The treatment of mandibular fractures affecting the condylar head (CHF) can be either closed or open. In the case of an open approach, the headless bone screw (HBS) is an option. This study was performed to investigate the efficacy of osteosynthesis with HBS using three-dimensional radiographic imaging and clinical evaluation over long-term follow-up. This was a single-centre retrospective study. Clinical parameters and three-dimensional radiographic scans were collected during follow-up, DICOM datasets were segmented, and model analysis was conducted. Forty-five patients who received a HBS and met the eligibility criteria were included. There were significant improvements in all clinical parameters (mouth opening, protrusion, laterotrusion; all P < 0.05) except for the laterotrusion of the unaffected side (P = 0.071). Mean volume and surface area changes (from postoperative (mean 1.9 days) to final follow-up (mean 1675 days)) were 127.2 mm³ and −22.4 mm², respectively, and were not statistically significant (P = 0.18 and P = 0.51). There were radiographic signs of condylar remodelling. Nine HBS in nine patients required removal due to the screw penetrating the articular surface of the healing condylar head. This single-centre retrospective study found good functional outcomes using HBS for CHF, with a screw removal rate of 20%.