LO 5 - Molars Flashcards
1
Q
Describe the overall shape and function of molars
A
- 12 permanent molars
- Largest and strongest teeth in the mouth
- Grind or crushed food
- Eruption occurs distal to the second primary molars
- First molars are the largest teeth in the dentition, the maxillary first is the largest, the second and third molars are progressively smaller
2
Q
Molars are blank _______, which means they do not replace any primary teeth
A
Nonsuccedaneous
3
Q
When is there evidence of calcification of maxillary first molars?
A
Birth
4
Q
When is enamel of maxillary first molars completed?
A
4 years of age
5
Q
When is eruption of maxillary first molars?
A
6-7 years
6
Q
What are the roots of maxillary for a smaller completed?
A
9-10 years
7
Q
How many roots do maxillary first molars have?
A
3
8
Q
How many pulp horns do maxillary first molars have?
A
4
9
Q
How many cusps do maxillary first molars have?
A
4 (5 including the cusp of carabeli)
10
Q
How many developmental lobes do maxillary first molars have?
A
5 - 2 facial, 3 lingual
11
Q
Where are the proximal contact areas of maxillary first molars?
A
- Mesial - middle third
- Distal - middle third
12
Q
What is the height of contour on maxillary first molars?
A
- Facial - cervical third
- Lingual - cervical third
13
Q
Describe the facial aspect of maxillary for molars
A
- Four cusps can usually be seen - mesiobuccal, distobuccal, mesolingual, and distolingual
- Two lingual cusps are located distal and lingual to the buckle cusp
- Mesiobuccal cusp is broader than the distobuccal cusp
- Distobuccal cusp is usually sharper and longer
- Buccal developmental groove divides the two buccal cusps
- It splits into a buccal pit with two small grooves radiating from it
- The cervical line is a regular and curved, generally toward the occlusal side at the New Zealand distal ends
- Mesial outline of the crown - straight from the cervical line to the mesial contact area
- Distally, the outline of the crown is convex
14
Q
Describe the lingual aspect of the maxillary first molar
A
- Two lingual cusps can be seen
- The mesiolingual is the largest and longest of all the cusps on this crown; the distolingual is the smallest and shortest of the functioning cusps
- View of the cusp of carabelli, when present, is generally on the mesolingual cusp
- This tubercle varies greatly and prominence and is afunctional
- Usually see at least a trace of the cusp of carabelli
- A mesiolingual groove separates this cusp from the large mesolingual cusp
- All three routes can be seen from the lingual aspect
- On average, the roots are about twice as long as the crown
- The lingual root is usually longer than either of the two buccal roots, which are the same length
15
Q
Describe the mesial aspect of the maxillary first molar
A
- The mesial aspect of a maxillary first molar usually shows a clear profile of the cusp of carabelli
- The cervical line is slightly convex mesially
16
Q
Describe the distal aspect of a maxillary first molar
A
- The crown has a tendency to taper distally
- Distal cervical line is usually straighter and less curved than that on the mesial side
- Slight concavity from the cervical line to the distobuccal root
- Distal marginal ridge is shorter and less prominent than the mesial marginal ridge
- The distobuccal root is the narrowest of all three roots
17
Q
Describe the occlusal aspect of maxillary first molars
A
- Has a rhomboidal occlusal outline
- Crown is wider mesially than distally semicolon it is also wider lingually than buccally
- Only tooth that is wider lingually than buccally
- Lines connecting the three largest cusps form a triangle
- A prominent oblique ridge which runs from the tip of the mesolingual cusp to the tip of the distobuccal cusp
- The distilingual cusp is less developed than the three larger cusps
- The mesial lingual cusp has the widest mesiodistal dimension
- There are three observable faucet - the mesial, central, and distal which frequently each have a pit
- The three major grooves are the central groove (divided into its mesial and distal portions), the distolingual groove, and the buccal groove
18
Q
When is there evidence of calcification for maxillary second molars?
A
3 years
19
Q
When is the enamel of maxillary second molars completed?
A
7 to 8 years
20
Q
When did maxillary second molars erupt?
A
11-13 years
21
Q
When are maxillary second molars roots completed?
