Upload
makaila-lathem
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
Prosthodontics and Occulsion
The Prosthodontics is a part of the dental science that improve the esthetic and functional aspects of the oral and maxillofacial region through artificial restoration of the lost teeth and adjacent soft tissues
Complete denture ProsthodonticsThe part that restore all the natural teeth and related tissue artificially
Removable partial denture ProsthodonticsThe part that restore one or more absent teeth and soft tissue through removable prosthesis
Fixed ProsthodonticsThe part that restore one or more absent teeth through fixed prosthesis
Dentulous – Full complement of teeth.Edentulous – Lost all the teethPartially edentulous – Lost a few teeth
Upper arch – Maxillary arch
Lower arch – Mandibular arch
Surfaces of teeth –
MesialDistal
BuccalLingual
Occlusal
Mandibular movements
Vertical movement
• Opening
• Closing
Horizontal movement
• Protrusive or
forward
• Retrusive or
Backward
• Right lateral
• Left lateral
All these movements together will anable mastication
Occlusion -What is occlusion? Occlude means ‘to close’
Any contact between the incising or masticatory surfaces of the maxillary and mandibular teeth’
is termed as occlusion
Occlusal Plane -Average plane established by incisal and occlusal surfaces of the teeth
Curve of spee – seen in Natural dentition.Anatomic curvature of occlusal surfaces of
teeth beginning at the tip of the lower canine and following the buccal cusps of the premolars and the molars, continuing to the anterior border of the Ramus,
Curve of Wilson:It is the mediolateral curve that contacts the
buccal and lingual cusp tips on each side of the arch. It results from the inward incination of the posterior teeth ( mandibular molars ), making the lingual cusps lower than the buccal cusps.
Centric Occlusion – the occlusion the patient makes when they fit their teeth together in maximum intercuspation
- A cusp to fossa relation.
The masticatory (or stomatognathic) system
is generally considered to be made up of
three parts:
the Teeth, the Periodontal Tissues,
and the Articulatory System.
Key of occlusion First key,
Molar inter-arch relationship, the upper first molar's mesio-buccal cusp should essentially occlude into the buccal groove, of the lower first molar.
The first upper molar's mesio-palatal cusp must occlude into the central fossa of lower first molar
Second key
The mesial slope of the maxillary canine is in line with the distal slope of the mandibular canine.
When the maxillary and mandibular teeth contact simultaneously the condylar
proceses are fully seated in the mandibular fossae
MAXILLARY AND MANDIBULAR TEETH
SHOULD CONTACT EVENLY
TO ALLOW OPTIMUM FUNCTION,
TO MINIMIZE TRAUMA TO THE
SUPPORTING STRUCTURES, AND
TO ALLOW AN EVEN LOAD DISTRIBUTION
THROUGHOUT THE DENTITION.
OCCLUSAL INTERFERENCES
Interferences are undesirable occlusal
contacts that may produce mandibular
deviation during closure to maximum
intercuspation.
When there is occlusal
interferences there is trauma
which cause tissue changes in
periodontal ligament space
CENTRIC RELATION
CENTRIC RELATION IS DEFINED AS THE
MAXILLOMANDIBULAR RELATIONSHIP IN WHICH THE
CONDYLES ARTICULATE WITH THE THINNEST
AVASCULAR PORTION OF THEIR RESPECTIVE DISKS
WITH THE CONDYLES IN THE ANTEROSUPERIOR
POSITION AGAINST THE SHAPES OF THE ARTICULAR
EMINENCES.
THIS POSITION IS INDEPENDENT OF TOOTH CONTACT.
The masticatory movements takesplace with in the following
movements
During mastication
Mandibular movements seen are• Opening
• Closing
• Protrusive or forward
• Retrusive or Backward
• Right lateral
• Left lateral
All these movements together will anable mastication
Types of condylar MovementsDuring opening or closing of
the mandible
Rotational movement
Translational movement
Rotational Movement Around the horizontal axis (hinge axis)
Opening of the jaw
Translational movement
Wide opening
Translational movement
RetrusiveProtrusive
Movement around the vertical axis
Border movements of the Mandible in
Sagittal plane
Left lateral border
Right lateral border
Functional movements
Border Movement of the Mandible
Horizontal Plane and Frontal plane
Border Movement of the Mandible
Horizontal Plane and Frontal plane
Movement in the frontal plane
Movement in the saggital plane
Movement in the horizontal plane
It is with in this boundary that all the movements
of the mandible and the movements of Mastication takes place.
This Masticatory system is disturbed in patients with occlusal interference.
Occlusal schemes in Natural dentition.
Canine guided occlusion – During lateral excursive movement the canine contacts each other only and no other posterior teeth contact is seen,
Group function - During lateral excursive movement the canine contacts each other as well as other posterior teeth contact is seen.
Christensen's Phenomenon
During protrusive movements, there will be no contact of the posterior teeth
It is important to be familiar with
Definitions Components of the masticatory systemOcclusal interferenceKey of occlusionMandibular MovementsOcclusal scheme in Natural dentition.
Thank you