ABNORMALITIES OF TEETH

1
ABNORMALITIES OF TEETH

• Environmental Alterations of Teeth
• Developmental Alterations of Teeth

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ENVIRONMENTAL ALTERATIONS OF TEETH

• Developmental tooth defects
• Turners tooth
• Hypoplasia caused by antineoplastic therapy
• Fluorosis
• Syphilitic hypoplasia
• Postdevelopmental structure loss
• Tooth wear
• Internal and external resorption
• Discolorations of teeth
• Intrinsic stains
• Extrinsic stains
• Localized disturbances in eruption
• Primary impaction
• Ankylosis

3
Enamel development

• Three stages1. Matrix formation protein laid
  down
• 2. Mineralization minerals deposition,
  majority of original prot. removed-- diffuse,
  opaque white, soft enamel
• 3. Maturation final mineralization--
  translucent, hard enamel
• Amelogenesis imperfecta
• Enamel hypoplasia

4
Enamel development

• No remodeling after initial formation
• Timing of ameloblastic damage has a great impact
  on location appearance of the defect
• Development of crown from 14th week of
  gestation to 12 months of age in deciduous
  dentition 6 months to 15 y/o in permanent
  dentition
• Neonatal ring on deciduous enamel and deposition
  with a rate of 0.023mm/day

5
Factors associated with enamel defects
See Box 2-2

• Systemic-
• 1. Birth-related trauma premature birth
• 2. Chemicals antineoplastic C/T, fluoride,
  tetracycline
• 3. Chromosomal abnormalities trisomy 21
• 4. Infections chicken pox, CMV, syphilis
• 5. Inherited diseases Vit.D-dependent rickets
• 6. Malnutrition Vit. A deficiency
• 7. Metabolic disorders hypoparathyroidism,
  maternal diabetes
• 8. Neurologic disorders cerebral palsy

6
Factors associated with enamel defects
See Box 2-2

• Local-
• 1.Local acute mechanical trauma
• 2. Electric burn
• 3. Irradiation
• 4. Local infection periapical inflammatory
  disease

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Clinical and Radiographic Features

• Environmental enamel defects
• 1.Hypoplasia pits, grooves or large area of
  missing enamel
• 2. Diffuse opacities variation in translucency,
  normal thickness, white opacity without clear
  boundary
• 3. Demarcated opacities increased opacity, a
  sharp boundary with adjacent normal enamel,
  normal thickness

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Turners hypoplasia, Turners tooth

• Permanent teeth
• Periapical inflammatory disease of the overlying
  deciduous tooth, less frequently in anterior
  teeth
• Traumatic injury- not rare
• -45 children sustain injury to their
  deciduous teeth, 23 permanent teeth
  development disturbed

Turners hypoplasia secondary to previous trauma
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Turners teeth
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Hypoplasia caused by antineoplastic therapy

• Under 12 y/o, esp. under 5y/o
• Age at treatment, forms of therapy
• Chemotherapy-
• Less alteration than radiation
• Increased number of enamel hypoplasia and
  discolorations, slight smaller tooth size,
  radicular hypoplasia

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Radiotherapy-

• 0.72 Gy related to mild defects in enamel, dentin
  (?????????????2Gy)
• Dose, radiation field

12

• Developmental radicular hypoplasia and
  microdontia caused by radiotherapy

13

• Hypodontia, microdontia, radicular hypoplasia,
  enamel hypoplasia, mandibular hypoplpasia,
  reduced in vertical development of lower 1/3 of
  face
• Mandibular hypoplpasia may caused by Radiation
  ?impaired root development ?reduced alveolar bone
  growth
• Cranial radiation? altered pituitary gland
  function? growth failed

