Dentition Teeth of Mammals B Sc II Mrs
Dentition (Teeth) of Mammals B. Sc. II Mrs. S. M. Jaunjal Department of Zoology GKG College Kolhapur
Hard and pointed structure connected to jaw bones in buccal cavity is called teethes
Arrangement of teeth in upper and lower jaw is called Dentition
Dentition is highly specialized in mammals except
Primary function of teethes
Importance of Dentition
Differenation or shape of teeth
Homodont / isodont Ex- Whales, dolphins, porpoies and armadillos etc Function- Prevent the escape of the struggling of fishes
Heterodont
Attachment of teeth
Succession of teeth
Monophyodont moles
Examples
Kinds of teeth
Incisors teeth
Front teeth by premaxillae in upper and dentaries in lower jaws
Single rooted, monocuspid and long
Curved and Sharp Chisel like Edges Ex- Rodents Cutting, biting and
Sloth bear (incisors totally absent)
Canines
Single, occur in half of each jaw, outside the incisors, upper canine is first teeth of maxillae
Elongated, single rooted and with sharp conical monocuspid crown
Piercing and tearing the flesh of prey
offence and defense
Diastema
Premolar and molar Cheek teeth / grinders
And Premolar Broad surface with ridges and tubercles
Difference
Carnassial teeth In carnivorous animals, last premolar of upper jaw and first molar of lower jaw is very sharp cups. For cracking bones and shearing tendons
Wisdom Teeth
Types
Tricodont teeth Three cones are arranged in linear series Ex- Mesozoic mammals (Extinct mammals)
Trituberculate teeth Three cones, arrange in trianges Ex- Fossil Mammals
Bunodont Crown- Rounded, small, separate tubercles for crushing Found- mammals and mixed diet animals Ex- Man, dog, pig etc
Secodont Sharp cutting edges For tearing and cutting flesh Found in carnivorous animals
Ex - Dog Last upper premolar and first lower molar are large and sharp cutting edges They bite on each other like scissors for cutting flesh Also called cranassial teeth, shearing, sectorial teeth
Selenodont teeth Crown of these teeth bears vertical crescentric cups of hard enamel Ex- Grazing animals for grinding the food Two Types
Normal teeth Lowcrowned With short tooth Ex- Ground Squrial Elongated Prism shaped High crown Low roots Ex- Grazing animals (horse and cattle)
Lophodont Intricate folding of Enamel and Dentine Cups are connected by transverse ridges called loops. Ex- elephant Single large 30 cm x 10 cm Present half of each jaw Adapted to grind all sorts of plants and grasses
Dental formula
• Number of teeths in different species, but number of teeth are constant and characteristic of same species • Number and kind of teeth I mammals represented by the formula called dental formula • It represent each type of teeth present in half of the jaw • Teeth of upper jaw paced in numerators and those of the lower jaw as denominator • Kinds of teeth are denoted by initial letters-i, c, pm and m respectively • Number of teeth present in the dental formula multiplied by the two gives total number of teeth in a species.
- Slides: 52