Class II Division 1 Flashcards
What is the BSI definition of 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
Why do you treat Class II div 1 malocclusions?
Aesthetic concerns
Dental health concerns (risk of trauma especially with incompetent lips)
What skeletal pattern (A/P) is typical of a Class II div 1 malocclusion?
Class II skeletal pattern
Commonly due to a retrognathic mandible (rather than a maxillary prognathism)
What is the FMPA typically for this malocclusion?
A reduced FMPA
What habit can be associated with this malocclusion?
A sucking habit of things such as a thumb, fingers, a blanket, a lip or a combination of things.
Effect depends on duration and intensity
What are the occlusal features of a sucking habit?
Proclination of upper anteriors
Retroclination of lower anteriors
Localised AOB or incomplete OB (to have a skeletal effect, needs to be a bad habit)
A narrow upper arch
What are the habit treatment principles?
Stop the habit
Allow spontaneous improvement of malocclusion
Treat residual malocclusion if required
How can you stop a habit of sucking?
Reinforcement- requires patient co-operation
Removable appliance habit breaker - requires patient co-operation
Fixed appliance habit breaker- last resort
What are the management options for a Class II div 1 malocclusion?
Accept- aware of risk of trauma
Attempt growth modification- has to be at the right age
Simple tipping of the teeth (URA)
Camouflage
Orthognathic surgery
What are functional appliances used for?
Functional appliances utilise, eliminate, or guide the forces of muscle function, tooth eruption and growth to correct a malocclusion
Used mostly for Class II div 1
What are the different types of functional appliance?
Removable
Fixed
What are the removable types of functional appliance?
Tooth borne - twin-block, activator
Soft tissue borne- Frankel (FR II)
How are functional appliances used in growth modification?
They aim to produce restraint of maxillary growth & encourage mandibular growth
Success depends on favourable growth & an enthusiastic patient
What are the therapeutic effects of functional appliances?
Mostly dento-alveolar changes
—Distal movement upper dentition
—Mesial movement lower dentition
—Retroclination of upper incisors
—Proclination of lower incisors
Minor degree of skeletal changes
When should you use a functional appliance?
It should be used during growth
If possible it should coincide with pubertal growth spurt
Early use- about 10 years old (2 phase treatment)
Later use- late mixed or early permanent dentition (1 phase treatment)
—ideally during period of maximal growth
—Females 11-13
—Males 13-15