| Field | Value |
|---|---|
| ID | OA-0157 |
| Type | habit_appliance |
| Category | habit_appliance |
| Fixed/removable | fixed |
| Primary function | habit interruption (thumb-sucking; tongue thrust) |
| Malocclusion target | anterior open bite; anterior proclination from digit habit |
| Inventor | Dr. Bruce Haskell & Dr. John Mink |
| First year | 1991 |
| Period | modern |
| Status | current |
| Uses TADs | no |
The Bluegrass appliance was designed in 1991 by Dr. Bruce Haskell (University of Louisville) and Dr. John Mink (University of Kentucky) — named for the Bluegrass region of Kentucky. Unlike the tongue crib which creates a physical barrier, the Bluegrass uses a hexagonal acrylic (Teflon) roller bead that rotates freely on a palatal wire behind the upper anterior teeth. The bead is positioned so the tongue (or thumb) contacts it and spins it, creating a pleasurable sensory distraction that redirects the habit behavior through positive reinforcement rather than punishment. The design concept was inspired by copper-roller bits used in equine training to calm horses. The Bluegrass produces high patient acceptance and habit cessation rates comparable to cribs, with better patient cooperation and less psychological stress.
The rotating bead sits at the location the tongue normally contacts during thrust (just behind the upper incisors, at the alveolar ridge area). When the tongue presses forward, instead of meeting a hard wire barrier (as in a crib), it contacts the smooth rolling bead. The tactile experience of spinning the bead becomes its own reward — patients "play" with the bead rather than the original habit. Over weeks to months, the original thumb or tongue habit is extinguished as the bead interaction replaces it, and the natural eruption forces bring the open bite closed. The positive reinforcement mechanism produces less anxiety and better habit cessation in many children compared to barrier-type cribs.
Thumb or finger sucking habit in mixed dentition (ages 5–10 ideal); tongue thrusting anterior open bite; motivated young patients; cases where the clinician prefers a positive-reinforcement approach over barrier; patients who have had traumatic experiences with other habit appliances; mild-to-moderate anterior open bite expected to self-correct once habit ceases.
The bead must remain freely rotating — if it binds on the wire, the distraction mechanism fails. Parents must be counseled not to "punish" the child for using the bead (which reinforces the positive-reinforcement mechanism). Less effective if the patient becomes fixated on the bead as a new habit rather than being distracted from the original. Like the crib, not effective for skeletal open bite.
molar bands
the wire
colored beads; glass beads
anterior teeth at mid-palate level
The bead must rotate freely on the wire — too tight a fit prevents rotation and defeats the mechanism. The wire must pass through the bead's central bore without binding. Bead positioning is critical: too far posterior doesn't engage the habit zone; too anterior contacts the incisors. For colored or novelty beads (which increase patient engagement), the bead material must be biocompatible and autoclavable. CFL offers Bluegrass (standard wire) and (possibly includes larger bead or more complex wire design).
.
stimulation.
barrier-type alternative; different mechanism.
comprehensive combined approach.
AAPD](https://www.aapd.org/globalassets/media/publications/archives/haskell-13-02.pdf)
Labs](https://odlortho.com/products/blue-grass-appliance/)
Ortho](https://www.accutechortho.com/orthodontic-laboratory-products/fixed-appliances/bluegrass-appliance/)
PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC7243892/)
fabrication, business notes.