microstomia microstomia microstomia is a small mouth (micro- a combining form meaning small + -stomia a combining form meaning mouth = (abnormally) "small mouth" in greek.) microstomiaacquired microstomia from congenital syphilisspecialtymedical genetics congenital it is a feature of many craniofacial syndromes, including freeman–sheldon syndrome and sheldon-hall syndromes (or distal arthrogryposis multiplex congenita). it may present with whistling-face feature, as well, as in freeman-sheldon syndrome. in this syndrome, it impairs alimentation and may require repeated oral surgeries (called commissurotomy) to improve function. acquired microstomia can occur as a result of scarring due to many conditions. it is seen as complication of facial burns. it can also be a feature of systemic scleroderma.