Developmental Dental Abnormalities Flashcards
Give some conditions associated with hypodontia
Ectodermal dysplasia
Downs
Cleft palate
Hurlers syndrome
What is often a large restorative problem when maxillary laterals are missing
Overeruption of mandibular canines
What are some abnormalities of tooth shape and size?
Microdont - peg lateral
Macro don’t
Double teeth
- gemination - one tooth splits into two
- fusion - two teeth fuse into one
Odontomes
Taurodontism - flame shaped pulp
Dilaceration of crown or rooth
Talon cusp - extra cusp
What is dens in dente?
Tx?
‘Tooth within a tooth’
Invagination of the tooth enamel and dentine into the pulpal chamber
Treatment includes immediately sealing off invaginations to prevent bacterial ingress
What anomalies of root structure may occur?
Short root anomaly - permanent max incisors, often canines and premolars too
Radiotherapy
Dentine dysplasia
Accessory roots
What may cause some enamel defects?
Amelogenesis imperfecta
Environmental enamel hypoplasia
Localised enamel hypoplasia
MIH
What are the main forms of amelogenesis imperfecta?
Hypoplastic
Hypo calcified
Hypomaturational
Mixed forms
What is hypoplastic amelogenesis imperfecta
Presentations?
Thin or insufficient enamel formation leading to teeth that appear smaller and are more susceptible to toothwear and damage
Enamel is often roughed, pitted or grooved giving teeth a yellow or discoloured appearance
Enamel crystals do not grow to the correct length
What is hypocalcified amelogenesis imperfecta?
Presentations?
Enamel is formed but is soft but poorly calcified making it easily worn away
Tooth typically chalky and susceptible to wear and pathology
Enamel crystals do not grow to correct thickness or width
What is hypomaturational amelogenesis imperfecta?
Enamel not matured properly leading to translucent/opaque or cloudy enamel with white or brown discolourations
Enamel generally harder than in hypocalcified
Enamel crystals grow to correct length, but incorrect width or thickness and have poor mineralisation
What is mixed form amelogenesis imperfecta?
Characteristics of multiple types of AI are presenting
Give some possible causes of enamel hypoplasia
Systemic illness such as liver or kidney failure
Poor nutrition during development
Infection - measles
Turners hypoplasia
- periapical infection or trauma
- to primary tooth
CONGENITAL SYPHILLIS!
- HUTCHINSONS incisors
What are the main causes of localised hard tissue defects?
1 - trauma
2 - caries
3 - abscess of primary tooth
How would one treat fluorosis?
Micro abrasion therapy
Veneers
Vital bleaching
Give some prenatal causes of generalised environmental enamel defects
Rubella
Thalidomide
Fluorosis
Congenital syphilis
Cardiac and kidney disease
Give some neonatal causes of generalised environmental enamel defects
Premature birth
Meningitis
Give some postnatal causes of generalised environmental enamel defects
Measles
Chickenpox
TB
Pneumonia
/ infectious diseases
Vitamin deficiency
Heart disease
How would make a diagnosis of AI?
Familial inheritance - take a family history
Generally affects both dentitions
Affects all teeth and their size, structure and colour
Take radiographs
Problems / signs / symptoms of AI?
Sensitivity
Caries / acid susceptibility
Poor aesthetics
Poor oral hygiene
Delayed eruption
Anterior open bite
3 types of dentinogenesis imperfecta?
Type 1 - with osteogenesis imperfecta ‘brittle bone disease’
Type 2 - autosomal dominant - gene linked - not on sex chromosome
Brandywine
What is type 1 dentinogenesis imperfecta?
Problems?
Associated with osteogenesis imperfecta
- translucent blue / grey hue of teeth
- normal enamel but discoloured and poorly formed dentine beneath
Rapid wear, chipping and breaking of tooth and also bulbous crown appearance
What is type 2 dentogenesis imperfecta
Dentin formation affected due to mutations in odontoblasts
No association to OI
Brown / blue opalescence of teeth
Defects in structure of dentine leading to teeth susceptible to wear, bulbous crowns, pulpal obliterations etc
Give some abnormalities of cementum and what they are
Cleidocranial dysplasia
- hypoplasia of cellular component of cementum
Hypophosphatasia
- hypoplasia or aplasia of cementum
- early loss of primary teeth
Why may delayed eruption of teeth occur?
Malnutrition
Low birth weight
Downs
Hypothyroidism
Gingival hyperplasia
Why may premature exfoliation occur?
Trauma
Following pulpotomy
Hypophosphatasia
Why may delayed exfoliation occur?
Infra occlusion of teeth
‘Double’ primary teeth
Hypodontia
Ectopic permanent successor
Trauma
Diagnose
Taurodontism
- body of tooth enlarged at expense of root
Diagnose
Dens in dente
What is MIH?
Molar Incisor Hypomineralization (MIH) is a qualitative developmental dental defect that affects the enamel of permanent molars and incisors
What is mild MIH?
Demarcated opacities located at non-stress bearing areas
No caries associated with affected enamel
No hypersensitivity
Very mild or no incisor involvement
What is moderate MIH?
Demarcated opacities present on both molars and incisors
Post-eruptive enamel breakdown is limited to one or two surfaces without cuspal involvement
Normal dental sensitivity
May require atypical restorations
What is severe MIH?
Post eruptive enamel breakdown
Crown destruction
Caries associated with affected enamel
History of dental sensitivity and aesthetic concerns
What is enamel hypoplasia?
Quantitative defect with reduced enamel thickness
- smooth borders of enamel indicating developmental and pre-eruptive lack of enamel
Most common clinical problems with MIH?
Enamel breakdown leading to dentine exposure - risk of pulpal involvement
Tooth sensitivity - can lead to poor oral hygiene as less likely to perform measures
Aesthetic issues on incisors
Dental fear / anxiety from tx
Sharp enamel due to shearing of poorly mineralised enamel
What are thought to be the causes of MIH?
Acute or chronic illness during eruption
Exposure to environmental pollutants
Genetically impacted
Frequent childhood illness
What defects occur at the bud stage?
Congenitally missing teeth
Supernumerary teeth
- dependant on number of placodes
Which DDAs occur at the cap stage?
Cyst
Odontoma
Gemination
Fusion
Dens in dente
What occurs at the bell stage? What DDAs occur at the bell stage?
HISTODIFFERENTIATION
- formation of ameloblasts and odontoblasts
- from inner and outer enamel organ
Morphodifferentiaiton - crown shape and size
- macro/microdontia
Apposition - ameloblasts and odontoblasts start depositing
- enamel hypoplasia, enamel pearls
Amelogenesis imperfecta
Dentogenesis imperfecta
What occurs after cap stage?
Which DDA’s?
Maturation (4-5 years to complete) - long time so illness can affect these ones
- deposition of enamel and dentin
- calcification of crown
DDAs
- enamel hypomineralisaiton
- fluorosis
- tetracycline staining
What are the cells of the tooth germ?
Enamel organ
- ameloblasts
Dental papilla
- odontoblasts
- pulp cells
Dental follicle
- cementoblasts
- Osteoblasts - alveolar bone
- fibroblasts - PDL
What is AI?
Intrinsic alteration of enamel
- hereditary
- autosomal dominant, recessive or X-linked
- effects both dentitions
- thin to no enamel
What is DI?
Autosomal dominant intrinsic alteration of dentine
- resulting in bulbous crowns
- short roots
- obliterated pulps
What is enamel pearl?
Chunk of enamel blocking attachment of sharpens fibers
- automatic periodontal pocket
- wont remove with PMPR
- only in molars
