Chin implant (fastened by screws) mandibular angle implants and boxing. Will this affect the implants?

It's a very good question but I have to say screws or not I think it's one or the other.  Boxing or the implants for now.  Once the implants are fibroused into place the screws become much less important but either way if you take a significant blow on that site it could be a real problem for you.  Why?  Not just because the implants could move (and they could) but because the implants and screws themselves will erode the bone a bit, which is normal, and thus create a situation where it's easier to fracture your mandible.Oh, and I agree with Dr. Palmer, screws aren't really needed once the implant has a capsule around it.  
Maybe just wait and keep boxing my friend.  Could you box with them in?  Yes.  But I'd wait.
Chase Lay MD
Retired amateur fighter and not-so-proud recipient of several ass-whoopins'

 Hi, I have performed many facial shaping procedures using dermal fillers, facial implants (cheek, chin), liposuction and/or facelifts for over 30 years.  Following my beauty principles, men look chiseled and handsome with angularity in the cheeks, chin and mandibular angles.  When the chin is weak, this creates an imbalance making the nose appear larger, the mid face top heavy, the lower face looks short, de-emphasizes the lips and allows early formation of a "double chin".  Proper placement of a silastic chin implant adds forward projection to the chin thereby creating harmony and balance to the lower face.  Using the same incision, liposuction can be performed to reduce the fat and further shape the neck.  Excess skin, from below the chin, can also be removed through the same incision.  I have found that placement of a silastic chin implant, through a small curved incision under the chin (also allows excess skin removal) to be very safe, quick, highly effective and far less invasive than a sliding genioplasty (requires extensive tissue dissection, bone cuts and placement of metal screws and plates to secure the cut bone segments).  I perform chin implant surgery in 30 minutes or less, often using a local anesthetic alone.   I have placed silastic cheek implants for 30 years in military, SWAT, LE, professional fighters, as well as actors and many regular people who are active.  When placed below the covering of the bone and when the layers of the cheek are closed from the inside out, there is no need for fixation screws or sutures in my humble opinion.  I do ask that all my cheek implant and chin implant patients sleep on a U-shaped pillow for 1 month following the surgery.  In addition, I have had the opportunity on numerous occasions to replace silastic implants (placed by others) that had been screwed into the cheek bone.  During the replacement it was evident that the metal screws pushed right through the soft implant as it was tightened down on the hard bone.  Which makes perfect sense.  So in the long run, these fixation methods alone are no guarantee that the implant won't move.  Proper placement, proper implant pocket creation and meticulous closure of all the tissues layers is what is required in my humble opinion. At 1 month the chin implant should be locked in place and shouldn't move.  Strenuous activity can be resumed at that time but direct contact to the chin should be avoided for another 1 -2 months.  Blunt force trauma can lead to bleeding around the implant which may cause inflammation in the post-opperiod.  The tissues should be fully healed at 3 months post-op if the implant was placed through the submittal approach (intra oral placement will take 4 - 6 months to heal and always have an increased risk of upward chin implant displacement). I have not heard of an incident when blunt force trauma has shifted a stable chin or cheek implant, however the jaw can be broken.  If the mandible is broken, below the implant, the bone fragments may shift which would mean the implant shifts as well.  As you know, this is a risk of the fighting profession. In contrast, mandibular implants must be stabilized with multiple screws, is an invasive surgery with a prolonged recovery and has unwanted side effects.  I prefer using a dermal filler to augment the mandibular angles which carries no such added risk. Hope this helps.