A couple of things I've noticed in the statements I've read so far:
1. Use "oral and maxillofacial surgery" once followed by "(OMFS)", then substitute OMFS for the remainder of your statement. Same goes with other long references, like the name of your dental school or STFU.
2. Avoid using prepositional phrases where possible because they are hard to read on the computer in my room at my desk in my house in my city in my state on the planet earth. Get it?
3. Resist the false and tempting belief that passive voice sounds good. For example, it would be akward if I said, "That the passive voice sounds good is a false and tempting belief that should be resisted". Once or twice is fine, more than that wears me out.
4. Subjects and verbs must agree.
4b. Use a subject and verb in each sentence.
5. Demonstrative pronouns (this, that, these, those) and interrogative pronouns (which, what) must be used carefully. I'd better be able to, at a glance, figure out their antecedent. If the reference is broad, replace the pronoun with a noun or give the antecedent. For example, "your personal statement blows ass, which accounts for your inability to match" is not as good as "your personal statement blows ass, accounting for your inablility to match", or "your personal statement blows ass, a fact which accounts for your inability to match".
6. Watch out for run on sentences.
