Occlusion ,dental anatomy , dental education

1. {

2. Occlusion
Is the relation of the upper
and lower teeth during various
activities of the mandible as in
mastication and swallowing

3. Contact of teeth in opposing
dental arches:
When the jaws are closed=
"static occlusal relationships“
During various jaw movements=
"dynamic occlusal relationships".
Occlusion

4. Centric occlusion
Is a tooth-to-tooth relationship
(interdigitation of teeth) when:
1 - Upper and lower teeth are in
maximum intercuspation.
2 - Condyles are resting in the most
etruded -unstrained- position in
mandibular fossae.

5. Centric Occlusion
maximum
inter-
cuspation
most retruded unstrained position
of condyles in glenoid fossa
GLENOID
FOSSA
TOOTH –TO- TOOTH RELATIONSHIP
1
2

6. 1.First permanent teeth to erupt
in the oral cavity.
2.Occupy a central position in the jaw
(antro-posteriorly).
Key of Occlusion:
Maxillary & mandibular
1st permanent molars
serve as “Key of
occlusion”:
Why?

7. 3- Their positions in the jaws
are guided by the presence of
the deciduous molars preceding
them.
4- Their eruption is not disturbed as
they have no predecessors.
5- 6 is considered more accurate than
6 as it is attached to a bone fixed to
the base of the skull.

8. MB cusp 6
MB groove 6
Classification of Occlusion
Class I :
Centric occlusion:
Angle’s Classification:
MB
MB groove

9. MB cusp 6 MB groove 6
Class I : centric occlusion
Orthognathic profile
Classification of Occlusion

10. Class I
Class II
Class III
Angle’s Classification:

11. Class II malocclusion
Retrognathic profile
Classification of Occlusion

12. Class III malocclusion
Anterior cross bite

13. 6
6
6
6
Malocclusion
6
6
Malocclusion
Centric occlusion

14. 1- Opposing teeth:
I) Centric Occlusion of Permanent Teeth
Each tooth in a dental arch
occludes with two teeth in
the opposing arch ,
except:
the mandibular central incisor
the maxillary third molar.
General Concepts:
1
1 2
5
5
4

15. *The neighboring teeth
migrate, to fill the
space.
Loss of tooth leads to:
* The opposing tooth
may elongate.
This results in: disturbance in the centric
occlusion, caries and periodontitis.

16. 2-Maxillary anterior teeth
overlap mandibular teeth:
 Horizontal overlap: “Overjet”
Incisal edges of maxillary
anterior teeth are labial to
incisal edges of mandibular teeth
 Vertical overlap: “Overbite”
Incisal edges of the maxillary teeth
extend below the incisal edges of mandibular
teeth
Relationship of
Anterior teeth
General Concepts:

17. Overbite

18. Overjet

20. Vertical overlap:
“overbite”
Horizontal overlap:
“overjet”
General Concepts:

21. Relationship of
Individual Teeth
in
Centric Occlusion

22. Maxillary posterior teeth
are slightly buccal to
mandibular posterior teeth:
Relationship of
Posterior Teeth
•The lingual cusps of the
maxillary teeth rest in the
occlusal fossae of the
mandibular teeth.
General Concepts:
•The buccal cusps (free of
contact)

23. • Buccal cusps of mandibular teeth
rest in occlusal fossae
of maxillary teeth.
• Lingual cusps
(free of contact)
.
Relationship of
Posterior Teeth
The mandibular posterior teeth:
General Concepts:

24. The buccal cusps (free of contact)
MBC Free, in the opposing B groove
DBC Free in the opposing embrassure between their
antagonistic teeth and the distal one
8……. DB slope of DBC of 8
MBC DBC
Maxillary molars

25. MLC Opposing central fossa
DLC 6…….. MMR 7
7 ……..DMR of 7
8 (if present) ……... DMR of 8
Lingual relation of maxillary molars

26. Forms of Malocclusion
Anterior
open bite
Crowding
Cross bite