Jaw Augmentation in a 24-Year-Old Patient | Dr. Parsa Behnia

A 24-year-old male patient presented with the chief complaint of improving the proportion and definition of the lower third of the face. Clinical examination and radiographic evaluation revealed no significant skeletal deformity or soft tissue deficiency. Nevertheless, the patient desired increased chin projection and enhanced mandibular angle definition. Based on the patient’s aesthetic goals and the surgeon’s assessment, advancement genioplasty combined with bilateral mandibular angle augmentation using patient-specific implants (PSIs) was planned. The patient was subsequently referred for the design and fabrication of customized mandibular angle implants.

Physician profile

Dr. Parsa Behnia

Oral and Maxillofacial Surgeon
Board-Certified, Shahid Beheshti University

Pre-operative Planning

To ensure accurate implant design and optimal adaptation to the patient’s anatomy, preoperative planning was performed using computed tomography (CT) data. The DICOM images were imported into specialized biomedical engineering software, where a three-dimensional reconstruction of the patient’s craniofacial skeleton was generated.
Initially, key skeletal and anatomical landmarks were identified as reference points, and the facial midsagittal plane was established. This enabled a comprehensive evaluation of skeletal relationships, facial proportions, and the corrective requirements of the mandible and chin.
Virtual surgical planning of the genioplasty was then performed according to the proposed treatment plan. A wedge resection genioplasty was designed, incorporating approximately 6 mm of bony reduction and 8 mm of chin advancement. The osteotomy line was planned at the level of the mandibular first molar region (mesial to the first molar). Following removal of the wedge-shaped bone segment, the mobilized chin segment was advanced anteriorly and rigidly fixed in its new position to improve chin projection and optimize the facial profile.
Following determination of the final chin position, the mandibular contour and jawline were re-evaluated. Bilateral patient-specific mandibular angle implants were subsequently designed to achieve harmonious lower facial proportions and a continuous mandibular contour. In addition to improving the overall balance of the lower third of the face, the implant design incorporated augmentation of both the mandibular angle and the ramus.
According to morphometric analyses and aesthetic studies, the average mandibular width-to-bizygomatic width ratio in males is approximately 0.72, whereas an ideal aesthetic facial skeletal ratio has been reported to be approximately 0.78. In the present patient, the measured bizygomatic width was 13.2 cm and the mandibular width was 9.7 cm, resulting in a ratio of approximately 0.73, which is consistent with the reported male average. Accordingly, 3 mm of lateral augmentation was selected as the optimal amount to improve the mandibular width ratio and enhance the contour of the mandibular angle.
Following verification of anatomical adaptation, evaluation of aesthetic parameters, and final approval by the operating surgeon, the definitive design was finalized for fabrication of the customized implants.

Identification of the facial midsagittal plane based on anatomical landmarks

Design of the patient-specific implants according to the patient's anatomy while preserving facial symmetry

Virtual simulation of genioplasty and design of bilateral mandibular angle implants

Surgical Treatment

Considering the aesthetic nature of the procedure and the importance of avoiding visible facial scars, surgery was performed through an intraoral approach. After adequate surgical exposure was obtained, the two patient-specific mandibular angle implants were positioned according to the preoperative virtual plan.
Taking into account the position of the mandibular angle implants and their influence on the final facial contour, the osteotomy and repositioning of the genioplasty segment were further optimized intraoperatively based on the newly established jawline and inferior mandibular border, thereby achieving optimal harmony between chin projection and the reconstructed mandibular contour.
Once the desired result had been achieved, rigid fixation was performed using titanium screws. The mandibular angle implants were secured using a trocar-assisted screw fixation system, allowing accurate implant positioning and stable fixation. After confirming implant stability and satisfactory lower facial contour, the mucoperiosteal flaps were repositioned and the surgical wounds were closed in layers.

Accurate registration of the patient-specific implants on the mandibular surface and chin advancement

Post-operative Follow-up

Following placement of the customized mandibular angle implants and advancement genioplasty, the patient had an uneventful postoperative course and remained in stable condition. Postoperative clinical evaluation demonstrated excellent adaptation of the implants to the surrounding anatomical structures, stable fixation, and no significant complications.
Treatment outcomes showed a marked improvement in the contour of the lower third of the face, enhanced jawline definition, and improved proportionality between the chin and the mandible. Clinical examination also demonstrated good bilateral facial symmetry and a smooth, continuous mandibular contour.
The operating surgeon expressed complete satisfaction with the final outcome and emphasized that the use of digital surgical planning and patient-specific implants enabled predictable, reproducible results that closely matched the patient’s aesthetic objectives.