mandibular 1st molars Flashcards
When do mandibular 1st molars begin formation?
At birth
When do mandibular 1st molars erupt?
6–7 years
When is root completion for mandibular 1st molars?
9–10 years
What numbers are the mandibular 1st molars?
19 & #30
Which teeth are normally the largest in the mandibular arch?
Mandibular 1st molars
Which are usually the first permanent teeth to erupt?
Mandibular 1st molars
How many developmental lobes do mandibular 1st molars have?
5
How many cusps does the mandibular 1st molars have?
5 cusps
What are the three buccal cusps of mandibular 1st molars?
MB, DB, and D
What are the two lingual cusps of mandibular 1st molars?
ML and DL
How many cusps can be seen from the buccal view of mandibular 1st molars?
3
What is the shape of the mesial outline in the buccal view of mandibular 1st molars?
Convex crown, slightly concave at the cervical third
Which surface is wider on the mandibular 1st molars : buccal or lingual?
Buccal
What is the shape of the distal outline in the buccal view of mandibular 1st molars?
Rounded or convex
How many developmental buccal grooves are present on mandibular 1st molars?
2
Where are the mesial and distal contact areas located on mandibular 1st molars?
At the junction of the occlusal and middle thirds
Name the two developmental buccal grooves on mandibular 1st molars.
MB groove and DB groove
Are the Mesial Lingual and Distal Lingual cusps on the mandibular 1st molars almost equal in size
Yes
What is the profile of the lingual surface in mandibular 1st molars?
Convex
What separates the ML and DL lingual cusps of mandibular 1st molars?
Lingual developmental groove
How do lingual cusps compare to buccal cusps on mandibular 1st molars?
Lingual cusps are higher and more pointed than the buccal cusp
How many roots do mandibular 1st molars have?
Two roots: mesial and distal
How does the root trunk of mandibular 1st molars compare to mandibular 2nd molars?
The root trunk is shorter on the 1st molar than the 2nd
How do the roots of mandibular 1st molars compare to mandibular 2nd molars?
Roots are more divergent toward the apex on the 1st molar
Are the roots of mandibular 1st molars usually straight or bent?
Many roots are bent
What is the most common direction of root bending in mandibular 1st molars?
Toward the distal
How far is the root bifurcation of mandibular 1st molars from the CEJ on the buccal and lingual?
3mm buccal
4mm lingual
How does the furcation of mandibular molars compare to maxillary molars?
It is closer to the cervical line in mandibular molars than in maxillary molars
Which cusp is longer and more pointed from the mesial view: ML or MB?
Mesial Lingual cusp
How is the crown oriented from the mesial view?
Tilted lingually
Which root is broader and longer in mandibular 1st molars?
Mesial root
Can you see the distal root from the mesial view of mandibular 1st molars?
No
What is the shape of the CEJ from the mesial view of mandibular 1st molars?
Slightly curved
How does the crown appear from the distal view of mandibular 1st molars?
The crown is shorter, allowing more of the occlusal surface to be seen
How does the distal root compare to the mesial root in mandibular 1st molars?
The distal root is smaller than the mesial root
What can be seen behind the distal root from the distal view of mandibular 1st molars?
The wider mesial root
What shape does the occlusal view of mandibular 1st molars resemble?
Pentagon
How many triangular ridges are present on the mandibular 1st molar?
4
What is the order of the cusps from highest to lowest in mandibular 1st molars?
ML > DL > MB > DB > D
Which triangular ridges are longer on the mandibular 1st molar?
The triangular ridges of the lingual cusps are longer
How many fossae are present on the mandibular 1st molar?
3
What does the distal transverse ridge consist of in the mandibular 1st molar?
triangular of DB
triangular of DL
What does the mesial transverse ridge consist of in the mandibular 1st molar?
triangular of MB
triangular of ML
How many transverse ridges are present on the mandibular 1st molar?
2
What are the three fossae of the mandibular 1st molar?
- Large central fossa/pit
- Smaller mesial triangular fossa/pit
- Smallest distal triangular fossa/pit
What is the largest fossa/pit in the mandibular 1st molar?
central fossa/pit
What is the second to last smallest triangular fossa/pit in the mandibular 1st molar?
mesial triangular fossa/pit
What is the smallest triangular fossa/pit in the mandibular 1st molar?
distal triangular fossa/pit
What is the main groove that runs through the mandibular 1st molar?
Central groove
What are the three grooves that branch off the central groove?
Llingua, Mesial and Distal grooves
Where does the MB groove start and extend on mandibular 1st molars?
Starts at the central pit and extends/separates between the MB and DB cusps
Where does the DB groove start and continue on mandibular 1st molars?
Starts at the central pit/groove and continues between the DB and D cusps separating them
Where does the lingual groove start and extend on mandibular 1st molars?
Starts at the central pit and extends lingually between the ML and DL cusps separating them
What is the characteristic pattern of grooves on mandibular 1st molars?
Y-pattern: 2 buccal grooves and the lingual groove
Are supplemental groove present on mandibular 1st molars?
Yes, but theres more on the 2nd
What are the three triangular grooves on mandibular 1st molars?
- Mesiobuccal
- Mesiolingual
- Distolingual
What are the two marginal grooves on mandibular 1st molars?
- Distal
- Mesial
Why is the mandibular 1st molar important in occlusion?
Its role is crucial, as its loss can significantly affect occlusion.
Why is the mandibular 1st molar more likely to be lost?
It is the first permanent tooth to erupt into the oral cavity, making it more susceptible to damage or decay.
Why are buccal pits on mandibular 1st molars at increased risk of caries?
Due to increased dental biofilm retention and the thinness of enamel forming the walls of the pit.
What is the stamp cusp of the mandibular 1st molar?
Buccal
