Presentation on theme: "Developmental anomalies of the teeth, specific and non – specific disorders of hard dental tisuess 6 DM."— Presentation transcript:
1Developmental anomalies of the teeth, specific and non – specific disorders of hard dental tisuess 6 DM
2Developmental anomalies tooth development is strict under genetic controldisturbances in tooth development result from gene mutationtooth development may be disturbed at different stages of morphogenesisdefinitive result depends on the timing and the type of insult
3Developmental anomalies Disturbances in tooth development:numerical variations (missing or supernumerary teeth)variations in size of teethvariations of shape of teethdisturbances in eruption
4Developmental anomalies Numerical variations1.Hypodontianumber of teeth is decreasethe most commonly missing teeth are:the third molars, second premolars, maxillary lateral incisors- oligodontia, anodontia, agenesis
5Developmental anomalies Numerical variations1.Hypodontia in deciduous dentiotion:- prevalence 0.1 – 0.7%central incisorsoligondontia and anodontia is rare, may be found in connection with ectodermal dysplasia
6Developmental anomalies Ectodermal dysplasia:describes a group of developmental, often inherit, disorders involving the ectodermally structures(hair,teeth, nails, skin and sweat glands)presentation:multiple missing teeth, fine, sparse hair, dry skin, maxillary hypoplasia, eversion of the lips, pigmentation around the mounth and eyes. The teeth are conical, small, often with a large diastema.
7Developmental anomalies Numerical variations1.Hypodontia in permanent dentiotion:prevalence 6 – 10%usually affects 2 or more teeth in 50% of the casesoften occures symmetrical hypodontiaparticular relation with the microdontia
8Developmental anomalies Solitary median maxillary central incisor syndromeis very raremidline symetrical maxillary central incisorcan be associated with cleft palate, choanal stenosis, umbilical hernia, hypoplasia of sella turcica, pituitary dysfunction, growth hormone deficiency
10Developmental anomalies Numerical variations2. Hyperodontianumber of the teeth is increseis quite rare as hypodontiaFrequency: primary teeth 0,3 - 0,8%permanent teeth 1,0 – 3,5%
11Developmental anomalies Numerical variations2. Hyperodontia- shape is conical or normalsupernumerary teeth can erupt or cause anomalous eruption of neighbouring teethmost frequent is mesiodenspart of syndrom cleidocranial dysplasia
12Developmental anomalies Cleidocranial dysplasia:short statureaplasia or hypoplasia of claviclesdelayed ossificationdelayed eruption of teethdentigerous cyst formation
13Developmental anomalies Dentes praelactalesfrontal region in a newbornsno rootsTh: extraction
15Developmental anomalies Variations in tooth size:Macrodontiateeth are larger than normaltrue macrodontia involving the whole dentition2. Microdontiaone or more teeth are smaller than normalmost affect the maxillary third molars
16General microdontia: is a rare conditionoccuring in connection with congenital Local microdontia: involving single teeth, associated with hypodontia3. Rhizomicry-lenght of the root is shorter than the height of the crownconnected with osteoporosispredominantly affecting maxillary incisors and premolars
17Developmental anomalies Variations on tooth shapeDens invaginatusmalformation due to an invagination of enamel epitelium resulting in a chanel or lumen surrounded by hard tissues within the tooth. The anomaly occurs most frequently in the palatal surface of max. lateral incisor.2. Conical peg-shaped tooth
18Developmental anomalies Variations on tooth shape3. Taurodontismelongated root- stem with the furcation more apical than normally4. Double formation of teetha) concrescence- two normal appearing crowns are present and the fusion involves only the cementum
19Developmental anomalies Variations on tooth shapeb) Fusion – union in dentin and/or enamel between two or more normal teethc) Gemination – incomplete division of a tooth germ or a union between normal and a supernumerary tooth5. Dnes evaginatus- is an extra cusp, usually in the central groove or ridge of a posterior teeth and in the cingulum of the central or lateral incisor
20Developmental anomalies 6. Dens in denteis a condition resulting from invagination of the inner enamel epithelium producing the appearance of a tooth within a tooth7. Dilaceration- an abnormal bend of the rooth during its development and is thought to result from a traumatic episode
23Developmental anomalies Variations in tooth eruptiontooth retentiontooth semiretentionanomalous position after eruption
24Non – specific disorders of hard dental tisuess HypoplasiaHypomineralizationHypoplasia:Ethiology:- metabolic disorders, fever, endocrinic disease,trauma, inflammationCl. picture: anomalous shape of dental crown, grooves and fissures, color-dark brown, yellowbrown.
