Permanent molars Flashcards
Which molars have the larger, more pronounced cusps?
The Maxillary molars
How are the crowns of molars different to premolars?
Molars have larger but shorter dimensions than premolars.
How is the occlusal surface of molars shaped?
Maxillary molars are usually wider bucco-lingually than mesio-distally and are more rhombic in shape, Second and third molars can be heart shaped.
Mandibular molars are usually more long, rectangular, or square with the widest measurement mesiodistally.
What is the maxillary molar cusp triangle?
Maxillary molars have a small distopalatal cusp that becomes smaller as you gor from 6 to 7 to 8.
What is another name for the disto-palatal cusp? What does this cusp do?
The maxillary plunging cusps.
They articulate with the opposing fossae of the mandibular molars.
When do first molars erupt?
6 - 7 years
When do second molars erupt?
Maxillary: 12 - 13 years
Mandibular: 11 - 13 years
When do third molars erupt?
17 - 21 years
What is the shape of the occlusal surface of the maxillary first molar?
Irregular rhombus with four cusps: Mesio-palatal, mesio-buccal, disto-buccal, and disto-palatal.
The crown is wider buccopalatally than mesiodistally.
What are the major fossae of the maxillary first molar?
Central and the distal fossae
What are the minor fossae of the maxillary first molar?
Mesial and distal triangular
What are the pits of the maxillary first molar?
The mesial and distal pits
Which 2 cusps does the oblique ridge connect?
The tip of the mesiolingual cusp diagonally across the tooth to the tip of the disto-buccal cusp.
The oblique ridge is produced by the meeting of the triangular ridge of the disto-buccal cusp and the distal cuspal ridge of the mesiolingual cusp.
How high is the low point of the oblique ridge?
It is at the same level as the mesial and distal marginal ridges
Where are the major fossae located?
The central fossa and distal fossa are located on either side of the oblique ridge.
Which cusps of the maxillary first molar are longer?
The buccal cusps
Which cusp is the cusp of cerebelli connected to?
The mesio-palatal cusp
What can be seen on the palatal root extending to cervical of the tooth?
A slight mid-third depression
What does the cervical line of the distal aspect of the maxillary first molar look like?
The cervical line is straight from buccal to palatal.
How are traits that make it easier to differentiate between maxillary 1st and 2nd molars?
- Roots are more widely spread in 1st
- Roots with less distal bend in 1st
- Buccal groove is longer with a possible pit in 1st
- Buccal cusps are almost the same size in 1st whereas mesio-buccal cusp is larger than disto-buccal cusp in 2nd.
- Cusp of cerebelli in 1st
Where do the 1st and 2nd mandibular molars form transverse ridges?
On both the first and second mandibular molars, the triangular ridges of the mesio-buccal and mesio-lingual cusps meet to form
a transverse ridge. The triangular ridges of the disto-buccal and disto-lingual form a second transverse ridge.
What are the developmental grooves of the mandibular first molar?
The Occlusal surface has four developmental grooves: Central, Mesiobuccal, Disto-buccal & and lingual.
What are the 3 fossae of the mandibular first molar?
There are three fossae Mesial, Central and
Distal
What is the shape of the central developmental groove of the first mandibular molar? What does the lingual groove look like relative to it?
The central development groove forms a “zigzag” Mesio-distally and the lingual
groove forms a “y” as it
connects to the central groove
What are the buccal cusps of the mandibular first molar? Which is the largest?
MB, DB, D (the mesio-buccal is the largest). The crown has two buccal grooves buccal and disto-buccal.
What does the cervical junction of the mandibular first molar look like?
The cervical junction is parallel to the occlusal surface. At times enamel can dip into the furcation depression (Buccal).
What other ridges and grooves run on the buccal surface?
There is a distinct buccal ridge and groove that runs
horizontally mesio-distally.
Which mandibular molar root is longer?
The mesial root is longer and the distal root is straighter
What separates the ML and DL cusps of the first mandibular molar?
Has Two Cusps - ML & DL which are separated
by the lingual groove.
What is the cervical margin like on the lingual side of the first mandibular molar?
It is straight
Which is higher the MB or the ML cusp?
The lingual cusp is higher. The two mesial cusps are larger than the distal cusps.
What is wider the mesial or the distal side?
The bucco-lingual width is greater mesial than distal.
How does the cervical margin curve in the mandibular molar on the mesial side?
Occlusally
Features of the Distal surface:
The disto lingual cusp is the largest. The distal contact point is more buccally located and is centered over the long axis of the distal root. This reflects the reduction of mesio-distal width as the Tooth tapers towards the distal. The distal root is shorter allowing the mesial root to be viewed from this Perspective
What are the features of mandibular 1st molars?
- Five cusps: three buccal, two lingual. Mesiobuccal cusp
largest. - Bulbous, lingually inclined buccal surface with two grooves.
- Largest mandibular tooth.
- Buccal aspect: all five cusps visible. Lingual aspect:
three cusps visible. - Crown longer mesiodistally than bucco-lingually; buccal
surface longer than lingual. - Occlusal outline approximately oblong.
7.. Neonatal line, classically on the mesiobuccal cusp. - Two roots: mesial root longer, flattened mesiodistally,
grooved longitudinally and curved distally; distal root more
rounded and less distally curved.
What are the features of mandibular 2nd molars?
- Square occlusal outline – rounded corners.
- Four cusps: two lingual, two buccal, separated
by a pronounced central cruciform fissure
pattern on occlusal surface. - Not as wide mesiodistally as lower first molar.
- Buccal surface bulbous and lingually inclined
with one groove. - Lingual cusps higher than buccal cusps.
- Two roots similar to lower first molar but less
broad, closer together and occasionally fused.
Axes or both roots approximately parallel and
curved distally.
Traits that distinguish first mandibular
molars from second mandibular molars:
Mandibular first 1.Usually has five cusps. 2. Less prominent buccal ridge. 3. More crown taper from buccal to lingual. 4.Fewer Secondary grooves. 5. Central groove zigzags mesially to distally. 6. Mesiobuccal & distobuccal grooves do NOT align with lingual groove.
Mandibular second 1. Usually has four cusps. 2. Buccal ridge more prominent. 3. Less crown taper from buccal to lingual. 4. More secondary grooves. 5. Central groove straighter. 6. Buccal and lingual grooves align to intersect with central groove like a shape “+”
