Maitlen and Maizlen ae thought to be variant forms of Maitland, which transmuted from Mautalent to Maitland in Scotland between the 12th and 15th centuries.
Many early records in America were written down by people who were not familiar with the conventional spelling of a name, and spelt the names phonetically; the bearers of the names may not have been literate, and thus unable to determine the correct spelling. So a Scots emigrant registering in the eighteenth century in America might well have encountered an official of German or say Swedish origin, who wrote down what he heard. So, Metlin could be a variant of Maitland. At this stage we don't know. Visitwww.clanmaitland.org.uk for more information. There is a Maitlen web site as well