Final answer:
Angular cheilitis is the condition that involves splitting of the lips and corners of the mouth, distinguished from other similar conditions like cleft lip and infections such as oral thrush and herpes simplex.
Step-by-step explanation:
Condition Characterized by Splitting of the Lips and Angles of the Mouth
The condition characterized by splitting of the lips and angles of the mouth is known as angular cheilitis. This condition can involve cracks or sores on the outer surface of the lips, known as cheliosis, and can also be associated with inflammation and redness of the tongue, as well as a skin condition called seborrheic dermatitis. Unlike cleft lip, which is a developmental defect presenting a gap or cleft in the upper lip, or oral thrush and herpes simplex, which are infections that cause lesions in and around the mouth, angular cheilitis specifically refers to the inflammation and cracking at the corners of the mouth.