A
14 to 16 years
22
Q
How many roots does a maxillary second molar have?
A
Three
23
Q
How many pulp horns do maxillary second molars have?
A
4
24
Q
How many cusps do maxillary second molars have?
A
4
25
How many lobes does maxillary second molars have?
4 - two facial, two lingual
26
What are the proximal contact areas of maxillary second molars?
1. Mesial - middle third
2. Distal - middle third
27
What is the height of contour for maxillary second molars?
1. Facial - cervical third
2. Lingual - middle third
28
Describe the characteristics of maxillary molars
1. Get shorter and narrower as you move back
2. More supplemental grooves and pits as you move back
3. Oblique ridge gets less prominent as you move back
4. The cusp of care belly usually disappears on the second molars and disappears almost entirely on maxillary third molars
5. The distolingual cusp is less developed on maxillary second molars and disappears almost entirely on maxillary third molars
6. The occlusal outline of the second molar is less rhomboidal and more heart-shaped and third molars are even more heart-shaped
7. The roots of the second molars have a tendency to lie closer together and may even be fused
8. Mesiobuccal roots of second and third molars have a greater tendency to curve distally in a apical third
9. Distobuccal root of Max second is straighter than Max first while the max third root has a tendency to curve distally in apical third
10. Roots of Max second molars are almost as long and sometimes longer than Max first molars, but Max third molars are almost always smaller than first or second
11. Molars show more variety in Roots as you move back in the mouth
29
Describe the facial aspect of maxillary second molars
1. The crown of a maxillary second molar is shorter and narrower than that of a maxary first molar - the distobuccal cusp is also smaller
2. **The buccal roots are about the same length as each other and are closer together**
3. The distobuccal root is straighter up and down than that of the maxillary first molar, and it has no mesial curvature
4. The mesiobuccal root has a greater curvature distally at its apical third
30
Describe the lingual aspect of the maxillary second molar
1. Lingual view shows no fifth cusp of carabelli
2. The distolingual cusp is smaller than that of the first molars
31
Describe the mesial aspect of the maxillary second molars
1. Mesial view shows the second molar Crown to be shorter than the first molar, but it's buccolingual measurement is about the same as that of a maxillary first molar
2. The roots are closer together
32
Describe the distal aspect of maxillary second molars
1. The distobuccal cusp is smaller than the mesiobuccal cusp, thus more of the mesiobuccal cusp can be seen from the distal view
33
Describe the occlusal aspect of maxillary second molars
1. Last rhomboidel than maxillary first molars - the increase in size of the mesolingual cusp and the absence of the cusp of carabelle makes this possible
2. The distolingual cusp is smaller
3. The mesiodistal diameter of the crown is smaller, but the buccolingual diameter is about the same as that of the maxillary first molar
34
When is there evidence of calcification for maxillary 3rd molars?
7 years
35
When is the enamel for maxillary third molars completed?
12 to 16 years
36
When do maxillary 3rd molars erupt?
17 to 22 years
37
When are the roots of maxillary 3rd molars completed?
18 to 25 years
38
How many roots do maxillary third molars have?
1 to 4
39
How many pulp horns do maxillary third molars have?
1 to 4
40
How many cusps do maxillary 3rd molars have?
Three to five
41
How many developmental lobes do maxillary third molars have?
4
42
Where are the proximal contact areas of maxillary 3rd molars?
1. Mesial - middle third
2. Distal - not applicable
43
Where is the height of contour for maxillary 3rd molars?
