Fig. (2) Diagram showing the cranial base angle (θ), the synchondrosis (SOS) and the jaw relationship. The growth in SOS affects θ and the relative jaw positions x₁, x₂ horizontally and y₁, y₂ vertically. If θ is small, the mandible is relatively more anterior with the maxilla. Conversely, if θ is large, the mandible is relatively more posterior with the maxilla.