Also, changes could be made to official styles without damaging already extant items except when these items were re-adapted. The chief royal sculptor, responsible for oficial images of the king, usually developed at least one "court style" but styles often varied from one dynasty to the next, and two or more styles often evolved during a single dynasty or even a single reign.
Several forces could result in a new style. A pharaoh's death could motivte the chief royal sculptor to devise a fresh "standard" for depicting his successor. The replacement of one chief sculpture by another might also inspire innovation. Or perhaps young carvers reacted to the teachings of the chief sculptor, introducing subtle modifications that, over time, became an entirely new style.
After excavating hundreds of sculptures, nineteenth-century archaeologists recognized that a large number of Egyptian stone statues have broken noses. Egyptologists still find mutilated statues in sealed tombs that have not been disturbed for millennia, indicating that the breakage occurred in ancient times. There are several explanations for this phenomenon.
Falling-forward (accidental) breakage.
The most practical explanation is that when a statue falls forward, the nose is the first point to hit the ground.
Intentionally nullifying the statue.
Many statues show evidence of deliberate disfiguring with a hammer and chisel. Ancient Egyptians believed that tomb statues could be transformed into living beings through a funerary ritual called the Opening of the Mouth. The "living statue" then served as an eternal home for the deceased's soul. Smashing the nose effectively "killed" the statue.
A tomb robber or a person anxious to destroy the soul of a dead enemy simply broke the statue's nose to prevent the deceased from exacting revenge. Also, certain crimes in Ancient Egypt (ie, perjury, temple robbery) were punished by cutting off the culprit's nose. Perhaps some damaged statues belonged to individuals whose crimes were discovered and punished posthumously.
An urban legend surrounding the Great Sphinx says that when Napoleon invaded Egypt in 1799, he chose the Sphinx's face as the target for his artillery's practice. However, long before that time, numerous renderings of the Sphinx showed that its nose was already gone (ie F L Norden, Travels in Egypt and Nubia, drawn in 1755 and published 1757). According to several medieval Arab authors, the Giza Sphinx was defaced in 1378 by a Sufi zealot nammed Mohammed Sa'im al-Dahr who felt the statue was sacrilegious.