ther is no medical term "otomy" the correct term ist tomia (tomy) the "o" is just a binding vowel to connect this word to the organ to be cut, e.g. Bronchus and tomie -> bronchotomy. This is true for other comopsite words like bronchoscopy ... --Uwe Gille (talk) 09:13, 12 January 2015 (UTC)
Several usages of "otomy" as a free morpheme -- as a medical term beyond merely a suffix -- can be seen in this Google Scholar query. Tomy and tomia are no more medical terms than otomy -- all are typically suffixes.
But try a Google search for tomy, tomia and otomy. Only the last returns relevant results; thus "otomy" is the preferable morpheme for this template. Emw (talk) 02:14, 13 January 2015 (UTC)