Difference between revisions of "Teeth - Pathology"

From WikiVet English
Jump to navigation Jump to search
m
(Redirected page to Category:Teeth - Pathology)
 
(8 intermediate revisions by 3 users not shown)
Line 1: Line 1:
{{toplink
+
#REDIRECT[[:Category:Teeth - Pathology]]
|backcolour =BCED91
 
|linkpage =Alimentary System - Pathology
 
|linktext =Alimentary System
 
|maplink = Alimentary System (Content Map) - Pathology
 
|pagetype =Pathology
 
}}
 
<br>
 
==Introduction==
 
 
 
See [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|anatomy and physiology of the teeth]]
 
 
 
==Functional Anatomy==
 
 
 
*The [[Cavity & Gingiva - Pathology|gingival crevice]] is an important site for disease processes in mouth to begin.
 
 
 
*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).
 
**Approximately 75% of wasting horses have dental abnormalities.
 
 
 
*This is not a problem in carnivores as do they not use [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] for [[Mastication|mastication]].
 
 
 
*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. 
 
**Seen mostly in rodents - [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] may even penetrate through [[Lips - Anatomy & Physiology|lip]].
 
 
 
==Defence Mechanisms==
 
 
 
==Developmental Pathology==
 
===Erythropoietic Porphyria.===
 
*"Congenital Pink [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|Tooth]]" 
 
*Occurs in cattle, cats and sometimes pigs
 
*[[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|Teeth]] are pink due to congenital inability to metabolise haemoglobin pigments. These pigments also produce [[photosensitivity]] in skin.
 
*This results in severe sunburn if animal exposed to normal levels of sunlight.
 
 
 
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]].
 
 
 
===Photosensitising agents===
 
*Phenothiazine which was used as an anthelmintic
 
*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.
 
*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]].
 
 
 
===Abnormal Wear of Teeth===
 
*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.
 
*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.
 
**The condition is sometimes known as “'''shear mouth'''”.
 
 
 
*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]].
 
*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.
 
*Malocclusions in dogs and cats may arise from retention of deciduous [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] in the young animal.
 
 
 
*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:
 
**'''Prognathism''' is an abnormally long lower jaw.
 
**A similar effect is produced by '''brachygnathia superior''' (ie short maxilla). Both conditions may be referred to as ''undershot jaw''.
 
***A typical breed affected is the '''Boxer'''.
 
**'''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''.
 
***Typical breeds affected are the '''Borzoi''' or '''Rough Collie'''.
 
 
 
===Abnormal Numbers of Teeth===
 
 
 
*Abnormal numbers of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] can vary from total lack (anodontia), to too few (oligodontia), to increased numbers (polyodontia).
 
[[Image:oligodontia.gif|right|thumb|75px|<small><center>Oligodentia (Courtesy of Alun Williams (RVC))</center></small>]]
 
 
 
==Infection of teeth==
 
===Dental caries===
 
*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.
 
*Infection may spread to [[Pulp|pulp]] cavity.
 
[[Image:toothinfection.gif|right|thumb|125px|<small><center>Stages of tooth infection (Courtesy of Alun Williams (RVC))</center></small>]]
 
===Infundibular Impaction===
 
*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]].
 
===Direct infection of pulp cavity===
 
*For example, a dog whose canine has been snapped off while biting stones etc. exposes [[Pulp|pulp]].
 
*Also possible that infection in [[Pulp|pulp]] cavity originates from a circulating pyaemia producing pulpitis.
 
===Gingival crevice inflammation===
 
*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.
 
*Dental plaque becomes calcified and whole [[Crown|crown]] may become covered in brown chalky material.
 
*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 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.
 
 
 
*Pyorrhoea is unusual in sheep but, nonetheless, periodontal disease with “broken mouth” is a major cause of culling of ageing ewes.
 
 
 
===Alveolar Periostitis===
 
*A more virulent infection into the alveolus produces alveolar periostitis.
 
*Infection spreads from [[Pulp|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]].
 
**Seen in infection of carnassial teeth in dogs as chronic sinus discharging below eye. So called 'malar' abscess.
 
*Only treated by removal of [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|tooth]].
 
*Abscess may break through into maxillary sinus. If drained will get recovery.
 
**Other maxillary cheek [[Oral Cavity - Teeth & Gingiva - Anatomy & Physiology|teeth]] can be involved in pyaemic infection with sinus formation.
 
*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.
 
 
 
==Granulomatous and pyogranulomatous Inflammation==
 
===Mandibular Osteomyelitis===
 
[[Image:Lumpyjaw1.gif|right|thumb|125px|<small><center>Lesion caused by Actinomyces Bovis(Courtesy of Alun Williams (RVC))</center></small>]]
 
*"Lumpy jaw"
 
====Clinical====
 
 
 
*Seen mainly in cattle and exotics caused by [[Actinomycetes|''Actinomyces bovis'']] producing [[Bones Inflammatory - Pathology#Osteomyelitis|osteomyelitis]] of mandible.
 
