc cementum thickness of root surface, affecting apical third most commonly.
=> not significant unless periapical lucency or other signs of pulpal pathosis
Approximate eruption times
At what age can permanent teeth be radiographically evaluated?
12 weeks - crowns calcified
Common sites of hypodontia?
Small breed dogs: Mandibular second molar
Brachys: Crowded, rotated or absent premolars
Where are supernumerary teeth most commonly seen?
Incisors, premolars
List 5 causes of defects in formation, mineralisation or or maturation during tooth development
Trauma,
inflam/infec
Drugs
Nutrition
Metabolic
Define concresecense and germination / twinning
Both FUSION of two adjacent teeth
Concresence: United by cementum only -> abdnormal pulp cavity radiographically
Germination: Two crowns from one root
Fusion of multirooted teeth more common dog than cat
Incidence of supernumerary roots?
In dogs and cats. BUT RARE IN DOGS (3% incidence)
Dogs:
- MAX>MAND
- 3rd premolar (44%) and first premolar (33%)
Cats:
- Max 3rd premolar (10% incidence)
What is the most common tooth abnormality in the dog?
Dilaceration
What is Dens in dente (dens invaginatus)?
- Infolding of developing tooth -> periodontal / endodontic involvement
=> Usually with convergent roots and a coronoal displacement of the floor of the pulp chamber at the furcation region
What is the most common clinical dental abnormality occuring in dogs and cats?
Periodontal disease!
What 4 structures constitute the periodontium?
Attaches tooth to the jaw!
Gingiva
Periodontal ligament
Cementum
Alveolar bone
List 7 descriptors of periodontitis
Alveolar marginal bone loss
Horizontal bone loss
Vertical bone loss
Combined (horizontal and vertical) bone loss
Furcation exposure
Furcation involvement = loss of bone between roots
Widening of periodontal ligament space
List 3 common complications of periodontal disease. And one less common
- Endodontic disease
- External root resorption
- Weakness / fracture of mandible
- (Oronasal fistula)
What is the common statement in veterinary dentistry!
85% of dogs and cats > 6yrs have periodontal disease (Inc gingivitis and alveolar bone loss)
What is the difference between abrasion and attrition?
Abrasion: Gradual wear against external source e.g. foreign objects, allergic derm
Attrition: Due to wear against teeth, commonly malocclusion
What are caries? Where do they commonly develop? Why are dogs not predisposed (5% incidence / never reported in cats?
- Bacterial infection starting on tooth surface, extending to pulp
- Most common sites:
pits/fissures on molar occlusal surfaces (Type 1)
Developmental groove of max 4th premolar
Distal cusp mandibular first molar
- Conical shape (molars more susceptible), and more alkaline saliva pH (7.5 vs 6.5) buffer to acids
What are clinical signs of endodontic disease?
Fracture with pulpal exposure
Discoloured tooth
Intraoral draining fistula (parulis)
Extraoral draining fistula
=> Definitive dx can be difficult as unable to reliably test pulp in animals
In the absence of radiographic evidence of disease, what percentage of teeth had histologically confirmed periodontal disease?
40%!
*Rx has POOR PPV for periapical disease*
List 7 radiographic signs of endodontic lesions in periapical tissues:
- Periapical widening of periodontal ligmanet space / apical oedema (apical peridontitis)
- Loss of lamina dura in peripaical region / lateral canals (if present)
- Diffuse periapical luceny -> may reflect abscess
- Well-defined periapical lucency -> more chronic lesion e.g. cyst / granuloma
- Sclerosing osteitis (inc opacity surrounding periapical lucency
- Change in periapical trabecular bone (sinus tract or parulis)
List 5 radiographic endodontic lesions of the tooth
- Periapical root resorption
- Internal surface resorption
- External root resorption
- Pulpal necrosis (wider root canal)
- Pulpitis (maturation of tooth)
What is a chevron lucency?
- Artefactual lucency, commonly dog canines and max incisors. Due to trabecular bone / vascular channels.
What is condensing osteitis / focal sclerosing osteomyelitis? How does it differ from osteosclerosis?
- Inflam condition -> focal bony reaction due to loq grade inflamm stimulus of non-vital tooth.
=> Well-defined opacity of variable size adjacent to and associated with apex that has widened ligmanet or periapical lucency
=> DISTINGUISHING FEATURE -> TOOTH ALWAYS NON-VITAL
What are the features of osteosclerosis?
- Benign bony proiferation, not associated with endodontic disease
- Opacities usually <1cm, circular
Learn stages (severity) and types (location) of feline resorptive lesions
*See text in thrall for details*
Regarding resorptive lesions:
Which features are associated with increased incidence in cats (x2)?
