A diagnostic dental cast is a cast model of a person’s teeth that a dental professional uses as a guide in the application of corrective or restorative dentistry. Such diagnostic casts are often referred to colloquially as “study models.” Casts of this type are frequently used by orthodontists to visualize the current and adjusting bite of a patient, and by implant specialists to ensure the proper placement of an implant for good bite structure.
To ensure the cast captured is a reliable replica of your entire mouth, tissues and biting mechanism, your dentist needs to first determine the correct position of your jaw in its most relaxed state. To do this, you may be asked to rest your upper teeth on a tongue depressor for several minutes. This causes the jaw to relax and allows your dentist to move your lower jaw into a stable “centric” position. From this relaxed position, a silicone or wax mold called an “interocclusal record” is made of your bite, and sent to a dental laboratory to be made into a full cast mold of dental stone.
Once complete, the stone casts of your teeth are placed on a machine that mimics the action of the jaw, and the interocclusal record is used to line up the stone casts in the correct centric position. The cast is then returned to the office of your doctor for evaluation and planning for your ortho or implant work.