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 over erupt 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 placement 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.