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what is occlusion (basic definition)?

act of closure or being closed

what type of relationship does occlusion describe (structurally)

static, morphological tooth contact relationship

what type of relationship does occlusion describe (functionally)?

a contact relationship of teeth in function or parafunction

most definitions of occlusion are based on what

static positions of teeth, occlusal contacts, or position in the arch

what has recently been included in some occlusion concepts

functional criteria

why are functional criteria important in occlusion

because the dentofacial complex is highly mobile

what is often misunderstood about occlusion

occlusal stability

what aspects are included in optimal occlusion concepts

static and functional aspects (teeth, joints, head and neck muscles)

occlusion is the basis for what?

functional analysis of the masticatory system

Vertical occlusion/dimension

what does vertical occlusion describe

distance between maxilla and mandible in vertical direction

Vertical occlusion/dimension

in which condition is vertical occlusion measured

fully dentulous dentition (all teeth) in occlusion

Vertical occlusion/dimension

it describes the distance of the maxilla and mandible position om a fully dentulous dentition in a vertical direction in the occlusion position,

there are 2 types what are they

• rest vertical dimension

• occlusal vertical dimension

Vertical occlusion/dimension

rest vertical dimension - very simple what does this mean

teeth not in contact and lips closed

Vertical occlusion/dimension

occlusal vertical dimension - simple what does this mean

teeth in contact (distance less)

Vertical occlusion/dimension

what is rest vertical dimension

vertical dimension when teeth are not in contact and lips are closed

Vertical occlusion/dimension

what is occlusal vertical dimension

vertical dimension when teeth are in contact

lip closure line

what does a lip closure line describe

height pf the masticatory level

(how far teeth can be apart with lips closed)

Smile Line

what does the smile line represent

corresponds to the course of the upper lip when smiling

sagittal and horizontal occlusion

what does this describe

relationship of the maxilla and mandible in sagittal and horizontal planes

sagittal and horizontal occlusion

what curves are related to saggital.horizontal plane

curves of Spee and Wilson

resting position

what happens to the dental arches in the resting position

they are unconsciously held a few millimetres apart

resting position

where are the condyles and articular disc located in the resting position

in the posterior wall of the articular tubercle

resting position

what determines the resting position

tone of the masticatory muscles

resting position

what external factor also affects the resting position

head position

resting position

what muscle maintains the resting position

temporalis muscle

resting position

simple terms tell me what this is and what it takes into account

• teeth are NOT in contact

• takes into account TMJ and muscle activity

terminal occlusion location

what is terminal occlusion location

final position of the mandible, where the teeth are in their maximum cups-fossa-dentition position

terminal occlusion location

what is another name for terminal occlusion location

intercuspation

terminal occlusion location

what happens to the fossa roof in intercuspation

it is only slightly loaded

terminal occlusion location

why is the roof of the fossa only slightly loaded

mastication pressure is distributed over teeth along viscerocranium trajectories

terminal occlusion location

simple terms what does this mean and what does it include

• all the teeth are in contact

• does not take into account TMJ or muscle activity

look

done

primary dentition

it is arranged in 2 arches called what

maxillary and mandibular

primary dentition

what describes the outline of the maxillary dental arch

the buccal and labial surfaces of the maxillary teeth

primary dentition

what is the shape of the maxillary arch outline

an ellipse

primary dentition

how does the maxillary arch compare in size to the mandibular arch

it is larger

primary dentition

how many opposing teeth does each primary tooth usually occlude with

2

primary dentition

what is the general rule for occlusion in primary dentition

each tooth occludes with 2 teeth on the opposite arch

primary dentition

why do most teeth occlude with 2 antagonists

to maintain stability and continuous occlusal contact

primary dentition

which primary tooth occludes with only 1 instead of 2 - MANDIBULAR

mandibular central incisor

primary dentition

which primary tooth occludes with only one tooth instead of two - MAXILLAR

second maxillary molar

primary dentition

by what age should primary teeth be bin normal alignment and occlusion

around 2 years old

primary dentition

by what age are the roots of primary teeth completely formed

around 3 years old

primary dentition

what happens to occlusion after age 2?

teeth should be in their usual alignment and occlusion

primary dentition

why is primary dentition important for oral motor function?

