Can malocclusion cause a lisp?

Yes: Teeth that do not meet correctly or harmoniously may not allow for the proper lip support or tongue movement that allows for proper enunciation.

It's possible: Lisps are usually caused by air escaping between your teeth where there are spaces. If you have not had any dental changes and your lisp just recently appeared then the answer is that it probably did not contribute to it.

Yes: Developmentally, when speech patterns are learned, the relationship of front teeth can have a marked impact upon speech pathology. Tongue placement is influenced by the teeth relationships, and s's and th's are very common problems that are seen with anterior malocclusions.

Yeth: Tip of tongue is supposed to sit behind upper front teeth, on the roof of the mouth, when making soft-c or s. If upper jaw too narrow, open bite, large horizontal overbite, upper jaw too far forward or lower jaw too far back child may have anterior list. If upper jaw too narrow, or if back teeth don't meet vertically, child may have lateral lisp. See both orthodontist & speech pathologist.

Yes: If there is a space or spaces between your upper and lower front teeth, it will allow air to escape and cause the lisp if your tongue can not compensate and close the gap.

Definitely, yes: Malocclusion means the teeth are not aligned properly. Speech difficulties that are rare including lisp may be a symptom of the malocclusion.