Class II Division 1 Malocclusion Flashcards
What is the BSI definition of a class II division 1 malocclusion?
- the lower incisor edges lie posterior to the cingulum plateau of the upper incisors
- there is an increased overjet
- the upper central incisors are proclined or of average inclination
What is the prevalence of Class II Div 1 malocclusions?
15-20%
What are the possible reasons for treating a class II div 1 malocclusion?
- concerns about aesthetics
- concerns about dental health
What are the dental health concerns for a class II div 1 malocclusion?
trauma
- prominent incisors are at increased risk of trauma
- especially in case of incompetent lips
- overjet >9mm twice as likely to suffer trauma
- IOTN 5a
What are the aesthetic concerns for a class II div 1 malocclusion?
- may be self-conscious
- may be getting bullied at school
What are the dental health concerns for a class II div 1 malocclusion?
- risk of trauma
- prominent incisors
- increased by incompetent lips
- overjet >9mm twice as likely for trauma
- IOTN 5a
What are the A/P skeletal pattern features of a Class II Div 1 malocclusion?
- usually associated with class II skeletal base
- can be seen on class I
- rarely seen on class III
- tipping of teeth
- commonly retrognathic mandible
- maxillary protrusion less common
What can cause overjets is class II div. 1 malocclusions?
- skeletal pattern
- tooth inclination
- combination of both
What vertical skeletal patterns are associated with class II div 1 malocclusions?
- associated with a range of vertical skeletal patterns
- reduced overbite
- anterior open bite
- reduced FMPA
- more horizontal
What transverse skeletal patterns are associated with class II div 1 malocclusions?
- no particular association with transverse problems
What soft tissue features may be seen in a class II div 1 malocclusion?
- incompetent lips
- prominence of incisors
- underlying skeletal pattern
- difficulty achieving anterior oral seal
- lower lip trap
- aetiological factor in increased overjet
How may patients with a class II div 1 malocclusion achieve an anterior oral seal?
- activity of circum-oral musculature
- mandible postured to allow lips to meet
- lower lip drawn up behind incisors
- tongue placed forwards between incisors and lower lip
- combination of all of the above
What dental factors are involved in a class II div.1 malocclusion?
- increased overjet
- proclined or average incisors
- overbite varies
- aligned, crowded or spaced
- molar relationships
- habitually parted lips
- dying of gingiva
- exacerbation of pre-existing gingivitis
How can sucking habits be involved in class II div 1 malocclusions?
- effects depend on the duration and intensity
- thumb
- fingers
- blanket
- lip
- combination of the above
- angulation of incisors
- proclination of upper anteriors
- retroclination of lower incisors
- localised AOB or incomplete OB
- usually asymmetrical AOB
- narrow upper arch
- unilateral posterior crossbite possible
- buccinator muscles left unopposed
What must be done about a sucking habit before commencing orthodontic treatment?
- stop habit
- reinforcement
- motivated patient
- removable appliance habit breaker
- motivated patient
- can be removed
- fixed appliance habit breaker
- reinforcement
- allow spontaneous improvement
- AOB and overjet
- around 1-1.5 years
- treat residual malocclusion
- if required
What are the 5 management options for Class II Div 1 malocclusion?
- accept
- attempt growth modification
- simple tipping of teeth
- camouflage
- orthographic surgery
When can a class II div 1 malocclusion be accepted?
- mildly increased overjet
- significant overjet but not unhappy with teeth
What advice must be given surrounding accepting a classII div 1 malocclusion?
- increased risk of trauma
- especially young patients
- consider a mouthguard
- future treatment options reduced
- beyond 14 growth modification challenging
What are the different options for growth modification for a class II div 1 malocclusion?
- headgear
- restrain maxillary growth
- horizontally
- vertically
- restrain maxillary growth
- functional appliance
What is a functional appliance?
functional appliances utilise, eliminate or guide the forces of muscle function, tooth eruption and growth to correct a malocclusion
How is the mandible postured by a functional appliance for a class II div 1 malocclusion?
- downwards
- forwards
What are the different types of functional appliance available?
- removable
- tooth borne
- twin-block
- activator/bionator
- soft tissue borne
- Frankel (FRII)
- tooth borne
- fixed
- Herbst
What is the aim of functional appliance use and what does success depend on?
- aim
- produce restraint of maxillary growth
- encourage mandibular growth
- success
- favourable growth
- motivated patient
What are the therapeutic effects of functional appliances?
- mostly dento-alveolar changes
- distal movement of upper dentition
- mesial movement of lower dentition
- retroclination of upper incisors
- proclination of lower incisors
- minor degree of skeletal changes
- maxillary restraint
- 1-2mm
- mandibular growth
- 1-2mm
- significant variation
- maxillary restraint
When should a functional appliance be used?
- during growth
- ideally coinciding with pubertal growth
- males - 13-15 years
- females - 11-13 years
- ideally coinciding with pubertal growth
- early use
- 10 years old
- 2 phase treatment
- later use
- late mixed or early permanent
- 1 phase treatment
What are possible disadvantages of early treatment of a class II div 1 malocclusion with a functional appliance?
- early skeletal effects not maintained long term
- overall treatment time increased
- 2 phase treatment
- early functional appliance + retention
- fixed appliance in early permanent
- 2 phase treatment
What are the potential benefits of early treatment of a class II div 1 malocclusion with a functional appliance?
- improved appearance early
- reduced teasing
- potential psychological benefit
- reduced risk of trauma
- often better compliance
- appliance wear
How can simple tipping of teeth be used to treat a class II div 1 malocclusion?
- limited role in treatment of increased overjets
- suitable for:
- very mild class II or class I
- overjet due to proclination and spacing
- incisors
- overbite favourable
Describe an appliance design for retroclining anterior teeth
A: Robert’s Retractor 0.5mm tubing
R: Adam’s clasp 6/6, 0.7mm HSSW
A: stops mesial to 3/3
B: flat anterior bite plane
How can camouflage be used for a class II Div I malocclusion?
- upper arch extractions
- space for distal movement
- overjet reduction
- fixed appliances
- better for moving roots
How can orthographic surgery be used to treat a class II div 1 malocclusion?
- carried out when growth is complete
- used for severe skeletal discrepancies in the antero-posterior or vertical direction
- usually involves mandibular surgery
- may also involve maxillary surgery
- fixed appliances required
- before surgery
- during surgery
- after surgery
