It has been and is my experience that structure and style changing over time are due in large part to editors who's charter is to "reflect" their readers' ear. The tenets of Japanese haiku (Shiki's coinage) having a key linguistic component, the cutting word or phrase, prevents on the most part, haiku from being grammatically structured as a complete sentence. This, restriction, transfered to non-Japanese poems can, at times, manifest itself as complete sentences in other languages (since, for example in English, there is no grammatical equivalent to represent the impact of the Japanese cutting word or phrase, that is to say, it is very difficult to represent an equivalent).
That said and my mantra, "if it ain't Japanese it ain't haiku", I agree with Al and John, "sentencing" is a matter of style and whim. I readily admit to shun sentence structure in the short English poems I write and try to adopt the haiku equivalents for kireji (cutting word or phrase), thus, avoiding using a sentence.
But, I recommend and encourage you to explore and gather your own conclusions and develop your own style(s).