a question i dont understand NBDE 1

[Torbe]

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In an ideal occlusal relationship, when an exaggerated Bennett component is present in lateral jaw movement, it will have its greatest potential for interference with the

a) mesiodistal positioning of cusp tips.
b) buccolingual positioning of cusp tips.
c)position of the central fossa.
d) depth of the distal fossa.

answer is A!! can someone explain it???
🙁

 

[Dentdocdent]

The Bennett movement is the lateral shift that occurs very early in lateral excursion. The mesiodistal cusp tips need to be spaced sufficiently to allow the opposing cusp tip to slide between them without interference. At least that's how I understand it. Hope that helps.

 

[Torbe]

In lateral excursion on a patient with ideal occlusion, the mesial cusp ridge of the mandibular first premolar contacts the

a)distolingual surface of the maxillary canine.
b)distolingual slope of the buccal cusp of the maxillary first premolar.
c)mesiolingual slope of the buccal cusp of the maxillary first premolar.
d) None of the above

this one i had an idea was C, and thats the right answer.. but if i really try to understand it, i dont get it completely...We know that on ideal occlusion 1 premolar of mandibular teeth ocludes on mesial triangular fossa of max 1 premolar and distal marginal ridge of max canine, but my doubt is why not answer d????? i think that the contact will be on the distolingual slope and not on the mesiolingual slope..

thanks

 

[Torbe]

mmmmm it makes sense, sometimes answers are just common sense but that one didn't cross my mind. thank you..

 

[Torbe]

i ve never heard of eskimo teeth!!!

A V-shaped incipient enamel extension coronoradicularly on a crown may be found

a)crossing the cervical line on the mesial surface of a deciduous molar.
b) to be the etiological factor for localized periodontal disease.
c) in bifurcated areas of any multirooted teeth and commonly on Eskimo teeth.
d) routinely on the mesial surface of a maxillary first premolar and will be pathogenically involved.

answer c is the right answer

 

[Torbe]

In centric relation, the cusp tip of the distolingual cusp of the permanent mandibular first molar

a) contacts the distolingual surface of the opposing tooth.
b)contacts the lingual groove of the opposing molar.
c)ascends above the middle third of the opposing crown.
d) functions above the plane of orientation.
e) has no antagonist.

how could be the answer is E??
There is no contact in premolars, but distolingual cusps contact lingual grooves!!!!