Tooth Development Flashcards
Outline tooth development
Distinct thickenings on the oral epithelium form the labiogingival groove and the dental ledge/lamina
Ectodermal proliferations along the dental lamina give rise to dental buds which project into the mesenchyme
Below the dental cap forms the dental papilla, the mesenchymal component of the developing tooth
The epithelial cels differentiate into ameloblasts which are responsible for the development of enamel
Cells in the dental papilla differentiate into ondotoblasts which are responsible for dentin
Types of teeth
hypsodont
have a huge length behind the gum and continually erupt
ARADICULAR = open roots e.g. rabbits have continued growth
RADICULAR = closed roots e.g. horses roots growth decreases with age
brachydont
deciduous permanent teeth
homodont all teeth the same
heterodont teeth are different
monophydont have one set of teeth
polyphydont teeth replaced throughout life
contact surface
occlusal surface
The masticatory apparatus
The teeth of mammals develop different teeth in different regions of the mouth are known as heterodonty. This allows incisors, canine and premolar and molar groups.
A single replacement of the first erupted teeth is provided by a second stronger set that is better adapted to the longer jaw and stronger mastication of an adult. This is known as diphyodonty. In contrast with polyphyodonty.
The term diastema is a term used for a considerate gap between the teeth, usually between the incisors and premolars.
Different parts of the tooth
Enamel= densely calcified, acellular and lacks regenerative. The enamel casing may get breached and the softer dentin which wears more rapidly will be exposed. The folding of the enamel increases the surface area and increases mastication efficiency.
Cement= the initial deposition is thin but thoroughout life increases. Collagen fibres extend from the peridontal ligament which fastens the tooth
Dentin= ondotoblasts make dentin
Pulp= heavily vascularised and have lots of nerves.
Mastication
Coronoid process
Chondylar process
Temporomandicular joint
Jaw opening
digastricus
Jaw closing
temporal
masseter
lateral and medial pterygoids
