Overview: This guide explains the step-by-step process to capture a protruding bite scan for a sleep apnea device to ensure proper alignment and device fit.
Prerequisites
A projection of the patient's therapeutic bite position.
A bite gauge, jig, or firm makeshift stabilization device.
Preparing the Therapeutic Bite
Positioning the Sleep Apnea Bite
Position the patient's jaw into the projected therapeutic bite position before starting the scan. Ensure the sleep apnea bite position remains consistent throughout the scanning process.
Establishing Bite Clearance
Maintain roughly 3mm of vertical clearance between the dental arches. Ensure a 5mm gap exists between the opposing anterior teeth to provide adequate space for the sleep apnea device.
Capturing the Intraoral Scan
Stabilizing the Jaw Position
Secure the jaw in the therapeutic bite position using a bite gauge, jig, or firm makeshift device. Stabilization prevents the jaw from shifting, which is critical for an accurate sleep apnea bite scan.
Performing the Bite Scan
Scan the bite on both the left and right sides of the patient's mouth. The bite scan must cover at least 3-4 teeth on each side to allow the software to achieve proper alignment.
George Gauge
The George Gauge is used to measure a patient’s absolute range of horizontal jaw movement. This data allows you to calculate a precise clinical starting position (typically 60% to 70% of maximum protrusion) and capture it using bite registration material.
1. Device Assembly & Initial Setup
Insert the Bite Fork: Loosen the upper set screw on the George Gauge body and slide the bite fork (typically choosing a 2mm or 5mm clearance fork) into the upper slot. Set the indicator precisely to "0" on the millimeter scale.
Fit the Lower Clamp: Loosen the lower turn screw. Place the lower incisor notch over the patient's bottom front teeth.
Align and Secure: Ensure the gauge's midline indicator aligns perfectly with the center of the patient's lower midline. Cinch and tighten the lower clamp to lock the gauge securely onto the lower arch.
2. Measure the Range of Motion (ROM)
Position the Upper Arch: Place the assembled device back into the mouth. Align the gauge with the patient’s upper midline and guide them to bite firmly into the upper notch of the bite fork.
Record Maximum Protrusion: Instruct the patient to slide their lower jaw as far forward as possible. Note and record this number (e.g., +8 mm).
Record Maximum Retrusion: Instruct the patient to slide their lower jaw as far back as possible. Note and record this number (e.g., -2 mm).
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Determine Total Range: Add the absolute values of both measurements together to establish the patient's total range of motion.
Example: 8 mm (protrusion) + 2 mm (retrusion) = 10 mm total range.
3. Calculate and Lock the Starting Position
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Calculate the Target: Establish a therapeutic starting position by calculating 60% to 70% of the patient's total range of motion.
Example Calculation: If the total range is 10 mm, 60% of that maximum range is 6 mm.
Lock the Gauge: Remove the gauge from the mouth. Slide the bite fork indicator to your calculated target number on the millimeter scale (e.g., 6) and firmly tighten the upper set screw to lock the position.
4. Capture the Bite Registration
Apply Material: Extrude George Gauge registration material (such as bite silicone or softened registration wax) evenly onto both the upper and lower prongs of the bite fork.
Guide the Patient: Return the locked device to the mouth. Instruct the patient to close their upper and lower teeth directly into their respective notches on the bite fork, keeping their midlines perfectly aligned.
Set the Material: Instruct the patient to maintain a firm, steady bite and hold the position until the impression material sets completely.
5. Removal and Verification
Disassemble: Once the material is completely cured, carefully remove the entire assembly from the patient's mouth. Detach the bite fork from the main support frame body.
Trim Excess: Carefully trim away any excess material flashing using a laboratory knife or scissors.
Inspect the Quality: Verify that the indentations of both the upper and lower teeth are deep, crisp, and clearly visible. Ensure no registration material has bled into or obstructed the anterior divot areas, which could distort the final appliance fabrication.