1. Facial - cervical third
2. Lingual - middle third
44
Describe maxillary 3rd molars compared to other maxillary molars
1. They very in size, shape, and relative position more than any other teeth
2. Rarely as well developed as maxillary second molar
3. Often appears as a developmental anomaly or does not form at all
4. Shorter crown than Max second and Roots tend to fuse into one root
5. Occlusal outline is heart-shaped
6. The distolingual cusp is poorly developed or even absent
7. Greater tendency to be impacted than any other teeth - caused mostly by underdeveloped jaw and hence insufficient space to accommodate them
8. Congenitally missing third molars is a modern genetic trend in humans, which is becoming more predominant
45
Describe the roots of maxillary molars
1. Maxillary molar roots are trifurcated - mesiobuccal, distobuccal, lingual
2. Transportation gives maxillary molars sturdy Anchorage against forces that would tend to displace them
3. The lingual root is the longest, and the **distobuccal is the shortest**
4. All three routes are usually visible from the buccal view
5. The two buccal roots incline distally, with the mesial buccal root starting to curve at its middle third
6. The distal root is usually straighter and tends to curve mesially at its middle third
7. Deep developmental groove between two buckle roots
8. Deciduous molars have shorter root trunk than permanent molars and the buckle roots of deciduous molars flare apart rather than curved toward each other
46
Describe how maxillary molar Roots change from the anterior to the posterior
1. Become shorter as you move posterior
2. Become less divided as you move posterior (third molar often has fused roots)
3. The Roots become more varied in shape, size, and direction of curvature as you move posterior
47
Describe the pulp cavity of maxillary molars
1. Consists of a pulp chamber and three main pulp canals - one for each root
2. The lingual root canal is the largest, the distobuccal is the smallest, and the mesiobuccal is slightly larger than the distobuccal
3. The maxillary first molar has a tendency to have four root canals, with two canals in the mesiobuccal root
4. In the fused route form, only one large fruit with one root canal may be evident
5. If four roots are present, as in some maxillary third molars, four root canals may be present to - one for each root
6. Each cusp has one pulp horn
7. The maxillary molars would then have four pulp horns - mesiobuccal, distobuccal, mesolingual, and distolingual
48
When is there evidence of calcification for mandibular first molars?
Birth
49
When is the enamel of mandibular first molars completed?
3 years
50
When do mandibular first molars erupt?
6 years
51
When are mandibular first molar roots completed?
9 to 10 years
52
How many roots do mandibular first molars have?
2
53
How many pulp horns do mandibular first molars have?
5
54
How many cusps do mandibular first molars have?
5
55
How many developmental lobes do mandibular first molars have?
5 - three facial, two lingual
56
Where are the proximal contact areas of mandibular first molars?
1. Mesial - middle third
2. Distal - middle third
57
What is the height of contour for mandibular first molars?
1. Facial - cervical third
2. Middle - middle third
58
Describe mandibular molars
1. Permanent manipular molars are larger than any other mandibular teeth (but do have shorter crowns)
2. Function as chewing or grinding tools
3. Progressively decrease in size the more posterior the tooth
4. The roots are not as long as some other mandibular roots, but they're bifurcation results in excellent Anchorage
59
What traits distinguish mandibular molars from maxillary molars
1. As a rule, mandibular molars only have two Roots - one mesial and one distal
2. Generally, four major cusps are on mandibular molars; if a fifth cusp is present, it is a minor cusp
3. Mandibular molar crowns are always broader mesiodistally than buccolingually
4. Mandibular molars have two buccal cusps that are nearly equal in size; they also have two lingual cusps that are almost equal in size
60
What is unique about mandibular first molars?
