Microgenia is the medical term for an unusually small or deformed chin. The contrasting condition, an enlarged chin, is called "macrogenia". There are seven different chin deformities: Class I: Macrogenia (chin excess) Class II: Microgenia (chin deficiency) Class III: Combined excesses and deficiencies Class IV: Assymmetric deformity Class V: Witch's chin Class VI: Pseudomacrogenia Class VII: Pseudoretrogenia Class II microgenia is the most commonly encountered chin deformity, followed by class II macrogenia. .