Presentation on theme: "Abnormalities of the Teeth Advanced Oral Pathology"— Presentation transcript:
1Abnormalities of the Teeth Advanced Oral Pathology
2Environmental Effects on Tooth Structure Development
3Environmental Effects on Tooth Structure Development Visible environmental enamel defects can be classified into one of three patterns:Enamel hypoplasia – pits, grooves, or larger areas of missing enamelDiffuse opacities of enamel – variations in translucency or normal thickness; increased white opacity with no clear boundary with adjacent normal enamelDemarcated opacities of enamel show areas of decreased translucence, increased opacity, and a sharp boundary with adjacent enamel; normal thickness
4Environmental Effects on Tooth Structure Development Common pattern, occurs as result of systemic influences (such as exanthematous fevers) which occur during the first two years of life; horizontal rows of pits or diminished enamel on anterior teeth and first molars; enamel loss is bilateralSimilar pattern in cuspids, bicuspids, and second molars when the inciting event occurs at age 4-5
5Enamel Hypoplasia associated with exanthematous fevers
6Turner’s Hypoplasia (1) Secondary to periapical inflammatory disease of the overlying deciduous toothEnamel defects vary from focal areas of white, yellow or brown to extensive hypoplasia involving the entire crown.Most frequently affects permanent bicuspidsTraumatic injury to deciduous teeth also causes Turner’s teeth (45% of children sustain injuries to primary teeth)
7Turner’s Hypoplasia (2) Trauma can displace the already formed hard tooth substance in relationship to the remaining soft tissue for root formation causing dilaceration (a bend in the tooth root)Severe trauma early in tooth development can cause disorganization of the bud resembling a complex odontoma. Severe trauma later on can lead to partial or total arrest of root formation.
10Hypoplasia Caused by Antineoplastic Therapy Degree and severity related to age, form of therapy (chemotherapy/radiotherapy) and doseDefects include hypodontia, microdontia, radicular hypoplasia, enamel hypoplasia and discolorationsRadiotherapy effects more severe than chemotherapy alone but sometimes used togetherDose of radiation as low as 0.72 Gy can cause mild defects in enamel/dentinMandibular hypoplasia due to direct radiation, alveolar deficiency or pituitary effects.
12Dental FluorosisCritical period is age 2-3, if fluoride levels greater than 1 part per million are ingestedFluoride comes from several sources besides water: adult-strength fluoride toothpastes, fluoride supplements, infant foods, soft drinks, and fruit juicesSeverity is dose dependent (higher intakes during critical periods associated with more severe fluorosis)
15Syphilitic Hypoplasia Mulberry molars – constricted occlusal tables with disorganized surface anatomy resembling surface of a mulberryAnterior teeth called Hutchinson’s incisors, have crowns shaped like straight-edge screwdrivers; incisal taper & notchTreatment - Most are cosmetic problems; treatment includes acid-etched composite resin restorations, labial veneers, and full crowns
18Postdevelopmental Loss of Tooth Structure: Attrition Loss of tooth structure caused by tooth-to-tooth contact during occlusion and mastication.Pathologic when it affects appearance and function.Process can be accelerated by poor quality or absent enamel, premature edge-to-edge occlusion, intraoral abrasives, erosion, and grinding habits.
19Attrition Can occur in deciduous and permanent dentitions Most frequently, incisal and occlusal surfaces involvedLarge flat wear facets found in relationship corresponding to pattern of occlusionInterproximal contact points also affectedOver time, interproximal loss can result in shortening of arch length
20Postdevelopmental Loss of Tooth Structure: Attrition
21Postdevelopmental Loss of Tooth Structure: Abrasion Pathologic loss of tooth structure secondary to the action of external agentMost common source is tooth brushing with abrasive toothpaste and horizontal strokes.Also pencils, toothpicks, pipe stems, bobby pins, chewing tobacco, biting thread, inappropriate use of dental floss
22Abrasion Variety of patterns, depending on the cause Toothbrush abrasion presents as horizontal cervical notches on buccal surface of exposed radicular cementum and dentin; degree of loss greatest on prominent teethThread-biting, pipe stem, bobby pins etc., produce rounded or V-shaped notches in incisal edges of anterior teethDental floss, toothpicks result in loss of interproximal radicular cementum and dentin
24AbrasionAbrasion from partial claspAbrasion from improper flossing
25Postdevelopmental Loss of Tooth Structure: Erosion Loss of tooth structure by chemical reaction, not that associated with bacteria (caries)Secondary to presence of acid or chelating agentSource can be dietary (e.g., vinegar, lemons), internal (gastric secretions – perimolysis), or external (e.g., acids, industrial, atmosphere)“If it is not abrasion or attrition, it must be erosion”
26ErosionCommonly affects facial surface of maxillary anteriors and appears as shallow spoon-shaped depressions in cervical portion of the crownPosterior teeth exhibit loss of occlusal surface, where dentin is destroyed more rapidly than enamel, resulting in concave depression of dentin surrounded by elevated rim of enamelErosion limited to facial surfaces of maxillary anterior dentition is usually associated with dietary acid.
