Transcript Environmental effects on tooth structure development

ABNORMALITIES OF
TEETH

Environmental Alterations of Teeth

Developmental Alterations of Teeth
牙齒的異常-環境與發育的影響
王文岑
高雄醫學大學 牙醫學系
[email protected]
ENVIRONMENTAL ALTERATIONS OF
TEETH
Developmental tooth defects
Turner’s 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
Wen-Chen Wang
Enamel development

Three stages:
1. 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
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Amelogenesis imperfecta
Enamel hypoplasia
Wen-Chen Wang
Enamel development
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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
Wen-Chen Wang
See Box 2-2
Factors associated with enamel defects
Systemic1. 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
Wen-Chen Wang
See Box 2-2
Factors associated with enamel defects
Local1.Local acute mechanical trauma
2. Electric burn
3. Irradiation
4. Local infection: periapical inflammatory
disease
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
Wen-Chen Wang
Turner’s hypoplasia, Turner’s tooth
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Permanent teeth
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Periapical inflammatory
disease of the overlying
deciduous tooth, less
frequently in anterior teeth
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Traumatic injury- not rare
-45% children sustain injury to
their deciduous teeth, 23%
Turner’s hypoplasia secondary
permanent teeth
development disturbed
to previous trauma
Wen-Chen Wang
Turner’s teeth
Wen-Chen Wang
Hypoplasia caused by antineoplastic
therapy
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Under 12 y/o, esp. under 5y/o
Age at treatment, forms of therapy
Chemotherapy
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Less alteration than radiation
Increased number of enamel hypoplasia
and discolorations, slight smaller tooth
size, radicular hypoplasia
Wen-Chen Wang
Radiotherapy
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0.72 Gy related to mild defects in enamel,
dentin (一般成人頭頸癌照射一次約為2Gy)
Dose, radiation field
Wen-Chen Wang
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Developmental radicular hypoplasia and
microdontia caused by radiotherapy
Wen-Chen Wang
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Hypodontia, microdontia, radicular
hypoplasia, enamel hypoplasia, mandibular
hypoplpasia, reduced in vertical
development of lower 1/3 of face
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Mandibular hypoplpasia may caused by
Radiation →impaired root development
→reduced alveolar bone growth
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Cranial radiation→ altered pituitary gland
function→ growth failed
Wen-Chen Wang
*Dental fluorosis
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1901, Dr. Frederick S. McKay: Colorado brown stain
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1909, Dr. F.L. Robertson in Bauxite, Arkansas
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1930, H.V. Churchill: high concentration of fluoride of
Bauxite(13.7ppm) and Colorado
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1931, Dr. H. Trendley Dean: association between
fluoride, dental fluorosis and prevalence of caries
among children
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1.0 ppm reduced caries by 50~70% and associated with
low and mild mottled enamel
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0.7~1.2 ppm water fluoridation was recommended after
1962, currently 0.7ppm is recommended due to
increased dental fluorosis
Wen-Chen Wang
Dental fluorosis
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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
Wen-Chen Wang
Dental fluorosis
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Critical period for clinical dental fluorosis is
the 2nd and 3rd year of life, dose dependent
Caries resistant
Wen-Chen Wang
Syphilitic hypoplasia
•Congenital syphilis
•Hutchinson’s incisors &
mulberry molars
Wen-Chen Wang
POSTDEVELOPMENTAL LOSS OF
TOOTH STRUCTURE
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Begin from enamel surface (tooth wear):
Attrition, abrasion, erosion, abfraction
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Begin from dentin, cemental surface:
internal or external resorption
Wen-Chen Wang
Attrition
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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
Wen-Chen Wang
Abrasion
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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)
Wen-Chen Wang
Abrasion
Wen-Chen Wang
Improper use of hair grips
Abrasion
Long-term use of tobacco pipe
Wen-Chen Wang
Erosion
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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 affecteddietary source
Posterior teeth extensive loss of occlusal surface,
and palatal surface concave dentin surrounded by
an elevated enamel rim- regurgitation of gastric
secretion
Wen-Chen Wang
Erosion
concave dentin surrounded
by an elevated enamel rim
Wen-Chen Wang
Erosion
A bulimia patient
Wen-Chen Wang
Abfraction
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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
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Wedge-shaped cervical defects, deep, narrow Vshaped, not allow toothbrush to contact base; if the
defect, often affect a single tooth
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Almost exclusively on facial surface and more often
in bruxism, higher in mandibular dentition
Wen-Chen Wang
Abfraction
Wen-Chen Wang
Treatment and prognosis of tooth
