The word "microdentism" refers to the condition of having abnormally small teeth. It is pronounced /ˌmaɪkroʊˈdɛntɪzəm/ and spelled with the prefix "micro-" meaning small or tiny, and the suffix "-dentism" which refers to the teeth. The IPA transcription shows that the word begins with the "maɪ" sound, similar to the word "my," followed by "kroʊ" as in "crow," and "dɛnt" as in "dentist." The final syllable is pronounced "ɪzəm" with the emphasis on the second-to-last syllable.
Smallness of the teeth.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.