14
Dental fluorosis

• 1901, Dr. Frederick S. McKay Colorado brown
  stain
• 1909, Dr. F.L. Robertson in Bauxite, Arkansas
• 1930, H.V. Churchill high concentration of
  fluoride of Bauxite(13.7ppm) and Colorado
• 1931, Dr. H. Trendley Dean association between
  fluoride, dental fluorosis and prevalence of
  caries among children
• 1.0 ppm reduced caries by 5070 and associated
  with low and mild mottled enamel
• 0.71.2 ppm water fluoridation was recommended
  after 1962, currently 0.7ppm is recommended due
  to increased dental fluorosis

15
Dental fluorosis

• Retention of the amelogenin protein in enamel
  structure? hypomineralized enamel? permanent
  hypomaturation? increased surface and subsurface
  porosity? alters light reflection and create
  white, chalky area

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Dental fluorosis

• Critical period for clinical dental fluorosis is
  the 2nd and 3rd year of life, dose dependent
• Caries resistant

17

• Syphilitic hypoplasia
• Congenital syphilis
• Hutchinsons incisors mulberry molars

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POSTDEVELOPMENTAL LOSS OF TOOTH STRUCTURE

• Begin from enamel surface (tooth wear)
• Attrition, abrasion, erosion, abfraction
• Begin from dentin, cemental surface internal or
  external resorption

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Attrition

• Tooth to tooth contact during occlusion and
  mastication, some are physiologic
• Accelerated by poor quality or absent enamel,
  premature contact, intraoral abrasives, erosion,
  grinding habits
• Incisal, occlusal and interproximal surfaces

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Abrasion

• Pathologic loss of tooth structure or restoration
  secondary to the action of an external agent (ex.
  Toothbrush, hair grips, toothpicks, chewing
  tobacco, biting thread, dental flossing)
• Toothbrush abrasion horizontal buccal cervical
  notches of exposed radicular cementum and dentin
  with smooth surface.
• Greater on prominent teeth ( canines, premolars ,
  and teeth adjacent to edentulous area) and side
  of the arch opposite to the dominant hand
• Demastication- when tooth wear is accelerated
  by chewing an abrasive substance between opposing
  teeth (both attrition and abrasion)

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Abrasion
22
Abrasion
Improper use of hair grips
Long-term use of tobacco pipe
23
Erosion

• Chemical process, exposure to acidic foods or
  drinks, medications (chewable Vit. C, aspirin),
  involuntary regurgitation (ex. esophagitis,
  pregnancy), voluntary regurgitation (ex.
  psychologic problems, bulimia)
• Perimolysis- dental erosion from gastric
  secretion
• Facial surface of maxillary anteriors
  affected-dietary source
• Posterior teeth extensive loss of occlusal
  surface, and palatal surface concave dentin
  surrounded by an elevated enamel rim-
  regurgitation of gastric secretion

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Erosion
concave dentin surrounded by an elevated enamel
rim
25
Erosion
A bulimia patient
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Abfraction

• Repeated tooth flexure caused by occlusal
  stresses (tensile stress)
• ? concentrate at the cervical fulcrum
• ? may produce disruption in the chemical
  bonds of enamel crystal
• ?cracked enamel can be lost or removed by
  erosion or abrasion
• Wedge-shaped cervical defects, deep, narrow
  V-shaped, not allow toothbrush to contact base
  if the defect, often affect a single tooth
• Almost exclusively on facial surface and more
  often in bruxism, higher in mandibular dentition

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Abfraction
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Treatment and prognosis of tooth wear

• Resolve pain and sensitivity
• Identify the cause of tooth structure loss
• Protection

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INTERNAL EXTERNAL RESORPTION

• Internal resorption- by cells located in pulp,
  rare
• Follows injury to pulp tissues, physical trauma
  or caries, continue as long as vital pulp
  remains, may result in communication of the pulp
  and PDL
• External resorption- by cells in PDL, common

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Factors associated with external resorption
31
Clinical and Radiographic Features

• Internal resorption-
• Inflammatory resorption- dentin replaced by
  inflamed granulation tissue
• Pink tooth of Mummery internal resorption
  involved coronal pulp Balloonlike enlargement of
  the canal
• Replacement, or metaplastic absorption- pulpal
  dentinal walls are replaced by bone or
  cementum-like bone

