Occlusion Flashcards
What is occlusion?
The contact relationship between maxillary and mandibular teeth when the jaws are fully closed, as well as the relationship between teeth in the same arch.
What is centric occlusion?
The relation of opposing occlusal surfaces.
What is centric relation?
The position of the mandible to the maxilla when the condyles are in their most posterosuperior unstrained positions in the fossae.
What is overjet?
The horizontal overlap of the maxillary teeth over the mandibular teeth.
What is overbite?
The vertical overlap of the maxillary teeth over the mandibular teeth.
What can occlusal disharmony lead to?
Pain, occlusal trauma, and worsened periodontal disease.
What is malocclusion?
A deviation in the maxillary and mandibular teeth relationships in centric occlusion.
How many types of malocclusion are there?
Three types: Class I, Class II, and Class III.
What does Angle’s Classification of Occlusion focus on?
The relationship of the maxillary mesial buccal cusp of the 1st molar to the mandibular molar mesial buccal groove.
What is used when molars are unavailable in Angle’s Classification?
The canine relationship or using incisors.
What is the relationship of the maxillary 1st molar in ideal occlusion?
The maxillary 1st molar MB cusp is in the mandibular 1st molar MB groove.
Where does the maxillary canine cusp rest in ideal occlusion?
Just distal to the mandibular canine.
How are the incisors positioned in ideal occlusion?
Normal
What is malocclusion?
Malrelationships between individual teeth or groups of teeth.
What may malocclusion include?
Crowding within the dental arch
Overbite
Open bite
End-to-end bite
Crossbite
What is the relationship of the maxillary 1st molar in Class I malocclusion?
Max 1st molar MB cusp is in the mandibular 1st molar MB groove.
Is Class I malocclusion the same as ideal occlusion?
Yes, but there is Crowding
What is a characteristic of maxillary central incisors in Class II Division 1 malocclusion?
The maxillary central incisors protrude.
What is the relationship of the maxillary 1st molar in Class II Division 1 malocclusion?
The max 1st molar MB cusp is mesial to the mandibular 1st molar MB groove.
Where does the maxillary canine cusp rest in Class II Division 1 malocclusion?
It rests anterior to the mandibular canine, between the canine and lateral incisor.
What are the characteristics of the incisors in Class II Division 1 malocclusion?
Severe overjet and deep overbite.
What is the characteristic of the maxillary central incisors in Class II Division 2 malocclusion?
The maxillary central incisors retrude.
What is the relationship of the maxillary 1st molar in Class II Division 2 malocclusion?
The max 1st molar MB cusp is mesial to the mandibular 1st molar MB groove.
Where does the maxillary canine cusp rest in Class II Division 2 malocclusion?
It rests anterior to the mandibular canine.
What are the characteristics of the incisors in Class II Division 2 occlusion?
Deep overbite with no overjet.
What is the relationship of the maxillary 1st molar in Class III malocclusion?
The max 1st molar MB cusp is distal to the mandibular 1st molar MB groove.
Where does the maxillary canine cusp rest in Class III occlusion?
It rests significantly distal to the mandibular canine, with the cusp on the premolar.
What is the relationship of the incisors in Class III occlusion?
End-to-end.
What causes overjet?
Class II Division 1 occlusion.
What is the normal relationship for overbite?
2.5mm.
What causes overbite?
Class II Division 2 occlusion.
What is a crossbite?
A condition where the cusps of a tooth in one arch exceed the cusps of a tooth in the opposing arch, either buccally or lingually (reversed relationship).
What causes crossbite?
Eruption sequence and crowding.
What is a common tooth feature in crossbite?
A rotated tooth.
Common Parafunctional Habits
Clenching
Bruxism
Thumb or finger sucking
Rocking of teeth
What is primary trauma from occlusion?
Injury from excessive occlusal forces on a periodontium that hasn’t been affected by disease.
What is secondary trauma from occlusion?
Injury from normal or excessive occlusal forces on a weakened periodontium.
What causes the periodontium to weaken in secondary trauma?
Periodontal disease with apical migration of the junctional epithelium and loss of connective tissue.
