Dr. Rob Veis Problem: Lower Anterior Crowding. Solution: Crowding of 1.5 mm or less can usually be corrected with a Spring Hawley Retainer. One of the most common problems that adult patients ask their dentist about is crowding of the lower anteriors. Correcting this problem can often be easy if you take the time to carefully evaluate the severity of the crowding and the relationship of the upper and lower anteriors to each other in occlusion. In the clinical case shown here, a minimum amount of lower anterior crowding occurred because the patient did not wear his final retainers after completing his orthodontic treatment. Although this crowding may not appear serious, once the intexproximal contact points have been broken, the drifting and crowding will only get worse over time if left untreated. When crowding of the lower anteriors is 1.5 mm or less, it can usually be corrected by recontouring the interproximal enamel of each tooth from cuspid to cuspid and placing a retainer called a Spring Hawley retainer. This appliance is useful in correcting minor rotations of lower or upper anterior teeth. Its spring action works by directing light labial-lingual forces to align the teeth.

Treatment procedures:

1. Start by taking a set of accurate alginate impressions and pour them up in yellow stone.
   
2. Take a centric occlusion bite relationship to assure that the lab will be able to accurately articulate the models.
   
3. Evaluate the severity of the crowding and rotation of the anteriors. The rotation must be minimal and the crowding should be within the 1.5mm or less criteria to be successful.
   
4. Evaluate the relationship of the upper and lower anteriors to each other. If the patient's bite relationship is too deep and the lower anteriors already make contact with the upper anteriors, you will not be able to move them, regardless of the amount of recontouring performed or force exerted by the appliance.
   
5. Fill out your lab slip completely. Write Lower Spring Hawley Retainer #1065 and make sure to tell the lab which teeth you intend to re-contour.
   
6. When the lab receives your models, they will reset the anteriors and align them to your specifications. The Spring Hawley retainer is then made to this pre-set ideal position.
   
7. On the day of delivery of the appliance, and not before, re-contour the enamel. This will allow the teeth to be guided into the ideal position pre-set by the appliance.
   
8. Tooth movement with this appliance is rapid. Once it is accomplished, the appliance can continue to be worn as a final retainer.