Lord Buddha's head and facial expression has deep meaning.
The Buddha head statues are normally depicted with curly, short hair, in order to show that the prince Siddhartha had cut off his topknot to renounce his prince-hood and his privileged past.
Though the historical accounts and evidences suggest the Buddha had a shaved head, the hair of Buddha head statues is neither totally shaved nor long, representing Buddha's path of the middle i.e. life between the extremes of indulgence and mortification.
Generally, the Buddha head statues are depicted with a protruding head, which symbolises the disconnection between the mind and body. Such state is also known as Bodhisattva.
Similarly, Buddha heads are also known to have another protuberance, on the top of the Buddha's head, known as the Ushnisha, which is a three-dimensional oval at the top.
The ushnisha represents the attainment of the Buddha's enlightenment and his reliance in the spiritual guide, though the original function of the ushnisha may have been to represent a crown on the Buddha's head.
The facial structure of the Buddha heads usually have half-closed eyes which show a state of meditation, looking inward into the self as well as outward. It signifies looking beyond materialistic things and only towards the truth.
The faint smile on the statue also depicts the serene nature and nobility of the Buddha after attaining enlightenment.
A dot between the eyes, or the urna, is also another peculiar feature of the Buddha heads. It signifies to the devotes to inculcate ethical behaviour, indulge in meditation, be generous, make offerings and free oneself from materialistic provocations. This round tuft of hair between the eyebrows symbolize the supernatural vision of the Buddha with the ability to see past our mundane universe of suffering.
Though elongated earlobes in the Buddha heads represent the Buddha's hearing power which is believed that he hears what is needed in the world, the exact reason behind is elongated earlobes may be due to the vestiges of his life as a prince, when he wore extravagant and heavy jewellery and earrings on his ears.
Buddha heads are therefore an icon of confidence, awareness, knowledge, compassion and concentrated meditative practices.
These are the meaning la,