FUSION(SYNODONTIA)DEFINITION: y Fusion of teeth results from the combining of adjacent tooth germs resulting in union of the developing teeth. ETIOLOGY: Some physical force or pressure generated during development causes contact of adjacent tooth buds.

CLINICAL FEATURES:

y Reduced number of teeth in the arch. y More common in anterior teeth. y More common in deciduous teeth. y May be total or partial depending n the stage of

odontogenesis and the proximity of developing teeth. y A bifid crown or two recognizable teeth may be joined by dentin or enamel.

RADIOGRAPHIC FEATURES:y More evident on the

radiograph than on clinical examination.y Fused teeth may show an

unusual configuration of the pulp chamber,root canal or crown.

DIFFERENTIAL DIAGNOSIS: y Gemination y Macrodontia MANAGEMENT:y If the affected teeth are deciduous,they may be

retained as they are. y In case of fused secondary teeth,the fused crowns may be reshaped with a restoration that mimic two independent crowns.

CONCRESCENCEDEFINITION: Concrescence occurs when the roots of two or more teeth are united by cementum. ETIOLOGY: Traumatic injury. Crowding of teeth with resorption of interdental bone. CLINICAL FEATURES: Frequently involved teethmaxillary molars,especially third molars and a supernumerary tooth. Involved tooth may fail to erupt or may erupt incompletely.

RADIOGRAPHIC FEATURESy A radiographic examination

may not always distinguish between concrescence and teeth that are in close contact or are simply superimposed.y When the condition is

suspected on a radiograph and extraction is one of the teeth is being considered,additional projections at different angles may be obtained to better delineate the condition.

DIFFERENTIAL DIAGNOSIS: Fusion MANAGEMENT: y Concrescence affects treatment only when the the decision is made to remove one or both of the involved teeth.This condition complicates the extraction. y The clinician should warn the patient that an effort to remove one might result in the unintended and simultaneous removal of the other.

GEMINATION(TWINNING)DEFINITION: y Gemination arise from an attempt at division of a single tooth germ by an invagination with resultant incomplete formation of two teeth. y In rare cases complete division throughout the crown and root producing identical structures. CLINICAL FEATURES: y More frequently affects primary teeth ,usually in the incisor region. y The enamel or dentin may be hypoplastic or hypocalcified.

RADIOGRAPHIC FEATURESy Radiopaque enamel outlines the clefts in the crowns . y The pulp chamber is usually single and enlarged and may be partially divided. y In rare case of premolar gemination,the tooth image suggests a molar with an enlarged crown and 2 roots.

DIFFERENTIAL DIAGNOSIS Fusion MANAGEMENT y Affected teethmay be removed(esp if deciduous),or the crown may be restored or reshaped,or the tooth may be left untreated and periodically examined to preclude the development of complications.

TAURODONTISMDEFINITION y It is an anomaly in which the body of the tooth is enlarged at the expense of roots. y May occur either in both dentition. y Mostly seen in molars and less often in premolars.

CLINICAL FEATURES Because the body and roots of taurodontic tooth lies below the alveolar margin,the distinguishing features of these teeth are not recognizable.

RADIOGRAPHIC FEATURESy The peculiar feature is an extension of the rectangular pulp chamber into the elongated body of the tooth. y Shortened roots and root canals are a function of long body and normal length of the tooth. y The size crown is normal.

DIFFERENTIAL DIAGNOSIS Developing molar MANAGEMENT Taurodont teeth do not require treatment.

DILACERATIONDEFINITION: Dilaceration is a disturbance in tooth formation that produces a sharp bend or curve in the tooth. CLINICAL FEATURES: y Most cases of radicular dilaceration are not recognized clinically. y If the defect is in crown of an erupted tooth,it may readily recognized as an angular distortion.

RADI

RAPHI FEAT RES

y Best means of detecting radicular dilaceration. y If the root bends mesially or distally,the condition

is clearly apparent on periapical radiograph. y When buccally or lingually bend,the dilacerated portion appears at the apical end of the unaltered root as a rounded opaque area with a dark shadow in its central region cast by the apical foramen and root canal(an appearance like a bull s eye). y The PDL space around this dilacerated portion may be seen as a radiolucent halo and the radiopacity of this segment of root is greater than the rest of the root.

Dilaceration

DIFFERENCIAL DIAGNOSIS: Fused roots MANAGEMENT: y Dilacerated root generally does not require treatment because it provides adequate support. y Dilacerated crowns are frequently restored with a prosthetic crown to improve esthetics and function.

