BACKGROUND This study aims to prospect the soft and hard tissue changes after augmentation of two different local mandibular contour defects using polyetheretherketone (PEEK) patient-specific onlay implants. METHODS Six patients with disfiguring local mandibular deformities were included in this study (five males and one female) and received seven PEEK patient-specific implants (PSI), virtually designed and surgically settled to augment seven mandibular defects, three deficient chins, and four mandibular angels. The analysis of the soft and hard tissue changes utilized the superimposition of the preoperative and the 6-month postoperative sagittal and coronal CT views, after standardizing the radiographic interpretation. RESULTS The soft tissue gain for the chin was 6.8 mm ± 0.98 with a 45.8% increase versus 4.42 mm ± 0.41 with a 22.9% increase for the angle. The difference in the soft tissue gain between the two groups was statistically significant (P = 0.0001). Comparing the soft tissue gain to the planned implant thickness, the percentage of the soft tissue gain for the chin recorded 109.2% versus 65.57% for the angle. The difference between the two groups was also statistically significant (P < 0.0001). CONCLUSIONS PEEK patient-specific onlay implants represented an efficient and straightforward modality to augment local mandibular contour deformities with favorable esthetic outcomes; the total soft tissue profile gain of the chin region markedly exceeded that of the mandibular angle.