Occlusion Flashcards

Questions and Answers

What type of occlusion is Class I?

Ideal occlusion

What percentage of the population has an ideal occlusion?

72%

What percentage of the population has a Class II malocclusion?

22%

What percentage of the population has a Class III malocclusion?

6% Signup and view all the answers

How are classes of occlusion defined?

By the relationship between the permanent 1st molars or canines if molars are missing. Signup and view all the answers

How are molars aligned in a Class I occlusion?

Mesiobuccal cusp of maxillary 1st molar is aligned with the mesiobuccal groove of the mandibular 1st molar. Signup and view all the answers

How are canines aligned in a Class I occlusion?

Maxillary canine fits into the facial embrasure space between the mandibular canine and mandibular 1st premolar. Signup and view all the answers

What type of occlusion is Class II?

Malocclusion Signup and view all the answers

Another name for Class II occlusion?

Disto-occlusion Signup and view all the answers

What type of occlusion is Class III?

Malocclusion Signup and view all the answers

Where is the mandible in a Class II occlusion?

Behind where it should be. Signup and view all the answers

What is the size of the mandible in Class II occlusion?

Too small. Signup and view all the answers

How are molars aligned in a Class II occlusion?

Mesiobuccal groove of mandibular 1st molar is distal to the mesiobuccal cusp of maxillary 1st molar by at least the width of a premolar. Signup and view all the answers

What is the tendency toward Class II?

Alignment of mandibular molar is distal to where it should be by less than the width of a premolar. Signup and view all the answers

What is Class II Division I?

Mandible is retruded and all maxillary incisors are protruded. Signup and view all the answers

What is Class II Division II?

Mandible is retruded and one or more maxillary incisors are retruded. Signup and view all the answers

Another term for Class III occlusion?

Mesio-occlusion. Signup and view all the answers

Where is the mandible in a Class III occlusion?

Anterior to the maxillary arch. Signup and view all the answers

What is the size of the mandible in a Class III occlusion?

Mandible is relatively large compared to maxillae. Signup and view all the answers

How are molars aligned in a Class III occlusion?

Mesiobuccal groove of mandibular molar is mesial to the mesiobuccal cusp of maxillary molar by at least the width of a premolar. Signup and view all the answers

What is the tendency toward Class III occlusion?

Mandible is mesial to where it should be by less than the width of a premolar. Signup and view all the answers

What is labioversion?

An anterior tooth out of alignment to the labial. Signup and view all the answers

What is buccoversion?

A posterior tooth out of alignment to the buccal. Signup and view all the answers

What is linguoversion?

A tooth out of alignment to the lingual. Signup and view all the answers

What is posterior crossbite?

Mandibular posterior teeth outside maxillary teeth. Signup and view all the answers

What is anterior crossbite?

Mandibular anterior teeth outside maxillary teeth. Signup and view all the answers

What is torsiversion?

Twisted tooth. Signup and view all the answers

What is end-to-end occlusion?

Maxillary and mandibular cusp tips line up directly over each other. Signup and view all the answers

What is edge-to-edge bite?

Incisal edges of maxillary and mandibular incisors meet. Signup and view all the answers

What is open bite?

Posterior teeth occlude, but there is a space between anterior incisal edges. Signup and view all the answers

What is overjet and which occlusion does it occur with?

All maxillary anterior teeth are protruded; occurs with Class II Division I. Signup and view all the answers

Which occlusion does a severe overbite commonly occur with?

Class II Division II. Signup and view all the answers

Study Notes

Types of Occlusion

Class I occlusion is considered ideal occlusion.
Class II represents a type of malocclusion, also known as disto-occlusion.
Class III is another form of malocclusion, referred to as mesio-occlusion.

Population Statistics

72% of the population has an ideal (Class I) occlusion.
22% of people exhibit Class II malocclusion.
6% of the population has Class III malocclusion.

Definitions and Classifications

Classes of occlusion are determined by the relationship of the permanent first molars or canines in their absence.
Molar alignment in Class I: Mesiobuccal cusp of the maxillary first molar aligns with the mesiobuccal groove of the mandibular first molar.
Canine alignment in Class I: Maxillary canine fits into the facial embrasure space between mandibular canine and first premolar.

Class II Occlusion Details

In Class II occlusion, the mandible is positioned behind its ideal location and often too small.
Molar alignment in Class II: Mesiobuccal groove of the mandibular first molar is located distally to the mesiobuccal cusp of the maxillary first molar by at least the width of a premolar.
Class II Division I: Mandible is retruded with all maxillary incisors protruded.
Class II Division II: Mandible is retruded with one or more maxillary incisors tilted inwards.

Class III Occlusion Details

In Class III occlusion, the mandible is positioned anterior to the maxillary arch and tends to be relatively larger than the maxilla.
Molar alignment in Class III: Mesiobuccal groove of the mandibular molar is located mesially to the mesiobuccal cusp of the maxillary molar by at least the width of a premolar.

Occlusion Characteristics

Labioversion refers to an anterior tooth that is out of alignment towards the labial side.
Buccoversion describes a posterior tooth misaligned towards the buccal area.
Linguoversion indicates a tooth misaligned towards the lingual side.

Specific Malocclusion Types

Posterior crossbite occurs when mandibular posterior teeth are positioned outside maxillary teeth.
Anterior crossbite happens when mandibular anterior teeth are positioned outside maxillary teeth.
Torsiversion refers to a twisted tooth.
End-to-end bite occurs when maxillary and mandibular cusp tips align directly.
Edge-to-edge bite is characterized by the incisal edges of maxillary and mandibular incisors meeting.
Open bite is noted when posterior teeth occlude, leaving a space between the anterior incisal edges.

Overjet and Overbite Relation

Overjet occurs in Class II Division I, where all maxillary anterior teeth are protruded.
A severe overbite is commonly associated with Class II Division II.

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Description

Test your knowledge about dental occlusions with these flashcards. This quiz covers definitions and statistics related to class I, II, and III occlusions. Perfect for dental students or professionals wanting to refresh their understanding of occlusion concepts.