For those of you who don't know thumb rings are rings worn on the thumb rather than any of the other four fingers. Thumb rings can and are worn by both men and women. The thumb is connected with a person's compel of will both for themselves and how strongly they work on others.
Esoterically the custom of wearing a thumb ring means you're whether trying to emphasis your independence and individuality or inhibiting some aspect of the self. I guess its anything you feel like or you may be doing both.
Historically, (ie, the 1500's) wearing a thumb ring meant you were a doctor or pretending to be one. Also, centuries ago women would wear their husbands wedding rings on their thumbs when they left for battle or died.
You can also select which thumb to wear a thumb ring on. To wear a ring on the left hand is a reflection on the subconscious or your instincts, beliefs, and basic attitudes. To wear a ring on the right is a focus on the conscious, reflecting logic, awareness, and the material world. More recently to wear a thumb ring on the right indicates that you are into same sex relations.
Many habitancy seem to be involved about whether or not its okay for them to wear a thumb ring. I say forget the current trend in meaning and wear one if you want because it enduringly changes. Interestingly thumb rings are regularly interchangeable with your index or middle finger. They are also more comfortable when worn on the non-dominant hand.
Currently thumb rings are sold anywhere from gumball machines to upscale jewelry manufacturers. They can be made of plastic or platinum and made in a simple band or justify framing with braiding, or shapes like hearts inside.