32
Clinical and Radiographic Features

• External resorption-
• Moth-eaten loss of tooth structure, less
  well-defined and variation in density in
  radiography
• Most involved apical or midportions of root,
  occasionally, begin from cervical (invasive
  cervical resorption)

33
Histopathologic Feature

• Increased cellularity, vascularity and
  collagenization
• Numerous multinucleated dentinoclasts
• Inflammatory cells infiltration

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Treatment and prognosis

• Internal resorption-
• Removal of all soft tissue from site of
  resorption
• Endodontic treatment before perforation in
  internal resorption
• Placement of calcium hydroxide paste for
  remineralization
• Surgical exposure and restoration
• Extraction
• External resorption-
• Identification and elimination the accelerating
  factor

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ENVIRONMENTAL DISCOLORATION OF TEETH

• Extrinsic- surface accumulation of exogenous
  pigment
• Intrinsic-secondary to endogenous factors that
  result in discoloration of underlying dentin

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Extrinsic stains

• Bacterial- Chromogenic bacteria, green,
  black-brown, orange coloration Frequently in
  children, labial surface of maxillary ant. in
  gingival third
• Iron- formation of ferric sulfide
• Tobacco
• Food and beverage- chlorophyll
• Gingival hemorrhage- Hb. breakdown to biliverdin
• Restorative material ex. Amalgam
• Medications- iron, iodine, silver nitrate,
  chlorhexidine, stannous fluoride

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Intrinsic stains

• Amelogenesis imperfecta
• Dentinogenesis imperfecta
• Dental fluorosis
• Erythropoietic porphyria
• autosomatic recessive disorder of porphyrin
  metabolism, increased synthesis and excretion of
  porphyrins and their related precursors
• Porphyrin deposition in teeth, reddish-brown
  coloration, red fluorescence when exposed to a
  Woods UV light
• Present both in dentin and enamel in deciduous
  teeth, but only dentin affected in permanent
  teeth

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Erythropoietic porphyria
Hyperbilirubinemia
39
Intrinsic stains

• Hyperbilirubinemia- bilirubin, breakdown product
  of RBC, jaundance (yellow-green discoloration),
  erythroblastosis fetalis, biliary atresia
• Biliverdin deposition, green discoloration of
  teeth (chlorodontia)
• Ochronosis-alkaptonuria, blue-black discoloration
• Trauma- coronal discoloration, pulp necrosis
• Localized RBC breakdown

40
Intrinsic stains

• Medications-
• Tetracycline (bright yellow to dark brown),
  chlortetracycline (gray-brown), oxytetracycline
  (yellow) , minocycline hydrochloride
• Time of administration dose, duration
• Avoid from pregnancy up to 8 yrs of age

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Minocycline hydrochloride

• Tx for Acne
• Blue-gray from incisal 3/4, to dark green or
  black in roots, also affect developed teeth
• Skin, nail, sclera, conjunctiva, thyroid, bone
  discoloration in susceptible individuals

Stained alveolar bone
42
Treatment and prognosis

• Extrinsic stains- polishing
• Intrinsic stains- bleaching, bonded restoration,
  crowns

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LOCALIZED DISTURBANCES IN ERUPTION

• PRIMARY IMPACTION- Teeth cease to eruption before
  emergence
• ANKYLOSIS -Cease of eruption after emergence and
  anatomic fusion of tooth cementum or dentin with
  alveolar bone

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Impaction

• 3rd molars, maxillary canines, mandibular
  premolars, mandibular canines, maxillary
  premolars, maxillary central incisors, maxillary
  lateral incisors, and mandibular second molars
  usually angulated or diverted
• Factors associated with impaction
• Crowding and deficient maxillofacial development
• Overlying cysts or tumors
• Trauma
• Reconstructive surgery
• Thickened overlying bone or soft tissue
• A host of systemic disorders, diseases or
  syndromes

45

• Classification
• Partially erupted or full bony impaction
• according to angulation Mesioangular,
  distoangular, vertical, horizontal or inverted
• Eruption sequestrum

