Jaw abnormality sagittally divides the face into five equal parts: It is insufficient to derive at a diagnosis of jaw deformity solely based on the clinical examination. Hence, additional information is gathered from diagnostic tests, which may include dental model analyses and radiographic imaging studies. Mandibular micrognathia is the condition when lower jaw is smaller than normal. Failure of the ramus to develop will give rise to micrognathia.<ref name="Elsevier/Churchill Livingstone"></ref> Micrognathia can be classified as either congenital or acquired. Clinical appearance of some patients with congenital type of mandibular micrognathia can have a severe retrusion of the chin but by actual measurements,
Jaw coupling in no torque being transmitted. When used with a stiff elastomer, the curved jaw design can maintain a zero-backlash fit required for many motion control applications. Zero-backlash curved jaw couplings are best suited for applications that rely on a stop-and-go type of movement, where accuracy needs to take place upon stopping in order to perform any number of precision tasks, such as taking a high resolution picture (machine vision system). Absorbing vibrations decreases the settling time the system needs, which increases through-put. The curved jaw coupling is less suited for applications that rely on a constant scanning type of motion,