27ErosionTooth loss confined to incisal portions of anterior dentition of both arches indicates environmental source.Erosion on palatal surfaces of maxillary anterior teeth and occlusal surfaces of posterior teeth of both dentitions probably caused by regurgitation of gastric secretions.
28ErosionFizzy Drinks Are Major Cause of Teen Tooth Erosion Thu Mar 11, 7:06 PM ET LONDON (Reuters) - Fizzy drinks are the major cause of tooth erosion in British teenagers but many parents are not aware of the problem, researchers said on Friday. The sodas and pop drunk by up to 92 percent of UK 14-year-olds wear away the enamel protective coating on teeth. Dental erosion weakens teeth and can cause thinning or chipping of the tooth edges."This research identifies fizzy drink as by far the biggest factor in causing dental erosion among teenagers," said Dr Peter Rock, of Birmingham University."Drinking fizzy drinks only once a day was found to significantly increase a child's chances of suffering dental erosion," he added.Drinking four or more glasses of fizzy drinks a day raises a 12-year-old's chances of suffering from tooth erosion by 252 percent. Heavy consumption in 14-year-olds increased the risk to 513 percent, according to research published in The British Dental Journal.Unlike tooth decay, which results from high levels of sugar, erosion is caused by acidic substances in the drinks. Even diet versions are harmful.Drinking milk and water, instead, reduces the risk."Erosion is a growing problem among British teenagers, yet many parents don't understand the difference between decay and erosion," said Professor Liz Kay of the British Dental Association."Parents need to understand...it is the acidity of certain products that cause erosion," she added in a statement.
30Postdevelopmental Loss of Tooth Structure: Abfraction Loss of tooth structure resulting from repeated tooth (enamel & dentin) flexure produced by occlusal stressesDisruption of chemical bonds at cervical fulcrum leads to cracked enamel that can be vulnerable to abrasion and erosion
31Abfraction Wedge-shaped defects limited to cervical area Deep, narrow, V-shapedSometimes single tooth or subgingivalMore common in mandibular dentition and among those with bruxism
33Treatment of Postdevelopmental Loss of Tooth Structure Early diagnosis and intervention to restrict severity of tooth lossPatient educationMouth guardsLimit (redirect) tooth brushing & flossingReplacement of lost posterior teeth and avoidance of edge-to-edge occlusionComposite resins, veneers, onlays, full crowns
34Internal & External Resorption Internal resorption is caused by cells located in dental pulp. Rare, usually follows injury to pulpal tissues.External resorption is caused by cells in the periodontal ligament. Most patients are likely to have root resorption on one or more teeth.
35Internal ResorptionInternal resorption presents as a uniform, well-circumscribed symmetrical radiolucent enlargement of pulp chamber. When it affects the coronal pulp, crown can display pink discoloration (pink tooth of Mummery)
36External resorptionExternal resorption presents with a “moth-eaten” loss of root structure in which radiolucency is less well-defined and demonstrates variations in density. Most cases of external resorption involve apical or mid-portions of root
37Internal & External Resorption Cervical pattern of external resorption is often rapid (invasive resorption)Multiple idiopathic root resorption – involves several teeth, underlying cause not obviousTreatment involves the removal of all soft tissue from sites of dental destruction. For external resorption, determine if an accelerating factor is present, and eliminate it.
40Environmental Discoloration of Teeth: Extrinsic Arise from surface accumulation of exogenous pigmentBacterial stains – occur most frequently in childrenExcessive use of tobacco, tea, coffeeFoods that contain abundant chlorophyllRestorative materials, especially amalgamMedicationsStannous fluoride and chlorhexidineExtrinsic stains can be removed by polishing with fine pumice, (sometimes with added 3% hydrogen peroxide); recurrence is likely unless the associated cause is altered
41Environmental Discoloration of Teeth: Extrinsic Amalgam stainTobacco stain
42Environmental Discoloration of Teeth: Intrinsic Secondary to endogenous factors that discolor underlying dentinCongenital erythropoietic porphyria (Günther’s disease) is an AR disorder of metabolism that results in increased synthesis and excretion of porphyrinsHyperbilirubinemia due to jaundice, erythroblastosis fetalis (hemolytic anemia of newborns secondary to blood incompatibility, usually Rh factor), biliary atresia (sclerosing process of the biliary tree), and chlorodontia (green discoloration).
