Class II div 1 Flashcards
british standards definition of a class II div 1 malocclusion
the lower incisor edges lie posterior to the cingulum plateau of the upper incisors AND there is an increased overjet. The upper central incisors are proclined or of average inclination
why treat class II div 1 malocclusions
- aesthetic concerns
- dental health concerns e.g trauma
most common skeletal aetiology for a class II skeletal base
retrognathic mandible
what aspect of soft tissues may be an aetiological factor of a class II div 1 malocclusion
lip trap
what is the most common molar classification in class II div 1 patients c
class 2
name 4 potential features of a digit sucking habit
proclination of upper incisors
retroclination of lower incisors
narrowed maxillary arch
localised AOB
unilateral posterior crossbite
what habits may be an aetiological factor of class II div 1 malocclusions
non nutritive sucking habits
why might digit sucking see a narrowed maxillary arch
freeway space is increased, tongue is lowered and buccinator is left unopposed
normal SNA value
81 +/- 3
normal SNB value
78 +/- 3
normal ANB angle
3 +/- 2
normal FMPA
27 +/- 4
normal inclination of upper incisors
109 +/- 6
normal inclination of lower incisors
93 +/- 6
beyond what age is use of growth modification appliances limited
14
what do functional appliances do
utilise, eliminate or guide the forces of muscle function, tooth eruption and growth to correct a malocclusion
what malocclusion are functional appliances most commonly used for
class II div 1
name an example of a tooth borne and a soft tissue borne removable functional appliance
tooth - twin block
soft tissue - frankel (expensive and difficult to make)
when should a functional appliance ideally be used
during period of maximal growth i.e pubertal growth spurt
as a guide 11-13 in females and 13-15 in males
discuss the therapeutic effect of functional appliances
mostly dentoalveolar changes - distal movement of upper dentition, mesial movement of lower
- proclination of lowers, retroclination of uppers
only minor degree of skeletal changes, studies estimate 1-2mm of mandibular growth
early treatment with functional appliance
involves 2 phases , initial functional appliance stage whilst still in mixed dentition
then fixed appliance at a later date for fine tuning of occlusion
advantages and disadvantages of early use of a functional appliance
advantages - improved appearance at earlier age, reduced risk of trauma, better compliance with wear*
disadvantages - early skeletal effects may not be maintained longterm, overall treatment time increased, research show s little difference in results between those treated early and those treated late
treatment of choice for patients with mild -moderate class II div 1 maocclusion who is concerned with tooth position rather than jaw position
camouflage with fixed appliances
premolars may be extracted to give adequate space
do you still need fixed appliances if getting orthognathic surgery
yes, they will be required before and after surgery
can URAs be used in treatment of class II div 1 malocclusions
limited role in treatment of increased overjets
only if very mild class II or class I due to proclined incisors
