Not grammatically. When writing prose or nonfiction you shouldn't use line breaks, but rather full paragraphs. Whomever does the final layout will add line breaks to correct or avoid hyphenation errors, avoid columns of white space, or other typographical artifacts distinct to the actual layout.
When you're writing, there is no medium level of separation between a "sentence" and a "paragraph". Two sentences are either part of the same paragraph or they aren't -- although the rules are different for poetry and signage.
(Also, be aware that an editor may separate a paragraph for purely ascetic reasons. A paragraph that goes on for three pages may be grammatically correct, but it's physically hard to read and should be separated.)