Mandibular Premolars (permanent) Flashcards
Which mandibular permanent premolar is smaller / bigger?
Mandibular first premolar is smaller than mandibular second premolar.
What is the relationship of the lingual and facial cusp on a mandibular premolar?
Facial cusp is much bigger than lingual cusp
In comparison to maxillary premolars are the mandibular premolars more or less similar?
Mandibular premolars are less similar (they have more distinguishing features)
What are the Universal numbers of the mandibular first premolar?
21 (left)
28 (right)
From the facial view, what is the shape (not geometrical) of the mandibular first premolar?
Pentagonal
From the facial view, what is the geometrical shape of the mandibular first premolar? which way does it taper?
Facial View –> Trapezoidal / tapering cervically
Which two teeth in the entire mouth have similar HOC (medial & distal)
Mandibular Central and Mandibular first premolar
Where is the mesial & distal HOC on a mandibular first premolar?
M-HOC & D-HOC are both at middle third
Distal may be slightly occlusal
Which cusp on a mandibular first premolar is longer / shorter?
MB cusp is shorter
DB cusp is longer
Which premolar has the most variable lingual cusp?
mandibular first premolar
What feature is found on a mandibular first premolar that is between the mesial marginal ridge and the Lingual Cusp?
Mesial marginal groove
What is the geometric shape of a mandibular first premolar from a proximal view?
Rhomboidal
Inclined lingually
Where is the buccal cusp tip in relationship to the root on a mandibular first premolar from a proximal view?
Buccal cusp tip on a mandibular first premolar is centered over root midline (mandibular second premolar is not)
Where is the lingual cusp tip in relationship to the root on a mandibular first premolar from a proximal view?
Lingual cusp tip is centered over lingual root surface with the tip slightly more lingual
From mesial view, at what angle is the mesial marginal ridge inclined on a mandibular first premolar ?
Mesial Marginal ridge on a mandibular first premolar is inclined 45 degrees?
From proximal view, which marginal ridge is more cervical in a mandibular first premolar?
Mesial marginal ridge is more cervical than the distal marginal ridge in a mandibular first premolar
What is the general view of mesial and distal marginal ridges on premolars?
Generally, distal marginal ridge is more cervical than mesial marginal ridge (exception is mandibular first premolar )
What groove is found on the mesial side of the mandibular first premolar?
Mesial Lingual groove
Is there a distal marginal groove present on a mandibular first premolar?
No
From which view can one see more of the occlusal table on a mandibular first premolar (mesial or distal) and why?
Mesial because mesial marginal ridge is more cervical than distal marginal ridge
How does the distal marginal ridge compare to the mesial marginal ridge on a mandibular first premolar? (2 main factors)
Distal marginal on a mandibular first premolar is more occlusal and more horizontal (mesial marginal ridge is more vertical and cervical)
What outline does the mandibular first premolar have?
Diamond shape
Which is longer FL or MD on a mandibular first premolar ?
FL>MD on a mandibular first premolar
What shape is the occlusal table on a mandibular first premolar
Triangular in shape
Do the Buccal and Lingual cusp on a mandibular first premolar offset in any way? if so, which way?
Buccal & Lingual cusp are offset mesially on a mandibular first premolar
Form an occlusal view on a mandibular first premolar, how much space doe the buccal cusp take up?
2/3rds of an occlusal surface
Does the mandibular first premolar have a pronounced transverse ridge?
Yes unlike maxillary first premolar
Which fossa on a mandibular first premolar is larger?
Distal fossa on a mandibular first premolar is larger and more circular than mesial fossa, which is more linear.
Which posterior tooth has the shortest F-L dimension?
Mandibular First Premolar
Which premolar is the smallest?
Mandibular First Premolar
Which posterior tooth is the only tooth to exhibit more cervical M-HOC than the D-HOC
Mandibular First Premolar
Much of the occlusal surface of the Mandibular First Premolar is visible from the lingual view, a characteristic not seen in other posterior teeth
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What is the cross section of a Mandibular First Premolar at the cervical region?
