Can an oval face get sharp, square jawlines with mandibular angles? Lipo on jaw and chin implant or genioplasty? (Photos)

 Hi, in your particular case it would require adding volume to the mandibular angles in order to create angularity and flare in the jaw line.  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.  From the photos, your cheeks are blunted by a slight excess of fat below the cheeks, the chin doesn't appear to be weak (this can be confirmed with a profile view), however the mandibular angles are indeed weak.  This combines to create an elongated rectangularly shaped face.  The following procedures would create a more ruggedly handsome face.
  Liposuction can reduce any excess fat to further shape the cheeks and face.
If the chin is indeed weak, Chin augmentation, using a chin implant, to add projection to the chin creating harmony and balance to the lower face.  I have performed many facial shaping procedures, including Chin Augmentation with dermal fillers or silastic chin implants, for over 30 years.  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.  In my opinion, you are a good candidate for chin implant surgery.  
Augmentation of the mandibular angles using a dermal filler (jaw implants have too many unwanted side effects IMHO) to add volume, angularity and flare to the jaw line.
Hope this helps.
 

Dear BackDoorMan, A set of profile and frontal photographs of yourself would be helpful in determining candidacy and proposed results with these procedures. With that said it is possible to achieve a strong jawline and a balanced profile with a combination of techniques as shown in the video and link below. Best regards, Michael V. Elam, M.D.