46
Treatment and Prognosis

• Choice of treatment
• Long-term observation
• Orthodontically assisted eruption
• Transplantation
• Surgical removal
• The risks associated with nonintervention
• Crowding dentition
• Resorption and worsening of the periodontal
  status of adjacent teeth
• Development of pathologic conditions, ex
  infections, cysts or tumors

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The risks associated with intervention

• Transient or permanent sensory loss
• Alveolitis
• Trismus
• Infection
• Fracture
• TMJ injury
• Periodontal injury
• Injury to adjacent teeth

48
ANKYLOSIS

• Infraocclusion, secondary retention,
  submergence, reimpaction, reinclusion

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ANKYLOSIS

• Clinical And Radiographic Features
• Pathogenesis is unknown, may be secondary to many
  factors and result in PDL barrier deficiency.
• May occur at any age, any tooth
• Most affect 89yr-old children and D , E , D , E
• PDL absent
• Occlusal, periodontal problems, impaction of the
  underlying teeth
• Treatment and Prognosis
• Variable extraction, orthodontics, segmental
  osteotomy

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DEVELOPMENTAL ALTERATIONS OF TEETH

• SHAPE Gemination, Fusion, Concrescence
  Accessary cusps
• Dense in dente Ectopic Enamel
• Taurodontism
• Dilaceration Hypercementosis
• Supernumerary roots

• NUMBER Hypodontia
• Hyperdontia
• SIZE Microdontia Macrodontia
• STRUCTURE Amelogenesis imperfecta
  Dentinogenesis imperfecta
• Dentin dysplasia I II Regional
  odontodysplasia

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Missing teeth

• 1.6-9.6 , excluding 3rd molars, female
  predominance
• Hypodontia missing one or more teeth
• Oligodontia missing 6 or more teeth
• Anodontia total missing
• 8 gt 5 gt 2 gt 1
• Deciduous mandibular incisors
• Gene mutation, ex PAX9, MSX1, AXIN2 gene,
  He-Zhao deficiency, maps to chromosome 10q11.2
• AXIN2 mutation associated with the development
  of adenomatous polyps of colon, and colorectal
  carcinoma
• Ectodermal dysplasia
• orofaciodigital syndrome

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Hypodontia
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Ectodermal dysplasia
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
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Supernumerary teeth, hyperdontia

• Mesiodens
• 4th molar
• Paramolar
• Distomolar, distodens
• deciduous - lat. incisors
• 86 single supernumerary
• multiple impaction
• cleidocranial dysostosis
• Gardners syndrome

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Mesiodens

• The most common in supernumerary.
• Premaxillary area , usually between upper central
  incisors
• Cone-shaped crown short root
• One or two in number

56
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
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Cleidocranial dysostosis

• 1.Skull flat appearance, sutures remain open
• 2.Jaws underdeveloped, high narrow palate
• 3.Teeth prolonged retained deciduous teeth,
  
• delayed eruption of permanent
  teeth
• 4.Clavicles complete or partial absent

58
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
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Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
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Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
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Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
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(No Transcript)
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Gardners syndrome

• 1.multiple polyposis of the large intestine
• 2.osteoma of the bone
• 3.multiple epidermoid cysts or sebaceous cysts of
  the skin
• 4.desmoid tumors
• 5.impacted supernumerary permanent teeth

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Predeciduous dentition

• Neonatal teeth within 30 days
• Natal teeth newborns
• Most are prematurely erupted deciduous teeth
• Removal only if mobile and at risk of aspiration

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(No Transcript)
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Microdontia

• True
• 1.General -pituitary dwarfism
• 2. Single -peg lat., 3rd molar
• Relative microdontia

67
Macrodontia

• True macrodontia
• 1. Generalized-pituitary gigantism
• 2. Localized- single, hemifacial hypertrophy
• Relative macrodontia small jaw, child

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(No Transcript)
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Gemination, Fusion, Concrescence
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Gemination

