Enamel Hypoplasia

The term enamel hypoplasia was first used by Zsigmondy in 1894. It may be defined as an incomplete or defective formation of the organic enamel matrix of teeth 

Types: 

• Hereditary type: Amelogenesis  imperfecta 
• Environmental 

Environmental enamel hypoplasia 

• Caused by environmental factors 
• Either dentition may be involved i.e. primary or permanent 
• Three patterns are present - 

1. 1. Hypoplasia 
   2. Diffuse opacities 
   3. Demarcated opacities 

Hypoplasia – Clinical features: 

Mild condition: 

    - few grooves, pits or fissures on the enamel surface. 

Severe condition: 

    - rows of deep pits arranged horizontally across the surface of tooth. 

    - may be single row of such pits or several rows indicating a series of injuries 

Diffuse opacities: appear as variations in the translucency of the enamel. 

      - normal thickness; it has increased white opacity with no clear boundary with the adjacent normal enamel 

Demarcated opacities: Enamel show areas of decreased translucence, increased opacity, and a sharp boundary with the adjacent enamel. 

     - enamel is of normal thickness, and the affected opacity may be white, cream, yellow or brown 

Factors causing hypoplasia of enamel

• Nutrition deficiency- Vitamin A,C and D
• Exanthematous diseases
• Congenital syphilis
• Hypocalcemia
• Birth injury, prematurity, Rh hemolytic disease
• Local infection or trauma
• Ingestion of chemicals
• Idiopathic causes
• Deficiency of Vitamin A & C during the time of tooth formation
• Rickets: Vitamin D deficiency
• Exanthematous diseases: Measles, Chicken pox, Scarlet fever 

Enamel hypoplasia due to Congenital syphilis 

• Maxillary and mandibular permanent incisors and the first molars are invloved. 
• Not of pitting variety 
• Presents a characteristic, almost pathognomonic appearance 
• Hutchinson’s teeth of incissors, Mulberry molars 
• Hutchinson’s triad: Intestinal keratosis, Hutchinson’s incisor and 8th nerve deafness 
• When anterior teeth are affected, they are called as Hutchinson’s teeth. 
• Upper central incisor: “Screw driver’’ shaped, mesial and distal surfaces of crown tapering, notching and converging towards incisal edge. 
  • Cause: Explained on the basis of the absence of the central tubercle or calcification center. 
• Mulberry Molars - Well formed cusps are not seen, instead they appear to be arranged in an agglomerate mass of globules. 
• Crown is narrower on occlusal surface than at cervical margin 

Hypocalcemia 

• Tetany: Vitamin D deficiency and Parathyroid deficiency. 
• Low serum levels of calcium leading to enamel hypoplasia i.e. here serum calcium level fall as low as 6to 8mg.per 100ml. 

Birth injuries 

• Schour in 1936: Neonatal line or ring in deciduous teeth and first permanent molars- a type of enamel hypoplasia. 
• Evidences suggest, enamel hypoplasia in prematurely born children. 
• Rh hemolytic disease. 
• GIT disturbances in mother or illness may cause hypoplasia of prenatal enamel 

Local infection or trauma 

• Due to carious infection of deciduous tooth during formation of succeeding permanent tooth. 
• Trauma to deciduous tooth. 
• Most commonly one of the permanent maxillary incisors or a maxillary or mandibular molar 

Turner’s Hypoplasia 

• Frequent pattern of enamel defect  
• Seen in permanent teeth 
• Caused by periapical inflammatory disease of overlying deciduous tooth 

Flouride: Mottled enamel 

• Ingestion of water with high fluoride content 
• Due to disturbance of ameloblasts during formative stage of tooth development 
• Enamel matrix is defective or deficient 
• Higher levels of fluoride influence the calcification process of matrix 
• Wide range of severity: 
• Occasional white flecking or spotting of the enamel: Very mild  
• White opaque areas: Mild changes 
• Pitting and brownish staining of surface: Moderate to severe changes 
• Corroded surface, tendency to fracture: Severely affected 

Treatment and Prognosis

• Micro abrasion for dental fluorosis. 
• Aesthetically or functionally defective teeth can be restored through a variety of cosmetically pleasing techniques such as: 
  • Acid etch composite resin restorations 
  • Labial veneers 
  • Full crowns 

Article by Dr. Siri P.B.