Interdental relations
= contact between neighboured teeth and teeth in
oppposite dental arches , if they are in contact.
Interdental relations :
horizontal
(horizontally, approximally)
contact points
vertical
(vertically, occlusallly)
intercuspidation
Interdental relations
Vertical interdental relationship = teeth in ideal position
make contact between cusps and opposite fissures of
opposite dental arch.
Inclination of distal teeth :
- In maxilla are teeth long axis palatally inclinated,
- In mandible are crowns of distal teeth turned lingually
Interdental relations
Principles :
• In maximal intercuspidation of regular teeth – upper
frontal teeth cover frontal lower teeth  upper dental
arch is wider than lower dental arch = basic of
occlusion .
• Occlusal linea (biting linea ) = linea where upper and
lower dental arches are in full contact .
Interdental relations
• Occlusal contact - contact of surfaces of opposites teeth in
both dental arches in position of maximal intercuspidation .
• Sum of surfaces is named occlusal field .
• Height of bite = distance between bases of upper and lower
fornices vestibuli oris measured in frontal part in position
of maximal intercuspidation.
• Supportive zones – opposite teeth groups (same type), which
are in contact in occlusion. Functionally in permanent teeth
are distinguished : premolar´s and molar´s supportive
zones .
Interdental relations
• Occlusio – occlusion = any contact between teeth in
maxilla and mandible.
• Static occlusion – habitual intercuspidation =
– status when cusps of one dental arch are in contact
in intercuspal fissures of opposite dental arch.
– between upper and lower teeth is maximal number
of contacts. Chewing movement is stopped.
– during habitual occlusion teeth are in intercusp
position .
Interdental relations
Dynamic occlusion
( former named as a articulation )
– status when cusps of one dental arch glide on group of
cusps of opposite teeth,
–
maxilla and mandible are in motion and grind the
food.
Static and dynamic occlusion are mutually
influented between themselves by 3 factors :
Factor 1 :
= slant of cusps , borders and fissures on occlusal
surfaces premolars and molars.
Inclination of slants conditione lateral line of
mandible during mastication. Anterio-posterior
line is done by inclination of palatal surface of
upper incissors and canines. Under dominant
participation is distinguished incissal line or
canine line.
Static and dynamic occlusion are mutually
influented between themselves by 3 factors :
Factor 2 :
inclination of dorsal slant of articular cusp of TMJ
and on this perpendicular roof-like shape of TMJ
- head.
Factor 3 :
active factor is represents by masticatory muscles.
Static and dynamic occlusion are mutually
influented between themselves by 3 factors
:
On cusps are prominentiae of different shapes :
triangle
central
additive
Traumatic occlusion
Status where on periodontium develop pathologic changes
by influence of higher forces on occlusal tooth surface.
The force of is higher than periodontiun is capable to
transport without tissue damage.
• Its absolut size is individual and different, periodontal
reaction depends on periodontal immunity, logevity of
influence and age of patient
Traumatic occlusion
higher power ⇨ healthy periodontium
higher power ⇨ diseased periodontium
physiologic power ⇨ diseased periodontium
Traumatic occlusion
• Primary - includes changes on healthy periodontium,
e.g. high filling, bruxisms drifting or extrusion into
edentulous spaces, and orthodontic movement.
• Secondary – includes changes which influent
pathologically changed periodontium.
– they are differences when primary are present
inflammation or atrophy.
Traumatic occlusion
3) Combined Occlusal Trauma: Injury from an excessive
occlusal force on a diseased periodontium
In this case, there is gingival inflammation, some pocket
formation, and the excessive occlusal forces are generally
from parafunctional movements.
