Ortho - C2D2 Flashcards
What is the BSI definition of Class 2 Division 2.
The lower incisor occludes posterior to the cingulum plateau of the upper incisor and the upper incisors are retroclined
The overjet is reduced but can also be increased
What are the Skeletal causes of C2D2? (2)
Anteropostero:
Usually associated with a mild/moderate SK2 base
(Can also be associated with SK1 or 3)
Vertical:
- reduced FMPA
- forward rotational growth pattern of the mandible
- Progenia (prominent chin)
Describe the soft tissue causes of C2D2? (5)
- High resting lower lip line (secondary to a reduced lower face height)
- Lower incisors can also be retroclined due to the forces of the tight lower lip
- Marked labio-mental fold
- High masseteric forces = ortho space closure problems
- Upper 2’s have shorter clinical crown height = escape the effect of the lower lip and can trap the lower lip
Describe how the upper centrals are retroclined but the upper laterals are not and can sometimes be proclined.
High resting lower lip line (secondary to a reduced lower face height)
The lower lip sits higher up on the upper incisor crown = retroclines upper incisors
Upper 2’s have shorter clinical crown height = escape the effect of the lower lip height and can trap the lower lip (why they are not retroclined like centrals and flared/proclined instead)
List the dental features associated with C2D2. (7)
- Retroclined upper centrals
- Upper 2’s crowded, mesio-labially rotated or normal/proclined (depends on their position relative to the lower lip line)
- Reduced arch length = worsens crowding
- Laterals have poor cingulum = increased/deep overbite as there is less of an incisal stop
- reduced overjet
- Lower incisors occlude the upper incisors (posterior to the cingulum plateau) or the palatal mucosa
- class 2 buccal segments
Why should we treat these patients? (3)
- Aesthetic concerns
- Dental health concerns
- traumatic overbite
if there is palatal trauma = higher tx need
if there is labial mucosa trauma = overbite can cause gingival stripping = higher tx need
What IOTN is awarded to C2D2 patients with a traumatic overbite?
4f
What do the treatment options for C2D2 depend on? (4)
- Severity of malocclusion
- Age and motivation
- Dental health and OH status
- Patients concerns
Briefly list the 4 tx options for C2D2.
- Accept
- growth mods
- camo
- Orthognathic surgery
When would we accept C2D2 and do nothing? (3)
- Aesthetics acceptable (no significant malocclusion features)
- Patient not concerned
- Overbite not a significant problem i.e. traumatic
When would we use growth mods to treat C2D2?
At what age is this suitable to use for girls and boys?
Use in mild/moderate skeletal 2 pattern
- Boys 14 (+2)
- Girls 12 (+2)
describe how modified twin blocks are used to correct C2D2. (2)
Modify the twin block and use to convert C2D2 to C2D1
ELSA Spring makes appliance active = procline upper labial segment/ procline the retroclined upper centrals.
Define orthodontic camouflage.
Accept underlying skeletal base relationship and aim for class 1 incisor relationship
When would we use ortho camo to treat C2D2?
Use in mild/moderate class 2 when px’s have stopped growing.
Describe how ortho camo is used to correct C2D2. (2)
what does this achieve?
Uses Fixed appliances to;
* Reduce the overbite (will relapse if not corrected)
- Correct the inter-incisal angle via
- Palatal root torque the upper incisors
- Proline the lower incisors
= normalises inclination and increases stability
