LO 5 - Molars Flashcards
Describe the overall shape and function of molars
- 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
Molars are blank _______, which means they do not replace any primary teeth
Nonsuccedaneous
When is there evidence of calcification of maxillary first molars?
Birth
When is enamel of maxillary first molars completed?
4 years of age
When is eruption of maxillary first molars?
6-7 years
What are the roots of maxillary for a smaller completed?
9-10 years
How many roots do maxillary first molars have?
3
How many pulp horns do maxillary first molars have?
4
How many cusps do maxillary first molars have?
4 (5 including the cusp of carabeli)
How many developmental lobes do maxillary first molars have?
5 - 2 facial, 3 lingual
Where are the proximal contact areas of maxillary first molars?
- Mesial - middle third
- Distal - middle third
What is the height of contour on maxillary first molars?
- Facial - cervical third
- Lingual - cervical third
Describe the facial aspect of maxillary for molars
- 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
Describe the lingual aspect of the maxillary first molar
- 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
Describe the mesial aspect of the maxillary first molar
- 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
Describe the distal aspect of a maxillary first molar
- 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
Describe the occlusal aspect of maxillary first molars
- 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
When is there evidence of calcification for maxillary second molars?
3 years
When is the enamel of maxillary second molars completed?
7 to 8 years
When did maxillary second molars erupt?
11-13 years
When are maxillary second molars roots completed?
14 to 16 years
How many roots does a maxillary second molar have?
Three
How many pulp horns do maxillary second molars have?
4
How many cusps do maxillary second molars have?
4
How many lobes does maxillary second molars have?
4 - two facial, two lingual
What are the proximal contact areas of maxillary second molars?
- Mesial - middle third
- Distal - middle third
What is the height of contour for maxillary second molars?
- Facial - cervical third
- Lingual - middle third
Describe the characteristics of maxillary molars
- Get shorter and narrower as you move back
- More supplemental grooves and pits as you move back
- Oblique ridge gets less prominent as you move back
- The cusp of care belly usually disappears on the second molars and disappears almost entirely on maxillary third molars
- The distolingual cusp is less developed on maxillary second molars and disappears almost entirely on maxillary third molars
- The occlusal outline of the second molar is less rhomboidal and more heart-shaped and third molars are even more heart-shaped
- The roots of the second molars have a tendency to lie closer together and may even be fused
- Mesiobuccal roots of second and third molars have a greater tendency to curve distally in a apical third
- Distobuccal root of Max second is straighter than Max first while the max third root has a tendency to curve distally in apical third
- 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
- Molars show more variety in Roots as you move back in the mouth
Describe the facial aspect of maxillary second molars
- The crown of a maxillary second molar is shorter and narrower than that of a maxary first molar - the distobuccal cusp is also smaller
- The buccal roots are about the same length as each other and are closer together
- The distobuccal root is straighter up and down than that of the maxillary first molar, and it has no mesial curvature
- The mesiobuccal root has a greater curvature distally at its apical third
Describe the lingual aspect of the maxillary second molar
- Lingual view shows no fifth cusp of carabelli
- The distolingual cusp is smaller than that of the first molars
Describe the mesial aspect of the maxillary second molars
- 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
- The roots are closer together
Describe the distal aspect of maxillary second molars
- The distobuccal cusp is smaller than the mesiobuccal cusp, thus more of the mesiobuccal cusp can be seen from the distal view
Describe the occlusal aspect of maxillary second molars
- 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
- The distolingual cusp is smaller
- The mesiodistal diameter of the crown is smaller, but the buccolingual diameter is about the same as that of the maxillary first molar
When is there evidence of calcification for maxillary 3rd molars?
7 years
When is the enamel for maxillary third molars completed?
12 to 16 years
When do maxillary 3rd molars erupt?
17 to 22 years
When are the roots of maxillary 3rd molars completed?
18 to 25 years