Untitled Quiz

Questions and Answers

What are the 3 facial profiles?

Mesognathic (correct)

Orthognathic

Retrognathic (correct)

Prognathic (correct)

How are the 3 facial profiles measured?

by the gnathic index (or alveolar index), that is, the ratio of the distance from the middle of the nose to the chin.

What does mesognathic describe?

Having slightly protruded jaws giving the facial outline a relatively flat appearance.

What does retrognathic describe?

Having a prominent maxilla and a mandible posterior to its normal relationship. Signup and view all the answers

What does prognathic describe?

Having a prominent, protruded mandible and normal (usually) maxilla. Signup and view all the answers

Angle's classification of malocclusion describes normal or ideal occlusion.

False Signup and view all the answers

Describe Class I Malocclusion.

The mesiobuccal cusp of the maxillary first molar occludes with the MB groove of the mandibular first molar and the maxillary canine occludes with the distal half of the mandibular canine and mesial half of the mandibular first premolar. Signup and view all the answers

Describe the position of the molars in Class I Malocclusion.

The mesiobuccal cusp of the maxillary 1st molar occludes with the MB groove of the mandibular 1st molar. Signup and view all the answers

Describe the position of the canine in Class I Malocclusion.

Maxillary canine occludes with the distal half of the mandibular canine and the mesial half of the mandibular first premolar. Signup and view all the answers

What facial profile do patients with Class I Malocclusion have?

Normal facial profile or mesognathic profile. Signup and view all the answers

What is Distoclusion?

Class II Malocclusion. Signup and view all the answers

Describe Class II Malocclusion.

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

Describe the molars in Class II Malocclusion.

The mesiobuccal cusp of the maxillary 1st molar occludes mesial to the MB groove of the mandibular 1st molar. Signup and view all the answers

Describe the canines in Class II Malocclusion.

The distal surface of the mandibular canine is distal to the mesial surface of the maxillary canine by at least the width of a premolar. Signup and view all the answers

What factors determine Class II Malocclusion subgroups?

The position of the anteriors, shape of the palate, and resulting facial profile. Signup and view all the answers

Describe Class II Malocclusion: Division 1.

Maxillary anteriors protrude facially from the mandibular anterior and the mandibular incisors usually over-erupt, causing a severe overbite. Signup and view all the answers

Describe the facial profile of Class II Malocclusion: Division 1.

The facial profile shows an overbite, protruding upper lip, or recessive mandible and chin, or convex profile. Signup and view all the answers

What is the facial profile in Class II: Division 1?

Retrognathic. Signup and view all the answers

Describe the palate in Class II: Division 1.

Often narrow and v-shaped. Signup and view all the answers

Describe Class II Malocclusion: Division 2.

The molars are in the same position, maxillary laterals are either tipped labially or they overlap the central incisors, and maxillary centrals are upright or retruded and in deep overbite. Signup and view all the answers

What is the facial profile of Class II: Division 2?

Mesognathic. Signup and view all the answers

What is Class III Malocclusion?

Mesiocclusion. Signup and view all the answers

Describe Class III Malocclusion.

Mesiobuccal cusp of the maxillary 1st molar occludes distal to the MB groove of the mandibular 1st molar and the distal surface of the mandibular canine is mesial to the mesial surface of the maxillary canine. Signup and view all the answers

Describe the facial profile of Class III Malocclusion.

Usually shows a rather prominent mandible and possibly a normal or even retrusive maxilla, thus a concave profile. Signup and view all the answers

What is the facial profile of Class III Malocclusion?

Prognathic. Signup and view all the answers

Describe the molars in Class III Malocclusion.

The mesiobuccal cusp of the maxillary 1st molar occludes distal to the MB groove of the mandibular 1st molar. Signup and view all the answers

Describe the canines in Class III Malocclusion.

The distal surface of the mandibular canine is mesial to the mesial surface of the maxillary canine. Signup and view all the answers

Study Notes

Facial Profiles

Three facial profiles: mesognathic, retrognathic, and prognathic.
Measurement through the gnathic index, defined as the ratio from the middle of the nose to the chin.

Mesognathic Profile

Characterized by slightly protruded jaws giving a straight facial profile.

Retrognathic Profile

Defined by a prominent maxilla and a mandible that is positioned posteriorly, resulting in a convex profile.

Prognathic Profile

Features a protruded mandible with a typically normal maxilla, producing a concave profile.

Angle's Classification of Malocclusion

Focuses exclusively on malocclusion of the molars and canines, excluding normal or ideal occlusion.

Class I Malocclusion

The mesiobuccal cusp of the maxillary first molar occludes with the MB groove of the mandibular first molar.
Maxillary canine occludes with the distal half of the mandibular canine and the mesial half of the mandibular first premolar.
Facial profile is generally normal or mesognathic.

Class II Malocclusion

Known as distoclusion; the mesiobuccal cusp of the maxillary first molar occludes mesial to the MB groove of the mandibular first molar.
The distal surface of the mandibular canine is positioned distal to the mesial surface of the maxillary canine by at least the width of a premolar.

Class II Malocclusion Characteristics

Two subgroups: Division 1 and Division 2, based on anterior position, palate shape, and facial profile.
Division 1: Features maxillary anteriors protruding with a deep overbite, resulting in a retrognathic profile and a often narrow, v-shaped palate.
Division 2: Characterized by maxillary laterals overlapping centrals and centrals may be retruded or upright, leading to a mesognathic facial profile.

Class III Malocclusion

Referred to as mesiocclusion; the mesiobuccal cusp of the maxillary first molar occludes distal to the MB groove of the mandibular first molar.
The distal surface of the mandibular canine is mesial to the mesial surface of the maxillary canine.
Typically presents with a prominent mandible and potentially a retrusive maxilla, resulting in a prognathic facial profile.