Enamel and dentine defects diagnosis and tx

Question 1

Enamel defects aetiology

Answer 1

Genetic
Environmental
Idiopathic

Question 2

Enamel defects presentation

Answer 2

hypoplasia
hypomineralisation (hypocalcified and hypomineralised)

Question 3

Amelogenesis imperfecta

Answer 3

Clinically and genetically heterogenous group of conditions that affect enamel, occasionally in conjunction with other dental, oral or extra oral tissues
Mutation of genes coding for amelogenesis

Question 4

Classification of amelogenesis imperfecta

Answer 4

Phenotype:
1. Type 1 (hyperplastic)
2. Type 2 (hypocalcified)
3. Type 3 (hypomature)
4. Type 4 (mixed with taurodontism)

Genetic
1. Autosomal dominant
2. Autosomal recessive
3. X-linked

Question 5

Hypoplastic general clinical features

Answer 5

Thin enamel
Hard
Shiny
Discoloured yellow through yellow brown

Question 6

Hypocalcified

Answer 6

Enamel softer
Normal thickness
Discoloured
Teeth affected not usually evenly distributed around the arch, although tends to show bilateral symmetry
Enamel at cervical margin may be more highly mineralised and resistant to wear

Question 7

Hypomature

Answer 7

Very soft enamel
Defects often limited to the incisal portion of crowns in anterior teeth and occlusal portion in posterior teeth
Mottled with flecks of opaque white ground glass appearance
Maxillary teeth > mandibular teeth

Question 8

Chronological enamel hypoplasia

Answer 8

Defect is related to the timing of the insult (prenatal/perinatal/postnatal)

Chronologically arranged changes (range from hypomineralised enamel mottling to more severe hypoplastic pitting and degree of disturbance to amelogenesis is generally determined by the severity)

100 aetiological agents report (metabolic disturbances, infections, chemicals and drugs)

Question 9

Fluorosis

Answer 9

Disturbance of amelogenesis caused by excessive ingestion of fluoride
Vary from white opaque lines to scattered white flecking or a more opaque and confluent dense white chalking that may contain brown discolouration.
Fragmentation of outer layers can lead to pitting or more extensive loss can resemble hypoplastic changes that stain brown

Question 10

Turner’s hypoplasia

Answer 10

Enamel hypomineralisation
patches of opaque white or yellow/brown discolouration
severe changes less common but an isolated hypoplastic area may be seen

Aetiology: trauma to primary predecessor/infection

Question 11

Dentine defects classification

Answer 11

Primarily involving dentine:
1. Dentinogenesis imperfecta type II (coronal)
2. Dentine dysplasia type I (radicular dentine dysplasia)
3. Dentine dysplasia type II (coronal dentine dysplasia)
4. Fibrous dysplasia of dentine

Those that form part of a more generalised disorder:
1. Osteogenesis imperfecta
2. Ehlers-Danlos syndrome
3. Vitamin D - resistant rickets/dependent rickets
4. Hypophosphatasia

Question 12

Dentinogenesis imperfecta type II

Answer 12

Teeth in both dentitions affected
1:8000
Inheritance (autosomal dominant)

Question 13

Clinical features of dentinogenesis imperfecta type II

Answer 13

Opalescent on transillumination
bluish or brownish in colour
crowns bulbous
roots thin and short
root canals and pulp chamber rapidly obliterated
abnormal adj

Question 14

Radiographic appearance dentinogenesis imperfecta

Answer 14

short bulbous crowns
marked cervical constriction
short roots
progressive obliteration of pulp chamber
attrition - may lead to loss of vitality and periapical pathology

Question 15

Dentine dysplasia type I

Answer 15

Colour of teeth - normal to slight bluish
Teeth lost early due to extreme mobility and ease of avulsion with minor trauma
AD inheritance

Question 16

Radiographically dentine dysplasia type I

Answer 16

Excessively short roots
Blunt roots
Pulp chambers appear small demilunes or obliterated
Root canals absent

Question 17

Dentine dysplasia type II

Answer 17

Primary teeth resemble those in DI type II
Permanent teeth clinically normal

Question 18

Radiographically dentine dysplasia type II

Answer 18

Thistle shaped pulp chambers partially occluded by pulp stones
Root canals gradually narrow to point of obliteration

Question 19

Fibrous dysplasia of dentine

Answer 19

Rare
Teeth normal colour and form
Pulp chambers and root canals represented only by a few radiolucent areas

Question 20

Osteogenesis imperfecta with DI type I

Answer 20

OI is a group of CT disorders involving inherited abnormalities of type I collagen
Systemic clinical features:
1. Inc bone fragility
2. Blue sclera
3. Lax joints
4. Opalescent health
5. Hearing loss

Dental features:
- primary teeth resemble DI type II
- permanent teeth: (max anterior tooth normal colour and appearance) (mandibular incisor and canine teeth opalescent, discoloured bluish-brown with wear at incisal edges)

Radiographic:
- Variable calcific occlusion of pulp chambers and root canals
- Maxillary anterior teeth may retain pulp chambers and root canals longer than mandibular teeth. This distinguishes type I from type II.

Question 21

Regional odontodysplasia

Answer 21

rare developmental anomaly
M:F
Affects primary and permanent dentitions
Aetiology? : hereditary/infection/trauma?
CF: segment affected/ delayed eruption/ abscess formation/ malformed crowns
RF: short roots/ wide pulp chambers/ thin, immature enamel