Changes

*Only really seen in primates, but may be seen in horse caused by bacterial decalcification of [[Enamel|enamel]].

*Only really seen in primates, but may be seen in horse caused by bacterial decalcification of [[Enamel|enamel]].

*Acid producing organisms enter dentine and underun enamel.  

*Acid producing organisms enter dentine and underun enamel.  

*Infection may spread to [[Pulp|pulp]] cavity.

*Infection may spread to [[Pulp - Anatomy & Physiology|pulp]] cavity.

[[Image:toothinfection.gif|right|thumb|125px|<small><center>Stages of tooth infection (Courtesy of Alun Williams (RVC))</center></small>]]

[[Image:toothinfection.gif|right|thumb|125px|<small><center>Stages of tooth infection (Courtesy of Alun Williams (RVC))</center></small>]]

===Infundibular Impaction===

===Infundibular Impaction===

*Seen in the ruminant and horse.  

*Seen in the ruminant and horse.  

*Food material impacted in infundibulum undergoes bacterial fermentation and results in enzymic damage to [[Enamel|enamel]] and [[Dentine|dentine]].

*Food material impacted in infundibulum undergoes bacterial fermentation and results in enzymic damage to [[Enamel - Anatomy & Physiology|enamel]] and [[Dentine - Anatomy & Physiology|dentine]].

===Direct infection of pulp cavity===

===Direct infection of pulp cavity===

*For example, a dog whose canine has been snapped off while biting stones etc. exposes [[Pulp|pulp]].  

*For example, a dog whose canine has been snapped off while biting stones etc. exposes [[Pulp - Anatomy & Physiology|pulp]].  

*Also possible that infection in [[Pulp|pulp]] cavity originates from a circulating pyaemia producing pulpitis.

*Also possible that infection in [[Pulp - Anatomy & Physiology|pulp]] cavity originates from a circulating pyaemia producing pulpitis.

===Gingival crevice inflammation===  

===Gingival crevice inflammation===  

*Mostly in carnivores (also cats), may occur in horses.   

*Mostly in carnivores (also cats), may occur in horses.   

*[[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|Gingival]] inflammation starts because of dental calculus (tartar) from diets high in minerals and diets consisting of soft rather than hard crunchy food.

*[[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|Gingival]] inflammation starts because of dental calculus (tartar) from diets high in minerals and diets consisting of soft rather than hard crunchy food.

*Dental plaque becomes calcified and whole [[Crown|crown]] may become covered in brown chalky material.

*Dental plaque becomes calcified and whole [[Crown - Anatomy & Physiology|crown]] may become covered in brown chalky material.

*Calculus gives brittle dirty brown covering to [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].  

*Calculus gives brittle dirty brown covering to [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].  

*This may not affect [[Enamel|enamel]] at all but may produce mild [[Cavity & Gingiva - Pathology|gingivitis]] round edge and the gum may start to recede.  

*This may not affect [[Enamel - Anatomy & Physiology|enamel]] at all but may produce mild [[Cavity & Gingiva - Pathology|gingivitis]] round edge and the gum may start to recede.  

*This exposes more of [[Crown|crown]], may reach level of [[Dentine|dentine]] and infection may enter the alveolus and loosen ligaments holding [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] in and ultimately the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] will become loose and fall out.

*This exposes more of [[Crown| - Anatomy & Physiologycrown]], may reach level of [[Dentine - Anatomy & Physiology|dentine]] and infection may enter the alveolus and loosen ligaments holding [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] in and ultimately the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] will become loose and fall out.

*Pyorrhoea is unusual in sheep but, nonetheless, periodontal disease with “broken mouth” is a major cause of culling of ageing ewes.

*Pyorrhoea is unusual in sheep but, nonetheless, periodontal disease with “broken mouth” is a major cause of culling of ageing ewes.

===Alveolar Periostitis===

===Alveolar Periostitis===

*A more virulent infection into the alveolus produces alveolar periostitis.  

*A more virulent infection into the alveolus produces alveolar periostitis.  

*Infection spreads from [[Pulp|pulp]] or from gingivitis to produce the periostitis.  

*Infection spreads from [[Pulp - Anatomy & Physiology|pulp]] or from gingivitis to produce the periostitis.  

*This may then break out of the alveolus into the bone causing [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]].

