Headgear Flashcards
Define Headgear
An orthodontic appliance that provides:
EOA - extra oral anchorage
EOT - extra oral traction
Via attachment if another appliance
(Fixed and removable)
Define EOA Headgear
Prevents unwanted tooth movement outside the mouth
How is EOA achieved
Prevents forward movement of the molars
Force applied - back of the head = distalising the molars
EOA - force and duration
200 -250g per side
10 - 12 hours a day
Define EOT Extra Oral Traction
Moving teeth using forces outside the mouth
How is EOT achieved?
Force applied behind the head to hold the anchor teeth back
What tooth movements are created with EOT
Distals molars
Extrusion/ intrusion molars
Maxillary restraint
Reduction in Overjet
Correction of crossbites
Creates space
Can EOT change facial heights and the Frankfort - mandibular plane angle?
Yes LAFH/ FMPA can increase or decrease
Helped by encouraging growth rotations
EOT magnitude and duration
450- 500g per side
14-16 hours
Name the three types of headgear
- Cervical (Low)
- Combi (straight)
- High Pull
What does Cervical low pull headgear achieve?
Distalisation and extrusion of the molars
Increases LAFH by extrusion of molars
What pts are Cervical low pull headgear used on?
Skel II
Decreased LAFH/ FMPA
Deep/ increased overbite
Forward growth rotations
What growth rotation is encouraged with Cervical Low pull headgear
Backward growth of the mandible by:
Extruding the molars
Increases the MMPA and LAFH=
Furthers buccal extrusions and reduces the deepbite
Where is the force transmitted with Cervical low pull headgear
BELOW the occlusal plane
What does Combi/ Straight pull headgear achieve?
Distalisiation of the molars and EOA
What direction of pull does the Combi/straight pull have?
High and low pull
Where is the force transmitted with combi/straight pull headgear?
Level with the occlusal plane
What does High pull headgear achieve?
Distalisiation of the molars
Intrusion of the molars
Maxillary restraint
What type of patient would have High Pull Headgear?
Skel III
Increased LAFH/FMPA
AOB or decreased overbite
Backward growth rotations
What growth rotation is encourage with High pull Headgear?
Forward Growth rotations:
Intrudes posterior segment in the maxilla = forward growth of the mandible
- Reduces MMPA and LAFH
- Reduces AOB
Where is the force located with High Pull?
Above the occlusal plane
where is the centre of resistance found with High Pull?
pre molar region of maxilla
Name the three components of Headgear
- Way of attachment
- Neck strap/headcap
- Elastic/spring mechanism
What is an example of a way of an attachment on Headgear?
Facebow
J hooks
Where do Facebow’s slot in on removable and functional appliance?
A tube is soldered into the bridge of the adam’s clasp
Where do Facebow’s slot in a fixed appliance?
Tubes on molar bands
Where do J hooks hook into a fixed appliance?
Directly into the archwire
Where do J hooks hook into a removable appliance?
Loops on a removable appliance
What type of Headgear uses a neck strap?
Cervical low pull and
Combi Straight
What type of headgear uses a Headcap?
High pull
What is the function of the Elastic component or spring mechanism?
To connect the way of attachment and neckstrap/headcap
It controls the magnitude of the force
How is the Elastic force produced?
Elastic Strap
EO elastic bands
Spring mechanisms
How many safety features do Headgear have to have?
At least 2
1. Extra Oral
1. Intra Oral
Name Intra Oral safety Mechanisms on Headgear
Locking Facebow with blunt ends and catches to lock in the tubes
Name Extra Oral safety Mechanisms on Headgear
1.Rigid Masal Strap - prevents facebow being dislodged
2. Snap away modules
What cases are Reverse Headgear used on?
Class III
What is the function of reverse headgear?
1.Forward movement of the maxilla
2.move teeth mesially - to close space
3. stop the mandible from protruding
What is used for the force of resistance in Reverse Headgear?
The forehead
What is used to measure force on Headgear
Correx Gauge
What is small Correx gauge used to measure?
The forces of extra oral or intra oral elastics
What is a big Correx Gauge used to measure?
The forces on Headgear
Headgear Instructions
• remove for brushing 3xaday
•not to eat with the appliance in
•ensure safety mechanisms are used
•to wear as prescribed
• if it comes apart at night, to remove asap and to contact the Orthodontist asap
• could be painful 3-5 days. To take what you would for a headache
