1. Morphological norm of permanent dentition - occlusion Prof. dr hab. n. med. Teresa Matthews-Brzozowska

2. Features of permanent dentition with functional analysis - occlusion and articulation

3. Characteristic features of permanent dentition: - number of teeth: 32 - shape of the upper dental arch – semi-elliptic, lower dental arch - parabola - dental arches without spacings with retained contact points - upper dental arch overlaps lower dental arch - long axes of incisors are slightly inclined forward (upper: from 5° to 15°, lower: from 0° to 5°)

4. Characteristic features of permanent dentition: - midline of upper and lower incisors is aligned with facial median line - teeth are set in triads (exceptions: lower central incisor and the last upper molar – second or third) - Angle’s Class I within the area of molars - vertical overlap of incisors:1/3 of their length, horizontal overlap: 2mm - occlusal plane shaped in the form of the Curve of Spee – at the level of molars it raises backward and upward

5. Characteristic features of permanent dentition: 1) Shape of the dental arch. Dentition in mandible and maxilla is placed in arches: upper and lower. Dentition in mandible and maxilla is placed in arches: upper and lower. Each tooth touches an adjacent tooth with proximal surfaces. Maxillary dental arch has the shape of an ellipse, mandibular dental arch – of a parabola

6. Characteristic features of permanent dentition: 2) Contact points The mesial contact point of upper central incisors is located at the junction of 1/3 middle into 1/3 incisal of tangent surface; the distal contact points are moved toward the incisal. Upper second incisor: mesial contact point is located at 1/3 of the crown’s height, distal contact point contacts the mesial angle of canine. Distal angle of canine contacts first premolar. The contact point of the first premolar is located at the buccal side.

7. Characteristic features of permanent dentition: 2) Contact points The contact point of the first and second premolar is shifted toward the palatal, to the centre of the proximal surface. The other teeth in the dental arch placed backwards have similar locations of contact points. Contact points in the lower dental arch are located similarly to contact points in the upper dental arch. The exception are contact points between incisors as the contact points are located closer to the incisal ridge.

8. Contact points in dental arches of maxilla and mandible.

9. Characteristic features of permanent dentition: 3) Teeth position Upper incisors incline on the long axis of the tooth from their vertical line from 5° to 15°. Such an inclination smaller in the case of canines. Premolars and molars are positioned almost vertically. Mandibular incisors and canines are almost vertical with a possible slight inclination of 0° to 5°. Premolars and molars are slightly lingually inclined.Crowns of teeth feature lingual-labial inclination.

10. Wargowo-językowe nachylenie koron zębów

11. Characteristic features of permanent dentition: 4) Dental triads. Proper relationship of the whole dental arches means that when maxilla and mandible come together, a particular tooth bites against two antagonistic teeth; exception: lower central incisor and upper last molar. Triads of lateral teeth Triads of anterior teeth

12. Triady w zębach bocznych

13. Triady w zębach przednich

14. Characteristic features of permanent dentition: 5) Midline of the upper and lower dental arch lies on the facial medial surface

15. Characteristic features of permanent dentition: 6) Incisors relationship Upper incisors cover labially 1/3 of crowns of lower incisors (vertical overlap). The overlap of incisors is 2-3mm (horizontal overlap).

16. Characteristic features of permanent dentition: Proximal crown surface is inclined to the perpendicular to the occlusal surface at an angle of ca. 7°, the angle between the proximal crown surface and the long tooth axis amounts to 18°. Lower incisor is inclined at -1° and the angle between its proximal to the crown and the long tooth axis is 16°.

17. Relationships between upper and lower incisors.

18. Characteristic features of permanent dentition: 7) Class I according to Angle. In an ideal occlusion, upper and lower first molars should bite against one another in such a way, so as the mesiobuccal cusp of the upper tooth occludes with the groove between the mesiobuccal and middle buccal cusp of the lower first molar (in the case of a tooth with four cusps – in between its lateral anterior and posterior cusps).

19. Angle’s Class I - proper occlusion of molars.

20. Characteristic features of permanent dentition: 8) Curve of Spee Often, in a proper occlusion, occurs a characteristic curvature of occlusal alignment of teeth falling downward from canines in the distal direction and then raising again. Such a curvature of occlusal surfaces forms an arch concave downward – sagittal compensation curve of Spee.

21. Occlusion - Occlusion (occlusio) refers to maxilla-mandibular relationship when dental arches are in contact. - Centric occlusion refers to the relation of opposing occlusal surfaces of teeth providing maximum intercuspation in the sagittal and transverse axis, while the pressure is placed centrally on parodontium. Articular heads of the mandible are located in articular fossi, usually in a more frontal position in comparison to the most posterior position. It can be retroposed by ca. 1.5mm.

22. Okluzja

23. Occlusion and articulation Dynamic occlusion refers to the occlusal contacts made while e.g. chewing, in comparison to centric static occlusion. Dynamic occlusion is also known as articulation and biting teeth (articulating) of mandible and maxilla are referred to as antagonists.

24. Intercuspation, muscles (muscular system) and temporomandibular joint should work in harmony. The criterion is lack of complaints and of sensitivity to pressure during comparative palpable muscles examination with a relaxed motor system, whereas during instrumental analysis the static and dynamic occlusion are identical.

25. Proper intercuspation of anterior teeth with proper labial support

26. Stabilizacja zębów bocznych When all lateral teeth come together, the anterior teeth only slightly touch one another, without direct contact.

27. Incisor guidance Even the slightest protrusive movement of mandible causes occlusion of upper and lower teeth leading to malocclusion of lateral teeth.

28. Canine guidance When mandible moves to the right/left, the guidance is taken by canines which may lead to a slight malocclusion of lateral teeth located on the same side (working side) and a greater malocclusion on the other side (balancing side).

29. Thank you for your attention Thank you for your attention