• single tooth germ division
• single root root canal 2 complete or
  incomplete separated crowns
• tooth no. normal
• twinning

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Fusion

• Union of 2 separate tooth germs
• Contact of tooth germ before calcified
• Confluent of the dentin
• Complete- form a single tooth
• Incomplete- after calcified begins
• Tooth no. less one

72
Concrescence

• Fusion after root formation
• Cementun united
• Traumatic injury or crowding
• Pre-extraction x-ray check

73
Talon cusp

• Eagles talon
• Lingual projection from the cingulum area of ant.
  teeth
• Most contain a pulp horn
• Both in deciduous permanent dentition

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Dens evaginatus

• ( central tubercle, occlusal tuberculated
  premolar Leongs premolar evaginated odontome
  occlusal enamel pearl )
• An accessory cusp or a globule of enamel on
  central groove or buccal cusp of premolars or
  molars unilateral or bilateral.
• 15 in Asians, rare in whites

75
Dens evaginatus
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
76

• Shovel-shaped incisors

77
Dens in dente

• (Dens invaginatus Dilated composite odontome)
• Tooth within a tooth, incidence 5
• Invagination of the enamel organ into dental
  papilla before calcification
• Coronal type 3 types
• maxillary lateral incisors are common

78
Dens invaginatus, coronal type II
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Dens invaginatus

• Radicular type
• Hertwigs sheath invagination
• Food deposition? caries ? pulp infection
• Restorated as soon as possible

80
Taurodontism

• Bull-like teeth
• Bi- or trifurcation near the apex
• Pulp chamber greater apico-occlusal height and
  no constriction at the cervical of the tooth

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Syndromes associated with taurodontism
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Hypercementosis
83
Supernumerary roots

• Any tooth may develop accessary roots
• No tx required, but critical important in
  endodontic procedure

84
Dilaceration

• Angulation, sharp bend of root or crown
• Trauma during tooth is forming
• Pre-extraction x-ray check

85
Amelogenesis imperfecta

• (Hereditary enamel dysplasia Hereditary brown
  enamel Hereditary brown opalescent teeth)
• Defects in--
• Formative stage?hypoplastic type ? defective
  formation of matrix
• Calcification stage ?hypocalified ? defective
  mineralization of formed matrix
• Maturation stage ? hypomaturation ? enamel
  crystallites remain immature
• Genes mutation AMELX, ENAM, MMP-20, KLK4, DLX3

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Amelogenesis imperfecta
87
1.Hypoplastic type

• Thin enamel with pitted, rough or smooth glossy
  surface yellowish to brown
• undersized, squared crown, lack of contact
• flat occlusal surface low cusps, attrition

88
Hypoplastic type
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
89
Hypoplastic type
90
2.Hypomaturation

• normal thickness of enamel, but mottled surface
  cloudy white, yellow or brown, opaque in color
• softer than normal
• same density as dentin

91
Hypomaturation type
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
92
3.Hypocalcified type

• normal thickness of enamel, density less than
  dentin
• normal size shape when erupt, abrade or
  fracture away rapidly
• permeability increase, darkened stained

4.Hypomaturation-hypocalcified with
taurodontism
93
Hypocalcified type
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Tricho-dento-osseous syndrome
Hypoplastic-Hypomaturation type
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Dentinogenesis imperfecta

• (Hereditary opalescent dentin)
• Classification of DI (Shields)
• Type I DI OI (osteogenesis imperfecta)
  COL1A1,
• 
  COL1A2
• Type II Isolated DI. (1/8000)
  DSPP
• Type III DI of the Brandywine type
  DSPP
• A racial isolate in Maryland,
  
• DI multiple pulp exposures in deciduous
  teeth

96
Osteosclerosis imperfecta
Blue sclera
M Greenwood, J G Meechan,General medicine and
surgery for dental practitioners Part 8
Musculoskeletal system. British Dental Journal
2003 (195) 243 - 248 ,
97
Clinical features

• type I deciduous severe than permanent teeth
• type II equally affected
• type III both dentitions affected.
• Gray to brownish violet or yellowish brown color,
  with translucent or opalescent hue.
• Enamel lost early through fracture, esp. on the
  incisal occlusal surface, and dentin attrition
  rapidly.
• Caries rate is not increased.