25Non – specific disorders of hard dental tisuess Hypomineralization:Ethiology:- metabolic disorders, fever, endocrinic disease,trauma, inflammationCl. picture: normal shape of dental crown, in hard dental tisuess are quality changes. Color- white or brown smudges, localization on labial surfaces of incisors
26Specific disorders of hard dental tisuess Dysplasia of hard dental tisuess1.DENTIN DYSPLASIAEthiology: ingestion of chemicals, prematurity birthweight, severe malnutrition, bilirubinemiaTyp I: radicular dentin dysplasia or rootless toothTyp II: anomalous dysplasia of dentin with frequent discoloration of primary teeth, permanent teeth often appear normal clinically but have thistle-tube formed pulp chamber. Pulp stones may occure.
27Specific disorders of hard dental tisuess 2. Fluoride induced defect
28Specific disorders of hard dental tisuess 3. Tetracycline defects- TTC has a strong affinity to mineralized tisuess, primary to dentin and bonesdentin defects are persistentdiscolored horizontal bands may appear gray, bluishdiscolored enamel has some translucency leftthis ATB shoud not be prescribed to children below the age of 8, pregnant women, lactating mothers
29Specific disorders of hard dental tisuess 4. Molar – incisor hypomineralizationdemarcated opacities in the perm. first molars, perm. incisors are often also involvedmay affect one or all molars and one or more incisorscreamy white spot to yelowish brown discolorationdefect are porous
30Specific disorders of hard dental tisuess Subj. symptoms:shooting pain during brushing teeth or breathing cold airEthiology:- unknown, but suggestion are: medical problem related to birth, respiratory diseases during first 3 years of life
32Specific disorders of hard dental tisuess Amelogenesis imperfectaDefinition:AI represents a roup of condition, genomic in origin, which affect the structure and clinical appearance of the enamel of all or nearly all teeth in a more or less equal manner, and which may be associated with morphologic or biochemical changes elsewhere in the body.
33Specific disorders of hard dental tisuess - autosomal dominant, autosomal recessiveincidence 1 in4 major categories, 14 subtypesGeneral manifestation:normal intelligence, good general healthCraniofacial/dental manifestation:enamel defect that affects both dentitions, appearance is yellow- brown to orange depending on subtyp
34Specific disorders of hard dental tisuess Typ I:- hypoplastic (occuring in the histodifferation stage of tooth development, insufficient quantity of enamel is formed)TypII:- hypomaturation (defect of in enamel matrix apposition)Typ III:- hypocalcified (enamel is normal, but qualitatively the matrix is poor calcified with a resultant fracturing of the enamel surface. Hypocalcified enamel is soft and fragile, especially at the incisal region, and is easily fractured, exposing dentin.
35Specific disorders of hard dental tisuess Typ IV:- hypomaturation, hypoplastic with taurodontism (the enamel appears mottled with a yellow-brown color and is pittedon the facial surfaces. Molar teeth demonstrate taurodontism.
37Specific disorders of hard dental tisuess Dentinogenesis imperfectaDefect of predentin matrix that result amorphic, disorganized, and atubular circumpulpal dentin.incidence 1 in 80003 basic typesShields type 1Shields type 2Shields type 3
38Specific disorders of hard dental tisuess Shields type 1occurs with AIinherit defect in collagen formationosteoporotic brittle bonesbowing of the lipsblue sclerabitemporal bossingobliteration of pulp chamber,periapical radiolucencies, bulbous crowns, root fractures
39Specific disorders of hard dental tisuess Shields type 2hereditary opalescent dentinautosomal dominantaffect primary and permanent dentitionShields type 3is rare, bell-shaped crown,it has occured exclusively in a triracial isolated group in Maryland