W3 Occlusion relationship Flashcards
What is the horizontal alignment controlled by?
The tongue, lips and cheeks, along with the cuspal relationship with the opposing teeth
Define the Curve of Spee
The curve of the buccal cusp tips of posterior teeth from an anterior-posterior direction
Define the Curve of Wilson
The curve of the posterior teeth from a left to right direction
Define Centric Relation
The relationship of the Maxilla and Mandible when jaws are closed together.
To find tilt the head back as far as possible and close teeth gently together
Define Centric Occlusion
The relationship of the teeth within the jaws that allows the most contact between teeth
To find tilt the head forward
Define contact points
Where the occlusal surface of one tooth touches the occlusal portion of the opposing teeth. The contact points create what we know as the occlusion
Define Flush terminal plane
Distal surfaces of both Maxillary and mandibular molars are even
Define Mesial Step
Maxillary molar is situated more distally then the Mandibular molar
Define Distal Step
Maxillary molar is more mesial than the Mandibular molar
Define Normal Molar Occlusion relationship
Mesiobuccal cusp of maxillary first molar occludes with the mesiobuccal groove of mandibular first molar
Describe Cainine/premolar relationship in normal occlusion
Maxillary canine occludes with the distal half of the half of the Mandibular canine and mesial half of the mandibular first premolar
Describe Incisor relationship in Normal Occlusion
Lower incisors occlude below or at the cingulum of upper incisors
Describe Class II occlusion in the Molar relationship
(Distal step) Mesiobuccal groove of mandibular first molar is positioned distally to the mesio buccal cusp of Maxillary first molar
What is Class II Division 1?
Is when the Maxillary anterior teeth are proclined and a large overjet is present
What is Class II Division 2?
Is where the maxillary anterior teeth are placed lingually and a deep overbit exists
Define Class III occlusion of the Molar relationship
Mesiobuccal groove of Mandibular first molar is positioned mesially to the mesiobuccal cusp of Maxillary first molar
Describe the Incisor relationship in Class III occlusion
- Cross bite
- Edge to edge
Define Class I Malocclusion in Molar/Canine relationship
Similar to normal occlusion. Mal-relationships between other individual or groups of teeth
Describe the Incisor relationship in Class I Malocclusion
May be openbite, end to end bit, over bite
Describe Overjet
Distance between the labial surface of the mandibular incisors and the incisal edge of the Maxillary incisors
Horizontal relationship
Describe Overbite
The amount of overlap of the mandibular teeth by the Maxillary teeth
Vertical relationship
What 3 malocclusion are Transverse Relationships?
Cross bite Scissorbite Midlines
Define cross bite
Can be anterior or posterior. Occlude with tooth in opposing arch in the opposite relation to normal
Define Scissor bite
When the mouth if closed the molars miss each other and overlap with no contact
Define Midline shift
The dental midline may be shifted in either direction away from the facial midline
What is a Contact Area?
The areas of the teeth where the proximal surfaces touch eachother
Benefits of touching contact areas?
Prevent food packing Provide anchorage and support to eachother Protection from traumatic forces
Define embrasure
Space between the teeth that are surrounding the contact areas
What are the prinipal differences in crown morphology of deciduous and primary?
- Deciduous teeth have a pronounced cervial margin
- The cervical buldge is accentuated in the mesiobuccal area of deciduous molars
- The crowns of anterior deciuous teeth are bulbous with a pronounced labial cingulum
What are the prinipal differences in root morphology of deciduous and primary?
- Roots of deciduous teeth are short weaker and lighter in colour
- Roots of anterior deciduous teeth are longer in porportion to the crown
- Root of posterior deciduous teeth are more divergent to allow developing pernament successor
What are the prinipal differences of enamel in deciduous and primary?
- Decidous teeth enamel appears white
- More opaque
- Giving the crown a lighter colour
- More permeable easily worn down
- Depth of enamel more consistent and thinner than in pernament teeth
What are the prinipal differences in dentine, pulp and CEJ of deciduous and primary
Pulp chambers are larger than those of pernament
Prominent pulp horns
Root canals are fine in deciduous teeth
Dentine depth is less
CEJ is less sinuous
Deciduous teeth display consistant morphology and have less variations
What is natural spacing, primate spacing and lee way spacing?
- Natural spacing is the nature space for deciduous teeth
- Primate spacing is the space between cainines eg Maxillary mesial to canines, Mandibular teeth (distal to canines)
- Leeway spacing extra space gained from exfoliation of deciduous molars and the eruption of smaller premolars
What is the effect of premature loss of primary tooth on the pernament dentition?
- Delayed/accelarted eruption
- Impaction/ectopic eruption
- Loss of arch length
