tooth anatomy basics Flashcards
Which cranial nerve innervates the 1st pharyngeal arch?
Trigeminal (MoM)
Which cranial nerve innervates the 2nd pharyngeal arch?
Facial (muscles of facial expression)
Which cranial nerve innervates the 3rd pharyngeal arch?
Glossopharyngeal
Which cranial nerve innervates the 4th pharyngeal arch?
Vagus
During the cap stage, a small group of ectomesenchymal cells stop producing extracellular substances and aggregate beneath inner enamel.
What is this structure known as and which cells / tissue does this give rise to?
Dental Papilla -
cells are odontoblasts which produce the dentine and pulp.
What is the structure formed where the outer and inner enamel epithelium meet and what does it give rise to?
(essential in root formation)
Cervical Loop -
gives rise to hertwig’s sheath.
At what age is the root structure of primary teeth developed?
3 years
Hard tissue formation of deciduous teeth occurs at how long in utero?
16 weeks
Full root formation occurs how long after eruption?
12 months
Which stage of root formation is impacted in hyper/hypodontia?
dental lamina formation
Missing permanent tooth germs in hypodontia results in lack of exfoliation and root resorption of deciduous teeth.
What occlusion issue may this cause and which teeth are commonly affected?
Infraocclusion -
commonly impacts Es
Which dentition is hyper/hypodontia most common in?
permanent
Which genetic condition is commonly associated with hypodontia and microdontia?
Other features include thin hair, dry skin and absence of sweating.
ectodermal dysplasia
What is the name for a supernumerary tooth that erupts in the anterior maxilla midline?
mesiodens
What autosomal dominant condition is associated with hyperdontia?
Common signs include supernumerary teeth.
Cleidocranial Dysplasia
Which GI condition involving growth of polyps in intestines may present with hyperdontia?
Gardener’s Syndrome
What stage of tooth development is impacted when size of tooth is abnormal?
morphodifferentiation
Which stage of tooth development is affected when accessory cusps are present?
morphodifferentiation
Where do cusps of carabelli occur?
mesiopalatal of permanent maxillary 1st molars
What is an accessory cusp of premolars known as?
dens invaginatus
What is a talon cusp?
accessory cusp appearing on incisors
What is taurodontism and how does this occur?
(think T Rex)
Where roots are shorter and the crown is longer - caused by late / failed invagination of hertwig’s root sheath.
Pt presents with peg laterals with notches on the incisal edge and multiple rounded rudimentary cusps on permane t1 at molars.
What congenital condition do you suspect they have?
congenital syphilis (these are hutchinsons incisors and moons/mulberry molars)
What intolerance can cause chronological enamel hypoplasia and what other developmental issue can it cause?
Coeliac Disease -
can cause delayed eruption.
Which viral infection of the skin and lymph nodes is linked to chronological hypoplasia?
rubella
Define amelogenesis imperfecta.
enamel deficiency caused by a lack of ameloblasts (teeth are brown due to exposed dentine)
What can dentinogenesis imperfecta cause in relation to the pulp?
Pulp Canal Obliteration
Describe the positioning of the 6s to define Class I Occlusion)
mesiobuccal cusp of U6 sits in the buccal groove of the lower
Describe the positioning of the 6s to define Class II Occlusion)
Mesiobuccal cusp of the Upper 6 occludes anteriorly to the buccal groove of the lower 6.
Describe the positioning of the 6s to define Class III Occlusion)
Mesiobuccal cusp of U6 occludes posteriorly to the buccal groove.
Pts with cleft lip and palate typically develop which type of malocclusion?
Class III
Which radiographic technique is used for locating ectopic canines?
parallax technique - OPG and PA
Which metabolic bone disease is linked to hypercementosis?
Paget’s Disease -
disrupts normal bone remodelling causing enlarged and deformed bones.
Which dental anomaly can show a PA radiolucency without presence of caries?
dens invaginatus
Best way to restore hypoplastic primary molars?
PMC
Which type of dentinogenesis imperfecta is present with osteogenesis imperfecta?
Type 1
What is a Turner’s tooth?
Enamel hypoplasia affecting only 1 tooth in the mouth