Reported in how many dogs?
- Older age and asian short-hair (siamese) breed
- 54% dogs, 11% teeth. Slower progression, less associated tooth loss
- > Age and BW in dogs assocaited with external replacement resoption
=> Most commonly frst max premolar, second mand premolar.
What % of discoloured teeh in dogs with pulpitis become non-vital?
92%
List 6 classifications of tooth fracture
- Enamel infarction:
=> incomplete fracture/crack in enamel, no loss of tooth substance
- Enamel fracture:
=> as above, loss of substance
- Uncomplicated crown fracture:
=> no pulpal involvment
- Complicated crown fracture:
=> pulpal involvement
- Complicated crown-root fracture:
=> Pulpal involvment
- Root fracture
What are odontogenic cysts? Where are they found?
List 5 types.
Which dogs overrepresented?
Epithelium-lined concavities, found on tooth bearing surfaces of mand / max
Dentigerous; eruption; periapical; odontogenic; lateral periodontal / radicular cysts
Can be inflammatory or developmental
Can undergo malignant transformation, and malignant neoplasia can be cystic. Hard to distinguish.
44% are incidental!
59% of cases are brachycephalics (pugs and boxers overrepresented
What is the most common odontogenic cyst in dogs?
Dentigerous cysts
Commonly young, and brachys
Describe rx appearance of dentifgerous cyst
Well demarcated, uni/multilocular lucency centred on crown of unerupted tooth, and attached to cementoenamel junction
Tooth often displaced.
Well defined cortical bone expansion may occur
Occasional root absoprtion of adjacent teeth
What is an eruption cyst?
Benign soft tissue cyst, accompanying an erupting primary or permanent tooth
Rx: Difficult to distinguish cystic space as both cyst and tooth are in soft tissues.
Yorkies with unerupted teeth at 9-10mo overrepresented
What is a periapical cyst?
Inflammatory cyst, associated with pre-existing periapical granuloma of a non-vital tooth
=> Epithealial proliferation.
Rx: Lucent, well defined round / oval, unilocular, periapical lesion, <1cm. CANNOT differentiate from periapical granuloma.
May resorb tooth, displace teeth, cause root resorption.
What is a lateral periodontal / radicular cyst?
Discovered in lateral periodontal region of vital tooth. Most commonly max canines of the dog
Rx: Well defined, circumscribed, round to ovoid, lucent lesion with sclerotic margin, pregerntiall localised between apex and cervical margin of tooth. Mostly unilocular. but polycystic variant exists.
What is an odontogenic keratocyst (canine odontogenic parakeratinised cyst)?
Contains viscous or caseous material derived from epithelial lining.
MINI SCHNAUZERS
AGGRESSIVE and DESTRUCTIVE behaviour, tend to recur. No evidence of metastasisyet reported
EXCLUSIVELY MAXILLA, fully erupted vital teeth
Rx: extensive inter-radicular expalnsion, cortical thinning, displacement of teeht
What does epulis mean?
ONLY MEANS On the gingiva .
Can be cyst or tumour!!
What are the two most common type of odontogenic tumour in the dog?
Acanthomatous ameloblastoma (Acanthomatous epulis)
Peripheral odonogenic fibroma (Fibromatous epulis)
What is an ameloblastoma?
EPITHELIAL
Ectodermal origin, benign neoplasm
Central (less common):
- Within cortical bone -> “soap bubble”
- Displacement of teeth without resorption
Peripheral / acanthomatous (most common odontogenic tumour)
- Aggressively invades bone
- 45% of odonotgenic tumours in dogs
- ROSTRAL MANDIBLE most common
- Rx: bony infiltration, extensive destruction, displacement of teeth
What is an amyloid-producing odontogenic tumour?
EPITHELIAL
RARE
Calcifying epithelial odontogenic tumour
- Bony or gingival expansion.
Rx: Locally invasive, may have cystic appearance
What is a feline-inductive odontogenic tumour?
EPITHELIAL
YOUNG CATS (8-18mo)
Raised submucosal soft tissue mass, typically rostral maxilla
No capsule, lesion invases bone
What is a peripheral odontogenic fibroma?
MESENCHYMAL
Slow-growing, benign neoplasm
Prliferation of fibrous tissue. Variety of osteoid, dentin or cemenum. like material.
Rx: Vary according to constituent substances
What is an odontoma?
MIXED MESENCHYMAL + EPITHELIAL
Benign, young cats and dogs (6-18mo)
May be associated with unerupted tooth, detigerous cyst, or normal tooth
Overrepresented in spaniels
Compound odontoma:
- Variable number of rudimentary tooth like structures
Complex odontoma:
- Opaque amorphous mass
