Geoff Lim photographed a Javan Myna (Acridotheres javanicus) with a deformed upper mandible at Gentle Drive, Singapore. The myna is still healthy, meaning that it is still able to forage and find food.
Unfortunately the image was taken with a hand phone and thus the deformed mandible is not that obvious in the image above.
An earlier post shows a Common Myna (A. tristis) with a deformed bill HERE. The post also refers to other species with deformed bills and discusses the causes and consequences of such deformities.