Module 16: Mixed Dentition and Occlusion

A set of vocabulary flashcards covering the stages of mixed dentition, eruption patterns, Angle's classification of occlusion, and various dental malpositions.

Mixed Dentition

A combination of some primary teeth and some permanent teeth occurring 6-12 years of age

Primary Dentition Premolars

There are NO premolars in the primary dentition; primary teeth consist only of incisors, canines, and molars.

Permanent 1st Molars

Teeth that erupt between ages $6$ to $7$ years for which no primary teeth are exfoliated to make room.

Age 5 years

Primary teeth erupt between ages 6 months and 2 ½ years.

Age to 6 & 7

Loss of mandibular primary teeth and eruption of permanent.

Age 7 & 8

Permanent incisors replace primary incisors in both arches

Age 10 to 12

All four first premolars erupt, all anterior teeth erupt, and lower canines erupt

Age 11 to 13

Primary upper canines erupt and primary upper and lower 2nd molars are the last to exfoliate.

Occlusion

The relationship of the teeth to each other when the incisal and occlusal surfaces of the mandibular arch contact those of the maxillary arch.

Malocclusion

The improper positioning of the teeth and jaws which can affect bite, plaque control, speech development, and appearance.

Overbite

The vertical overlap of the maxillary arch over the mandibular arch when teeth are closed and biting together.

Normal Overbite

A condition where maxillary anteriors cover the mandibular teeth no more than the incisal $1/3$.

Malocclusion affects

Bite, ability to maintain adequate plaque control, speech development, appearance

Severe Overbite

A condition where maxillary incisors completely cover the mandibular incisors and are near the cervical $1/3$.

Overjet

The horizontal distance or overlap between the anteriors of the maxillary and mandibular arch, measured in millimeters with a periodontal probe.

Centric Occlusion

The maximum contact when teeth occlude, where each tooth of one arch is in occlusion with two others in the opposing arch, except for mandibular central incisors and maxillary third molars.

Angle’s Classification

A system developed in $1887$ by Dr. Edward H. Angle that classifies the relationship of the mandibular first molar buccal groove to the maxillary first molar mesiobuccal cusp.

Class I Occlusion

A normal molar relationship where the buccal groove of the mandibular first molar is directly in line with the mesiobuccal cusp of the maxillary first molar.

Class II Occlusion (Distoclusion)

A relationship where the buccal groove of the mandibular first molar is distal to the mesiobuccal cusp of the maxillary first molar by at least the width of a premolar.

Class II, Division 1

A Class II molar relationship where the maxillary incisors protrude facially from the mandibular anterior teeth.

Class II, Division 2

A Class II molar relationship where the maxillary central incisors are either upright or retruded, and lateral incisors may be tipped labially.

Class III Occlusion (Mesioclusion)

A relationship where the buccal groove of the mandibular first molar is mesial to the mesiobuccal cusp of the maxillary first molar by at least the width of a premolar.

Mesognathic Profile

A facial profile with slightly protruded jaws giving a relatively flat appearance or straight profile, often associated with Class I.

Retrognathic Profile

A facial profile showing a protruding upper lip or recessive mandible and chin (convex profile), associated with Class II, Division 1.

Prognathic Profile

A facial profile that is concave, associated with Class III malocclusion and a prominent mandible.

Open Bite

A lack of vertical overlap between the maxillary and mandibular teeth, resulting in no contact when the jaws are closed.

Crossbite

A malocclusion where maxillary teeth are positioned inward (lingually) and mandibular teeth are positioned outward (facially).

Tendencies

to deviate from ideal occlusion that may lead to malocclusion. Occlusion is not a normal class I, II or III relationship.

Class 1 to class 2 tendency

means the mandibular groove moved back, but by less than the width of a premolar, so not a true class II

Class 1 to class 3 tendencies

class I to class 3, means the mandibular groove moved forward but by less than the width of a premolar, so not a true class III

Facioversion

A malposition where an individual tooth is sticking out buccally or towards the face.

Linguoversion

A malposition where a tooth is sticking out palatally or lingually.

Supraversion (Supraeruption)

A condition where a tooth has erupted past the normal occlusion line.

Tursiversion (Rotated Tooth)

A malposition where a tooth is turned or rotated from its normal position.