Tooth morphology and eruption dates

Tooth morphology
Permanent teeth

Upper 1 (central incisor)

 2 grooves on the labial surface
 mesial corner has a right angle
 distal corner has a curved angle
 palatal surface has a concave surface bounded by ridges (marginal ridges)
 it has a singulum – a rounded block on top

Upper 2 (lateral incisor)

 spade like shape on the labial side
 ride angle corner mesially against U1
 rounded corner against canine
 smaller than U1
 on the palatal side there is small pit (can fit an instrument into)
 the tip of the root bends towards the distal end
 longer root than U1

Lower 1 (central incisor)

 narrower than Upper 1 or Upper 2
 looks like upper 2
 lingual side has a scoop
 1 root
 The root has a groove on the distal side
 The other side is rounded on the root

Lower 2 (lateral incisor)

 Wider across the incisal edge than lower 1
 It is fan shaped
 The distal surface of the root has a groove
 The crown appears twisted on the root

Upper 3 (canine)

 Central cusp
 The labial surface is more curved than Upper 1 or upper 1
 The palatal side has a large singulum
 There is a ridge from the singulum to the cusp edge
 The root curves around
 The distal slope of the cusp is longer than the mesial slope

, Lower 3 (canine)

 Smaller singulum than upper 3
 Shorter mesial slope on the cusp than the distal
 Mesial surface meets the labial surface at a right angle
 Tip of the crown appears twisted

Upper Premolars

 Erupt after molars
 The approximal surface has 2 cusps
 One larger buccal cusp and one smaller palatal cusp
 Oval/egg shaped
 Wider buccal side than palatal side
 There is a fissure between the 2 cusps

Upper 4 ( 1st premolar)

 2 roots
 Well divided roots (although can be fused)
 There is a concave area at the base of the crown. It fits up against the canine
– so its on the mesial side. (how you can tell if its right or left)
 groove on the mesial surface of the marginal ridge

Upper 5 (2nd premolar)

 single root usually with a groove
 occlusal surface is oval shaped
 smaller palatal cusp
 has the fissure between the palatal and buccal cusp
 it doesn’t have the concave area either side of the crown, it is convex instead
 the tip of the palatal cusp is closer to the mesial surface of the tooth (how you
can tell right from left)
 there is a groove running mesially over the marginal ridge

lower premolars

 the crown is tilted towards the tongue (lingually)
 it has a marked buccal curvature
 the occlusal surface is circular shaped

lower 4 (lower 1st premolar)

 lingual cusp is much smaller than buccal cusp
 it has a ridge on the occlusal surface from the buccal to the lingual cusp
 single root
 flattened root from the mesial to distal side#
 the root is longer in relation to the crown