wear
Resolve pain and sensitivity
 Identify the cause of tooth
structure loss
 Protection
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Wen-Chen Wang
INTERNAL & EXTERNAL RESORPTION
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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
Wen-Chen Wang
Factors associated with
external resorption
Wen-Chen Wang
Clinical and Radiographic
Features
Internal resorption Inflammatory resorptiondentin replaced by inflamed
granulation tissue
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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
Wen-Chen Wang
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)
Wen-Chen Wang
Histopathologic Feature
• Increased cellularity, vascularity and collagenization
• Numerous multinucleated dentinoclasts
• Inflammatory cells infiltration
Wen-Chen Wang
Treatment and prognosis
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Internal resorption
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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
Wen-Chen Wang
ENVIRONMENTAL
DISCOLORATION OF TEETH
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Extrinsic- surface
accumulation of
exogenous pigment
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Intrinsic-secondary to
endogenous factors
that result in
discoloration of
underlying dentin
Wen-Chen Wang
Extrinsic stains
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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
Wen-Chen Wang
Intrinsic stains
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Amelogenesis imperfecta
Dentinogenesis imperfecta
Dental fluorosis
Erythropoietic porphyria –
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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 Wood’s UV light
Present both in dentin and enamel in
deciduous teeth, but only dentin affected in
permanent teeth
Wen-Chen Wang
Erythropoietic porphyria
Hyperbilirubinemia
Wen-Chen Wang
Intrinsic stains
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Hyperbilirubinemia- bilirubin, breakdown product
of RBC, jaundance (yellow-green discoloration),
erythroblastosis fetalis, biliary atresia
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Biliverdin deposition, green discoloration of teeth
(chlorodontia)
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Ochronosis-alkaptonuria, blue-black
discoloration
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Trauma- coronal discoloration, pulp necrosis
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Localized RBC breakdown
Wen-Chen Wang
Intrinsic stains
 MedicationsTetracycline (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
Wen-Chen Wang
Minocycline hydrochloride
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Tx for Acne
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Blue-gray from incisal 3/4,
to dark green or black in
roots, also affect developed
teeth
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Skin, nail, sclera,
conjunctiva, thyroid, bone
discoloration in susceptible
individuals
Stained alveolar bone
Wen-Chen Wang
Treatment and prognosis
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Extrinsic stains- polishing
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Intrinsic stains- bleaching, bonded
restoration, crowns
Wen-Chen Wang
LOCALIZED DISTURBANCES IN
ERUPTION
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PRIMARY IMPACTION- Teeth
cease to eruption before
emergence
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ANKYLOSIS -Cease of eruption
after emergence and anatomic
fusion of tooth cementum or
dentin with alveolar bone
Wen-Chen Wang
Impaction
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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
Wen-Chen Wang
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Classification :
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Partially erupted or full bony impaction
according to angulation: Mesioangular, distoangular,
vertical, horizontal or inverted
Eruption sequestrum
Wen-Chen Wang
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
Wen-Chen Wang
The risks associated with intervention:
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Transient or permanent sensory loss
Alveolitis
Trismus
Infection
Fracture
TMJ injury
Periodontal injury
Injury to adjacent teeth
Wen-Chen Wang
ANKYLOSIS
Infraocclusion, secondary retention,
submergence, reimpaction, reinclusion
Wen-Chen Wang
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 8~9yr-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
Wen-Chen Wang
DEVELOPMENTAL ALTERATIONS OF
TEETH
NUMBER
Hypodontia
Hyperdontia
SIZE
Microdontia
Macrodontia
STRUCTURE
Amelogenesis imperfecta
Dentinogenesis imperfecta
Dentin dysplasia I & II
Regional odontodysplasia
SHAPE
Gemination, Fusion, Concrescence
Accessary cusps
Dense in dente
Ectopic Enamel
Taurodontism
Dilaceration
Hypercementosis
Supernumerary roots
Wen-Chen Wang
Missing teeth
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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>5>2>1
Deciduous mandibular incisors
Gene mutation, ex: PAX9, MSX1, AXIN2 gene, HeZhao deficiency, maps to chromosome 10q11.2
AXIN2 mutation: associated with the development of
adenomatous polyps of colon, and colorectal
carcinoma
Ectodermal dysplasia
orofaciodigital syndrome
Wen-Chen Wang
Hypodontia
Wen-Chen Wang
Ectodermal dysplasia
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
Supernumerary teeth, hyperdontia
Mesiodens
 4th molar
 Paramolar
 Distomolar, distodens
 deciduous - lat. incisors
 86% single supernumerary
 multiple & impaction

cleidocranial dysostosis
 Gardner’s syndrome

Wen-Chen Wang
Mesiodens
The
most common in
supernumerary.
Premaxillary area , usually
between upper central incisors
Cone-shaped crown & short
root
One or two in number
Wen-Chen Wang
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
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
Wen-Chen Wang
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
Wen-Chen Wang
Gardner’s 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
Wen-Chen Wang
Predeciduous dentition
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Neonatal teeth: within 30 days
Natal teeth: newborns
Most are prematurely erupted deciduous teeth
Removal only if mobile and at risk of aspiration
Wen-Chen Wang
Wen-Chen Wang
Microdontia
True:
1.General -pituitary dwarfism
2. Single -peg lat., 3rd molar
 Relative microdontia

Wen-Chen Wang
Macrodontia
True macrodontia :
1. Generalized-pituitary gigantism
2. Localized- single, hemifacial hypertrophy
 Relative macrodontia: small jaw, child
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Wen-Chen Wang
Wen-Chen Wang
Gemination, Fusion, Concrescence
Wen-Chen Wang
Gemination
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single tooth germ
division
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single root & root canal +
2 complete or incomplete
separated crowns
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tooth no.: normal
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twinning
Wen-Chen Wang
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
Wen-Chen Wang
Concrescence
Fusion
after root
formation
Cementun united
Traumatic injury or
crowding
Pre-extraction x-ray
check
Wen-Chen Wang
Talon cusp
Eagle’s
talon
Lingual projection
from the cingulum area
of ant. teeth
Most contain a pulp
horn
Both in deciduous &
permanent dentition
Wen-Chen Wang
Dens evaginatus
( central tubercle, occlusal tuberculated premolar;
Leong’s 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
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Wen-Chen Wang
Dens evaginatus
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
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Shovel-shaped incisors
Wen-Chen Wang
Dens in dente
(Dens invaginatus; Dilated composite odontome)
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Tooth within a tooth, incidence 5%
Invagination of the enamel organ into
dental papilla before calcification
Coronal type: 3 types
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maxillary lateral incisors are common
Wen-Chen Wang
Dens invaginatus, coronal type II
Wen-Chen Wang
Dens invaginatus
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Radicular type
Hertwig’s sheath invagination
Food deposition→ caries → pulp infection
 Restorated as soon as possible
Wen-Chen Wang
Taurodontism
“ teeth
Bi- or trifurcation
near the apex
Pulp chamber :
greater apico-occlusal
height and no
constriction at the
cervical of the tooth
“Bull-like
Wen-Chen Wang
Syndromes associated with taurodontism
Wen-Chen Wang
Hypercementosis
Wen-Chen Wang
Supernumerary roots
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Any tooth may develop accessary roots
No tx required, but critical important in
endodontic procedure
Wen-Chen Wang
Dilaceration
Angulation,
sharp
bend of root or crown
Trauma during tooth
is forming
Pre-extraction x-ray
check
Wen-Chen Wang
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
Wen-Chen Wang
Amelogenesis imperfecta
Wen-Chen Wang
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

Wen-Chen Wang
Hypoplastic type
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
Hypoplastic type
Wen-Chen Wang
2.Hypomaturation
normal thickness of enamel, but
mottled surface; cloudy white,
yellow or brown, opaque in
color
 softer than normal
 same density as dentin
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Wen-Chen Wang
Hypomaturation type
Kaohsiung Medical University, Oral Pathology and image Diagnosis Wen-Chen
Dept. Wang
3.Hypocalcified type
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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
Wen-Chen Wang
Hypocalcified type
Wen-Chen Wang
Tricho-dento-osseous syndrome
Hypoplastic-Hypomaturation type
Wen-Chen Wang
Dentinogenesis imperfecta
(Hereditary opalescent dentin)
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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
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A racial isolate in Maryland,
DI + multiple pulp exposures in deciduous teeth
Wen-Chen Wang
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 ,
Wen-Chen Wang
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.
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Wen-Chen Wang
Dentinogenesis imperfecta
Wen-Chen Wang
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
Wen-Chen Wang
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
Wen-Chen Wang
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.
Wen-Chen Wang
Wen-Chen Wang
Kaohsiung Medical University, Oral Pathology and image Diagnosis
Dept.
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
Wen-Chen Wang
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”.
Wen-Chen Wang
Dentin dysplasia, type I
Wen-Chen Wang
Type II (coronal)
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Normal root length in both dentitions.
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Primary dentition similar to DI:
bulbous crowns, cervical constriction
thin roots , early obliterated pulp.
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Permanent teeth : normal coloration,
thistle tube-shaped or flame-shaped
pulp chamber with pulp stones.
Wen-Chen Wang
Dentin dysplasia,
type II (coronal)
Wen-Chen Wang
“Lava flowing around boulders”.
Dentin dysplasia
Large pulp stones
Wen-Chen Wang
Regional odontodysplasia
(odontodysplasia; odontogenic dysplasia;
odontogenesis imperfecta; ghost teeth)
One or several teeth in a localized area
 Maxi. > Mand.; both dentitions
 most in ant. area
 Delayed or total failure eruption
 Irregular appearance
 Defective mineralization

Wen-Chen Wang
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Radiographic features
1. Radiodensity ↓, “ghost appearance”
2. Large pulp, thin enamel & dentin
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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.
Wen-Chen Wang
Enameloid conglomerates
Odontogenic epithelium
Regional
odontodysplasia
Wen-Chen Wang
Summary
ENVIRONMENTAL ALTERATIONS OF
TEETH
Developmental tooth defects
Turner’s 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
Wen-Chen Wang
Summary
DEVELOPMENTAL ALTERATIONS OF
TEETH
NUMBER
Hypodontia
Hyperdontia
SIZE
Microdontia
Macrodontia
STRUCTURE
Amelogenesis imperfecta
Dentinogenesis imperfecta
Dentin dysplasia I & II
Regional odontodysplasia
SHAPE
Gemination, Fusion, Concrescence
Accessary cusps
Dense in dente
Ectopic Enamel
Taurodontism
Dilaceration
Hypercementosis
Supernumerary roots
Wen-Chen Wang