OB Reduction Flashcards
1
Q
Overbite
A
- vertical overlap of maxillary upper incisor to mandibular incisors
2
Q
Cause of Increased OB
A
- Skeletal
- Dental
20%
3
Q
Skeletal cause
A
- Excessive growth of mandibular ramus
- short mandibular body
- anterior growth rotation
4
Q
Dental Example
A
- Over eruption of anterior teeth
- Retroclined upper anterior teeth
- loss of posterior teeth
5
Q
Overbite reduction depends on?
A
- Vertical skeletal pattern
- Inclination of incisors
- Crowding
- Growth
6
Q
Aim of OB reduction mechanism
A
- flatten occlusal plane
7
Q
Means of overbite reduction?
A
- Extrusion / uprighting posterior teeth
- Intrusion of incisors/ canine
- Proclination of lower incisors
If sever - Orthognathic surgery
8
Q
Method of overbite reduction?
A
- URA with anterior bite plan
- Fixed anterior bite plane I.g bite turbos
- Lower arch wire in reverse curve of spee
- upper arch wire with increased curve of Spee
- Class II elastics
- Bonding lower second molars
- Sectional mechanism
- Orthognathic
9
Q
Removable anterior bite plane
A
- Very effective in growing patient
- Hold vertical position of lower incisor
- Encourage eruption of posterior teeth
- Lab instruction : anterior Bite plane OJ+2mm
10
Q
Fixed anterior bite plane
A
- Composite and metal bite turbos
- Hold vertical position of lower incisors
- Encourage eruption of posterior teeth
- 2 potential Issue- Inhalation risk and difficult to remove
- Advantage- no patient compliance required
11
Q
Continuous Archwire
A
- Flat SS arch wire or with
Upper - increased curve of spee
Lower- Reverse curve of spee - Rocking chair Niti lower
If left in situ for too long can cause premolar expansion and distolingual molar rotation. - Both above method results - Proclination of LLS due to labial crown tipping.
12
Q
Flat archwire
A
- Intrude lower incisors.
- Extrude posterior teeth.
- Best in growing patient.
- Bond/ band lower second molars.
13
Q
Curve of spee
A
- Further intrusions in incisors
- Extrusion of premolars
- Beware LLS Proclination
14
Q
Class 2 Intermaxillary elastics
A
- Effecting at extruding lower molars
- They also extrude upper incisors but:
1- This can be limited by adding a Curve of spee to upper wire
2- 1mm of molar extrusion will have greater effect on opening the bite as the molar is closer to the condylar hinge axis.
15
Q
Best way to reduce overbite cases
A
- Run lower fixed with upper removable appliance. When lower in heavy wire stop URA and go into upper fixed appliance