43Environmental Discoloration of Teeth: Intrinsic Localized red blood cell destruction (pink discoloration arising from hemoglobin breakdown within necrotic pulp tissue when blood has accumulated in the head)Lepromatous leprosy (pink discoloration secondary to infection-related necrosis and the rupture of numerous small blood vessels within the pulpMedications (tetracycline)Intrinsic stains are difficult to treat. Possible treatments include full crowns, external bleaching of vital teeth, internal bleaching of nonvital teeth, bonded restorations, composite build-ups, and laminate veneer crowns.
44Intrinsic Coloration of Teeth PorphyriaHyperbilirubinemiaTetracycline Stain
46Localized Disturbances in Eruption Eruption – the continuous process of movement of a tooth from developmental location to functional locationImpacted – teeth that cease to erupt due to physical obstructionEmbedded – teeth that cease to erupt due to lack of eruptive forceAnkylosis – teeth that cease to erupt due to anatomic fusion of tooth with alveolar bone
47Localized Disturbances in Eruption Primary impaction of deciduous teeth is extremely rare. Most commonly involves second molars often due to ankylosis.Primary impaction of permanent teeth most frequently affects third molars. Lack of eruption is most often related to crowding and insufficient maxillofacial development.Impacted teeth are frequently diverted or angulated, eventually losing their potential to erupt; mesioangular, distoangular, vertical, horizontal and inverted
48Localized Disturbances in Eruption Treatment includes long-term observation, orthodontic-assisted eruption, transplantation, or surgical removalRisks associated with both intervention and noninterventionSurgical removal of impacted teeth is the procedure most frequently performed by OMFS
49Localized Disturbances in Eruption Ankylosis – cessation of eruption after emergenceUsually develops between ages 7-18; peak 8-9; prevalence est %Fails to respond to orthodontic therapyFailure to treat can result in tilting, carious destruction, and periodontal diseaseWhen successor tooth present, best treated with extraction and space maintenance
50Localized Disturbances in Eruption Primary tooth impactionMesioangular impactionAnkylosis
52Developmental Alterations in the Number of Teeth Anodontia – total lack of tooth development. Rare; most cases occur in hereditary hypohidrotic ectodermal dysplasiaHypodontia – lack of development of one or more teeth. Uncommon in deciduous teeth, usually involves mandibular incisors. More common in permanent teeth, third molars most affected. More frequent in females than malesOligodontia – lack of development of six or more teeth
53Developmental Alterations in the Number of Teeth Hyperdontia – development of increased number of teeth. Additional teeth are supernumerary. Prevalence 1-3%. More common in males and usually develops by age 20.Maxilla is most common site (90%) for single tooth hyperdontia, especially incisor region (mesiodens)Most single supernumerary teeth are unilateral. Nearly 75% of supernumerary teeth in anterior maxilla fail to eruptNon-syndromic multiple supernumerary teeth occur mostly in mandible.
56Developmental Alterations in the Number of Teeth Mesiodens – supernumerary tooth in maxillary anterior incisor regionDistomolar/Distodens – accessory fourth molarParamolar – posterior supernumerary tooth situated lingually or buccally to a molar toothDental transposition – normal teeth erupted in an inappropriate patternNatal teeth – teeth present in newborns; teeth arising during the first 30 days of life; (85% mandibular incisor region)
59Treatment of Developmental Alterations in the Number of Teeth Hypodontia – often no treatment required for individual missing teeth; prosthetic replacement for multiple missing teeth.Hyperdontia – early removal of accessory tooth; delayed in therapy can delay eruption of adjacent teeth or cause displacement.Natal teeth – may be removed if they are loose; if stable, they should be retained; Riga-Fede disease (ulceration of ventral tongue associated with breast-feeding) can often be treated without removal of the teeth.
65Developmental Alterations in the Size of Teeth (1) Microdontia – small teeth. Can also be related to tooth size relative to jaw size. More common in females. Isolated microdontia within otherwise normal dentition is not uncommon (peg-shaped lateral %). Diffuse microdontia occurs in some hereditary disorders and sometimes associated with hypodontia. Increased in Down’s, pituitary dwarfism & a few other syndromes.Macrodontia – larger than average teeth. More common in males. Typically only a few teeth are abnormally large. Diffuse macrodontia may occur in pituitary gigantism. It can be associated with hyperdontia.
