Dentition Flashcards

Question

Approximate tooth eruption times

Answer 1

All deciduous 6 weeks All permanent dog-7 months, cat 6 months

Answer 2

I 3/3 C1/1 P4/4 M2/3=42

Answer 3

Teeth found in carnivorous mammals designed for shearing and slicing meat

Answer 4

Cat I3/3 C1/1 P 3/2 M 1/1 x2 = 30

Answer 5

a biofilm on the teeth that is formed by bacteria colonizing the dental pellicle (the protein film on the surface of the teeth formed by saliva and food). The most important strategy in prevention of periodontal disease is plaque control. Mechanical prevention – chewing coarse textured food and tooth brushing. Inorganic substances from saliva are deposited into bacterial plaque and form calculus (commonly called tartar). The surface of calculus is readily colonised further by plaque.

Answer 6

The most common oral disease seen in small animals - very common in domestic carnivores. Possibly the most common disease in in small animal practice. First stage is gingivitis - inflammation of the gingiva Second stage - early periodontitis – inflammation of gingiva and periodontal ligament Third stage - further breakdown of support tissues, tooth mobility, tooth loss. Advanced periodontal disease in the upper dental arcade, especially of the canine teeth, can lead to oronasal fistulas.

Answer 7

Tooth decay-caries, caused by bacteria, much less common in carnivores Abscesses may result in periodontal disease or factures

Answer 8

Malocclusion – different head shapes – esp brachycephalic, but also sometimes seen in dolicocephalic breads. Prognathism = lower jaw too long (brachycephalic) Brachygnathism = lower jaw too short (dolicocephalic)

Answer 9

Radicular teeth have a true root and as such are a complete tooth with only a finite amount of wear. Aradicular teeth have no true root – are open rooted and can continue growing throughout the animals life. • Horses have radicular hyposodont teeth – i.e. they are long crowned but with true roots • Ruminants have brachydont incisors and canines and radicular hypsodont premolars and molars • Species with aradicular dentition include some lagomorphs and rodents (diverse species course)

Answer 10

2 x (I3/3, C0/0 or 1/1, PM 3/3 or 4/4, M3/3) = 36 to 44 teeth

Answer 11

• Radicular hypsodont dentition • Cellulose is digested in herbivores by micro-organisms in gut. Ideally this is made available by crushing and grating vegetation. This causes considerable wear so teeth designed to permit this. • Teeth continue to erupt through life. i.e. as the tooth wears it moves outwards and the bone grows underneath to fill in the socket (all lower teeth mandible, upper incisors, canines, UPM1, UPM2 and UPM3) or the maxillary sinus expands (UPM4, UM1-3 in teeth in the maxilla). • The cementum initially covers the crown and creates a ridging due to the different hardness of cement, enamel and dentine.

Answer 12

formed as a response to injury and is also found in some horse teeth

Answer 13

Due to incomplete occlusion. Occurs at around 5-7 years, may recur at 11-13years. Only present in 60% of horses NOT RELIABLE!

Answer 14

Galvayne’s groove Occurs in horses over 10 years. Half way down tooth at 15 years, fully down at 20, then starts to ‘grow out’. Again, not reliable

Answer 15

Premolars and molars (PM2 – M3) very similar to each other in the horse and form a continuous row both in the upper and lower dental arcades. • Usually referred to as ‘cheek teeth’ • 6 on the upper arcade (plus maybe a wolf tooth UPM1) • 6 on the lower arcade (LPM1 usually absent, if present may be unerupted) • Tooth attrition is approx. 2-3 mm of wear per year. • Each cheek tooth erupts with one large pulp cavity. As the horse ages these separate into between 5 and 8 separate pulp cavities with varying degrees of intercommunication.

Answer 16

The whole upper tooth row is slightly curved out toward the cheek, the lower tooth row is straighter. Both tooth rows also curve up at the caudal end of the oral cavity (curve of Spee).

Answer 17

Upper cheek teeth wider and squarer, lower cheek teeth narrower and more rectangular So as the upper arcade is wider, and the teeth in it are also wider, when the mouth is closed about 1/3 of the occlusal surface of the upper cheek teeth is in contact with about half of the occlusal surface of the lower cheek teeth. Also, the occlusal surface is angled in a linguo-buccal direction - around 15 degrees rostrally and 30 degrees caudally in the normal animal.

Answer 18

In the upper cheek teeth there are 2 infundibula totally surrounded by dentine. In the lower cheek teeth there are infoldings of the enamel rather than true infundibulae. These are open on the lingual surface.

Answer 19

raised enamel structures that run across the occlusal (chewing) surface of the upper and lower cheek teeth. These ridges help horses efficiently grind down fibrous plant material (like hay and grass). They are a natural part of equine dentition and contribute to their hypsodont teeth, which continuously erupt throughout their lives. The wear is such that along each cheek tooth row there are around 12 transverse ridges. In occlusion the ridges of the upper arcade interdigitate with those of the lower arcade

Answer 20

Permanent premolars erupt 2.5 to 4 years, permanent molars 1 month – 3.5 years

Answer 21

Tooth Roots Extend Into the Maxillary Sinus The last three or four upper cheek teeth (specifically PM4, M1, M2, and M3) have roots that project directly into the maxillary sinus. As horses age, their teeth continue to erupt, and the roots gradually extend deeper into the sinus. Dental Disease Can Lead to Sinus Infections If an upper cheek tooth becomes infected (due to decay, fractures, or periodontal disease), the infection can spread into the maxillary sinus, causing sinusitis (inflammation and infection of the sinus). Signs of sinusitis include nasal discharge (often foul-smelling), swelling, and difficulty breathing. Tooth Extractions Can Affect the Sinus When a deeply rooted upper cheek tooth is extracted, it can leave an open connection (fistula) between the oral cavity and the maxillary sinus. This can require surgical closure to prevent food and bacteria from entering the sinus. Age-Related Changes In younger horses, the maxillary sinus is smaller, as the teeth are still growing and occupy more space in the skull. As the horse ages, the sinuses become larger, and the roots of older cheek teeth extend higher into the sinus cavity.

Answer 22

Per os– through the oral opening – incisors, wolf teeth, premolars. By buccotomy– surgical approach through the soft tissue structures of the cheek then removing some bone overlying the lateral side of the tooth - premolars By repulsion – surgical approach through the skull or mandible. The tooth is driven out from the root using a metal punch. – caudal premolar and molars.

Answer 23

Infraorbital teeth, parotid duct, dorsal and ventral buccal nerves Nasolacrimal duct and infraorbital canal

Answer 24

I0/3 C0/1 P3/3 M3/3 =32 =20 deciduous DECIDUOUS cattle: 3 weeks Sheep: 4 weeks Permanent cattle : 3.5 years Sheep:2.5 years, canines by 4 years