<p>To elaborate on what ucbalumnus said, there are a couple of ways in which it can matter. (And if you’re planning on a career in dentistry, none of them is likely to affect you.)</p>
<p>Many large universities have many divisions. They may be called “divisions” or “colleges” or “schools,” but the point is, the larger university is broken into parts. There may be, for example, a School of Health Sciences, a School of Engineering, a College of Arts & Sciences and a School of Education. Some of these may be more competitive than others, so it’s possible that if you want to become an electrical engineer, the School of Engineering’s admissions standards are higher than the standards you’d be held to if you wanted to become an elementary school teacher, and you were applying to the School of Education.</p>
<p>But if you want to become a dentist, you’ll probably find it easiest to major in one of the sciences, and all of the sciences would be in the same division, so this wouldn’t be likely to be an issue for you most places.</p>
<p>Another way that one’s choice of major could matter is that some universities and colleges cap the enrollment in very popular majors because they get more academically qualified applicants for these programs than they can accommodate. The University of California system calls them “impacted majors”; The University of Maryland calls them “limited enrollment programs.” Whatever the name, the point is that gaining admission to these programs is more competitive than gaining admission to the university at large.</p>
<p>If you want to become a dentist, you’ll need to complete certain required courses in the sciences during college. You could actually do that while pursuing almost any major, but most pre-medical and pre-dental students find it’s easiest to major in one of the sciences, so that they can count most of their pre-professional classes for their major as well. But whether you choose biology or chemistry or something else, they’re all likely to be in the same division of the university, and none of them is likely to limit enrollment.</p>
<p>So the answer to your question seems likely to be, “No, in your case the choice of a major won’t matter.” And, honestly, despite everything that I’ve said above, that’s most people’s answer. Because administrators at universities and colleges know that the majority of graduates leave college having majored in something other than what they’d planned on when they entered.</p>