1. Usually the first permanent teeth to erupt in the mouth
2. They are the only mandibular molars that usually have five cusps - two buckle and toolingual which are major, and one distal which is minor
3. The mandibular first molars are normally the largest teeth in the mandibular arch, with a crown usually about 1 mm longer mesiodistally than buccolingually
4. Generally have two Roots - one mesial and one distal
61
Describe the facial aspect of mandibular first molars
1. One distal and two buccal cusps can be seen
2. Mesiobuccal cusp is the widest of the three; the distal cup is the smallest
3. Mesiobuccal and distobuccal cusps are equal in height and are separated by the mesiobuccal groove; groove often ends in a pit
4. Distal cusp is much more conical in shape and is smaller in height and width than the other two - separated from distobuccal cusp by distobuccal groove
5. Cervical line on mandibular first molar dips apically toward the root bifurcation
6. Entire distal profile of the crown is convex
7. Mesial profile of the crown is convex at the middle and occlusal thirds, while the cervical third is concave
8. The cervical third of the crown is narrower than the occlusal third
9. The roots of this tooth are well formed
10. The mesial root is almost perpendicular to the middle third of the root; from this point, it curves distally towards its apex, which is located directly in line with the mesiobuccal cusp
11. The distal root shows little curvature and projects distally from the root base
12. The two roots are widely separated at their apices
62
Describe the lingual aspect of mandibular first molars
1. Two cusps of almost equal size - mesolingual and distolingual
2. The lingual developmental groove separates these two cusps
3. The lingual cusps are higher and more pointed than the two buccal cusps
4. The tooth is wider on the buckle than on the lingual side
5. The mesial and distal profiles of the lingual aspect are both convex
6. The bifurcation of the two Roots begins with the bifurcation groove on the root trunk located directly in line with the lingual developmental groove
7. The lingual surface is rather flat
8. The cervical line is straight mesiodistally
63
Describe the mesial aspect of mandibular first molars
1. From the Musial aspect, two cusps can be seen, the mesiolingual and the mesiobuccal
2. The mesial lingual is the higher and more conical of the two
3. Only the mesial root can be seen from The mesial view
4. The mesial marginal ridge has a prominent crest, which is divided by the mesial marginal groove
5. The buccal profile is marked by the buccal cervical ridge, a slight bulge in the cervical third of the buccal surface
6. The cervical line tends to curve occlusally about 1 mm in the center of the mesial surface - it is located higher on the lingual side than on the buccal side
7. The buccolingual measurements of the crown, root, and cusps are all greater on the mesial surface than on the distal surface
8. The mesial cusp is also higher than the distal cusp
64
Describe the distal aspect of the mandibular first molar
1. The distolingual cusp is the largest of the three cusps visible from the distal aspect
2. The distal buckle cusp is next in size, and the distal cusp is the smallest
3. The distal buckle groove can be seen separating the latter of the two cusps
4. The distal marginal ridge (not as wide as the mesial marginal ridge) is bisected by the distal marginal groove (lingual to the center of the tooth)
5. The crown of the first molar tapers and converges distally
65
Describe the occlusal aspect of mandibular first molars
1. The occlusal view of a mandibular first molar shows five cusps, four major and one minor - all five are functional
2. The occlusal outline is pentagonal
3. Medial cusps are wider bucklingually than the distal cusps
4. The mesiodistal measurement of the three buccal cusps together is much larger than the two lingual cusps combined
5. The mesiobuccal cusp is wider than either of the lingual cusps, which are about the same size
6. The distobuccal cusp is the smallest of the four major cusps, and the distal cusp is the smallest of all five
7. The developmental grooves that separate these cusps are the central developmental group, the mesiobuccal developmental groove, and the lingual developmental groove
8. All of the developmental grooves converge at the central pit in the center of the central fossa
9. The occlusal surface has three major fossae - the central (largest), musial, and distal
10. **The 2 buccal grooves and the lingual groove form a y-shaped pattern on the occlusal surface of the crown**
11. Mesial and distal marginal grooves may also be present
12. Several supplemental grooves radiate from the mesial and distal pits, which are usually found in the mesial and distal triangular fossae
66
When is there evidence of calcification for mandibular second molars?
2 to 3 years
67
When is enamel of mandibular second molars completed?
7 to 8 years
68
When do mandibular second molars erupt?
11 to 13 years
69
When are the roots of mandibular second molars completed?
14 to 15 years
70
How many roots do mandibular second molars have?
2
71
How many pulp horns do mandibular second molars have?
4
72
How many cusps do mandibular second molars have?
4
73
How many developmental lobes do mandibular second molars have?
4 - two facial and two lingual
74
Where are the proximal contact areas on mandibular second molars?
1. Mesial - middle third
2. Distal - middle third
75
What is the height of contour of mandibular second molars?