69Developmental Alterations in the Shape of Teeth Double teeth – two separate teeth exhibiting union by dentin and sometimes pulps (fusion).May result from fusion of two tooth buds, or partial splitting of one into two.Concrescence – union of two teeth by cementum without confluence of dentin.Gemination – single enlarged tooth or joined (double) tooth in which tooth count is normal when this tooth is counted as one.Fusion – single enlarged tooth or joined (double) tooth in which the tooth count is short one when this tooth is counted as one.
72Treatment of Developmental Alterations of Shape of Teeth Extraction of deciduous double teeth may be necessaryShaping with/without placement of full crownsMay require surgical removal with prosthesisConcrescence requires no therapy unless interfering with eruption
73Developmental Alterations in the Shape of Teeth: Accessory Cusps Cusp of Carabelli – accessory cusp located on palatal surface of mesiolingual cusp of maxillary molar. Very common in Caucasians (up to 90%), rare in Asians.Talon cusp (anterior dens evaginatus) – well defined additional cusp located on surface of anterior tooth extending at least half the distance from the cemento-enamel junction to the incisal edge (<1-8%). Usually projects from the lingual surface.Dens evaginatus – cusp-like elevation of enamel located in central groove or lingual ridge of buccal cusp of permanent premolar or molar teeth. Rare in whites; 15% Asians.
76Treatment of Accessory Cusps Talon cusps on mandibular teeth often require no therapy, talon cusps on maxillary teeth should be removedCusps of Carabelli require no treatment, unless deep groove is present, then it should be sealedDens evaginatus often results in occlusal problems, so should be removedShovel-shaped incisors – deep fissures should be restored
77Dens InvaginatusDeep surface invagination of crown or root that is lined by enamelCoronal dens invaginatus may be large, resembling a tooth within a tooth (dens in dente), or it may be dilated and disturb tooth formation resulting in anomalous tooth development (dilated odontome)Radicular dens invaginatus is rare, formation of strip of enamel extending along root surface; altered enamel forms a surface invagination into dental papilla
79Treatment of Dens Invaginatus Minor cases of coronal dens invaginatus do not require removal of the toothOpening of invagination should be restored to prevent cariesLarge coronal dens invaginations often disrupt normal coronal development and should be removedComplications of radicular dens invaginatus rare
80Ectopic Enamel Ectopic enamel – presence of enamel in unusual places. Enamel pearls – hemispheric structures projecting from the surface of the root, found mostly on the roots of maxillary molars.Cervical enamel extensions – located on buccal surface of root overlying bifurcation.Buccal bifurcation cyst – inflammatory cyst developed along buccal surface over the bifurcationTreatment: Enamel pearls – good oral hygiene, sometimes removal with caution. Buccal bifurcation cyst – surgical removal, periodontal treatment.
82TaurodontismEnlargement of body and pulp chamber of multirooted tooth with apical displacement of pulpal floor and bifurcation region ( %)Increased apico-occlusal height and bifurcation near apexUnilateral or bilateral; Affects permanent teeth more often than deciduous teethNormal (cynodont), Mild (hypotaurodontism), moderate (mesotaurodontism), severe (hypertaurodontism)No specific treatment; Prosthodontic, endodontic considerations.
84HypercementosisNon-neoplastic deposition of excessive cementum continuous with the normal radicular cementumThickness or blunting of root radiographically, localized or generalized.Local or systemic factors; loss of antagonist tooth, occlusal trauma, inflammation, Paget’s disease, acromegaly, etc.Significant generalized hypercementosis in persons with Paget’s diseaseNo specific treatment
86DilacerationAbnormal angulation or bend in root (or commonly the crown)During tooth development, it is thought to arise following displacement injury or less frequently secondary to the presence of an adjacent cyst or tumorTreatment - minor dilaceration in permanent teeth requires no therapy; grossly deformed teeth should be removed; extraction of deciduous teeth when eruption is delayed.
