Permanent Molars Anatomy Flashcards
How many molars are in each arch
6
Molar functions:
Chew food
Vertical dimension: prevents jaws from closing too far (protruding chin)
Arch integrity: maintains continuity of arches, keeps other teeth in alignment
Esthetics/cheek support: keeps cheeks normally full looking
What are the numbers of the first molars on the maxilla?
3, 14
What are the numbers of the second molars on the max?
2, 15
What are the numbers of the third molars on the maxilla
1, 16
What are the numbers of the first molars on the mand
19, 30
What are the numbers of the second molars on the mand
18, 31
What are the numbers of the third molars on the mand
17, 32
Which teeth are the first permanent teeth to show evidence of calcification?
First molars (at birth)
When do first molars erupt
6-7 yo
When do mandibular second molars erupt
11-13 yo
When do max second molars erupt
12-15 yo
When do third molars erupt
17-21 yo
How many developmental lobes form the maxillary molars? How many cusps?
4, 4
How many developmental lobes form the mandibular molars? How many cusps?
5,5
The combined mesiodistal width of the three mandibular molars in one quad makes up ______ of the mesiodistal dimension in their quadrant
Over half
The maxillary molars make up about ____ of the quadrants mesiodistal dimension
44%
Molar crowns are _____ occlusocervically than all other adult crowns and are shorter ______ than _____
Shorter
Occlusocervically , mesiodistally
On most molar crowns, the occlusal surface tapers from the ___ to the ____
Buccal, lingual
Molar crowns from the occlusal view tend to taper (prox) ?
Which tooth is this less apparent on and why?
Distally
Mand 1st molars, tooth may be widest BL in the middle third ***why the lingual embrasures is wider than facial embrasure
The height of contour on the buccal of the molars is in the ___ third
The HOC on the lingual is in the ____
Cervical, middle
Where are the mesial contact areas on molars?
Distal?
Junction of occlusal and middle , more cervical
The crowns of mand molars are much wider ____ than ____
Is this the same for max molars?
Mesiodistally , faciolingually
The opposite! Max = wider faciolingually
How would you describe the shape of max molars?
Mand molars?
Max = square/ parallelogram
Mand = rectangle/ pentagon
How many cusps can mandibular molars have?
4 or 5
Where are the cusps located on a 4 cusp type mand molar
2 buccal 2 lingual
Where are the cusps located on 5 cusp mand molars?
What tooth specifically would have this?
2 = sized lingual cusps
3 buccal; 1 smaller cusp called the distal cusp located just distal of the DB cusp on the buccal surface
**mand 1st molars
How many cusps can the max molars have?
3, 4, 5
Where are cusps located on a 3 cusp max molar?
What tooth specifically could have this?
Mesiobuccal, distobuccal, Mesiolingual
Max second molars
Here are the cusps located on a 4 cusp max molar?
Which cusp is smaller than the rest?
Larger= mesiobuccal, Mesiolingual, distobuccal
Smaller = distolingual
Where are the cusps located on a 5 cusp maxillary molar?
What tooth would have this?
2 = size lingual , 2 = size buccal
1 smaller on the lingual “carabelli” - lingual surface of Mesiolingual cusp
Which arch has molars that have a lingual tilt of their crowns?
Which has molars that are centered?
Mand
Max
How many roots to max molars have?
Where are they located?
Which is longest?
Shortest?
3
Mesio & disto buccal , lingual (palatial)
Lingual is longest
Distobuccal is shortest
How many roots do mand molars have?
Where are they located?
Which is the longest?
2
Mesial, distal
Mesial is longer
Which molars have the largest root to crown ratio?
Mandibular
** largest ratio in the whole mouth
Which arch has molars with shorter root trunks?
Why?
Mand
Bifurcation usually close to cervical line
What is the order of cusp lengths on max molars?
Longest Mesiolingual, mesiobuccal, distobuccal, shortest distolingual if present
Which tooth is normally the widest in the upper arch?
Max first molar
How many roots are present on max molars?
Where are they?
What is the order of lengths/
3
Mesiobuccal, distobuccal, lingual
Lingual is longest, disto buccal is shortest
Can you see the mesial and distal surfaces on the max first molar crowns from a lingual view?
Why?
Not likely
These teeth may be as wide or wider on the lingual half than on the buccal half due to a relatively wide distolingual cusp
Which teeth are exceptions to the rule for posterior teeth that there is a taper towards the lingual?
Max first molars & 3 cusp mand 2nd pm
Maxillary second molars are narrower in the _____ half due to the relatively smaller/ non existent ___
Lingual, distolingual cusp
Which cusp is normally the largest and highest on maxillary molars?
