Jantti is variant of Jentze. Jentze is German surname. On 16th century a vicar called Laurentius Laurentii Jentze moved to Rautalampi, Finland. Finns found it a bit difficult to pronounce Jentze so it became Jantti (with a dots), a Finnish surname.
At the beginning of the 20th century many Europeans, including many Janttis moved to North America. There are different family-branches in North America, but every Jantti moved from Finland are somehow related to each other. At least I think so..

tuuli

Hi Tuuli

I am still researching my family tree, but havn't been able to
get too much new information.
I wrote to you a couple of times,but didn't get reply.
Do you have a different email address now?
Yes, I have been told that all Jantti's are related. I guess i'll
have to visit Finland some day to do more research.