1. Facial - cervical third
2. Lingual - middle third
76
Describe mandibular second molars
1. They resemble the mandibular first molars except that usually no fifth or distal cusp is present
2. The roots of the second molar are shorter, closer together, and more distally inclined than those of the first molar
3. All four cusps of the mandibular second molars are nearly equal in size
4. The second molars have a more rectangular shape than the first molars
77
Describe the facial aspect of mandibular second molars
1. A second molar Crown is not as long mesiodistally and is slightly shorter
2. Only two buccal cusps which are equal in their mesiodistal measurement - separated by a single buccal groove
3. Roots maybe somewhat shorter and are usually located closer together than roots of a first molar
4. They are also more distally inclined
78
Describe the lingual aspect of mandibular second molars
1. The crown of the mandibular second molar converges far less lingually than that of a first molar (because no distal cusp is present)
2. The two lingual cusps are nearly the same size and are separated by a lingual groove which sometimes ends in a lingual pit
79
Describe the mesial aspect of mandibular second molars
1. The cervical line shows less curvature than the first molar does, and the mesial root is less broad
2. Otherwise, the mesial view is the same for both molars
80
Describe the distal aspect of mandibular second molars
1. The most noticeable difference between the first and second molars is the absence of a distal cusp
2. The contact area is there for a centered both buccolingually and cervico-occlusally
81
Describe the occlusal aspect of mandibular second molars
1. The occlusal outline of a second molar is rectangular
2. All four cops are equal in size
3. Developmental grooves are the buckle groove the lingual groove and the central developmental groove (mesial and distal portions)
4. Across groove pattern is characteristic of this crown
5. There are more secondary grooves on the second molar
6. The four triangular grooves include a distofacial, a distolingual, mesiofacial, and mesiolingual
7. Three pits may be present: mesial, distal, and Central
8. Three fossae: the mesial, central, and distal are found on the occlusal with a pit commonly found in each fossa
82
When do you manipular third molars show evidence of calcification?
8 to 10 years
83
When is the enamel of mandibular third molars completed?
12 to 16 years
84
When do mandibular third molars erupt?
17 to 21 years
85
When are the roots of mandibular third molars completed?
18 to 25 years
86
How many roots do mandibular third molars have?
Two Roots fused into one
87
How many pulp horns do mandibular third molars have?
Four or five
88
How many cusps do mandibular third molars have?
Four or five
89
How many developmental lobes do mandibular third molars have?
Four or five
90
What are the proximal contact areas of mandibular third molars?
1. Mesial - middle third
2. Distal- middle third
91
What is the height of contour of mandibular third molars?
1. Facial - cervical third
2. Lingual - middle third
92
Describe vandibular third molars
1. Irregular and unpredictable
2. Crown is usually shorter in all dimensions than second molars, although it is possible to find a third molar larger than even a first molar but this is an exception
3. The occlusal outline of the crown is more oval than rectangular, although the crown usually resembles that of a mandibular second molar
4. The two mesial cusps are larger than the two distal cusps
5. The occlusal surface has a very wrinkled appearance, within a regular groove pattern and numerous pits
6. The roots of the third molars are usually shorter than those of the second molars and are inclined acutely to the distal side - they are also very close together and often fused
93
Describe the root and pulp cavities of mandibular molars
1. Mandibular molars have two Roots - one mesial and one distal, with a single root trunk (bifurcated root)
2. The mesial root is the longer and stronger of the two
3. It curves mesially and then turns distillate in the apical portion
4. The distal root is usually quite straight and may curve mesialy or distally at its apical third
5. The root trunk is bifurcated very close to the cervical line - the trunk is short and is grooved on the buccal and lingual surfaces toward the bifurcation
6. Roots become shorter as the molar is more posterior, the roots are less divided as the molar is further posterior, the root becomes more varied in shape/size/direction as the tooth is more posterior
7. The pulp cavity of the mandibular molars consists of a pulp chamber and three pulp canals - distal, mesiobuccal, and mesolingual
8. The distal root canal is much larger than the other two canals and is the only canal in the distal root
9. The mesial houses two root canals - mesiobuccal and misilingual, often these two canals join into one single apical foramen and sometimes only one canal is in the medial root
10. On very rare occasions, two canals are in the distal root, chest is in the mesial root
11. Five pulp horns can be found - one for each cusp; in the forecast form, only for pulp horns are present
12. The first molar is more likely to have three root canals and five pulp horns
13. Although the second molar may have two canals, it is more likely to have three root canals
14. Third molars resemble second molars in pulpal anatomy
