OCCLUSION

DHYG 1902

SPRING SEMESTER

 

OCCLUSION

The relationship of the teeth in the mandibular arch with those in the maxillary arch when the jaws are in the closed position

EVALUATIONS

•      Centric Occlusion – Relationship between maxillary and mandibular occlusal surfaces that provides the maximum contact and or intercuspation.Evaluate occlusion in centric occlusion.

NORMAL OCCLUSION

•      Ideal occlusion

•      The molar relationship is such that the mandibular permanent molar is situated mesially to the maxillary first molar.

•      Maxillary teeth slightly overlap the mandibular teeth on the facial surfaces

•      All teeth in maxillary arch are in maximum contact with mandibular.

MALOCCLUSION

•      Any deviation from the physiologically acceptable relationship of the maxillary arch and/or teeth to the mandibular arch and/or teeth.

FACIAL PROFILES

•      Mesognathic

•      Retrognathic-

•       Prognathic

MALRELATIONS OF GROUPS OF TEETH

•      An individual may have a normal relationship between the maxillary and mandibular molars, but individual relations between other teeth may classify an individual as having malocclusion

ANTERIOR CROSSBITE

•      Maxillary incisors are linqual to the mandibular incisors

POSTERIOR CROSSBITE

•      Maxillary or mandibular posterior teeth are either facial or linqual to their normal position. This condistion may occur bilaterally or unilaterally

EDGE TO EDGE BITE

•      Incisal surfaces of maxillary teeth occlude with the incisal edges of mandibular teeth instead of overlapping.

END TO END BITE

•      Molars and premolars occlude cusp to cusp as viewed mesiodistally.

OPENBITE

•      Lack of occlusal or incisal contact between certain maxillary and mandibular teeth . The teeth cannot be brought together.

OVERJET

•      The horizontal distance between the labioincisal surfaces of the mandibular incisors and the linquoincisal surfaces of the maxillary incisors. Hold probe horizontally on the mandibular incisors to measure to the  maxillary incisal edge in millimeters.

UNDERJET

•      Maxillary teeth are linqual to mandibular teeth. The horizontal distance between the labioincisal surfaces of the maxillary incisors and the linquoincisal surfaces of the mandibular incisors.

OVERBITE

•      Vertical distance by which the maxillary incisors overlap the mandibular incisors.

•      Normal –incisal edges are within the incisal third of mandibular.

•      Moderate-within the middle third

•      Deep(Severe)-Incisal edges of maxillary are within the cervical third of the mandibular teeth.

MALPOSITIONS OF INDIVIDUAL TEETH

•      Labioversion-labial to normal

•      Linquoversion-position lingual to normal

•      Buccoversion-position buccal to normal

•      Supraversion-Elongated above the line of occlusion

•      Torsiversion-turned or rotated

•      Infraversion-depressed below the line of occlusion.

CLASSIFICATION OF OCCLUSION

•      Normal(Ideal)

•      Class I Malocclusion or Neutroclusion

•      Class II or Distoclusion

•      Class III or Mesioclusion

OCCLUSION OF PRIMARY TEETH

•      Canine Relationship- same as permanent dentition

•      Second Molar Relationship- The mesio buccal cusp of the maxillary second primary molar occludes with the buccal groove of the mandibular second primary molar.

PRIMARY MALOCCLUSION

 

PROXIMAL CONTACTS

•      Drifting-tooth moves into missing teeth spaces – in absence of disease, the periodontium adapts to newly positioned teeth.

•      Pathologic Migration – disease is present  due to destruction of supporting structures tooth is moved by forces.

EVALUATION

•      Maximum Incisal opening – measured from the incisal edges when mandible is opened to furthest extent.

•      Pathway of Opening or Closing –Note any deviations from a straight path of opening.

CENTRIC RELATION-CENTRIC OCCLUSION SHIFT

•      Initial Contacts in Excursions

–   Protrusive Excursion

–   Lateral Excursion

•      Centric Relations – the most retruded position of the mandible. Centric occlusion is typically slightly anterior to centric relation.

•      Protrusive excursion is the forward movement of the mandible from centric occlusion until the anterior teeth are edge to edge.Ideally there should be no contact between posterior teeth.

•      Lateral excursion is the movement of the mandible from centric occlusion or centric relation to the right or left until the cuspids are in a cusp to cusp relationship. There should be no contact on the teeth on the opposite side

FUNCTIONAL OCCLUSION

•      Functional occlusion consists of all contacts during chewing,swallowing or normal actions.

•      Functional contacts-normal contacts made during chewing and swallowing.

•      Parafunctional contacts- those made outside the normal range , may create wear facets or attrition and result from habits. Ie: bruxism,clenching,nail biting,thumb sucking, cheek biting etc.

TRAUMA FROM OCCLUSION

•      Pathologic changes to the supporting periodontium as a result of normal or excessive occlusal forces applied to the teeth.

•      Primary – excessive occlusal forces placed on a healthy periodontium that produces changes in the periodontal tissues. Ie. Orthodontic movement or high restoration

•      Secondary – normal forces of mastication on a periodontium with bone loss produces changes in the periodontal tissues.

OCCLUSAL SCREENING

•      Subjective signs and symptoms reported by the patient

–    Aching muscles

–    Tooth mobility

–    Pain when biting

–    Patients habits

 

CLINICAL & RADIOGRAPHIC FINDINGS

•      Clinical signs and symptoms

–    Mobility

–    Wear patterns

–    Malpositioned teeth

–    Faulty restorations

–    Changes in tooth position

–    Angles classification

–    Deviations from norm

·        Radiographic Findings

–    Thickening of PDL

–    Loss of lamina dura

–    Root resorption

OCCLUSAL ANALYSIS

To examine the tooth to tooth relationships, the TMJ relationship and movements of the mandible.

•      Palpation and auditory examination of the TMJ using a stethoscope- clicking,lateral movement,popping

•      Palpation of the muscles of mastication-masseter & temporalis muscles

•      Swallowing patterns

•      Angles classification,overbite,overjet

•      Movement from centric relation to centric occlusion

•      Examine right lateral excursion,left lateral excursion,protrusive excursion and initial contacts in centric relation

•      Measure opening – 36-42 mm normal