Difference between revisions of "Tooth - Anatomy & Physiology"
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==Anatomy of the Enamel Organ== | ==Anatomy of the Enamel Organ== | ||
[[Image:Soft Histology of Enamel Organ.jpg|thumb|right|150px|Histology of Enamel Organ - Copyright RVC 2008]] | [[Image:Soft Histology of Enamel Organ.jpg|thumb|right|150px|Histology of Enamel Organ - Copyright RVC 2008]] | ||
| − | + | [[Image:Enamel Organ Layers.jpg|thumb|right|150px|Enamel Organ Layers - Copyright RVC 2008]] | |
The main components which form the enamel organ are: | The main components which form the enamel organ are: | ||
*'''Outer epithelium''' | *'''Outer epithelium''' | ||
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The crown of incisors have only one '''cusp'''. The crown of molars have up to 4 cusps for the grinding of food. | The crown of incisors have only one '''cusp'''. The crown of molars have up to 4 cusps for the grinding of food. | ||
| − | + | ===Root=== | |
| + | Teeth may have one or more roots. The furcation angle is the point where roots diverge. The root ends in an apex which is where the nerves, blood vessels and lymphatics travel to the [[Pulp - Anatomy & Physiology|pulp]]. '''Hypsodont''' teeth can have open roots (aradicular) e.g. in rabbits which have continued growth. Hypsodont teeth can have closed roots (radicular) e.g. horse where growth decreases with age. '''Brachydont''' teeth have no capacity for growth and so the roots are closed. | ||
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| + | '''Species Differences''' | ||
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| + | The apex has a single foramen in dogs and cats. It remains open in herbivores. In the horse, the apex closes as the animal ages. Brachiocephalic dogs often have fused roots. Equine incisors have fused roots. In the horse's canines, the size of the root is much larger than the [[Enamel Organ#Crown|crown]]. | ||
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*'''[[Alveolar Bone|Alveolar bone]]''' | *'''[[Alveolar Bone|Alveolar bone]]''' | ||
*'''[[Lamina dura - Anatomy & Physiology|Lamina dura]]''' | *'''[[Lamina dura - Anatomy & Physiology|Lamina dura]]''' | ||
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*'''[[Pulp - Anatomy & Physiology|Pulp]]''' | *'''[[Pulp - Anatomy & Physiology|Pulp]]''' | ||
*'''[[Periodontal ligament - Anatomy & Physiology|Periodontal ligament]]''' | *'''[[Periodontal ligament - Anatomy & Physiology|Periodontal ligament]]''' | ||
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The main cells of the enamel organ are: | The main cells of the enamel organ are: | ||
Revision as of 23:52, 26 March 2011
Anatomy of the Enamel Organ
The main components which form the enamel organ are:
- Outer epithelium
- Stellate reticulum- star shaped cells lying between the outer and inner epithelial layers. It has the appearance of connective tissue but is of epithelial derivation.
- Inner epithelium which becomes the enamel secreting ameloblast layer
The enamel organ has many different components. These consist of:
Crown
The crown is covered by enamel. It meets the root at the cemento-enamel junction (CEJ).
The crown of incisors have only one cusp. The crown of molars have up to 4 cusps for the grinding of food.
Root
Teeth may have one or more roots. The furcation angle is the point where roots diverge. The root ends in an apex which is where the nerves, blood vessels and lymphatics travel to the pulp. Hypsodont teeth can have open roots (aradicular) e.g. in rabbits which have continued growth. Hypsodont teeth can have closed roots (radicular) e.g. horse where growth decreases with age. Brachydont teeth have no capacity for growth and so the roots are closed.
Species Differences
The apex has a single foramen in dogs and cats. It remains open in herbivores. In the horse, the apex closes as the animal ages. Brachiocephalic dogs often have fused roots. Equine incisors have fused roots. In the horse's canines, the size of the root is much larger than the crown.
The main cells of the enamel organ are: