This document discusses enamel defects including hereditary enamel dysplasia and enamel hypoplasia. It describes the three stages of enamel development and factors that can disrupt this process such as nutritional deficiencies, infections, trauma, and genetic conditions. Specific enamel defects are defined including pitted enamel hypoplasia and enamel discoloration seen in conditions like congenital syphilis and fluorosis. Classification systems for hereditary enamel dysplasia and clinical, radiographic, and genetic features are also summarized.

1. Dr. SANTHU SADASIVAN

2. Development of enamel has three major stages:
formative stage
deposition of organic matrix.
Calcification stage
matrix mineralization
Maturation stage
crystallites enlarge and mature

3. An incomplete or defective formation of the organic
enamel matrix of teeth
Types:
Hereditary type
• Both deciduous and
permanent dentitions
involved
• Only enamel is affected
Environmental factors
• Either dentition or single
tooth affected
• Both enamel and dentin
are affected

4. Factors producing injury to ameloblasts:
• Nutritional deficiency [vitamin A,C,D]
• Exanthematous diseases
[eg: measles, chicken pox, scarlet fever]
• Congenital syphilis
• Hypocalcemia
• Birth injury, prematurity, Rh hemolytic disease
• Local infection or trauma
• Ingestion of chemicals (fluoride)
• Idiopathic causes

5. Due to nutritional deficiency and Exanthematous fevers:
In Earlier studies ricketes was the major cause
• At present
vitamin A and C are also causes
 produce enamel hypoplasia due to interference in
metabolic function of ameloblasts
 result in pitting and pits tend to stain
• Central and lateral incisors, cuspids and first molars are
frequently involved [ primary teeth to appear]

6. Due to congenital syphilis
• Involves max and mand central incisors and first molars
• Anterior tooth affected are called “HUTCHINSON’S
TEETH”
• Molars referred as “MULBERRY MOLARS” [moon
molars, Fournier's molars]

7. Upper central incisor – screw driver shaped
tapering absence of central tubercle or calcification center
Crowns of 1st molars
irregular shaped enamel arranged in agglomerate mass

8. Hutchinson’s Incisor
characteristic of congenital syphilis
incisors are peg-shaped or screwdriver-shaped
widely spaced
notched at the end with a crescent-shaped deformity

9. Due to hypocalcemia
Tetany - Due to decreased level of calcium in blood [ fall
as low as 6 – 8 mg/100ml]
Most common – vitamin D deficiency and parathyroid
deficiency
• Causes Pitting

10. Due to birth injuries:
• Present in deciduous teeth and first permanent molars
• Disturbance produced in enamel and dentin
• Caused due to trauma or change of environment at the
time of birth
• Rh hump: Staining of teeth in Rh hemolytic diseased
children- deposition of blood pigment in enamel &
dentin- green, brown or bluish hue.( ring-like defect)

11. Due to local infections or trauma:
• Single tooth is involved [permanent max incisors or
max or mand premolars]
• Degree of hypoplasia ranging from mild, brownish
discoloration of enamel to severe pitting and
irregularity of tooth surface.
• Single tooth referred as “TURNER’S TEETH” condition -
>> TURNER’S HYPOPLASIA

12. Due to fluoride : mottled enamel
 First described by GV Black and Frederick.
 As a result of fluoride in water supply
 Maximum allowable level of fluoride :1 ppm
 The severity of the mottling increases with an
increasing amount of fluoride in the water.
Pathogenesis
 Higher levels of fluoride, there is interference with the
calcification process of the matrix.

13. C/F:
 white flecking or spotting on the surface.
 mild changes manifested by white opaque areas.
 moderate and severe changes showing pitting and brownish
staining of the surface and corroded appearance of the teeth
& may show a tendency for wear and fracture.

15.  A I
 Hereditary Enamel Dysplasia
 Hereditary Brown Enamel
 Hereditary Brown Opalescent Teeth

16.  It is a hereditary disorder affecting enamel formation in both
deciduous & permanent dentitions.
 prevalence is 1 in 700 to 4000 with slight male predilection.
Genes related to A I
 Mutations in the AMELX, ENAM, and MMP20 genes
 causes malfunction of the proteins in the enamel:
ameloblastin, enamelin, tuftelin and amelogenin.

17. Based on clinical, histological & genetic criteria-Witkop & Sauk
 Type I : Hypoplastic
I A Pitted, AD
I B Local, AD
I C Local, AR
I D Smooth, AD
I E Smooth, X-linked dominant
I F Rough, AD
I G Enamel agenesis ,AR
 Type II : Hypomaturation
II A Diffuse Pigmented, AR
II B Diffuse , X-Linked recessive
II C Snow-capped teeth, X-linked
 Type III : Hypocalcified
III A Diffuse AD
III B Diffuse AR
 Type IV : Combination Type
IV A Hypomaturation- hypoplastic with taurodontism,AD
IV B Hypoplastic- hypomaturation with taurodontism,AD

18.  AD
 Pin point or pin head sized pits are scattered across the
surface of the teeth.
 Pits arranged in rows or columns.
 Buccal surface affected more severely.

19.  Pin point/ pin head sized pits in rows.
 Linear depression or area of hypoplasia.
 Middle third of buccal surface.
 Incisal or occlusal unaffected.
 All teeth or some teeth affected
 Primary or both dentitions

20.  Thin, hard, glossy
 Looks like crown preparations- open bite.
 Opaque white to brown.
X-linked dominant – Type I E
 Similar features in males
 Alternating vertical bands of normal and abnormal
enamel seen in females.

21.  Thin, hard, rough
 Tapering of occlusal and incisal surfaces.
 Open contact & open bite.
Type I G (Enamel Agenesis)
 No enamel
 Yellow teeth
 Tapering

22.  Defect in the maturation of crystal structure.
 Teeth normal in shape.
 Mottled opaque white- brown- yellow discoloration
 Softer than normal- Tend to chip from underlying dentin.
 Snow capped – zone of white opaque enamel on incisal and
occlusal surface.

23.  No significant mineralization.
 Enamel soft and easily lost.
 Colour yellowish brown to orange on eruption but later
becomes stained brown to black.

24. H/P:
 Hypoplastic- disturbance in differentiation of
ameloblasts defects in matrix formation.
 Hypomaturation – alterations in enamel rod and rod
sheath structures.
 Hypocalcification – defects of matrix structure and
mineral deposition.

25. Radiographic features:
 The enamel may appear totally absent or as very thin
layer.
 It appears to have same approximate radiodensity as
that of dentin.