The significance of the dot on forehead of an unmarried woman is to indicate she is devoted to Lord. After marriage it is to ostentatiously convey her sole devotion and duty towards her husband as an image of the Lord to facilitate her spiritual growth. The dot is not worn when the woman becomes a widow symbolizing that she is no more interested in worldly beauty and released from worldly duty. Now the widow exclusively lives life of prayers and spiritual studies like a monk.
Dot on forehead is applied by men as well as women and other reasons for the dot are as follows.
Exactly behind the region of dot, which is in between the brows, in the brain, is located the Pituitary gland, which is the Queen of the endocrine glands of the human body, controller of emotions and well being.
When you look at the face of person with dot the attention rivets on the dot thus disfigurement of the face, the like and dislike thus triggered is out of focus.
When spiritual masters communicate with the devotees who are also bearing dot on their forehead as the spiritual master does there is kind of intuitive transmission of knowledge.
It is the same colour and material that is applied to the Lord during daily prayer and this mark of auspiciousness is applied on one’s forehead after every prayer of the Lord. It helps rememberance of Lord.
It is reminder of good faith for both the speaker and the listener and augers well for holiness in day to day transaction.
If nothing at all of this is acceptable you may consider it as a mark of beauty.