Clinical signs
•
•
•
•
•
•
•
•
Mobility
Pain on chewing or percussion
Fremitus
Occlusal prematurities/discrepancies
Wear facets in the presence of other clinical indicators
Tooth migration
Chipped or fractured tooth (teeth)
Thermal sensitivity
Radiographic findings
• 1) Widened - increased periodontal membrane space
• 2) Bone loss (furcations; vertical; circumferential)
• 3) Root resorption
Goals and rules of correction :
• To apply forces, which influent on whole alveolar ridge to be
transport in each position of occlusion on maximal teeth (the
best on all teeth )
• The occlusal force cannot be directed only on one tooth or
group of teeth
• The power influent on one tooth must applied on big field ,
not on small point or margin of occlusal surface of tooth
• To reduce inclination of contact surfaces and reduce the
height of clinical crown of tooth
By coreection cannot be :
• Reduced teeth function , it means food grinding,
phonation, esthetic in frontal teeth
• Reduced the biting heigh ( TMJ disorders)
• Permanently excluded some tooth from centric oclusion
(by active eruption – prolonged tooth clinical crown )
Determination of premature teeth contact
in centric occlusion :
1. Examination of centric occlusion : determine
premature teeth contact and after position of
occlusal contact
2. Wax bite
3. Model + articulating papers
4. Clinical examination :
abrased fasets on occlusal tooth surface, anemisation
of gingiva around affected tooth, anomal tooth
position
Determination of premature teeth contact
in centric occlusion :
5.
6.
Recording of centric or excentric occlusion =
contact of both dental arches – patient sit with
inclinated head, during mouth closing is tip of tongue
positioned on hard palate – silent positon
Basic principle of grinding = never gring cusp, which
is not in occlusion – consequence : increasing the
distance between teeth in opposite dental arch
Determination of premature teeth contact
in centric occlusion :
7. Determination of frontal and lateral occlusion = biting
on incisal edge of incissors and on left and right cusps
– movement of mandible anteriorly or laterally = in
contact are only the teeth which guided surfaces are
longer and other teeth are not in contact .
Occlusal relations
• Upper canine in regular dentition in complete bite fall into
between lower canine and lower first premolar. Relation
of canine is called as key of frontal occlusion.
• Key of lateral occlusion – position of first molars
• Occlussal contact - reciprocal touch of small and large
surfaces of antagonistic teeth in both dental arches in
position of maximally intercuspidation.
The sum of these surfaces is called as occlusal field.
Occlusal relations
• Overbite (in vertical linea) : determines the depth
of bitting : the bitting margins of upper incissors
cover vestibular surfaces of lower incissors.
• Overjet : incisal edge is in horizontal linea the
bitting margins of upper incissors are in front of
margins of lower incisors.
• Physiologic overjet and overbite = 2 mm
Occlusal relations
• The height of biting
distance between basis of upper and lower
vestibulum oris (fornices vestibuli oris ) measured
in frontal area in the position of maximal
intercuspidation
• Supportive zone – are formed by opposite teeth groups of
same type, which are in the contact between themselves in
occlusion.
• Functional aspect in permanent dentition : premolar´s and
molar´s supportive zone
Occlusal relations
Occlusion
Means any contact between teeth of upper and
lower dental arches.
static occlusion
(habitual intercuspidation)
dynamic occlusions
(former articulation)
Occlusal relations
Static occlusion – habitual intercuspidation
–
- condition where cusps of the teeth in one dental
arch inclinate ( fall) into intercuspidal fissure of the
teeth in opposite dental arch.
• – between upper and lower teeth is maximal number of
tooth contacts. The masticatory (chewing) process is
stopped..
• – during habitual occlusion teeth are in intercuspidal
position .
Occlusal relations
• Dynamic occlusion
–
condition where cusps of the teeth in one
dental arch glide on the group of cusps of opposite
teeth.
• –
maxilla and mandibula are in movement and
grinde the food.
Occlusal relations
• In the silent period without movement the
mandibula is in silent position , where teeth have
distant between themselves 2 – 4 mm. This gap
can be wider until to position of maximally
opening the mouth,.
Occlusal relations
• Working side = side where is directed lateropulsion of
cusps
• Balance side = opposite side – where during median
movement the occlusal surfacess move away.
• Protrusion movement of mandible
forward movement ,is relatively short. In centric
occocclusion lower incissors are moved on palatinal
surfaces of upper incissors , in direction downword until
incissal edges
• Lateral movement of manbible – movement in lateral
side, lateral movement of median line.