*Mostly young animals.
 
*Will not heal without treatment and jaw enlarges until animal cannot eat.
 
 
 
====Pathogenesis====
 
 
 
*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. 
 
*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.
 
*No real pus formation but "'''sulphur granules'''" in middle of lesion.
 
*Organism causes "'''pyogenic granuloma'''."
 
 
 
*Can grow to enormous size (e.g. size of grapefruit) and whole of mandible is blown apart by multiple foci of infection.
 
 
 
<small>Also see:[[Tongue - Pathology#Actinobacillosis|Actinobacillosis - "Wooden Tongue" (Courtesy of Alun Williams (RVC))</small>]]
 
 
 
====Pathology====
 
 
 
3 major features:
 
 
 
#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.
 
#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. 
 
#Masses of fibrous tissue surround the granuloma and fill the spaces where bone has been destroyed.
 
 
 
===Odontoclastic resorptive lesions===
 
*Cats
 
**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)
 
**20%+ of cats have them
 
**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
 
***continues with remodeling of [[Alveolar bone|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.
 
*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
 
 
 
==Eosinophilic Inflammation==
 
==Necrotizing Inflammation==
 
 
 
 
 
==Lymphocytic and plasmacytic Inflammation==
 
==Proliferative Pathology==
 
===Hyperplastic===
 
====Focal fibrous hyperplasia<ref name="epulides1"> </ref>====
 
*44% of cases.
 
*Dense collagenous tissue, with ulceration/superficial inflammation
 
*Dystrophic calcificaition within the fibrous connective tissue stroma (often highly cellular, with 'young stellate fibroblasts'
 
*No odontogenic epithelium seen.
 
*Occasional strands of surface epithelium growing down into the stroma.
 
*Most of these were previously diagnosed as fibromatous or ossifying epulides.
 
 
 
===Neoplastic===
 
====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>====
 
[[Image:epulis.gif|right|thumb|125px|<small><center>Canine Epulis (Courtesy of Alun Williams (RVC))</center></small>]]
 
*aka: Fibromatous epulis of periodontal ligament origin
 
*17% of cases.
 
*Proliferation of fibrous tissue with variety of osteoid, [[Cementum|cementum]] or [[Dentine|dentine]]-like material.
 
*Isolated strands or islands of odontogenic epithelium always present (ie: suggesting induction of connective tissue by the epithelial cells).
 
*The stroma contains neoplastic fibroblasts, with varying cellularity.
 
*The overlying epitheluim is normal.
 
 
 
====Peripheral ameloblastoma<ref name="epulides1"> </ref>====
 
[[Image:ameloblastoma.gif|right|thumb|125px|<small><center>Ameloblastoma (Courtesy of Alun Williams (RVC))</center></small>]]
 
*aka: basal cell carcinoma, acanthomatous ameloblastoma, acanthomatous epulis
 
*18% of cases.
 
*Islands and sheets of mature odontogenic epithelium within a collagenous fibrous connective tissue stroma of low/moderate cellularity.
 
*Each of the islands bounded by a row of tall columnnar cells.
 
*These palisading cells exhibit polarisation away from the basement membrane and had cytoplasmic vacuolation.
 
*Central cells had a basaloid appearance.
 
*Often infiiltrating into the underlying bone.
 
*Synonymous with basal cell carcinoma.
 
 
 
====Central ameloblastoma<ref name="epulides1"> </ref>====
 
*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]].
 
 
 
==Degenerative Pathology==
 
===Odontodystrophy===
 
 
 
*Damage to [[Ameloblasts|ameloblasts]] (which form [[Enamel|enamel]]) in utero upsets permanent incisor formation.
 
*[[Enamel]] is marked by pits, lines etc.
 
 
 
====In ruminants:====
 
*Damage to [[Enamel|enamel]] formation most often caused by fluoride poisoning. 
 
*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]].
 
 
====In canines:====
 
[[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]])
 
 
 
==Metabolic Pathology==
 
 
 
==Nutritiona Pathology==
 
 
 
==Traumatic Pathology==
 
 
 
==Vascular Pathology==
 
==References==
 
<small>
 
With thanks to Andrew Jefferies (Cambridge) and Alun Williams (RVC) for providing access to their lecture materials
 
<references/>
 
</small>
 
==Learning Tools==
 
[[Alimentary Flashcards - Pathology#Teeth Flashcards|Teeth Flashcards]]
 

Latest revision as of 10:53, 26 May 2010