What size and type of a chin implant do you recommend?

A rough guess would be a medium anatomical silastic implant. However, the surgeon you chose would be wise to have several different "sizers" to try during the actual procedure to see which one looks best. Another factor to consider is the fact that you have a very defined "sublabial groove", which corresponds to the internal attachment of your lower lip to the gum. So it is important not to increase the chin projection too much or it would produce a "witch's chin" deformity.

Your pictures demonstrate a mild to moderate form of microgenia (Latin for small chin). I recommend a small or a medium implant and the use mini-titanium screws to secure the implant to the jaw bone. I prefer to use a contouring device that allows me to better fit the implant to your face. What is commonly referred to as "wings" can be sculpted in a similar fashion to improve the transition between the implant and the bone for a more natural look and reduce the "over-augmentation" that can occur with wings if they are not secured to the bone. Make sure you review plenty of photos prior to your procedure.

Chin implants are manufactured in a variety of sizes and shapes by a variety of manufacturers.  A size medium might be a size small from a different company. In our practice,we use mostly size small and medium implants manufactured by Implantech.  We place the implants  through a sub mental incision, not the intra-oral  route. For many examples and more information, please see the link and  video below