Reduction of prominent jaw angles can be done by two different surgical techiques based on the dimensional changes needed. The most common technique in most Asian patients is a full thickness removal or bicortical removal of the jaw angle extending forward to the chin. The key to this full thickness bone cut is for it to be made below the course of the inferior alveolar nerve within the bone and for it to be symmetric on both sides.
While such mandibular bone cuts may sound relatively simple they are not. They are most commonly performed through an intraoral approach for aesthetic reasons. Making such full thickness bone cuts at 90 degrees from inside the mouth with limited vision has its challenges. Any technical strategy that makes performing this surgery in a more predictable and symmetric fashion is welcome.
In the October 2019 issue of the Journal of Craniofacial Surgery, an article was published entitled ‘Three-Dimension–Printed Surgical Guide for Accurate and Safe Mandibuloplasty in Patients With Prominent Mandibular Angles’. In this paper the authors present their experience using a 3D-printed surgical guide that fits onto the mandible for use as a bridge between simulation and actual surgery. The use of this 3D design guide was used in 7 patients for the reduction of their prominent jaw angles.
Using the patient’s 3D CT scans, a 3D printer was used to make the surgical guides. The surgical guides were designed to fit the lower border of the mandible and to cover the portion planned for removal.The resulting personalized 3D-printed surgical guides were applied on both mandibular angles to the body and along the lower border of the mandible. Full thickness bone cuts of the mandibular angle and body were performed along the applied surgical guide. All patients had an uneventful recovery without ay surgical complications.
Like all facial osteotomies that require bilateral surgery, the performance of the bone cuts is highly dependent on the surgeon’s experience and technique. Because of the ‘dominant handiness’ of the surgeon it is very easy to make inadvertent asymmetric bone cuts. A 3D printed surgical guide designed for each patient assures the proper level of the bone cut and its symmetric placement. The only issue is the cost per patient to design and fabricate the guide.
Dr. Barry Eppley
Indianapolis, Indiana