Primer aligner stages for lag issue resolution in low-stage clear aligner treatments
A set of primer appliances and a set of treatment appliances to be worn by a subject are provided. The primer appliances are first worn to prepare the local environment of the teeth for further repositioning of the teeth by the treatment appliances. The primer appliances may apply compression to the periodontal ligament, in a direction favorable for achieving the desired final position of a tooth. The compression may generate a biological response in the local environment of the teeth. The primer appliances may cause minimal or no repositioning of the teeth. The treatment appliances are worn to reposition the teeth from an initial position to an end position of a treatment stage. The primer appliances can improve the efficiency and accuracy of tooth movement by the treatment appliances.
1. A method for repositioning teeth of a subject, the method comprising:
generating an orthodontic treatment plan including a primer stage and a plurality of treatment stages for a first selected subset of teeth of the subject, by:
generating the plurality of treatment stages to incrementally move the first selected subset of teeth along respective tooth movement paths with a first rate of movement and not move a second selected subset of teeth, each of the plurality of treatment stages including one of a plurality of intermediate tooth arrangements in a repositioning of the first selected subset of teeth from an initial position towards a target position, wherein an initial intermediate tooth arrangement of the plurality of intermediate tooth arrangements is in a repositioning direction along a respective tooth movement path; and
determining geometries for one or more primer appliances for a primer stage, wherein the one or more primer appliances comprise: (a) a first plurality of teeth receiving cavities shaped to receive the first selected subset of teeth for repositioning by applying a force or torque to the first selected subset of teeth sufficient to induce a biological response of support structures of the first selected subset of teeth and (b) a second plurality of teeth receiving cavities shaped to receive and enhance an anchorage of the second selected subset of teeth, wherein the first selected subset of teeth are moved with a second rate of movement that is smaller than the first rate of movement; and
providing the one or more primer appliances to be placed on a plurality of teeth of the subject during the primer stage to prepare the support structures of the first selected subset of teeth for repositioning.
2. The method of claim 1 , wherein the one or more primer appliances are provided during an intermediate portion of treatment before a movement phase of the first selected subset of teeth.
3. The method of claim 1 , further comprising providing a plurality of appliances of an intermediate portion of treatment corresponding to the plurality of treatment stages for the first selected subset of teeth of the subject, the intermediate portion of the treatment comprising a plurality of repositioning stages.
4. The method of claim 1 , further comprising providing one or more finishing appliances for use in a finishing stage of treatment.
5. The method of claim 1 , wherein the one or more primer appliances lower resistance of a tissue of the subject to the repositioning of the first selected subset of teeth with a plurality of repositioning appliances.
6. The method of claim 1 , further comprising:
placing the one or more primer appliances on the plurality of teeth; and
placing one or more repositioning appliances on the plurality of teeth, wherein the one or more primer appliances are placed prior to the one or more repositioning appliances so as to reduce distortion of the one or more repositioning appliances when placed on the plurality of teeth.
7. The method of claim 1 , further comprising:
testing gingival crevicular fluid of the subject and determining the concentration of one or more of tissue necrosis factor, insulin-like growth factor, macrophage colony stimulation factors, and parathyroid hormone; and
determining that the biological response of the support structures has been induced based on a change of concentration of the one or more of tissue necrosis factor, insulin-like growth factor, macrophage colony stimulation factors, and parathyroid hormone in the gingival crevicular fluid of the subject.
8. The method of claim 1 , wherein the support structures comprise a periodontal ligament.
9. The method of claim 1 , wherein the second rate of movement is zero.
10. A method comprising:
identifying an orthodontic treatment plan including a primer stage and a treatment stage, the treatment stage moving a first selected subset of teeth of a subject and not moving a second selected subset of teeth of the subject, the primer stage including a plan to apply a first force on a particular tissue of the first selected subset of teeth without moving the first selected subset of teeth, and the treatment stage including a movement plan to move the first selected subset of teeth from an initial position towards a target position and not move the second selected subset of teeth;
determining geometries for one or more primer appliances to implement the primer stage, each of the one or more primer appliances comprises: (a) a first plurality of teeth receiving cavities shaped to receive the first selected subset of teeth to apply the first force on the particular tissue of the first selected subset of the teeth, thereby pre-conditioning the first selected subset of teeth to be moved in accordance with the movement plan at a first rate of movement and (b) a second plurality of teeth receiving cavities shaped to receive and enhance an anchorage of the second selected subset of teeth; and
providing one or more aligner appliances to implement the treatment stage, each of the one or more aligner appliances configured to move the first selected subset of teeth from the initial position towards the target position at a second rate of movement that is greater than the first rate of movement and not move the second selected subset of teeth.
11. The method of claim 10 , wherein the particular tissue is a periodontal ligament of the first selected subset of teeth.
12. The method of claim 10 , wherein the first force has a value sufficient to elicit a biological response from the subject to facilitate repositioning of the first selected subset of teeth during the treatment stage.
13. The method of claim 10 , wherein the first force comprises a compression force on the particular tissue.
14. The method of claim 10 , wherein the first rate of movement is zero.