All clinical types of Class II, 2 have one thing in common: excessive deep bite, most frequently with a “tin lid” arrangement with the characteristic palatal tipping of the maxillary incisors. The severity of the clinical form is dependent on the predominant musculature at the level of both elevators and lower lip. A genetic footprint is present but the clinical picture is further complicated by dysfunctional problems.

The skeletal vertical pattern very often involves anterior rotation. However, this can vary, as can the sagittal dimension. The degree of dental and skeletal Class II depends upon the vertical and transverse locks as well as on the mesial drift of the maxillary arch following primary dystopia of the upper canines.

In all primary and functional Class II, 2, the musculature plays a crucial role from both etiological and therapeutic standpoints.