The development of new jaw angle implant styles has finally allowed augmentation of the back part of the jaw to get caught up with that of the chin. The jaw angles have been overlooked for a long time as implant styles and sizes of the chin have progressed. With the chin and jaw angle implant styles that are now available the entire jawline can be augmented in the properly selected patient.
With newer jaw angle implant styles, it is important that the indications for their use are clear. Traditionally jaw angle implants really only provided width to the mandibular ramus. They were designed to sit on the bone on its natural shape, thus increasing its lateral projection. Making the jaw wider is an effective aesthetic strategy provided the mandibular plane angle is not too high. If the jaw angles are within 2 cms or lesss from the earlobe they would be considered high jaw angles. A high jaw angle that is made wider can potentially make the face look too full or chunky and not create a more defined and stronger jawline.
This is a 3D CT example of this exact mismatched jaw angle implant problem. This patient has very high jaw angles and a steep mandibular plane angle. While these widening jaw angle implants are reasonably well placed over the rami the patient developed an undesired facial appearance as the enhanced jaw angles remained too high.
Newer styles of jaw angles help vertically lengthen the lower border of the mandibular ramus to treat the high jaw angle patient. This is a very unique facial implant style as a portion of the implant sits off of the bone to create its effect. As much as one third of the implant does not sit on the bone. In lowering the jaw angle it becomes more visually defined and the lower face appears more filled out in the front view. Vertical lengthening of the jaw angle is the most assured way to create a more visible back part of the jaw as it effectively corrects a bone ‘deficiency’. (missing part of the jaw) However one must be careful to not over lengthen the mandibular ramus as it can also make the lower face look too heavy in the patient who has a normal mandibular plane angle.
This is a 3D Ct example of jaw angle implants that provide vertical lengthening. A portion of the implant design is off the bone to both lower and make more prominent the jaw angle shape at the back of the jaw. This is the appropriate jaw angle implant style for the high jaw angle patient.
Jaw angle implants today come in both widening and vertically lengthening styles. Each style does add some of the opposite dimension as well. Widening angle implants can add a little vertical length based on how they are positioned. Conversely the design of the vertical lengthening implant has built in width that increases the more it lowers the jaw angle
Like all facial implants not every standard shape and size works well for every patient. Significant jawline asymmetry, postoperative orthognathic surgery bony changes of the ramus and aesthetic dimensoonal needs beyond standard sizes are all reasons to consider custom jaw angle implant designs.
Dr. Barry Eppley