A 10-year-old girl complains of an aesthetic defect. She has a history of sucking her right thumb till the age of 7. Objectively: the height of the lower third of face is somewhat reduced. There is a 9 mm gap in sagittal direction between the upper and lower incisors, Engle's class 2. As a result of Eschler-Bittner test the girl's face appears at first better, then worse. What clinical form of occlusal anomaly is most likely?