98
Dentinogenesis imperfecta
99
Dentinogenesis imperfecta

• Histology
• 1.pulp chamber obliterated with dentin
• 2.flatten D-E junction
• 3.atypical granular dentin, enlarged tubles,
  poor calcification
• water contents 50 above normal

100
Radiographic features

• Partial or total obliteration of the pulp chamber
  root canal by continued formation of dentin, in
  both dentitions.
• Short and blunted roots
• Normal cementum, PDL supporting bone

101
Shell teeth

• Initial reported in the Brandywine population
• Normal thickness of enamel associated with
  extremely thin dentin and dramatically enlarged
  pulps (due to insufficent and deffective dentin
  formation)
• Short roots.

102
Kaohsiung Medical University, Oral Pathology and
image Diagnosis Dept.
103
Dentin dysplasia

• Hereditary, autosomal dominant. Normal enamel but
  atypical dentin formation with abnormal pulp
  morphology
• Type I (radicular type) Rootless teeth
• Type II (coronal) DSPP (dentin
  sialophosphoprotein) gene mutation

104
Type I (radicular type)

• Radiographically
• deciduous teeth affected more severely, little or
  no pulp, short or absent roots.
• If disorganization late---normal pulp chambers,
  with a large pulp stone.
• periapical lesions (R-L) no obvious cause.
• Histologic features
• Normal coronal enamel dentin.
• In root tubular dentin and atypical osteodentin
  surrounded with normal dentin --- appearance of
  Lava flowing around boulders.

105
Dentin dysplasia, type I
106
Type II (coronal)

• Normal root length in both dentitions.
• Primary dentition similar to DI
• bulbous crowns, cervical constriction
• thin roots , early obliterated pulp.
• Permanent teeth normal coloration, thistle
  tube-shaped or flame-shaped pulp chamber with
  pulp stones.

107
Dentin dysplasia, type II (coronal)
108
Dentin dysplasia
Lava flowing around boulders.
Large pulp stones
109
Regional odontodysplasia

• (odontodysplasia odontogenic dysplasia
  odontogenesis imperfecta ghost teeth)
• One or several teeth in a localized area
• Maxi. gt Mand. both dentitions
• most in ant. area
• Delayed or total failure eruption
• Irregular appearance
• Defective mineralization

110

• Radiographic features
• 1. Radiodensity ?, ghost appearance
• 2. Large pulp, thin enamel dentin
• Histologic features
• 1. Dentin?
• 2.Widening of the predentin layer,
• 3. Interglobular dentin and an irregular
  tubular pattern of dentin ?
• 4.Calcification of the reduced enamel epi.

111
Odontogenic epithelium
Enameloid conglomerates
Regional odontodysplasia
112
ENVIRONMENTAL ALTERATIONS OF TEETH
Summary

• Developmental tooth defects
• Turners tooth
• Hypoplasia caused by antineoplastic therapy
• Fluorosis
• Syphilitic hypoplasia
• Postdevelopmental structure loss
• Tooth wear
• Internal and external resorption
• Discolorations of teeth
• Intrinsic stains
• Extrinsic stains
• Localized disturbances in eruption
• Primary impaction
• Ankylosis

113
DEVELOPMENTAL ALTERATIONS OF TEETH
Summary

• SHAPE Gemination, Fusion, Concrescence
  Accessary cusps
• Dense in dente Ectopic Enamel
• Taurodontism
• Dilaceration Hypercementosis
• Supernumerary roots

• NUMBER Hypodontia
• Hyperdontia
• SIZE Microdontia Macrodontia
• STRUCTURE Amelogenesis imperfecta
  Dentinogenesis imperfecta
• Dentin dysplasia I II Regional
  odontodysplasia