Facially generated treatment planning guides us to establish the correct place for the anterior teeth in the face and the smile first.
What often follows is the discovery that the teeth are not in the correct place to restore them. The incisors may be over erupted; there may be too much overbite. There may not be enough clearance to restore the teeth to the ideal length. Spacing may be too much or too little.
Common questions arise about opening space, closing space or moving the space to a new position. During this process, we need to establish the correct overjet for the restorative correction needed. Will extraction help or do you need to open an implant space? Should it be anterior or posterior?
Overjet and Play-Doh
One important tool in determining the answers to your overjet puzzle is a diagnostic set up. The need for flexibility in this process is important to allow you and your interdisciplinary team to “try out” several options to get the best relationship. A simple in-house process can be done with a plaster pour up and Play-Doh. An alginate impression and MIP wax bite is made. The impression is poured up to just the gingival margins of the crowns. The most posterior teeth are stabilized with a wire loop placed in the setting plaster.
Alternatively, at seating “X” can be carved in the set plaster. Before the second pour is made, a thin layer of Vaseline is applied to the set plaster surface of the teeth that needs to be cut out and moved. Pour up as usual with a good base for a good working stability. Trim the casts with the wax bite so you have a reference for overbite and overjet. Using a saw, cut between the distal of the most posterior teeth in the set up. The entire segment of teeth will then be free of the base and the remaining stabilized posterior teeth. Turning the segment over, you can cut from the bottom to just before the interproximal is reached. The individual tooth will break at the contact ready for resetting.
Using the Play-Doh, you can now set the teeth in any position easily moving them around as you determine what provides you the ideal set up for your restorative plan for overjet. Once you have one option established, you can take an impression of the “Play-Doh set up” for a “set” copy of it to reference and present to your interdisciplinary team. You can maintain the Play-Doh set up in a seal plastic bag in case additional options need to be evaluated.
Donna J. Stenberg D.D.S., M.S., P.A. Spear Visiting Faculty and Contributing Author. [www.stenbergorthodontics.com]