However, caution should be taken when using vacuum-form retainers with respect to the occlusion especially when only one arch has been treated orthodontically. Open bites, both anterior and posterior, may be created with a vacuum-form retainer as this type of full-coverage retainer may allow selective teeth to overerupt and thus create more orthodontic problems. When a patient does not plan to have implant treatment immediately, resin- bonded bridges or transitional all-acrylic partial dentures are also acceptable options that satisfy the goals of retention, function and esthetics. The length of time in retention prior to implant place- ment will depend on the orthodontic treatment that was completed. For example, if significant rotations were corrected orthodontically, longer or possibly permanent retention may be required.