Ortho Flashcards
What is malocclusion?
A deviation from normal occlusion.
Name three conditions associated with malocclusion.
Tilting, bodily displacement, and rotation.
What is Lischer’s terminology used for?
Identifying malpositioning of individual teeth in relation to the line of occlusion.
Define labioversion.
Displacement of a tooth toward the lips.
Define linguoversion.
Displacement of a tooth toward the tongue.
What is torsiversion?
Rotation of a tooth around its axis.
Define buccoversion.
Displacement of a tooth toward the cheek.
Define supraversion.
A tooth positioned above the occlusal plane.
Define mesioversion.
Displacement of a tooth toward the midline.
Define infraversion.
A tooth positioned below the occlusal plane.
Define distoversion.
Displacement of a tooth away from the midline.
What is transversion?
A tooth displaced in a different location within the dental arch.
What is the anteroposterior malrelation of dental arches?
Deviation in the forward or backward relationship of arches.
What is excessive overjet?
Horizontal overlap of incisors beyond 2 mm.
Define edge-to-edge bite.
The incisors meet edge to edge with no overlap.
What is anterior crossbite?
A reverse horizontal relationship of anterior teeth.
What is posterior crossbite?
An abnormal buccolingual relationship of posterior teeth.
What is a unilateral posterior crossbite?
Crossbite affecting one side of the dental arch.
Define scissors bite.
A type of crossbite where the teeth occlude abnormally, with excessive buccal overlap.
What is excessive overbite?
Deep vertical overlap of incisors.
What is open bite?
Lack of vertical overlap between upper and lower teeth.
Define anterior open bite.
Open bite in the anterior segment of the dental arches.
Define posterior open bite.
Open bite in the posterior segment of the dental arches.
What is skeletal class I?
Normal anteroposterior relation of the mandibular basal arch to the maxillary basal arch.
What is skeletal class II?
Mandibular basal arch retruded relative to the maxillary basal arch.
Define skeletal class III.
Mandibular basal arch protruded relative to the maxillary basal arch.
What is the average normal overjet?
0-2 mm.
What is the normal vertical overlap of incisors?
One-third of the lower incisors or 2-3 mm.
Define orthognathic profile.
A normal anteroposterior skeletal relationship.
What is a retrognathic profile?
A retruded mandibular basal arch.
Define prognathic profile.
A protruded mandibular basal arch.
What is the purpose of Angle’s classification?
To describe malocclusion based on the mesiodistal relations of the first molars.
Define Angle’s class I.
Normal molar relation but with crowding or malposed teeth.
Define Angle’s class II.
Lower molar positioned distally to the upper molar.
Define Angle’s class III.
Lower molar positioned mesially to the upper molar.
What are the two divisions of Angle’s class II?
Division 1 (protrusion of upper incisors) and Division 2 (retrusion of upper incisors).
What is Dewey’s modification of Angle’s class I?
Further classification based on anterior crowding or individual tooth displacement.
What is Dewey’s type 1 modification?
Bunched or crowded maxillary anterior teeth.
What is Dewey’s type 3 modification?
Maxillary incisors in linguoversion to mandibular incisors.
Define buccoclusion.
Buccal displacement of teeth or dental arches.
Define linguoclusion.
Lingual displacement of teeth or dental arches.
What is supraclusion?
An abnormally deep overbite of a group of teeth.
What is infraclusion?
Open bite of a group of teeth or dental arches.
What does Simon’s classification consider?
Relationship of dental arches to the three planes of space.
Name the three planes in Simon’s classification.
Frankfort horizontal, mid-sagittal, and orbital planes.
What is protraction in Simon’s classification?
Anterior placement of the dental arch to the orbital plane.
Define retraction in Simon’s classification.
Posterior placement of the dental arch to the orbital plane.
What is contraction in Simon’s classification?
Dental arch closer to the mid-sagittal plane.
What is distraction in Simon’s classification?
Dental arch farther from the mid-sagittal plane.
Define attraction in Simon’s classification.
Dental arch nearer to the Frankfort horizontal plane.
Define abstraction in Simon’s classification.
Dental arch farther from the Frankfort horizontal plane.
What does skeletal deep bite indicate?
Excessive vertical overlap due to basal arch malrelations.
Define skeletal open bite.
Lack of vertical overlap due to basal arch malrelations.
What is Lischer’s modification to Angle’s classification?
Use of the term “version” to describe malpositions.
What is the significance of the Frankfort horizontal plane?
It serves as a reference for vertical relationships in Simon’s classification.
What is an edge-to-edge bite classified as in Dewey’s modification?
Type 1 modification of Angle’s class III.
What are the limitations of Angle’s classification?
It doesn’t differentiate skeletal and dental malocclusion.
What is the normal occlusion described by Angle?
The mesiobuccal cusp of the upper first molar aligns with the buccal groove of the lower first molar.
Define constricted maxillary basal arch.
A narrow upper arch, often associated with cleft palate.
Define overdeveloped mandibular basal arch.
Excessive lateral or anteroposterior mandibular growth.
What is deep bite associated with?
Excessive vertical overlap.
Define open bite.
No vertical overlap of incisors.
What does the term “constricted maxillary arch” indicate?
Narrow maxillary arch structure.
What is the significance of basal arches in malocclusion?
Determines skeletal dysplasia in malrelations.
What is the mid-sagittal plane?
Divides the cranium into two equal halves.