DENS IN DENTE(DENS INVAGINATUS,DILATED ODONTOME,GESTANT ODONTOME)DEFI I I : De s i e te res lts fr a f t e ter i f l i s rface i t t e i teri r f at t . y See st fte i t t cr s et a al s f t e e a el i f l i r a i t t e e tal a illa. y i r t,it a ears t e t e res lt f a i va i ati f Hert i s e it elial r t s eat .

CLINICAL FEATURESy Coronal dens in dente may be identified as a pit at the

incisal edge or the cingulum. y permenant maxillary lateral incisors>maxillary central incisors>premolars&canines>posterior teeth. y rare in deciduous teeth. y The clinical importance of dens in dente results from the risk of pulpal disease.

RADIOGRAPHIC FEATURESy The infolding of the enamel

lining is more radiopaque than the surrounding tooth structure and can be easily identified. y If coronal invagination is extensive ,the crown is almost invariably malformedwhich result in usually wide apical foramen.

MANAGEMENTThe condition must be recognized early &restored prophylactically.

DENS EVAGINATUS(LEONG S PREMOLAR)DEFINITION Dens evaginatus is the result of an outfolding of the enamel organ. CLINICAL FEATURES y Appears as atubercle of enamel on the occlusal surface of the affected tooth. y The tubercle often has a dentin core,and a very slender pulp horn frequently extends into the evagination.

RADIOGRAPHIC FEATURESy The dentin core is

usually covered with opaque enamel. y If the tubercle has been worn to the point of pulpal exposure or has fractured,pulpal necrosis may result.This is indicated by an open apical foramen and periapical radiolucency.

MANAGEMENT y Removal of the enamel of the tubercle and placement of the calcium hydroxide dressing to stimulate the odontoblast to produce reperative dentin. y If pulpally involved endodontic treatment is considered.

AMELOGENESIS IMPERFECTADEFINITION Amelogesis imperfecta is a group of disorders characterised by alteration of quality & quantity of enamel and is associated with significant dental disease. ETIOLOGY Gene mutation in the enamel matrix produces hypoplasia,hypomaturatio n and hypocalcification.

CLASSIFICATION Type I- ypoplasia Type II- ypomaturation Type III- ypocalcification Type IV- ypomaturationhypocalcification

CLINICAL FEATURES ypoplastic: y Teeth lacks normal enamel thickness. y Inadequate deposition of enamel matrix. y Enamel-pitted,have horizontal or vertical ridges.

Hypomaturation : y Normal depostion of enamel matrix. y Defective crystal structure mineralization. y Affected teeth shows mottled opaque white brown yellow discoloration. y Enamel is softer than normal and chip from the underlying dentin.

Hypomaturation hypocalcification: y Enamel is mottled yellow &brown. y Thin with areas of hypomaturation. y Molar teeth have taurodont shape. y Other teeth have enlarged pulp chambers.

RADOGRAPHIC FEATURESy The radiographic signs of hypoplastic amelogenesis imperfecta include a square shape of crown,a relatively thin opaque layer of enameland low or absent cusps. y The hypomaturation form demonstrates normal thickness of enamel but its density is same as that of dentin. y In the hypocalcified forms the enamel thickness is normal,but its density is even less than that of dentin.

DIFFERENTIAL DIAGNOSIS Dentinogenesis imperfecta MANAGEMENT Restoration of the esthetics and function of the affected teeth.

DENTINOGENESIS IMPERFECTA(HEREDITARY OPALESCENT DENTIN)DEFINITION Is a hereditary developmental disturbance of dentin,seen alone or in conjunction with osteogenesis imperfecta. CLINICAL FEATURES y All the teeth are affected y Deciduous >permanent y Blue to brown discoloration with distinctive amber like translucency. y Enamel separates from the defective dentin y Pulp are obliterated by excess dentin production

RADIOGRAPHIC FEATURESy Dentinogenesis

imperfecta charecteristically shows a constriction in the cervical portion of the root,a bulbous crown,short roots and a reduced size of the pulp chamber and root canals.

DIFFERENTIAL DIAGNOSIS Dentin dysplasia MANAGEMENT y Overdentures on the teeth to prevent alveolar resorption. y The teeth shouldnot be extracted in patients from 5-15 yrs.In adults extraction of teeth and their replacement can be recommented.

OSTEOGENESIS IMPERFECTAy A hereditary disorder (usually an autosomal dominant

trait)characterised by osseous fractures. y Patient may have blue sclera,wormian bones(bones in skull sutures),skeletal deformities and progressive osteopenia. y Oral findings: y Class III malocclusion, increased incidence of impacted 1st& 2ND molars.