Mesiolingual
On around _____ of max 1st molars, the smaller 5th cusp is found on the ___ surface and called the ___
2/3 , lingual, carabelli
Around ____ of max second molars have 4 cusps?
Which lingual cusp is larger?
2/3
Mesiolingual
Approx how many max second molars have only 3 cusps?
What are these called?
Where are the cusps located?
1/3
Tricuspid form
One lingual cusp and 2 buccal cusps
When the 1st and 2nd max molars have 2 lingual cusps, what else is present?
Is this present on 3 cusp max second molars?
Lingual groove
Not present; no distolingual cusp so no groove
Which cusps are visible from a mesial view on the maxillary first molars?
Only the mesial cusps, the broad MB ridge hides the DB cusp
On maxillary molars, the ____ marginal ridge is more occlusal than the ___
mesial, distal
For second max molars, there’s usually a ______ of the buccal cusps
The _____ cusp is noticeably larger
Greater difference
Mesiobuccal
On max molars, triangular ridges of the _____ and _____ cusps join to form a _________
Mesiobuccal, Mesiolingual
Transverse ridge
What forms the oblique ridge?
Which arch normally has molars with this ridge?
Distal cusp ridge on the Mesiolingual cusp crosses the occlusal table diagonally to join the triangular ridge of the distobuccal cusp
Most max molars ; less prominent on max 2nd
Where are the fossa on 4 cusp max molars?
On 3 cusp?
Central (largest)
Distal oblique (second largest)
Mesial triangular
Distal triangular
Mesial, central, distal
What shape does the occlusal outline of the 3 cusp type max molar make?
Heart
Mesial and distal contact areas of max molars are all slightly to the ____
Buccal
On max molars, the mesial contact is ___ buccal than the distal
More
Which tooth has the largest mesiodistal dimension in the mouth?
Mand 1st molar
How many cusps does the mand 1st molar normally have?
Where are they
5
3 buccal 2 lingual
What is the order of longest to shortest cusps on the mand 1st molar?
Mesiolingual, distolingual, distobuccal, distal
On both mand molars, which cusp is taller?
Lingual cusps
When there are 3 buccal cusps on the mand 1st molar, where are the grooves?
Which is longer?
Mesiobuccal = longer
Distobuccal = shorter
How many cusps does the mand 2nd molar have?
What’s the order longest to shortest?
4
Mesiolingual, distolingual, mesiobuccal, distobuccal
How many buccal grooves do mand 2nd molars have?
1
Which mand molar has proportionally more tapering of he crown from the contact areas to the CEJ?
Why?
Mand 1st has more tapering
Because of the bulge on the distal cusp
How many roots do mandibular molars have?
Which is longer?
The roots are nearly ______ as the crown
2
Mesial is longer
Twice as long
Which mand molars have more separated roots?
First
Are mand molars narrower on the buccal or lingual?
Lingual
What is the buccal cervical ridge?
On which arch can this feature be seen on molars?
A ridge running mesiodistally on the cervical third of perm molars (height of contour on Be)
Mandibular
On which mand molar is the buccal cervical ridge more prominent?
Mand 2nd
Are mesial or distal cusps higher on the mand molars?
Mesial
On which root of the mand molars are their both mesial and distal deep developmental depressions?
Mesial root
On the distal root of mand 1st molars, on which surface is there normally a developmental depression?
Distal
What is an easy way to distinguish between the first and second mand molars from a proximal view?
No distal cusp on 2nd molars
How many cusps does the mand 1st molar usually have?
Where are they
5
MB, DB, D
ML, DL
How many cusps does a mand 2nd molar normally have?
Where are they
4
MB, DB, ML, DL
What shape is the outline of the mand second molar from the occlusal view?
1st molar?
Rectangle
Pentagon (because of buccal budge on DB cusp)
Mandibular molars are wider mesiodistally on the _____ half
Buccal
How many transverse ridges are present on mandibular molars?
2 - mesial and distal
What are the fossa on the mand 1st molar?
2nd?
Mesial triangular, distal triangular, central
Same!
What grooves are present on the mand 1st molar?
Central, mesiobuccal, distobuccal, lingual
What grooves are present on the mand 2nd molar?
Central, buccal, lingual
Which molar shows more variation in development than any other tooth in the mouth?
Max 3rd molars
How does the crown of the max 3rd molar compare to the second?
Usually smaller, heart shaped, supplementary grooves
The average mand 3rd molar shows ______ of the crown (often ______) with ____ roots
Irregular development , abnormally large crowns, undersized
Which tooth is likely to be impacted?
Mand 3rd molars due to lack of space in the jaw
What is the tissue flap that covers the mand 3rd molar called?
What is the result of trauma or infection to this tissue called?
Operculum
Pericoronitis
