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| − | {{review}}
| + | #REDIRECT[[:Category:Teeth - Pathology]] |
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| − | {{toplink
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| − | |backcolour =BCED91
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| − | |linkpage =Alimentary System - Pathology
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| − | |linktext =Alimentary System
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| − | |maplink = Alimentary System (Content Map) - Pathology
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| − | |pagetype =Pathology
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| − | }}
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| − | <br>
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| − | ==Introduction==
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| − | See [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|anatomy and physiology of the teeth]]
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| − | ==Functional Anatomy==
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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 Porphyria.===
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| − | *"Congenital Pink [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|Tooth]]"
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| − | *Occurs in cattle, cats and sometimes pigs
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| − | *[[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|Teeth]] are pink due to congenital inability to metabolise haemoglobin pigments. These pigments also produce [[photosensitivity]] in skin.
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| − | *This results in severe sunburn if animal exposed to normal levels of sunlight.
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| − | Discoloration of a single [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] is more likely to be caused by pus in the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
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| − | ===Photosensitising agents===
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| − | *Phenothiazine which was used as an anthelmintic
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| − | *Tetracycline - if one injects bitches with tetracycline when pregnant, puppies are born with brown [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]], which fluoresce under UV light.
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| − | *Haemosiderin may also produce pinky / brown colour to [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] usually due to damage and haemorrhage into [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
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| − | ===Abnormal Wear of Teeth===
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| − | *Abnormal wear of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] in herbivores may result from irregular grinding of molars as well as from periodontal disease.
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| − | *Sharp edges usually form on the lingual aspect of the mandibular [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] and the buccal aspects of the maxillary molars and may cause quite severe oral lacerations.
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| − | **The condition is sometimes known as “'''shear mouth'''”.
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| − | *Malocclusion of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] may be acquired as a result of trauma and loss or displacement of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]].
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| − | *It is particularly important in those teeth which continue to grow excessive growth, interference with prehension of food or even growth of the [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]] into adjacent structures.
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| − | *Malocclusions in dogs and cats may arise from retention of deciduous [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] in the young animal.
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| − | *Malocclusion of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] may also occur as a result of malformations of the jaws. The terminology used for these is rather confusing and the following should assist:
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| − | **'''Prognathism''' is an abnormally long lower jaw.
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| − | **A similar effect is produced by '''brachygnathia superior''' (ie short maxilla). Both conditions may be referred to as ''undershot jaw''.
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| − | ***A typical breed affected is the '''Boxer'''.
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| − | **'''Retrognathism''' is an unusually short lower jaw. This may also be called '''brachygnathia inferior''' (i.e. short mandible). The condition is referred to as ''overshot jaw'' or ''parrot mouth''.
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| − | ***Typical breeds affected are the '''Borzoi''' or '''Rough Collie'''.
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| − | ===Abnormal Numbers of Teeth===
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| − | *Abnormal numbers of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] can vary from total lack (anodontia), to too few (oligodontia), to increased numbers (polyodontia).
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| − | [[Image:oligodontia.gif|right|thumb|75px|<small><center>Oligodentia (Courtesy of Alun Williams (RVC))</center></small>]]
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| − | ==Infection of teeth==
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| − | ===Dental caries===
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| − | *Only really seen in primates, but may be seen in horse caused by bacterial decalcification of [[Enamel - Anatomy & Physiology|enamel]].
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| − | *Acid producing organisms enter dentine and underun enamel.
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| − | *Infection may spread to [[Pulp - Anatomy & Physiology|pulp]] cavity.
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| − | [[Image:toothinfection.gif|right|thumb|125px|<small><center>Stages of tooth infection (Courtesy of Alun Williams (RVC))</center></small>]]
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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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