Laboratory

The following are guidelines and requirements for the dentist to follow if they want an OPTIMIZED CHAN ORTHOTIC properly fabricated by a trained and approved denal laboratory.

Impression Requirements:

1. Accurate undistorted PV impressions – Check the gingival margin details in the anterior and posterior regions.
2. Check the gingival margins for accuracy and details.
3. The lab prefers quality detailed PV impressions mailed to the lab in order that they themselves can pour up the model with their own stone.  They use special stone that has the proper stone expansion ratio required to make a properly fitting orthotic.

Requirements for Model Casts:

1. To fabricate the orthotic the lab will need to pour 2 sets of models free of bubbles and any irrigularities in the anterior and posterior regions. 
2. 2 sets of detailed and accurate undistorted models will be poured by the lab.
3. The Lab will need to pour these impressions at least 2 times.
4. Don’t send in only a single poured model – The lab will need to duplicate another set of models if you only send in one set of model casts and you will be charged for the time required to duplicate and manage the second set.  (It is better to send in accurate impressions that the lab can pour themselves).

Required Bite Registration Materials:

PV Bite Registration

1. The Bite Registration must be rigid enough – PV Aquasil Rigid is required for the lab to mount your case accurately to properly fabricate the Chan Orthotic.

Sapphire Bite Registration

1. The Sapphire Bite registration (Bosworth) should not be excessively thinned or trimmed, because it will become distorted and will not allow an accurate mounting.
2. Keep sufficient peripheral  thickness (bulk) around the edges of the Sapphire bite as a frame and matrix to prevent bite registration from warping.

Requirements Bite Registration:

1. Make sure you open the bite no less than 2 mm in the thinnest area between the upper and lower casts during bite registration.  If the bite is too thin the lab will contact you and will ask you to retake the bite so they can make the orthotic properly so there is no thinnest or holes in the orthotic.

Marking Vertical Lines on Models to Check Your Bite Relationship:

1. On one set of poured and trimmed models hand held in CO (centric occlusion);  Draw vertical pencil marks from the gingival margin of the upper mesial buccal cusps down to the lower molar vertically on both left and right side. 
2. Draw a vertical line between the maxillary central incisors down to the labial of the lower central incisors.  This will allow you to check your NM bite relationship. 
3. If the lower marked lines in the molar region are distal to the upper line, retake your bite over. 
4. If the lower molar line is at or anterior to the upper line, you are on the right track.  
5. Also check the frontal or lateral relationship using the anterior midline as your guide and reference.  (In general, the midlines should line up in most cases).  If the bite is skewed off to one side, reconsider if you have optimized the condyles and discs properly.

Filed under: Dental Laboratory Technology, Neuromuscular Orthotic, Optimized Chan Orthotic by Clayton A. Chan, D.D.S.
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