Ben Boardman Flashcards
What embryological epithelium will form the oral mucosa
What brachial arch moves ventraly to come in to contact with this
Primitive stomodeum
First brachial arch
Explain the process of reciprocal induction during dentinogenesis and amelogenesis
4
- As ectomesenchyme of first brachial arch grows down and forwards it comes into contact with oral epithelium
- Inductive signals (cytokine growth factors) are released from oral epithelium to extomesenchyme causing odontoblast differentiation
- At the same time ectomesenchyme feeds back to oral epithelium to regulate pattern of amelogenisis
- Dentine formation is required before enamel can begin to form hence reciprocal induction
When does the primary epithelial band form
What do the primary epithelial bands form
What do the primary epithelial bands form from
37 days
Dental arches
Ectomesenchyme (neural crest cells)
What two distinct structures do the primary epithelial bands give rise to
What do these structures proceed
Dental Lamina- teeth
Vestibular lamina- buccal and labial vestibules
What are the stages the dental lamina goes through to form the tooth
4
Bud stage
Cap stage
Bell stage
Crown stage
What happens during bud stage
Epithelium of dental lamina forms bud extending into underlying ectomesenchyme
What happens during cap stage
Epithelial bud grows down to form a cap called the dental organs
Ectomesenchyme condensations give rise to dental papilla and dental follicle
During late stage enamel knot is formed by clusters of non dividing cells particularly in molar teeth
What tissue does the dental organ go on to form
What forms the bulk of cap
What structures does the dental papilla form
What structures does the dental follicle form
What is the role of the enamel knot thought to be?
Enamel
Epithelial cells from primitive stomodeum
Dentine and pulp
Periodontal complex- pdl, cementum, alveolar bone
Tooth morphogenesis
What happens during bell stage
Dental hard tissues are laid down
Tooth becomes bell shaped
Distinct regions develop: epithelial layers in enamel organ, cervical loops, enamel chord, dental papilla, dental follicle
What are the epithelial layers surrounding the dental enamel organ? And their roles
4
Internal enamel epithelium - amelogenesis developing into ameloblasts
Stratum intermedium- mineralisation
Stellate reticulum- collapses when amelogenesis begins to bring internal and external enamel epithelial layers together
External enamel epithelium
What is the role of cervical loops
What is the role of enamel cord
Root formation
Eruption
What happens during crown stage
Differentiation of odontoblasts from dental papilla and mineralised dentin matrix formation
Commencement of amelogenesis by ameloblasts which develop from internal enamel epithelium
What is microdontia
What is macrodontia
What is germination
What is fusion
Abnormally small teeth
Abnormally large teeth
The partial development of two teeth from single tooth bud appearing clinically as double teeth
The development of one large tooth from two tooth germs
What is concresence
What is dilaceration
What is dens evaginatus
What is dens in dente
Fusion of roots of two teeth by cementum
Distortion of root occurring during development often as a result of trauma to the primary predecessor
Extra sharp cusp shaped tubercle projecting from palatal or buccal surface
Invagination of enamel giving radiographic appearance of tooth within tooth
What is taurodontism
What is turners tooth
A malformed multi rooted tooth characterised by normal lengthen crown, abnormally short roots and large pulp chamber extending deeply into roots
Tooth with area of localised enamel hypoplasia resulting in area of white or yellow discolouration possibly caused by trauma of associated primary tooth with periapical inflammatory lesion
