Help:i'm formulating a thesis title regarding how the structure of the speech organs affect our pronunciation.

It's all about Phonetics. Without more information it's hard to give you a complete answer to your question. However, my advice to you is to head to the local library and get a book on introductory Linguistics. There is usually a chapter related to which organs are directly related to how we form sounds and words, and what their role is. It's pretty dense material, but easy to find... Most books have pictures and diagrams as well...