Dentin Dysplasia

Dentin dysplasia (DD) is a rare hereditary disturbance is inherited as an autosomal dominant trait.

unknown etiology that affects approximately 1 :100,000.

In 1972, Witkop classified it into type I and type II which affect both dentitions.DD Type I

Radicular dentin dysplasia

Characterized by:-
1.Both dentitions are affected.
2.Normal appearing crowns
3.No or only rudimentary root development (rootless teeth)
4.Incomplete or total obliteration of the pulp chamber.
5.Teeth may exhibit extreme mobility and exfoliate prematurely.DD type II

coronal dentin dysplasia

Characterized by:-

1.partial pulpal obliteration.
2.Thistle-tube-or flame-shaped coronal pulp chambers
3. Thread-like root canals
4. Usually the absence of periapical radiolucencies.
5. In this type of anomaly, teeth roots are of normal shape and contour.The enamel and the immediately subjacent dentin appear normal.
Deeper layers of dentin show an atypical tubular pattern with an amorphous, atubular area, and irregular organization.
Normal dentinal tubule formation appears to have been blocked so that new dentine forms around obstacles and takes on the characteristic appearances described as “lava flowing around boulders”The radiograph revealed features of dentine dysplasia type I with normal appearance of crown but no root development Autosomal Dominant Disorder:

Manifested in heterozygous states
At least one parent of index case is usually affected
Both males and females are affected.
Clinical feature can be modified by variation in penetrance and expressivity. Some individual inherit the mutant gene but are phenotpically normal. This is reffered to as “incomplete penetrance”.
In many condition the age of onset is delayed.

Inheritance Pattern:

Typical pattern is a heterozygous affected parent with a homozygous unaffected parent.
Every child has one chance in two of having the disease
Both sexes are affected equally..Autosomal Recessive Disorder

Largest category of Mendelian disorder
Usually does not affect the parent of the affected individual, but sibling may show the disease.
Complete penetrance is common.
Onset is frequently early in life.
Usually affect enzymatic proteins.

Pattern Of Inheritance:

Typical pattern is two heterozygous unaffected (carrier) parent.
The triat does not usually affect the parent, but siblings may show the disease
Siblings have one chance in four of being affected
Both sexes affected equally.

1. Dentin dysplasia DR AMITHA . G, BDS, MDS DEPT OF ORAL AND MAXILLOFACIAL PATHOLOGY

2. Introduction: Dentin dysplasia (DD) is a rare hereditary disturbance is inherited as an autosomal dominant trait. unknown etiology that affects approximately 1 :100,000. In 1972, Witkop   classified it into type I and type II which affect both dentitions.

3. DD Type I Radicular dentin dysplasia Characterized by:- 1.Both dentitions are affected. 2.Normal appearing crowns 3.No or only rudimentary root development (rootless teeth) 4.Incomplete or total obliteration of the pulp chamber. 5.Teeth may exhibit extreme mobility and exfoliate prematurely.

4. DD type II coronal dentin dysplasia Characterized by:- 1.partial pulpal obliteration. 2. Thistle-tube -or flame-shaped coronal pulp chambers 3. Thread-like root canals 4. Usually the absence of periapical radiolucencies . 5. In this type of anomaly, teeth roots are of normal shape and contour.

5. Histopathologically The enamel and the immediately subjacent dentin appear normal. Deeper layers of dentin show an atypical tubular pattern with an amorphous, atubular area, and irregular organization. Normal dentinal tubule formation appears to have been blocked so that new dentine forms around obstacles and takes on the characteristic appearances described as “ lava flowing around boulders”

6. The radiograph revealed features of dentine dysplasia type I with normal appearance of crown but no root development

7. Patterns Of Inheritance: Autosomal Dominant. Autosomal Recessive. X-Linked Recessive. X-Linked Dominant

8. Autosomal Dominant Disorder: Manifested in heterozygous states At least one parent of index case is usually affected Both males and females are affected. Clinical feature can be modified by variation in penetrance and expressivity. Some individual inherit the mutant gene but are phenotpically normal. This is reffered to as “incomplete penetrance”. In many condition the age of onset is delayed. Inheritance Pattern: Typical pattern is a heterozygous affected parent with a homozygous unaffected parent. Every child has one chance in two of having the disease Both sexes are affected equally..