Ovoid
wider buccally than lingually
What tooth number are the Mandibular Second Premolar
20 & 27
Which is larger, Mandibular First Premolar or Mandibular Second Premolar? (Crown & Root)
Mandibular Second Premolar
Which is larger, Maxillary First Premolar or Maxillary Second Premolar?
Maxillary First Premolar
Generally, how many cusps does a Mandibular Second Premolar have?
3 cusps and 5 developmental lobes
From facial view, how is the cusp tip of a Mandibular Second Premolar centered?
cusp tip of a Mandibular Second Premolar is centered mesiodistally (where as mandibular first cusp tip is offset mesially).
From the lingual view, where is the HOC on a Mandibular Second Premolar?
Lingual HOC on a Mandibular Second Premolar is from middle third to occlusal third
what are the name of the three cusps on a Mandibular Second Premolar?
Mesiolingual, Distolingual, and Buccal cusp
Which lingual cusp is larger on a Mandibular Second Premolar
Mesiolingual cusp is larger than distolingual cusp on a Mandibular Second Premolar
What separates the Mesiolingual and Distoliwngual cusps on a Mandibular Second Premolar?
Lingual Groove
Where is the buccal cusp tip of a Mandibular Second Premolar in relationship to the midline from the mesial view
Buccal cusp tip is facial to the tooth midline from proximal view
How does the mesial and vital marginal ridge compare on a Mandibular Second Premolar
Distal marginal ridge is more cervical than mesial marginal ridge on a Mandibular Second Premolar
How many cusps are visible from the mesial view of a Mandibular Second Premolar?
One can only see 2 cusps from mesial view of Mandibular Second Premolar
How many cusps are visible from the distal view of a Mandibular Second Premolar?
All three cusps are seen on a Mandibular Second Premolar
What are the 3 occlusal groove patterns on a Mandibular Second Premolar
Y-Type (3 cusp)
U-Type (2 cusp)
H-Type (2 cusp)
Explain the Y-Shape Groove pattern on a Mandibular Second Premolar
Y-Shape is formed by lingual groove joining central groove
Works only for Mandibular Second Premolar with 3 cusp tips
No Transverse ridge
What are the three pits and fossae named on a Y-Type occlusal groove pattern of a Mandibular Second Premolar
3 pits: Mesial, Central, Distal
3 fossae: 2 triangular (mesial and distal) and 1 central fossa
What is the comparison of a Y-type to U & H shape groove pattern on a Mandibular Second Premolar
U or H shape groove pattern on a Mandibular Second Premolar apply for 2 cusp and are
More Rounded
Have more pronounced Transverse Ridge
DO not have lingual groove or central pit
In a 2-cusp variety for a Mandibular Second Premolar, which way is the lingual cusp pointed?
On a 2-cusp variety of a Mandibular Second Premolar, the lingual cusp is offset mesial
Is bifurcation possible for Mandibular Second Premolar?
Yes
What si the root cross section of a Mandibular Second Premolar at the cervical third?
Root Cross section of a Mandibular Second Premolar is ovoid
How doe the occlusal outline compare between Mandibular First and Second Premolar
Occlusal outline is more rounded in first and is more square in second
Form proximal view, which mandibular premolar has the buccal cusp tip centered over midline?
Mandibular First Premolar buccal cusp tip is centered over root midline
Mandibular Second Premolar buccal cusp tip is facial to the midline.
Does the Mandibular Second Premolar have a lingual crown taper?
Mandibular Second Premolar does not have a lingual crown taper
The MD dimension of the lingual half meets or exceeds the MD dimension of facial half
The Mandibular Second Premolar is the only premolar that has a central Fossa
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Which posterior tooth may be congenitally missing?
Mandibular second
Which anterior tooth may be congenitally missing?
Maxillary lateral incisor