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
What are hutchinsons incisors
What are mulberry/moon molars
Permanent incisors of abnormal shape in which Incisal edges are notched and narrower than cervical region
Small domed first permanent molars sometimes seen in patients with congenital syphilis
What is adontia
What is hypotonia
What is hyperdontia
Congenital absence of teeth
Decrease in number of teeth
Presence of more teeth than normal
What is the difference between exogenous stains and endogenous stains
Exogenous stains are intrinsic stains acquired after tooth eruption
Endogenous stains are intrinsic stains acquired during tooth development
What is fluorosis
What is amelogenesis imperfecta
Fluoride excess leading to hypo mineralisation ranging from chalky white spot to dark staining
A group of hereditary defects of the matrix of mineralisation of enamel causing it to be hypoplastic, hypocalcified, hypomatured
What is dentinogenesis imperfecta
What is dentin dysplasia
Type 1
Type 2
A hereditary condition affecting Dentin formation characterised by early calcification of pulp chamber and dark opalescent yellow/grey discolouration of teeth, early loss of enamel leads to attrition
Autosomal dominant defect in Dentine development
Type 1 has normal crown appearance but little or no root development or pulp
Type 2 leads to primary teeth with brown/blue discolouration with no pulp then adult teeth with enlarged pulp chamber
What causes primary herpetic gingivostomatitis
What are the oral symptoms
What is it’s treatment
HSV 1
Red vesicles on mucosa, hard palate, gingival tissues or dorsum of tongue which rupture to form shallow grey/yellow ulcers with red margins
Fluid intake, analgesia, hydrogen peroxide mouthwash (12+), topical anaesthetic gel benzocaine (2+), bonjela, aciclovir
What causes secondary herpes simplex (cold sore)
What are the oral symptoms
What are the treatments
Reactivation of latent HSV 1
Prodromal paraesthesia, painful vesicles on lip that enlarge, weep, rupture and crust
Fluid intake, analgesia, aciclovir
What causes chicken pox
What are the key symptoms
What is the treatment
HSV 3 varicella zoster virus
Macular eruptions all over body, may also be in mouth
Fluid intake, analgesia, calamine lotion, antihistamines
What causes shingles
What are the key symptoms
What is the treatment
Reactivation of varicella zoster HSV 3
Vesicular rash and stomatitis
Fluid intake, analgesia, aciclovir, immunisation
What causes glandular fever
What are the oral symptoms
What is the treatment
Epstein Barr virus HSV 4
Sore throat, pharyngitis, oral ulceration on posterior pharynx and soft palate, petechial heamorrhage on palate (small red dots), lymph node enlargement
Fluid intake, analgesia
What causes slapped cheek/fifth disease
What are the key symptoms
What is the treatment
Parvovirus B19
Initial bright red rash on cheeks followed by generalised rash
Fluid intake, analgesia
What causes herpangina
What are the oral symptoms
What is the treatment
Coxsackie A16
Small vesicles form 4-5 clusters on palate and back of throat
Fluid intake , analgesia
What causes hand foot and mouth
What are the key symptoms
What are the oral symptoms
What is the treatment
Coxsackie A16 and enterovirus 71
Maculo papular rash on hands, feet and mouth with erythematous margins
Around 10 small vesicles on palate and pharynx that rupture to form ulcers
Fluid intake, analgesia
What causes measles
What are the key symptoms
What are the oral symptoms
What is the treatment
Rubelola virus
Generalised rash with red maculo papular lesions starting on head
Kopliks spots
Fluid intake, analgesia, MMR vaccine
What causes Rubella/ German measles
What are the main symptoms
What is the treatment
Rubella virus
Generalised rash starting from behind ears
Fluid intake, analgesia, MMR vaccine
What causes mumps
What are the oral symptoms
What is the treatment
Rubulavirus
Parotid enlargement leading to unilateral or bilateral swelling
Opening of stensons duct appears erythematous and enlarged
Fluid intake, analgesia, MMR vaccine
Explain bone remodelling theory of tooth eruption
Evidence for and against
The selective absorption and deposition of bone causes eruption
Tooth eruption is prevented when there is a deficiency of osteoclasts
It is not clear if bone resorption causes tooth movement or tooth movement causes bone resorption
Explain root formation theory of tooth eruption
Evidence against
As root develops cellular proliferation occurs generating force against cushion hummock ligament causing eruption
Some believe this ligament is just a membrane with no bony attachment
Some teeth erupt further than their corresponding root formation
Some teeth erupt without full root formation
Explain vascular pressure theory of tooth eruption
Evidence for and against
Increased vascular pressure generates force causing eruption
Increasing hydrostatic pressure of blood vessels increases eruption speed
Stimulation of sympathetic nerves causing vasoconstriction decreases eruption speed
Hydrostatic pressure not sufficient to sustain eruption for long periods of time
Explain PDL traction theory
Evidence for and against
Fibroblasts in dental follicle contract to generate force causing eruption
Tooth eruption is prevented when there is a deficiency of osteoclasts
Fibroblasts don’t have contractile elements
Contractile collagen fibres connected to fibroblasts do not insert into bone during early eruption
