First off, I really feel for you. I HATED the PAT section. With that said, I would retake it. While your TS and AA are fine, schools do not only look at these two categories. They will look at each section and as others have already mentioned, many schools have a cut off of 17 for each section. Besides the low PAT score, I would really work on bringing the RC score up. RC is important to many schools. Also, your science GPA is on the lower end, so you really want to prove yourself by doing amazing on the DAT.
You can definitely bring your PAT score up. When I first started studying for the DAT, I was getting 12s and 13s on the PAT section. I thought for sure that the PAT section was going to ruin my dreams of being a dentist, but after doing all of the Crack the PAT practice tests, I was able to pull off a 19 on the actual DAT. While my final score still wasn't great, it has not hindered me from getting interviews. I was lucky to interview at each school that I applied to. So honestly, if I can bring my PAT score up, you definitely can too. You don't want something as dumb as the PAT section to stop you from getting into dental school.
My suggestion to you is to get Crack the DAT PAT and reading. I am not a visual person at all. So i knew that I would never do fabulous on this section. I just wanted an 18, so I would stand a chance at getting into dental school, so this is how I improved my score:
I knew pattern folding was hopeless for me, so I practiced it-- but I spent the least amount of time trying to improve this area. Cube counting and hole punching on the other hand can be easily improved by the visually challenged. For cube counting, write 0-6 on a sheet of paper and put a tally next to each number for each cube that has that many faces showing. Then count them up and your done. You can very easily get a perfect score on this part of it. For hole punching, draw it out. Work through each problem step by step putting an x in the box where a hole would be. Again, you can easily get a perfect score on this part. Main thing with these two methods is you must work on your speed. You need to draw and write quickly. If you can do amazing on these two sections and mediocre on the rest of them you can easily get an 18+, which will look much better than your current 13. Good luck!! I am sure you can easily bring up PAT and RC and you will be glad you retook it!!