*This may then break out of the alveolus into the bone causing [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]].

**Seen in infection of carnassial teeth in dogs as chronic sinus discharging below eye. So called 'malar' abscess.  

**Seen in infection of carnassial teeth in dogs as chronic sinus discharging below eye. So called 'malar' abscess.  

*Cats

*Cats

**Odontoclasts attack external and internal to the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].  

**Odontoclasts attack external and internal to the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].  

**Initially start at the neck/cervical region and extend into [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] [[Root|root]] and also enter the [[Root|root]] via the apical foramen (stage 3 lesions)

**Initially start at the neck/cervical region and extend into [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] [[Root - Anatomy & Physiology|root]] and also enter the [[Root - Anatomy & Physiology|root]] via the apical foramen (stage 3 lesions)

**20%+ of cats have them

**20%+ of cats have them

**Different from caries – demineralization by bacteria fermenting CHO on the [[Enamel|enamel]].  

**Different from caries – demineralization by bacteria fermenting CHO on the [[Enamel|enamel]].  

**ORLs – only occur when odontoclasts resorb the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]]/bone  

**ORLs – only occur when odontoclasts resorb the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]]/bone  

***continues with remodeling of [[Alveolar bone|alveolar bone]] until ankylosis  

***continues with remodeling of [[Alveolar bone - Anatomy & Physiology|alveolar bone]] until ankylosis  

*** fixation of [[Periodontal ligament|periodontal ligament]] and [[Lamina dura|lamina dura]] so that the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] is permanently fixed to the bone.

*** fixation of [[Periodontal ligament|periodontal ligament]] and [[Lamina dura - Anatomy & Physiology|lamina dura]] so that the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] is permanently fixed to the bone.

*Odontoclasts normally only active in young animals to resorb the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology#Temporary Tooth|deciduous teeth]] to make way for the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology#Permanent Tooth|permanent teeth]] – so represents abnormal activation in adults.

*Odontoclasts normally only active in young animals to resorb the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology#Temporary Tooth|deciduous teeth]] to make way for the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology#Permanent Tooth|permanent teeth]] – so represents abnormal activation in adults.

*Can have inflammatory infiltrates into the resportive lesions

*Can have inflammatory infiltrates into the resportive lesions

===Odontodystrophy===

===Odontodystrophy===

*Damage to [[Ameloblasts|ameloblasts]] (which form [[Enamel|enamel]]) in utero upsets permanent incisor formation.  

*Damage to [[Ameloblasts - Anatomy & Physiology|ameloblasts]] (which form [[Enamel - Anatomy & Physiology|enamel]]) in utero upsets permanent incisor formation.  

*[[Enamel]] is marked by pits, lines etc.  

*[[Enamel - Anatomy & Physiology|Enamel]] is marked by pits, lines etc.  

====In ruminants:====

====In ruminants:====

*Damage to [[Enamel|enamel]] formation most often caused by fluoride poisoning.   

*Damage to [[Enamel - Anatomy & Physiology|enamel]] formation most often caused by fluoride poisoning.   

*Seen in cattle grazing on pasture contaminated by cement works effluent.

*Seen in cattle grazing on pasture contaminated by cement works effluent.

*Chalky mottling and yellow brown pitting of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].

*Chalky mottling and yellow brown pitting of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].

====In canines:====

====In canines:====

[[Image:enamal-hypoplasia.gif|right|thumb|125px|<small>Enamal Hypoplasia Following a CDV infection (Courtesy of Alun Williams (RVC))<center></center></small>]]

[[Image:enamal-hypoplasia.gif|right|thumb|125px|<small>Enamal Hypoplasia Following a CDV infection (Courtesy of Alun Williams (RVC))<center></center></small>]]

Very severe systemic disease early in life / or in utero may result in severe discoloration or pitting of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] due to effect on [[Enamel|enamel]] formation. (e.g. [[Paramyxoviridae#Canine Distemper Virus (CDV)|distemper in dog]])

Very severe systemic disease early in life / or in utero may result in severe discoloration or pitting of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] due to effect on [[Enamel - Anatomy & Physiology|enamel]] formation. (e.g. [[Paramyxoviridae#Canine Distemper Virus (CDV)|distemper in dog]])

==Metabolic Pathology==

==Metabolic Pathology==