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,
Phossy jaw Phossy jaw Phossy jaw, formally known as phosphorus necrosis of the jaw, was an occupational disease affecting those who worked with white phosphorus (also known as "yellow phosphorus)" without proper safeguards. It was most commonly seen in workers in the matchstick industry in the 19th and early 20th centuries. It was caused by white phosphorus vapour, which destroys the bones of the jaw. Modern occupational hygiene practices have since eliminated the working conditions that caused this disease. Those with phossy jaw would usually begin suffering painful toothaches and swelling of the gums. The pain was characterized as "persistent yet progressive