Class 2 div 2 Flashcards
give the BSI definition for a Class II division II incisor relationship
lower incisors occlude posterior to the cingulum plateau of the upper incisors
the upper incisors are retroclined
the overjet is reduced but can also be increased
class 2 div 2 incidence
5-18%
class 2 div 2 aetiological factors
skeletal
soft tissue
dental
pathology
Class 2 div 2 common skeletal features
usually associated with a mild or moderate class 2 skeletal base
- can also be class 1 or 3
typically reduced FMPA
reduced face height
prominent chin
often associated with a forward rotational pattern of growth of the mandible
class 2 div 2 common soft tissue features
high resting lower lip line
- secondary to reduced face height
- retroclined upper incisors
marked labio-mental fold
high masseteric forces
- orthodontic space closure problems
upper 2s shorter clinical crown
- escape effect of lower lip
- trap lower lip
class 2 div 2 dental features
retrolination of upper central incisors
retroclined lower incisors
upper 2s often crowded
- may be normal or prolcined depending on position relative to lip line
reduced arch length
- exacerbates crowding
lateral incisors = poor cingulum
lower incisors may occlude with upper incisors or palatal mucosa
deep overbite
class 2 buccal segments
overjet usually reduced
incidence of developmental dental anomalies in class 2 div 2 patients
50% cases have a form of congenital dental anomaly
33% have impacted canine
reasons for treating class 2 div 2
aesthetic concerns
dental health concerns
- traumatic overbite
- IOTN DHC 4f
class 2 div 2 treatment options depend on…
severity of malocclusion
age and motivation of patient
dental health
patient’s concerns
Class 2 div 2 management options
accept
attempt growth modification
camouflage
orthodontic treatment
orthognathic surgery
Give examples of reasons why you might accept a class 2 div 2 malocclusion
acceptable aesthetics
patient not concerned
- or not suitable for treatment
overbite not a significant problem
class 2 div 2 growth modification indications
growing patient
- adolescent growth spurt
- boys 14 +/- 2 years
- girls 12 +- 2 years
mild to moderate skeletal 2 pattern
class 2 div 2 growth modification stages
convert class 2 div 2 into class 2 div 1
detail occlusion with fixed appliances
Aim of functional appliances in class 2 div 2
To procline the upper incisors
Examples of functional appliances for class 2 div 2
modified twin block
springs or screw
upper sectional fixed appliance
Camouflage in class 2 div 2 - define
accepting underlying skeletal base relationship and aiming to treat to class 1 incisor relationship
Class 2 div 2 camouflage - indications
mild to moderate class 2 skeletal pattern
Class 2 div 2 - why must care be taken when making decisions on extractions?
space closure difficult in low angle cases
Aim of fixed appliances in class 2 div 2
overbite reduction
correction of inter incisal angle
- torque
orthognathic surgery indications for class 2 div 2
too severe malocclusion for orthodontics alone
- severe ap or vertical discrepancy
non growing patients
profile concerns
Class 2 div 2 stability and retention considerations
difficult to treat
future facial growth can affect stability
rotated laterals and deep overbites can relapse
long term bonded retention usually required
Class 2 div 2 - when to refer
deep overbites
- best corrected when patient is growing
- Growth modification with functional appliance is AP discrepancy
- URA with FABP
orthognathic surgery/orthodontics if significant skeletal component
- after growth completed
