PERMANENT MAXILLARY CENTRAL INCISOR.pptx

The permanent maxillary central incisors are designated by a number. The right permanent maxillary central incisor is known as "8", and the left one is known as "9". In the Palmer notation, a letter is used in conjunction with a symbol designating in which quadrant the tooth is found.

1. PERMANENT MAXILLARY
CEN TRAE INCISOR

eg ee
&. Z
j j
3

2. Introduction

e Centered in the maxilla, one on either side of median
line, with mesial surface of each in contact with mesial
surface of other

+ Two in number
e Larger than the lateral incisor

e These teeth supplement each other in function, and they
are similar anatomically

3. + Shearing or cutting teeth

> Major function is to punch and cut food material during
the process of mastication

e These teeth have incisal ridges or edges rather than
cusps such as are found on canines & posterior teeth

4. Maxillary Central Incisor

Position | Function Number

Maxillary One tooth in each maxillary Biting, cutting, 02
Central quadrant which are closest to incising & shearing
Incisors midline

5. TOOTH NUMBERING :

- UNIVERSAL SYSTEM - 8, 9

+ ZSIGMONDY PALMER - 11

- FDI SYSTEM - 11,21

6. Mesiodistal
Diameter of

CHRONOLOGY

First evidence of calcification
Crown completion

Eruption

Root completion

Mesiodistal Labiolingual Labiolingual | Curvature of
Diameter at | Diameter at Diameter at | Cervical Line
Cervical Line | Crest of Curvature | Cervicalline | M D

3-4 months
4-5 years
7-8 years
10-11 years

7. “Labial Aspect

CROWN

+ Labial surface of crown is usually convex, especially toward
cervical 3rd, some central incisors are flat at middle &
incisal portions

+ Mesial outline of crown is only slightly convex, with crest of
curvature (representing the contact area) appraaailng
mesioincisal angle A

8. <a

+ Distal outline of the crown is more convex than mesial
outline, with the crest of curvature higher toward the
cervical line

Distal margin

shorter & rounded Mesial margin

straight

9. + Distoincisal angle is not as sharp as the mesioincisal
angle

e Incisal outline is usually regular and straight in a
mesiodistal direction

Distoincisal angle Mesioincisal angle
more rounded less rounded

10. AE ==
» Crown length is greater at center than at the two mesial
angles

e Cervical outline of the crown follows a semicircular
direction with the curvature root wise

onvexity in
cervical
third

Widest anterior
teeth

11. - » Developmental depressions - Two straight, shallow
depressions, which extend from incisal edge toward
gingival, and fade out in middle third

° Mesio-labial & Disto-labial developmental depressions,
and they represent division of the three labial lobes

MI & DI: Developmental depressions; 1,2 & 3: Lobes (4"" lobe not visible)

12. e Imbrication lines - Faint, curved lines which roughly
parallel the CEJ in cervical 34 of surface 4 not always
present

© Height of contour - The height of contour of the labial
surface is located in the cervical third

Maxillary Central Incisor
Labial View

13. Lingual Aspect |
CROWN

* The lingual outline is the reverse of that found on labial
aspect

e Lingual aspect has convexities and a concavity

14. + Outline of cervical line is similar, but immediately below
cervical line a smooth convexity is found — CINGULUM

Cervical line
convex

Labial aspect Lingual aspect

15. +» Between marginal ridges, below cingulum, a shallow
concavity is present - lingual fossa

16. e Lingual fossa is bordered by :
Mesially : Mesial marginal ridge,
Incisally : Lingual portion of the

incisal ridge,
Distally : Distal marginal ridge,
Cervically : Cingulum.

Developmental grooves extending

from the cingulum into the lingual
fossa

17. Mesial Aspect

+ Crown is wedge-shaped, or triangular, with
base of triangle at cervix and apex at incisal
ridge

e Line drawn through crown and root from
mesial aspect through center of tooth bisect
apex of root & incisal ridge of crown

18. + lingual outline

y Convex : crest of curvature at the cingulum

y Concave : at Middle portion

y Slightly convex : at linguo-incisal ridge & incisal edge

Convex near
cingulum

Labial margin
convex Concave in the

middle

19. » Cervical line mesially on maxillary central incisor
curves incisally to a noticeable degree

20. Se eat

Distal Aspect
+ The distal surface closely resembles mesial surface, with
following exceptions:

a.Distal surface is generally smaller than mesial surface,
because inciso-cervical dimension is shorter

b.Distal surface is more convex inciso-gingivally

21. c.The cervical margin does not curve
as far incisally

d.Because it contacts the lateral
incisor, which is a smaller tooth,
distal contact area is accordingly
smaller in size

+ Curvature of cervical line outlining
the CEJ is less in extent on the distal
than on the mesial surfaces

22. Po z
Incisal Aspect

» A view of the crown from this aspect superimposes it over
the root entirely so that root is not visible

+ labial face of the crown is relatively broad & flat in
comparison with lingual surface, especially toward
incisal 3°

© Cervical portion of crown labially is convex, although arc
described is broad

23. —

e Outline of lingual portion tapers lingually toward
cingulum

e Cingulum of crown makes up cervical portion of lingual
surface

24. » Crown of this tooth shows more bulk from incisal aspect
than from mesial or distal aspect

e The labiolingual calibration of crown is more than two
thirds as great as mesio-distal calibration

e The crown conforms to a triangular outline reflected by
outline of the root cross section at cervix

25. Root
e The root is single, conical, relatively straight, and tapers
to a rounded apex

+ Horizontal cross section of root near cervical line shows a
rounded triangular outline

26. = Normally, the root is wider at labial, which is the base of
the triangle, and narrower at lingual which is apex

e A mid root cross section usually reveals a somewhat
ovoid outline, which is wider labiolingually than
mesiodistally

27. ye. == 5
References

+ CONCISE DENTAL ANATOMY 8 MORPHOLOGY :
JAMES L FULLER

+ DENTAL ANATOMY, PHYSIOLOGY & OCCLUSION:
WHEELER'S

+ TEXTBOOK OF DENTAL ANATOMY, PHYSIOLOGY 8
OCCLUSION: RASHMI GS (PHULARI)

+ INTERNET