geometric outlines

maxillary first premolar - buccal

mesial and distal outlines are nearly concave

mesial and distal cusp slopes are slightly concave

cervical line is convex root wise

maxillary first premolar - lingual

lingual cusp shorter by 1mm and sharper

distal slope is longer than mesial slope

convex with max convexity at middle 1/3

maxillary first premolar - mesial

buccal outline: convex with max convexity at cervical 1/3

lingual outline: convex with max convexity at middle 1/3

occlusal outline: buccal cusp longer than lingual cusp

cervical line curves occlusally and decreases distally

maxillary first premolar - distal

distal surface is narrower

cervical line is less curved

root trunk is longer

mandibular first premolar - occlusal

mesial outline is slightly curved

distal outline is more convex

maxillary first molar - buccal

mesial outline: nearly straight until contact area at junction of occlusal and middle 1/3

distal outline: convex till contact area at middle 1/3

occlusal outline: mesiobuccal cusp is broader and shorter

cervical outline: irregular and slightly convex towards the root

maxillary first molar - lingual

NO LINGUAL CONVERGENCE

mesial outline: nearly straight with right angle with mesial slope of ML cusp

distal outline: convex and form semicircle with distal slope of the DL cusp

occlusal outline: ML cusp is largest and longest cusp

cervical outline: irregular and slightly convex toward the root

maxillary first molar - mesial

buccal outline: max convexity at cervical 1/3, concave at middle 1/3 (termination of buccal developmental groove), convex at occlusaly 1/3 (circuscribed MB cusp)

Lingual outline: convex with crest of curvature at middle 1/3

occlusal outline: ML and MB cusps and irregular MMR which curves cervically

cervical outline: irregular and convex occlusally

maxillary first molar - distal

narrower

less curved cervical line

DMR is more curved cervically

3 roots can be seen

Mandibular first molar - buccal

mesial outline: concae from root until contact area at junction of occlsual and middle 1/3

distal outline: straight until contact area beneath the distal cusp ridge

occlusal outline: MB, DB and D cusps

cervical outline: straight with dipping into root bifurcation

mandibular first molar - lingual

mesial: striaght until contact area at the junction of the occlusal and middle 1/3

distal outline: convex until the contact area beneath the distal cusp ridge

occlusal outline: ML and DL cusps of equal width

cervical outline: irregulra with dipping into root bifurcation

mandibular first molar - mesial

buccal outline: convex at cervical 1/3, concave at middle 1/3 (termination of buccal developmental groove) and convex at occlusal 1/3 (circumscribed MB cusp)

lingual outline: convex with crest of curvature at middle 1/3

occlusal outline: ML and MB cusp

mandibular first molar - distal

crown shorter distally, DMR is U shape and more cervical