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− | {{review}} | + | {{frontpage |
| + | |pagetitle =Teeth - Pathology |
| + | |pagebody = |
| + | |contenttitle =Content |
| + | |contentbody =<big><b> |
| + | <br><br> |
| + | <categorytree mode=pages>Teeth - Pathology</categorytree> |
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− | ==Introduction== | + | </b></big> |
| + | |logo =path-logo.png |
| + | }} |
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− | See [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|anatomy and physiology of the teeth]]
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− | ==Functional Anatomy==
| + | [[File:Toothinfection.gif|200px]] |
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− | *The [[Cavity & Gingiva - Pathology|gingival crevice]] is an important site for disease processes in mouth to begin.
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− | *In ruminants and rodents [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] may fail to oppose properly or to allow side to side movement of jaws. This produces uneven wear (especially in horse). Sharp edges are produced on the outside of the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] in the upper jaw and inside of the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] in the lower jaw, which causes painful feeding and inanition (not eating).
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− | **Approximately 75% of wasting horses have dental abnormalities.
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− | *This is not a problem in carnivores as do they not use [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] for [[Mastication|mastication]].
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− | *If a [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] is lost the opposing [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] may become very long and stop mouth closing properly.
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− | **Seen mostly in rodents - [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] may even penetrate through [[Lips - Anatomy & Physiology|lip]].
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− | ==Defence Mechanisms==
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− | ==Developmental Pathology==
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− | ===[[Erythropoietic Porphyra]].===
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− | ===[[Photosensitisation]]===
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− | ===[[Abnormal Wear of Teeth]]===
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− | ===[[Abnormal Numbers of Teeth]]===
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− | ==Infection of teeth==
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− | ===[[Dental caries]]===
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− | ===Infundibular Impaction===
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− | *Seen in the ruminant and horse.
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− | *Food material impacted in infundibulum undergoes bacterial fermentation and results in enzymic damage to [[Enamel - Anatomy & Physiology|enamel]] and [[Dentine - Anatomy & Physiology|dentine]].
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− | ===Direct infection of pulp cavity===
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− | *For example, a dog whose canine has been snapped off while biting stones etc. exposes [[Pulp - Anatomy & Physiology|pulp]].
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− | *Also possible that infection in [[Pulp - Anatomy & Physiology|pulp]] cavity originates from a circulating pyaemia producing pulpitis.
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− | ===Gingival crevice inflammation===
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− | *Mostly in carnivores (also cats), may occur in horses.
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− | *[[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.
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− | *Dental plaque becomes calcified and whole [[Crown - Anatomy & Physiology|crown]] may become covered in brown chalky material.
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− | *Calculus gives brittle dirty brown covering to [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
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− | *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.
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− | *This exposes more of [[Crown - Anatomy & Physiology|crown]], 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.
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− | *Pyorrhoea is unusual in sheep but, nonetheless, periodontal disease with “broken mouth” is a major cause of culling of ageing ewes.
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− | ===Alveolar Periostitis===
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− | *A more virulent infection into the alveolus produces alveolar periostitis.
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− | *Infection spreads from [[Pulp - Anatomy & Physiology|pulp]] or from gingivitis to produce the periostitis.
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− | *This may then break out of the alveolus into the bone causing [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]].
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− | **Seen in infection of carnassial teeth in dogs as chronic sinus discharging below eye. So called 'malar' abscess.
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− | *Only treated by removal of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
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− | *Abscess may break through into maxillary sinus. If drained will get recovery.
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− | **Other maxillary cheek [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] can be involved in pyaemic infection with sinus formation.
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− | *Hard to evaluate on [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]], may produce fistula that also needs [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] removal.
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− | ==Granulomatous and pyogranulomatous Inflammation==
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− | ===Mandibular Osteomyelitis===
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− | [[Image:Lumpyjaw1.gif|right|thumb|125px|<small><center>Lesion caused by Actinomyces Bovis(Courtesy of Alun Williams (RVC))</center></small>]]
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− | *"Lumpy jaw"
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− | ====Clinical====
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− | *Seen mainly in cattle and exotics caused by ''[[Actinomyces bovis]]'' producing [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]] of mandible.
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− | *Mostly young animals.
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− | *Will not heal without treatment and jaw enlarges until animal cannot eat.
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− | ====Pathogenesis====
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− | *Starts as alveolar periostitis of lower cheek [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]], due to ingestion of poor coarse roughage e.g. straw or hay with lots of thistles.
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− | *Slowly enlarging [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]] (occasionally [[Skull and Facial Muscles - Anatomy & Physiology#Maxilla|maxilla]]) due to granulomatous inflammation producing much fibrous tissue.
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− | *No real pus formation but "'''sulphur granules'''" in middle of lesion.
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− | *Organism causes "'''pyogenic granuloma'''."
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− | *Can grow to enormous size (e.g. size of grapefruit) and whole of mandible is blown apart by multiple foci of infection.
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− | <small>Also see:[[Tongue - Pathology#Actinobacillosis|Actinobacillosis - "Wooden Tongue" (Courtesy of Alun Williams (RVC))</small>]]
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− | ====Pathology====
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− | 3 major features:
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− | #Inflammatory removal of bone. As cortex of bone is pushed out by central inflammation produces thinning of bone cortex with proliferation of new periosteal bone. The centre of the [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]] is eroded forming a honeycomb-like bone. Eventually will erode through bone producing [[Granuloma|granulomatous]] lesion on bottom of [[Skull and Facial Muscles - Anatomy & Physiology#Mandible (mandibula)|mandible]] and eventually eroding through skin.
