Disorders Of Tooth Development Flashcards
What can be causes of variations of tooth development
Genetically determined
Local factor
Systemic factor
What is hypotonia
Missing teeth- the failure of teeth to develop
Commonly upper 2s 5s and 8s
What is anodontia
Complete lack of teeth
What is hyperdontia?
Extra teeth- supernumeraries
Are patients with missing primary teeth likely to have missing secondary teeth?
Yes. 30-50% with missing primary go on to have missing secondary
What would appropriate treatment for hypotonia be?
Full or partial denture
Implants
Composite build ups if accompanied with small teeth to mask conical or mishapen appearance
What is the ratio of hyperdontia male: female
2:1
What are common presentations of hyperdontia
Mesiodens- supernumerary in between central incisors
Paramolars- supernumerary in molar region- can be buccal, lingual or palatal
Distomolar- supernumerary distal to 8s
5x more common maxillary
What is megadontia
Larger teeth than normal
Seen in cases of pituitary gigantism
What is microdontia?
Smaller than normal teeth
Commonly affects maxillary lateral incisors and 3rd molars
What can be causes of disorders of root size?
Oriental background
Irradiation of jaws or chemo during root formation may cause shortened roots
Orthodontic tx 1mm reduction in root length per 1 years of tx
What is gemination
Separation of single tooth germ to produce 2 separate teeth
Rare
Anteriors and deciduous most commonly affected
What is fusion
Union of 2 separate adjacent tooth germs
Thought to be hereditary
More common in primary dentition
What is concrescence
Joining of 2 teeth by cementum
Caused by trauma or crowding
Maxillary molars commonly affected
What is dilaceration
Disruption of root formation
Caused by trauma to tooth germ during tooth development
Can impede tooth eruption
What are invaginated teeth?
Infolding of palatal surface of crown- lined with enamel
Dens in dente
Appears as crown with deep pit in area of Cingulum
Radio graphically- pear shaped mass
What tx is appropriate for invaginated teeth.
Fissure seal ASAP
Vitality test
RCT if pupal involvement.
What are evaginated teeth?
Small tubercle non occlusal surface of premolar- central part of fissure system
What is dens evaginatus
Talon cusp- horn projection of Cingular of maxillary incisor
What is taurodontism
Affects molar teeth
Pulp chamber lengthened and shortened roots
What are the two classifications of amelogenesis imperfecta?
Hypoplasia
Hypomineralisation
Describe Hypoplasia
Deficient enamel matrix Thinner enamel Grooved or pitted Glossy Hard/ translucent
Describe hypo mineralisation
Defect in mineralisation of enamel Normal thickness but soft Discoloured- brown/ yellow Opaque/ chalky Prone to caries
What is management of amelogenesis imperfecta
Restorative tx
PMC s on 6s
Treat aesthetics and sensitivity
What is dentinogenisis imperfecta?
Inherited disorder or dentine
Primary and permanent teeth affected
Teeth opalescent with greyish brown colour
Enamel prone to flake off due to poor adhesion
Pulpal exposure likely in deciduous
What is congenital syphilis?
Caused by spirochete treponema pallidum found in the dental follicle
Transmitted via placenta
Associated with blindness, deafness and paralysis
What 3 anomalies are associated with congenital syphiliis?
Hutchinson incisor- notch in incisal edge of upper 1s
Mulberry molars- 1st molars
Moon molars- round or dome shaped first molars
What is enameloma- enamel pearls
Small spherical enamel projection on root surface
Caused by abnormal displacement of ameloblasts during formation
Maxillary molars commonly affected
Rev fluorosis
Tetracycline staining
MIH
Revise above!!!!
What variations can occur in the development of teeth
Variations of size, form and structure
