maxillary incisors 2

Tooth #8 Coronal dimensions

incisal-cervical > mesial-distal length

tooth #8 crown and root ratio

close to 1
(crown and root are similar in length)

Tooth #8 CEJ

- smooth convex curve toward the apex of the root
- 2 Developmental Depressions sometimes apparent

tooth #8 root

-Smoothly tapered conical shape
-Apex may tend to curve slightly to distal or facial

Tooth #8 - Mesial Line angle Versus Distal Line angle

Mesial angle: approximately 90 degrees
Distal angle usually more rounded.

Tooth #8 - Coronal Outline

- M outline straighter than D outline
- D outline more curved than M outline and forms a constriction in the cervical 1/3 of the crown

Tooth #8 - Cingulum

Prominent Cingulum (the 4th lobe of development) - displaced toward the D on the crown

Tooth #8 - Lingual Fossa

- forms a concavity
- is surrounded by 4 convexities

4 convexities of lingual fossa (Tooth #8)

1. Mesial MR
2. Distal MR
3. Cingulum
4. Incisal Ridge/Edge

Triangle root cross section

unique to maxillary central incisors

#8 - CEJ Curvature (mesial view)

Greater CEJ curvature is noted on the mesial than on the distal.

#8 - Apex (mesial view)

Apex usually aligned with M contact and incisal edge.

#8 Coronal Dimensions (incisal view)

M/D>F/L

#8 - incisal edge from incisal view

the M contact, Incisal edge, and D contact form a straight line bisecting the crown F/L

Maxillary Central Incisor Formation

3-4 months

Maxillary Central Incisor Eruption

7-8 years

Maxillary Central Incisor Root Completion

10 years

Lateral central incisor - formation

10-12 months

Lateral central incisor - eruption

8-9 years

Lateral central incisor - root completion

11 years

Root length - maxillary central incisor vs maxillary lateral incisor

maxillary lateral incisor has longer root

Crown outline - maxillary central incisor vs maxillary lateral incisor

the crown outline on maxillary lateral incisor is more rounded overall, especially mesial and distal line angles

Facial surfaces - maxillary central incisor vs maxillary lateral incisor

in lateral central incisor, The facial surface is not usually as flat as that of the maxillary central, and the developmental depressions are less prominent.

lingual surfaces - maxillary central incisor vs maxillary lateral incisor

Lingual convexities and concavities may be more pronounced with a deeper lingual fossa (in lateral incisors).

Tooth #10 - cross section in cervical 1/3

ovoid