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− | #Granuloma with micro abscess's in centre with greenish / yellow granules in middle of pus. These granules known as "sulphur bodies". Sulphur body is a colony of tangled mass of Actinomyces filaments. This is surrounded by [[Neutrophils - WikiBlood|neutrophils]] and [[Macrophages - WikiBlood|macrophages]] forming a pyogenic granuloma.
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− | #Masses of fibrous tissue surround the granuloma and fill the spaces where bone has been destroyed.
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− | ===Odontoclastic resorptive lesions===
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− | *Cats
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− | **Odontoclasts attack external and internal to the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
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− | **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)
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− | **20%+ of cats have them
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− | **Different from caries – demineralization by bacteria fermenting CHO on the [[Enamel - Anatomy & Physiology|enamel]].
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− | **ORLs – only occur when odontoclasts resorb the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]]/bone
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− | ***continues with remodeling of [[Alveolar bone - Anatomy & Physiology|alveolar bone]] until ankylosis
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− | *** fixation of [[Periodontal ligament - Anatomy & Physiology|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.
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− | *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.
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− | *Can have inflammatory infiltrates into the resportive lesions
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− | ==Eosinophilic Inflammation==
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− | ==Necrotizing Inflammation==
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− | ==Lymphocytic and plasmacytic Inflammation==
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− | ==Proliferative Pathology==
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− | ===Hyperplastic===
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− | ====Focal fibrous hyperplasia<ref name="epulides1"> </ref>====
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− | *44% of cases.
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− | *Dense collagenous tissue, with ulceration/superficial inflammation
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− | *Dystrophic calcificaition within the fibrous connective tissue stroma (often highly cellular, with 'young stellate fibroblasts'
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− | *No odontogenic epithelium seen.
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− | *Occasional strands of surface epithelium growing down into the stroma.
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− | *Most of these were previously diagnosed as fibromatous or ossifying epulides.
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− | ===Neoplastic===
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− | ====Peripheral odontogenic fibroma<ref name="epulides1">J Comp. Path. 1992 (106), 169-182 The Histological Nature of Epulides in Dogs F. J. M. Verstraete*, A. J. Ligthelmf and A. WeberT. ... review of 154 oral 'epulis' from dogs reviewed with the current (at the time) human literature.</ref>====
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− | [[Image:epulis.gif|right|thumb|125px|<small><center>Canine Epulis (Courtesy of Alun Williams (RVC))</center></small>]]
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− | *aka: Fibromatous epulis of periodontal ligament origin
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− | *17% of cases.
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− | *Proliferation of fibrous tissue with variety of osteoid, [[Cementum - Anatomy & Physiology|cementum]] or [[Dentine - Anatomy & Physiology|dentine]]-like material.
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− | *Isolated strands or islands of odontogenic epithelium always present (ie: suggesting induction of connective tissue by the epithelial cells).
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− | *The stroma contains neoplastic fibroblasts, with varying cellularity.
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− | *The overlying epitheluim is normal.
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− | ====Peripheral ameloblastoma<ref name="epulides1"> </ref>====
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− | [[Image:ameloblastoma.gif|right|thumb|125px|<small><center>Ameloblastoma (Courtesy of Alun Williams (RVC))</center></small>]]
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− | *aka: basal cell carcinoma, acanthomatous ameloblastoma, acanthomatous epulis
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− | *18% of cases.
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− | *Islands and sheets of mature odontogenic epithelium within a collagenous fibrous connective tissue stroma of low/moderate cellularity.
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− | *Each of the islands bounded by a row of tall columnnar cells.
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− | *These palisading cells exhibit polarisation away from the basement membrane and had cytoplasmic vacuolation.
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− | *Central cells had a basaloid appearance.
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− | *Often infiiltrating into the underlying bone.
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− | *Synonymous with basal cell carcinoma.
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− | ====Central ameloblastoma<ref name="epulides1"> </ref>====
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− | *Different from peripheral ameloblastoma - cystic changes and follicular arrangement of ameloblasts and stellate reticulum cells, resembling the basic structure of the [[Tooth Anatomy - Anatomy & Physiology|enamel organ]].
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− | ==Degenerative Pathology==
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− | ===Odontodystrophy===
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− | *Damage to [[Ameloblasts - Anatomy & Physiology|ameloblasts]] (which form [[Enamel - Anatomy & Physiology|enamel]]) in utero upsets permanent incisor formation.
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− | *[[Enamel - Anatomy & Physiology|Enamel]] is marked by pits, lines etc.
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− | ====In ruminants:====
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− | *Damage to [[Enamel - Anatomy & Physiology|enamel]] formation most often caused by fluoride poisoning.
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− | *Seen in cattle grazing on pasture contaminated by cement works effluent.
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− | *Chalky mottling and yellow brown pitting of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
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− | ====In canines:====
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− | [[Image:enamal-hypoplasia.gif|right|thumb|125px|<small>Enamal Hypoplasia Following a CDV infection (Courtesy of Alun Williams (RVC))<center></center></small>]]
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− | 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]])
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− | ==Metabolic Pathology==
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− | ==Nutritiona Pathology==
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− | ==Traumatic Pathology==
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− | ==Vascular Pathology==
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− | ==References==
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− | <small>
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− | With thanks to Andrew Jefferies (Cambridge) and Alun Williams (RVC) for providing access to their lecture materials
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− | <references/>
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− | </small>
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− | ==Learning Tools==
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− | [[Alimentary Flashcards - Pathology#Teeth Flashcards|Teeth Flashcards]]
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| [[Category:Oral_Cavity_and_Gingiva_-_Pathology]] | | [[Category:Oral_Cavity_and_Gingiva_-_Pathology]] |