88Supernumerary Roots Increased number of roots No treatment necessary, but detection of extra root critical for endodontic therapy or exodontia
89Developmental Alterations in the Structure of Teeth
90Amelogeneis Imperfecta Group of conditions that demonstrate developmental alterations in enamel structure in the absence of a systemic disorderDevelopment of enamel has three major stages: (1) Elaboration of the organic matrix; (2) Mineralization of the matrix; and (3) Maturation of the enamelAt least 14 subtypes related to above with a variety of inheritance and clinical patterns
91Amelogeneis Imperfecta Witkop classification combines inheritance and clinical patternsType I hypoplastic; generalized/localized, smooth/pitted/rough, AD, AR. X-linkedType II hypomaturation; pigmented/non-pigmented, diffuse/snow capped; AD, AR, X-linkedType III Hypocalcified; diffuse AD/ARType IV Hypomaturation-hypoplastic or hypoplastic-hypomaturation with taurodontism; AD
92Amelogeneis Imperfecta Hypomineralized formHypoplastic form
93Hypoplastic Amelogenesis Imperfecta Inadequate deposition of enamel matrixGeneralized pattern – pinpoint sized pits scattered across surface of teethLocalized pattern – horizontal rows of pits, linear depression or one large area of hypoplastic enamelAutosomal dominant smooth pattern – smooth surface, enamel is thin, hard, and glossyX-linked dominant smooth pattern – alternating zones of normal and abnormal enamel related to active X chromosomesRough pattern – thin, hard, rough enamelEnamel agenesis – total lack of enamel formation
95Hypomaturation Amelogenesis Imperfecta Enamel matrix laid down appropriately and begins to mineralize, but there is defective maturation of enamel’s crystal structure; normal shape but abnormal mottled, opaque white-brown colorPigmented pattern (AR) – surface enamel is mottled and brownX-linked pattern – deciduous are opaque white; permanent are yellow-white that darken with ageSnow-capped pattern – zone of white opaque enamel on incisal or occlusal surface of the crown
96Hypocalcified Amelogenesis Imperfecta Enamel matrix laid down appropriately but no significant mineralization occurs (very soft enamel)Normal shape but enamel soft and easily lostTeeth yellow-brown to orangeUnerupted teeth and anterior open bite fairly common
98Hypomaturation/hypoplastic Amelogenesis Imperfecta Enamel hypoplasia combined with hypomaturation.Hypomaturation-hypoplastic pattern – primary defect is enamel hypomaturation; mottled yellow-white to yellow-brown.Hypoplastic-hypomaturation pattern – primary defect is enamel hypoplasia (thin enamel).Both patterns seen in tricho-dento-osseous dysplasia syndrome
99Treatment of Amelogenesis Imperfecta Depends on severity; Problems include aesthetics, sensitivity, vertical dimension, caries, open bite, delayed eruption and impactionWhere enamel is very thin, full coverage needed as soon as possibleLess severe cases, aesthetics are main consideration. Full crowns or facial veneers
100Dentinogenesis Imperfecta Hereditary developmental abnormality of the dentin (Hereditary opalescent dentin, Capdepont’s teeth)May be seen alone (type II) or in conjunction with osteogenesis imperfecta (type I—opalescent teeth)All teeth in both dentitions affectedBlue/brown discoloration, dentin demonstrates accelerated attrition“Shell teeth” – normal-thickness enamel, extremely thin dentin, enlarged pulps (Brandywine variant; Shield’s type III)TreatmentEntire dentition at riskMost need full dentures by age 30
101Dentinogenesis Imperfecta Radiographic features oftype I or II
103Dentinogenesis imperfecta III (“Shell teeth”, Brandywine variant, Shield's type III)
104Dentin DysplasiaDentin dysplasia type I (rootless teeth); 1/100,000; Loss of organization of root dentin leads to shortened root length; crowns appear normal; periapical pathology related to caries/exposure of threads of pulp tissueDentin dysplasia type II (coronal dentin dysplasia); thistle tube shape of pulp chamber; features of dentinogenesis imperfecta (bulbous crowns, cervical constriction, thin roots, early obliteration of pulp, blue to amber-brown coloration); pulp stones in enlarged pulp chambersTreatment - preventive care, good oral hygiene
107Regional Odontodysplasia (Ghost Teeth) Idiopathic, localized developmental abnormality (segment or region of jaw) with adverse effects on formation of enamel, dentin & pulp.Maxilla more common (2.5:1) with predilection for anterior teeth; deciduous & permanent involvement or permanent aloneExtremely thin enamel and dentin surrounding an enlarged radiolucent pulpTreatment is try to retain altered teeth to allow for appropriate development and preservation of surrounding alveolar ridge. Severely affected and infected teeth should be removed. Unerupted teeth covered with removable partial prosthesis until skeletal growth period has passed