oral_biology_tooth_morphology_20150331151423 Flashcards
(81 cards)
1
Q
Eruption date of Maxillary deciduous a
A
7 1/2 months
2
Q
Eruption date of Maxillary deciduous b
A
8 months
3
Q
Eruption date of Maxillary deciduous c
A
16-20 months
4
Q
Eruption date of Maxillary deciduous d
A
12-16 months
5
Q
Eruption date of Maxillary deciduous e
A
21-30 months
6
Q
Eruption date of Mandibular deciduous a
A
6 1/2 months
7
Q
Eruption date of Mandibular deciduous b
A
7 months
8
Q
Eruption date of Mandibular deciduous c
A
16-20 months
9
Q
Eruption date of Mandibular deciduous d
A
12-16 months
10
Q
Eruption date of Mandibular deciduous e
A
21-30 months
11
Q
Eruption date of Maxillary permanent central incisors
A
7-8 years
12
Q
Eruption date of Maxillary permanent lateral incisors
A
8-9 years
13
Q
Eruption date of Maxillary permanent canines
A
11-12 years
14
Q
Eruption date of Maxillary first permanent premolar
A
10-11 years
15
Q
Eruption date of Maxillary second permanent premolar
A
10-12 years
16
Q
Eruption date of Maxillary first permanent molar
A
6-7 years
17
Q
Eruption date of Maxillary second permanent molar
A
12-13 years
18
Q
Eruption date of Maxillary third permanent molar (wisdom tooth)
A
17-21 years
19
Q
Eruption date of Mandibular permanent central incisor
A
6-7 years
20
Q
Eruption date of Mandibular permanent lateral incisor
A
7-8 years
21
Q
Eruption date of Mandibular permanent canine
A
9-10 years
22
Q
Eruption date of Mandibular permanent first premolar
A
10-12 years
23
Q
Eruption date of Mandibular permanent second premolar
A
11-12 years
24
Q
Eruption date of Mandibular permanent first molar
A
6-7 years
25
Eruption date of Mandibular permanent second molar
12-13 years
26
Eruption date of Mandibular permanent third molar (wisdom tooth)
17-21 years
27
Define eruption:
The axial or occlusal movement of the tooth from its developmental position in the jaw to its functional position in the occlusal plane (a group of complex physiological tooth movements- both pre and post eruptive)
28
Where are permanent tooth germs located in comparison to deciduous tooth germs?
Lingal
29
Where do permanent tooth crowns normally lie before eruption?
At the apical 1/3 of the tooth root
30
When does tooth development start in utero?
6-7 weeks
31
When are 20 epithelial swellings first visible?
Week 8
32
What is intraosseous eruption?
movement of the tooth through bone
33
What is the speed of intraosseous eruption?
1-10 µm per day
34
When the tooth crown comes into contact with the oral epithelium which two types of epithelia fuse?
Reduced enamel epitheliumOral epithelium
35
At what stage does root development start?
When tooth eruption begins
36
What is the name of the canal necessary for eruption and what is its role?What is located within it?
Gubernacular canalPathway through the bone for the toothGubernacular cord = composed of epithelial cells and connective tissue
37
What happens to this canal prior to eruption?
It widens
38
What is the rate of eruption once the tooth has emerged into the oral cavity?
75 µm per day
39
What are odontoblasts?
Giant multi nucleated cells (4-20 nuclei)Ruffled border = increased surface area
40
Name a physiological post-eruptive movement:What is it?And what does it do?
Mesial driftDrifting of teeth towards the midlineMaintains inter-proximal contact between neighbouring teeth
41
Name a pathological post-eruptive movement: What is it?
Over-eruptionThe over-eruption of an opposing tooth following extraction
42
Why is it unlikely that the periodontal ligament fibrous tissue plays a role in tooth eruption?
It is not actually attached to the tooth until after eruption
43
What 4 things can we study to help us understand tooth eruption?
- genetically modified mice (knockout/in genes)- injections of putative eruption molecules into animal models following knockout- cultured dental follicle cells- genetic disorders in humans with failure/delayed eruption
44
What are the 3 main dental implications of cleidocraniaplasia and dysostosis?
1. delayed eruption2. supernumerous teeth3. osteoblasts affect osteoclasts
45
When we cannot determine why a tooth has been erupted what do we call it and what is it?
Primary failure of eruptionProblem with the dental follicle -> can be caused by inflammation of mucosa around deciduous teethN.B. = difficult to treat (often we just remove it!)
46
What is diphydonty?
Having 2 generations of teeth (deciduous & permanent)
47
What is heterodonty?
Having different tooth types/ forms(Incisiforme, caniniforme & molariforme)
48
What is the dental formulae for Deciduous teeth?
***
49
What is the dental formulae for permanent teeth?
***
50
What is the anatomical crown?
The part of the crown covered in enamel (fixed)
51
What is the clinical crown?
The part of the tooth you can see in the mouth (may also include exposed root in periodontitis)may be > or < than anatomical crown
52
What is the root?
The part of the tooth not covered in enamel but covered in cementum instead
53
What is the shape of the root for the maxillary incsisors?
Conical - can be rolled in fingers
54
What is the shape of the root in mandibular incisors?
Flatter- less able to roll!
55
How many roots do the permanent maxillary molars have?
3 roots
56
How many roots do the deciduous maxillary molars have?
3 roots
57
How many roots do the permanent mandibular molars have?
2 roots
58
How many roots do the -permanent mandibular molars have?
2 roots
59
What is the name of the ridge found on the permanent upper molars?And which cusps does it join?
Oblique ridgeMesiopalatal (largest) and distobuccal cusp
60
Which is the largest cusp in the molars?
Mesiopalatal
61
Which is the smallest cusp in the permanent first and second maxillary molars?
The distopalatal
62
Which cusp is sometimes missing from the permanent second maxillary molar?
The distopalatal cusp
63
Which tooth has the foramen cecum if it is present?
The Permanent maxillary lateral incisor
64
Which root sometimes contains more than one root canal in the permanent first maxillary molar?
Mesiobuccal
65
What is the name of the triangular shaped cusp located on the permanent first mandibular first molar?
Distal cusp
66
Which mandibular molar has only 4 cusps?
7
67
Which mandibular molar has 5 cusps?
6
68
Which tooth are the deciduous d's similar to?
The permanent 6's
69
On the permanent mandibular incisors which side of the root has the deepest grooves?
Distal
70
What is the key feature that can be used to determine that a tooth is deciduous?
It bulges more at the cervical margin
71
What is the most notable difference in the crowns of mandibular and maxilalry canines?
Mandibular canine = convex linguallyMaxillary not really convex - pretty much a straight surface
72
On which surface of deciduos mandibular molars is the tubercle of zukerkandal found?
Mesiobuccal
73
What is the occlusal shape of maxillary premolars?
Oval
74
What is the occlusal shape of mandibular premolars?
Round/square
75
How do you side the first maxillary premolar?
The Mesio-distal occlusal fissure crosses over the medial marginal ridge
76
Which cusp is larger in the first maxillary premolar?
The buccal cusp
77
In the mandibular permanent first premolar what is the name of the ridge that connects the two cusps called?
Transverse buccal-lingual ridge
78
In both mandibular permanent premolar which fossa is biggest?
Distal fossa
79
In which % of permanent maxillary first molars can carrabelli cusps be found?
50-75%
80
Which is the only permanent tooth to have a neonatal line?
The permanent first molars (6)
81
Which cusp is largest in the permanent mandibular first molar?
The mesiobuccal
