This is what I found from AADSAS site:
SUBMITTING YOUR OFFICIAL LETTERS OF EVALUATION/RECOMMENDATION TO AADSAS
1. Applicant Submits Official Letters of Evaluation/Recommendation
Request your Letters of Evaluation/Recommendation as early as possible to give your evaluators/recommenders sufficient time to respond to your request and to return the official Letters of Evaluation/Recommendation in a sealed envelope with the evaluator/recommender?s signature written across the envelope flap.
Letters must be submitted on official stationary and signed by the evaluator/recommender.
AADSAS will not process any Letter of Evaluation/Recommendation that exhibits evidence of tampering.
2.
Evaluator/Recommender Submits Letters of Evaluation/ Recommendation Directly to AADSAS
Official Letters of Evaluation/Recommendation may also be sent directly to AADSAS by the evaluator/recommender. When letters of evaluation/recommendation are sent directly from the health advisor?s office or individual faculty members, applicants should follow these additional instructions. An AADSAS Letter of Evaluation/Recommendation Matching Form must be downloaded and printed. Complete the form and submit it to your health advisor or individual evaluators/recommenders to request that your official Letter(s) of Evaluation/Recommendation be forwarded to AADSAS. Ask your health advisor or evaluator/recommender to attach the AADSAS Letter of Evaluation/Recommendation Matching Form to the letter. If your Letter of Evaluation/Recommendation is under a different name than the one on your AADSAS application, AADSAS will not be able to match the Letter of Evaluation/Recommendation with your application materials without the Letter of Evaluation/Recommendation Matching Form. The omission will delay the processing of your documents being mailed to the dental schools.
Please do not request that the Letters of Evaluation/Recommendation be sent to AADSAS before June 1.
So I guess you don't need to unless the evaluator(s) sends it directly to AADSAS. But it won't hurt if the matching form is attached no matter which option you choose.