It is essential for correct development of oral motor function

primary dentition

what system does occlusion influence during development

the nervous system

primary dentition

how does occlusion affect the nervous system

it impacts its maturation and interaction with the environment

primary dentition

what does rapid growth of the maxilla and mandible create

interdental spaces

primary dentition

what is another term for interdental space

Diastema

primary dentition

which teeth show an increased separation over time

anterior teeth

primary dentition

why do anterior teeth separate more over time

growth of the maxilla and mandible and the approach of permeant teeth from the lingual aspect

primary dentition

at what age do permanent teeth begin approaching from the lingual aspect

around 4-5 years

primary dentition

do canine and molars develop spacing like anterior teeth

no

primary dentition

what supports and improves occlusion after spacing develops ?

eruption of first permenant molars

primary dentition

where do the first permanent molars erupt

distal to the primary second molars

primary dentition

at what age do first permanent molars erupt

around 6 years old

CHRONOLOGY

what mainly determines the timing of tooth eruption

Heredity

CHRONOLOGY

how much do environmental factors affect eruption timing?

only slightly

CHRONOLOGY

is primary tooth development linked to general body development

no, it is independent

CHRONOLOGY

what type of environmental factors can influence occlusion development

local environmental factors

CHRONOLOGY

what does learning mastication depend on

stage of occlusion development and neuromuscular maturation

CONTRACT RELATIONS (primary dentition)

what do contract relations in primary dentition vary with?

the degree of bruxism

CONTRACT RELATIONS (primary dentition)

what is bruxism

grinding or clenching of teeth

CONTRACT RELATIONS (primary dentition)

is bruxism normal in children

yes

CONTRACT RELATIONS (primary dentition)

what are 5 factors influencing development of contract relations

• position of the tooth germ

• present of permanent teeth

• development of the condyles

• cuspal inclines

• neuromuscular influences

this isn’t included in the document but its useful i think

done

ARCH FORM

by what age is the form and width of dental arches established

around 9 months

ARCH FORM

why might this early development seem surprising

because facial appearance change later

ARCH FORM

what dimension of the arches changes significantly after 9 months

anteroposterior dimension

ARCH FORM

what determines the shape if dental arches

alveolar bone and basal bone

INTERDENTAL SPACING/ DIASTEMA

what happens with interdental spacing with age

it decreases slightly

INTERDENTAL SPACING/ DIASTEMA

what does interdental spacing relate to

size of primary teeth , position of permanent teeth, and size of dental aches

MOLAR RELATIONSHIP - IN EXAM

who describes the terminal plane relationship

Moyers

MOLAR RELATIONSHIP - IN EXAM
what determines the molar relationship in primary dentition

terminal plane relationship

MOLAR RELATIONSHIP - IN EXAM

what anatomical factor determines the terminal plane

greater mesiodistal (M-D) diameter of the second mandibular molar

MOLAR RELATIONSHIP - IN EXAM

\READ

done

MOLAR RELATIONSHIP - IN EXAM

read

done

MOLAR RELATIONSHIP - IN EXAM

what is the terminal plane describing

how the distal surface of the 2 second molars in primary dentition relate to each other

MOLAR RELATIONSHIP - IN EXAM

is there a difference in the mesial distal dimensions in the primary second molars

yes, the mandibular molar is wider mesiodistally than the maxillary molar

MOLAR RELATIONSHIP - IN EXAM

what are the 3 terminal plane options

• flush terminal plane

• distal step

• mesial step

MOLAR RELATIONSHIP - IN EXAM

flush plane means what

if they are in line with each other from the distal aspect

MOLAR RELATIONSHIP - IN EXAM

what is the distal step

if the mandibular tooths distal aspect is distal to maxillary

MOLAR RELATIONSHIP - IN EXAM

what is mesial step

is mandibular tooths distal surface is mesial to maxillary tooth

MOLAR RELATIONSHIP - IN EXAM

what does the terminal plane determine

where the 1st permeant molar will erupt

what can the terminal predict

the possibility of malocclusion

MOLAR RELATIONSHIP - IN EXAM

what is the terminal plane based on

difference in M-D diameter of the 2 second molars (in primary dentition)

simple difference between terminal plane and class I, II and II

terminal plane = primary teeth

classes = permanent teeth

what does class I, II and III determine

relationship between 1st maxillary and mandibular permanent molars

class I is what

ideal/correct/normal occlusion

class I is the correct relationship between permanent molars what does this mean

tip of mesiobuccal cusp to occlude directly in the mesiobuccal groove of the 1st mandibular molar

what is class II

tip of mesiobuccal cusp is mesial to the mesiobuccal groove of the 1st mandibular molar

what is class III

tip of mesiobuccal cusp is distal to the mesiobuccal groove of the 1st mandibular molar

what does a flush terminal plane usually develop into ?

50% = class I

50% = class II

what does the distal step tend towards?

class II

what does mesial step tend towards?

greater chances of class I but small chance of class II

DETAILS OF OCCLUSION

how are the maxillary and mandibular central incisors aligned

their mesial surfaces align at the midline

DETAILS OF OCCLUSION

what teeth does the maxillary centra incisor occlude with

mandibular central incisor and mesial third of mandibular lateral incisor

DETAILS OF OCCLUSION

where does contact occur for the maxillary central incisor

lingually above the incisal edge

DETAILS OF OCCLUSION

which teeth does the maxillary lateral incisor occlude with?

distal 2/3 of mandibular lateral incisor and mesial half of mandibular canine

DETAILS OF OCCLUSION

which teeth does the maxillary canine occlude with

distal half of mandibular canine and mesial third of mandibular first molar