9. Autosomal Dominant Disorders Nervous Huntington disease Neurofibromatosis Myotonic dystrophy Tuerous Sclerosis Urinary Polycystic Kidney disease Gastrointestinal Familial polyosis coli Hematopoietic Hereditary spherocytosis Skeletal Marfan syndrome Osteogenesis imperfecta Achondroplasia Metabolic Familial hypercholesterolmia Acute intermittent porphyria

10. Autosomal Recessive Disorder Largest category of Mendelian disorder Usually does not affect the parent of the affected individual, but sibling may show the disease. Complete penetrance is common. Onset is frequently early in life. Usually affect enzymatic proteins. Pattern Of Inheritance: Typical pattern is two heterozygous unaffected (carrier) parent. The triat does not usually affect the parent, but siblings may show the disease Siblings have one chance in four of being affected Both sexes affected equally.

11. Autosomal Recessive Disorder Metabolic Cystic fibrosis Phenylketonuria Galactosemia Homocystinuria Glycogen storage dise Haematopoietic Sickle cell anaemia Endocrine Congenital Adrenal hyperplasia Skeletal Alkaptonuria Nervous Friedrich ataxia Spinal muscular atrophy

12. X-Linked Recessive Disorders. All sex-linked disorders are X-linked, and almost all are recessive Usually expressed only in males Rarely, due to random X-inactivation, a female will express disease, called manifesting heterozygotes. Pattern Of Inheritance: Disease usually passed on from carrier mother. Expressed in male offspring, females are carriers. Skipped generations are commonly seen. In this case, Recurrence risk is half of sons are affected, half of the daughters are carriers. Recurrence risk: All the daughters are heterozygous carriers and all the sons are homozygous normal.

13. X-linked Recessive Disorders Musculoskeletal Duchene muscular dystrophy Blood Hemophilia A and B G6PD def. Immune Agammaglobulinemia Wiskott - aldrich syndrome Metabolic Diabetes insipidus Lesch-nyhan syndrome

14. AMELOGENESIS IMPERFECTA Enamel is defective in form or calcification as a result of hereditary and has an appearance ranging from essentially normal to extremely unsightly. Also called Hereditary enamel dysplasia or Hereditary brown enamel or Hereditary brown opalescent teeth. 3 types Hypoplastic Hypocalcified Hypomaturation

15. In radiographically, the overall shape of the teeth may or may not be normal depending upon the amount of enamel present on the tooth and the amount of occlusal & incisal wear. Enamel appear totally absent or when present appear as thin layer, chiefly over the tips of cusp and on interproximal surface. No treatment except for the improvement of cosmetic.

16. DENTINOGENESIS IMPERFECTA Is a hereditary condition in which only the dentin is defective. Normal enamel is weakly attached and lost early. Affecting both decidous and permanent detition . Affected teeth are gray to yellowish brown and have broad crowns with constriction of cervical area resulting a ‘ tulip ’ shape Radiographically, teeth appear solid, lacking pulp champers and root canals. Enamel is easily broken leading to exposure of dentin that undergo accelerated attrition.

17. 2 types Dentinogenesis imperfecta 1 Dentinogenesis imperfecta 2 Dentinogenesis imperfecta type 1 Also called Opalescent dentin or Capdepont teeth or Den. Imperfecta with out Osteogenesis imperfecta. Or Shields type II. Affects only the teeth, no bone fractures. Blue grey or amber brown or opalescent. On X-rays teeth as bulbous crowns, roots are narrow and pulp champers and root canals are smaller than normal or completely obliterated. Enamel split from dentin when subjected to occlusal stress.

18. Dentinogenesis imperfecta 2 Also called Shields type III or Brandywine type Crowns of the deciduos and permanent teeth wear rapidly after eruption. Multiple pulp exposure may occur. X-rays of decidous teeth show large pulp Champers and root canals & reduced in size as age advances. Permanent teeth have pulpal spaces that are either smaller than normal or completely obliterated. Appearance of shell teeth.

19. THANK YOU DR AMITHA . G, BDS, MDS DEPT OF ORAL AND MAXILLOFACIAL PATHOLOGY