| Field | Value |
|---|---|
| ID | OA-0196 |
| Type | component |
| Category | component |
| Fixed/removable | removable (extra-oral; removed by patient) |
| Primary function | extra-oral anchorage; Class II molar distalization |
| Malocclusion target | Class II |
| Uses TADs | no |
The facebow (inner bow + outer bow) is the intra/extra-oral component of cervical-pull or high-pull headgear. The inner bow inserts into the headgear tubes on the upper first molar bands; the outer bow extends laterally outside the mouth to connect to the neck strap (cervical pull) or head cap (high pull). The direction of the outer bow determines the direction of force on the upper molars — cervical pull forces have a disto-occlusal vector (distalizes and tips the molar down), while high pull forces have a disto-occlusal upward vector. The facebow is worn 12–14 hours/day (typically nights and evenings) for Class II molar distalization and anchorage.
The facebow (outer bow) is the extraoral component of headgear — the J-shaped wire that exits the mouth bilaterally and connects the intraoral inner bow (inserted into molar tubes) to the headgear force module (neck strap or high-pull cap). It transmits the extraoral traction force to the teeth and jaws, enabling growth modification and anchorage reinforcement that are not possible with intraoral mechanics alone.
Class II correction in growing patients: The most common use. Cervical-pull headgear (neck strap) applies a distal and downward force to the upper first molars, restraining maxillary forward growth and/or distalizing molars to create space for premolar extraction or arch coordination.
Anchorage reinforcement: In extraction cases with large space requirements and limited anchorage, headgear worn 10–14 hours per day prevents anterior anchor tooth loss during space closure.
Vertical control (high-pull headgear): A high-pull cap directs force posteriorly and superiorly, intruding upper molars and reducing the vertical component — useful in hyperdivergent cases or open bite correction requiring posterior vertical control.
A minimum of 10–12 hours per day of headgear wear is required for measurable skeletal effect. Orthopedic growth modification requires forces of 300–500 g per side; tooth movement (molar distalization only) requires 150–200 g per side. The outer bow length and angulation determine whether the force vector passes through or above the molar's center of resistance, affecting whether the molar tips distally or translates.
Headgear is 100% compliance-dependent — non-wearing patients show no benefit. Safety releases (break-away modules) are mandatory to prevent ocular injury if the headgear recoils. Not indicated in non-growing patients (adult Class II correction requires either extraction mechanics or surgical options).
Commercially manufactured; various inner bow lengths to accommodate molar width. Not lab-fabricated. Molar bands with headgear tubes are lab-fabricated.
Appliances that incorporate this component. ★ = fabricated by Clear Fusion Lab.
buccal tube; neutral vector
torque on upper molars during headgear wear
pull vector
occipital/high-pull vector
correct upper dental midline or unilateral Class II
PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC3713252/)