The aim of this article was to present a new computer-assisted genioplasty technique for the correction of chin asymmetries. The application of digital design technology compared to conventional techniques can provide various benefits for both surgeon and patient. Becoming more accurate and more predictable surgical outcomes and reduction in operating time are among significant advantages that are certainly of particular importance to surgeons.
Compared to previous conventional methods, this method has several advantages including more precise osteotomy and exact locating of adjacent sensitive structures such as mental nerves and roots of teeth, which is very important in reducing possible damage. However, it should be noted that the use of such a technique will not necessarily be effective in treating all deviations and asymmetries of the chin or mandible. The most important point in this regard is the comprehensive clinical and radiographic evaluation of the patient in order to accurately identify the etiology of deformity and then decision-making on the treatment plan. Certainly in cases where there are significant dental abnormalities and TMJ dysfunction, ignoring these problems and using this technique solely to correct the patient’s appearance is completely rejected.
For example, based on a patient’s problem, Singh et al. [16] proposed a treatment plan including orthodontics, sagittal split ramus osteotomy, intraoral vertical ramus osteotomy, and genioplasty to correct mandibular asymmetry in a 19-year-old patient.
Baik et al. [17] by examining a 30-year-old female patient with bialveolar protrusion, mandibular prognathism, chin retrusion, a long face, and severe facial asymmetry deducted that genioplasty alone would not be able to correct the patient’s abnormality, so they concluded that in order to improve the esthetic status, multiple complex surgical procedures should be used.
Thus, a series of procedures including anterior segmental osteotomy, LeFort I asymmetric impaction, bilateral sagittal split ramus osteotomy, 3-piece segmentation of the maxilla, anterior segmental osteotomy, advancement genioplasty, and mandibular angle contouring were performed concurrently for the patient. In contrast, the use of simpler and non-combination techniques for simpler cases is also quite common. For example, Gadre et al. [18] by using a single horizontal flip pedicled genioplasty for patients with unilateral temporomandibular joint ankylosis achieved reasonably satisfying outcomes.
In another study by Li et al. [19], the outcomes demonstrated that in patients with chin deformity, the chin template system provided a trusty method for the planning of two-piece narrowing genioplasty in a way that there were no reports of mental nerve injury, abnormal bleeding, template fracture, or difficulty in the application of the guide. In addition, all patients absolutely recovered well and were satisfied with the surgical results.
Perhaps the main limitation of this technique compared to conventional methods is the imposition of additional costs for three-dimensional computed tomography, the design of the digital treatment plan, and the fabrication of the surgical guide using Rapid Prototyping Technology.