This document discusses various dental terminology related to mandibular and maxillary relationships. It defines terms like centric occlusion, centric relation, rest position, maximum opening, vertical dimensions of occlusion and rest. It describes the curves of occlusion including the curve of Spee and curve of Wilson. It discusses the temporomandibular joint complex and the guidance systems, including posterior guidance by the TMJ and anterior guidance by teeth. It also covers concepts like mutually protected occlusion and balanced occlusion.

1. Noreen Mohammed
Naguib
5212322
G.11

2. Mandible to Maxilla relationships and
terminologies:
Centric occlusion It is the most closed complete
interdigitating of mandibular and maxillary teeth
irrespective of condylar position or centricity.
Centric relation :maxillo-mandibular relationship in
which the condyles articulate with the thinnest
avascular portion of the disk and being in the most
anterior-superior position against the articular
eminencies.
Rest position : Purely Muscle-guided position when
the mandible is at physiologic rest without any tooth
contacts, there will be a 1-3 mm space the freeway
space .
Maximum opening : maximum separation between
arches about 40-50 mm

3. Centric Relation of TMJ
• Its repetitive reproducible and recordable position
• Independent of presence and absence of teeth
• The final act of masticatory stroke ends in centric
relation
• It is a border position and the posterior limit of the
envelope of motion
• Can resist maximum loading by muscles with no sign of
discomfort
• Note: maximum intercuspation may or may not coincide
with centric occlusion
• if MI occurs with the condyles out of centricity, then both
positions would not coincide, the MI in this case, called
habitual closure, and is considered as an eccentric
position

4. Vertical dimensions:
Vertical dimension of occlusion (VDO): at maximum
intercuspation
Vertical dimension of rest (VDR): at rest with freeway
space
Plane of occlusion :
refers to an imaginary surface that theoretically
touches the incisal edges of the incisors and the tips of
the occluding surfaces of the posterior teeth

5. Curves of occlusion:
Two areas constitute the occlusal plane and should be
addressed separately.
1- the anterior teeth, Their position is determined by:
Esthetics
-demand for anterior guidance
-phonetic considerations.
2- Posterior teeth, position is determined by two
curves.
-curve of Spee
-curve of Wilson.

6. Curve of Spee
The anterior/posterior curve of maxillary
and mandibular occlusal surfaces
It is designed so that the posterior teeth
can be separated in protrusion, by the
affects of condylar guidance and anterior
guidance. This phenomenon reduces
posterior interference

7. Curve of Wilson
“It is the mediolateral curve that contacts
the buccal and lingual cusp tips on each
side of the arch it is always related to the
lower arch
Allows for the lingual cusps (working
cusps) of maxillary teeth to function with
the lower occlusal scheme without
interference.

8. Mandibular movements TMJ and articular
eminence (posterior guidance) Occlusion
curves Teeth shapes &surfaces Cusp heights
Central fossa Marginal ridges occlusal table -
Wilson -Spee Neuro-musculature -masticatory
muscles --ligaments PDL and perioception
occlusion Teeth (anterior) guidance: -Anterior
teeth guidance -Canine guidance -Group
function Occlusal interrelationship Mandible to
maxilla relation in 3 planes mainly horizontal
and vertical

9. The guidance systems
There are two systems that provide hard guidance
during mandibular movements; they are interrelated
and part of one system.
Posterior guidance
The temporomandibular joint ; made up of the head of
the condyle, articular eminence, the intra-articular disc
and the glenoid fossa
The anterior guidance system
is provided by which ever teeth naturally touch during
function to guide the mandible movements; happens
during dynamic occlusion or functional occlusion, and
any other contact that happens prematurely, or inhibits
harmony is referred to as Occlusal interference

10. Tempromandibular joint complex
It is a synovial joint but differs from most
synovial joints in that the articular surfaces of
the bony components are covered with dense
fibrous connective tissue, instead of hyaline
cartilage. In addition, the TMJ has a fibrous
articular disc, to which muscle fibers are
attached. This disc divides the joint into two
compartments, upper and lower, thereby giving
the mandible a wide range of movement.

12. Mutually Protected Occlusion An occlusal scheme in which
the anterior teeth protect the posterior teeth, and vice
versa.
The anterior teeth protect the posterior teeth by providing
guidance during excursions
thus allowing the cusps of the posterior teeth to disocclude
rather than strike one another during lateral or protrusive
movements from centric relation;
To prevent this from happening, the anterior teeth of each
arch will, ideally, be situated so as to come into contact
before the cusps of the posterior teeth do, thus preventing
wear on the posterior teeth.
The posterior teeth protect the anterior teeth by providing
a stable vertical dimension of occlusion. While anterior
teeth may retain their natural position even after loss of
posterior teeth, the masticatory forces will eventually
cause the single-rooted anterior to splay, thus leading to a
collapsed bite

13. Balanced occlusion
It’s a type of occlusion used in dentures and artificial
teeth
For lateral movement of the mandible
When the mandible moves laterally all posterior teeth
with the canine on both sides ;the working and non-
working ;contact, unlike functional guidance where
contact on the non-working side doesn’t happen
Compensating curves:
When artificial teeth have balanced occlusion the
curvetures of the teeth occlusal surfaces said to have
compensation curves; instead of curve of Spee and
curve of Wilson

14. Thank you