DENTIN DYSPLASIAy DEFINITION: y Is a rare disturbance of dentin formation characterized by normal enamel but atypical dentin formation with abnormal pulpal morphology. y Types : y Type I Radicular dentin dysplasia y Type II-Coronal dentin dysplasia

CLINICAL FEATURESy Type I[radicular]: y Both dention affected y Slight amber translucency y Extreme mobility y Exfoliative prematurely or after minor trauma.

TYPE II(CORONAL) y Deciduous teeth have yellow , brown or bluish grey opalescent appearance. y Clinical appearance of permanent dentition is normal.

RADIOGRAPHIC FEATURESType-I y Both the dentition , the roots are short , blunt conical or similarly malformed. y In deciduous teeth pulp chambers and root canals are usually completely obliterated. y In permanent crescent shaped pulpal remnant in pulp chamber. Type-II y Obliteration of pulp chamber and reduction in the caliber of the root.

DIFFERENTIAL DIAGNOSIS Dentinogenesis imperfecta MANAGEMENT Type I-Prosthetic replacement Type II-Abraded tooth can be crowned Discolored anterior teeth can be replaced by prosthetic treatment.

REGIONAL ODONTODYSPLASIA(ODONTOGENESIS IMPERFECTA)DEFINITION: y Is a localized disorder of the tissues of dental origin resulting in characteristically bizare clinical&radiographic appearances.

CLINICAL FEATURES y Teeth affected are mottled brown as a result of hypocalcified hypoplastic enamel. y Central incisor most affected,lateral incisor and canine also affected. y Eruption of defective teeth delayed or even may not erupt. Radiographic appearance y Ghost like appearance of tooth y Thin enamel and dentin y Pulp chambers are large and root canals wide

DIFFERENTIAL DIAGNOSIS Dentinogenesis imperfecta MANAGEMENT y Restoration of affected tooth y Severely damaged permanent teeth that become pulpally involved may require removal and replacement.

ENAMEL PEARLDEFINITION The enamel pearl is a small globule of enamel 1-3 mm in diameter that occurs on the roots of molars. CLINICAL FEATURES Develops at the trifurcation of maxillary molars and bifurcation of mandibular molars.

RADIOGRAPHIC FEATURES y Appears smooth,round and comparable in degre of radiopacity to the enamel covering the crown. DIFFERENTIAL DIAGNOSIS y A piece of calculus y Pulp stone MANAGEMENT y The clinician can remove the mass if its location at the CEJ predispose to periodontal disease.

TALON CUSPDEFINITION: The talons cusp is an accessory cusp like structure projecting from the cingulum area or CEJ of the maxillary or mandibular anterior teeth.

CLINICAL FEATURES y Appears as an additional cusp. y Projects from palatal surface of primary or permanent anterior teeth. y It extends at least half distance from CEJ to incisal edge.

RADIOPAQUE FEATURES y The radiopaque image of a talon cusp is superimposed on the crown of the involved incisor.MANAGEMENT y If talons cusp interfere with occlusion,then removed by periodic grinding of the cusp. y If deep fissures are present between the cusp and tooth then sealed using pit and fissure sealants.

TURNER S HYPOPLASIA(TURNER S TOOTH)DEFINITION y Turner s hypoplasia is a term used to describe a permenant tooth with a local hypoplastic defect in its crown. y May have been caused by extension of a periapical defect from its deciduous predecessor or by mechanical trauma transmitted through the deciduous tooth.

CLINICAL FEATURES y Mandibular premolars mostly affected. y The hypomineralised area may become stained and the tooth usually shows a brownish spot on the crown. y In severe case crown may show pitting. RADIOGRAPHIC FEATURES The involved region of the crown may appear as an illdefined radiolucent region. MANAGEMENT Restoration of the affected crown.

CONGENITAL SYPHILISDEFINITION y About 30% of people with congenital syphilis develop dental hypoplasia that involves the permenant incisors and first molars. y The affected incisor called Hutchinson s teeth and the molars,mulberry molars. CLINICAL FEATURES y The affected incisor has a characteristic screw driver shaped crown,with the mesial and distal surfaces tapering from middle of the crown to the incisal edge. y The affected molar appear smaller,sometime even smaller than 2nd molar.The enamel over the occlusal surface appear in irregular globules,like the surface of a mulberry.

RADIOGRAPHIC FEATURES The charecteristic shape of the affected incisor and molar can be identified in the radiograph. MANAGEMENT y Hutchinson s teeth and mulberry molar often do not require any treatment. y Esthetic restoration may be done to correct the hypoplastic defects indicated clinically.

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