CTB SBA Flashcards
Which genetic factor is associated with tooth type?
Msx1 - associated with incisors
Barx1/Dlx1and 2 - associated with molars
Odontogenic potential
What feature in enamel is part of the tooth self repair mechanism?
Its ability to undergo remineralisation e.g. white spot lesions. Unfortunately it cannot repair itself through cellular processes as all ameloblasts have died
What layer has a role in cementogenesis:
HERS disintegration allows for newly formed dentine to come into contact with the dental follicle cells which then differentiate into cementoblasts
Which fibres resist tooth extraction?
Alveolar crest
Apical
Interradicular
What components of the mandible are derived from sensory capsule and pharyngeal arch?
Mandible - pharyngeal arch I (intramembranous)
Lingula, mental ossicles, sphenomandibular ligament - meckel’s cartilage
Which cell from the list attaches by tight junctions distally
Ruffle-ended: (80%)
-tight junctions at distal (enamel) end
What is embryological origin of interparietal occipital bone
intramembranous; the other parts are all endochondral
Long period lines in enamel and dentine -
Daily period lines in enamel and dentine -
Long period lines in enamel and dentine - striae of Retzius/Andreson lines
Daily period lines in enamel and dentine - cross striations/von ebner
How does the maxilla grow in height:
Bone deposition at the zygomatic and frontal sutures
Bone remodelling at alveolar processes
Bone remodelling of the hard palate - deposition on the inferior palatal surface and resorption a the superior surface (floor of the nose and maxillary sinus)
How does the maxilla grow in width:
Growth at the mid palatal suture
Some external bone remodelling
How does the maxilla grow in length
Growth at the posterior surface of maxillary tuberosities (backward growth resulting in forward displacement of the maxilla)
Bone remodelling in area above the maxillary incisors
When does the hard palate fuse
the palatal shelves fuse around 9 months; they do not fully ossify until 12 weeks when they fuse with the primary palate/maxilla
When does the anterior fontanelle fuse
18 months. Metopic suture is 7 months and posterior fontanelle is 2 months
Periodontal cysts
formed as dental lamina does not break down
Deep bite correction (posterior open bite):
Mandibular compensation - development of a wider ramus
open bite correction (backward rotation of the mandible) - anterior open bite:
Caused by excess growth in the anterior face height
Mandibular incisors drift upwards and maxillary incisors downwards to compensate for malocclusion
i.e. dentoalveolar compensation
What produces chelating agents -
osteoclasts
phasic activity
osteoblasts
What determines shape of cusps?
Enamel knots
Which structure is derived from both nasal capsules and pharyngeal arches?
Temporal
Where does the occipital bone come from?
endochondral ossification
also Tongue muscles are derived from occipital somites
What closes both an anterior and posterior open bite?
Dentoalveolar compensation
What are tufts?
Hypomineralised voids which follow the direction of decussation, located in inner third of enamel
When do bones start growing into palatal shelves?
10-15 weeks
A deficiency in what causes enamel hypoplasia?
Protein – protein energy malnutrition (PEM)
Calcium - hypocalcaemia
Vitamin D – deficiency
Vitamin A – deficiency
calcium Is the one on the cheat sheet
for hypo mineralisation vitD and floruride are the ones in the notes
A deficiency in what increases risk of caries?
Vitamin D potentially
Which fibres resists extraction?
Alveolar crest group
What is the most common collagen in PDL?
Type 1
Which type of nerve ending is found at the apex and senses pressure?
Ruffini’s corpuscles
Why are blood vessels near the PDL fenestrated?
Generated increased diffusion capacity consistent with the high metabolic rate in PDL
What bone is made in response to a fracture in alveolar bone?
Wove bone maybe