Accuracy of Positioning Guide and Customized Plate in Zygomaticomaxillary Complex Fractures

The clinical workflow for managing unilateral Zygomaticomaxillary Complex (ZMC) fractures begins with a standardized diagnostic phase. Patients undergo a thorough medical and dental history followed by a comprehensive clinical examination. A high-resolution preoperative Computed Tomography (CT) scan (T0) is acquired within one week prior to the intervention to visualize fracture patterns and the extent of displacement. The Digital Imaging and Communications in Medicine (DICOM) data is imported into specialized medical imaging software, such as Materialise Mimics or 3-matic, for three-dimensional (3D) reconstruction and Virtual Surgical Planning (VSP).

During the digital planning phase, the fractured zygomaticomaxillary complex is virtually reduced by mirroring the unaffected contralateral side to achieve optimal anatomical symmetry. Based on this virtual model, a patient-specific positioning guide is designed to fit the bone surface and indicate exact locations for plate and screw placement. Simultaneously, a customized titanium plate is designed to conform perfectly to the reduced bone contours, incorporating optimal screw hole positions to maximize stability and avoid vital structures. These plates are fabricated using additive manufacturing techniques, specifically selective laser melting, to ensure high precision and biocompatibility.

The surgical procedure is performed under general anesthesia. Appropriate surgical approaches, including lateral eyebrow and intraoral vestibular incisions, are used to expose the fracture site. The positioning guide is utilized to facilitate the accurate relocation of ZMC fragments according to the preoperative virtual plan. Once the fracture is accurately reduced, the custom-made titanium plate is adapted to the bone surface and secured with screws to achieve rigid internal fixation, minimizing the need for intraoperative plate bending.

Postoperative care includes an immediate follow-up Computed Tomography (CT) scan (T1) within 1 to 3 days to assess the accuracy of fracture reduction and plate placement by superimposing the postoperative actual model onto the preoperative virtual plan. Clinical follow-up occurs at regular intervals (1 week, 1 month, 3 months, 6 months, and 1 year) to assess wound healing, facial symmetry, ocular function, and mouth opening. A long-term follow-up CT scan (T2) is obtained at 6 months to evaluate bone healing and the long-term stability of the fixation.

Inclusion criteria

• Patients diagnosed with Zygomatico-maxillary complex fractures requiring surgical intervention.
• Patients aged 18 years or older.
• Patients willing to provide informed consent and comply with follow-up protocols.
• Patients with adequate bone quality and quantity for stable fixation.

Exclusion criteria

• Patients with comminuted ZMC fractures that preclude the use of custom-made guides based on mirroring the contra lateral side.
• Patients with pre-existing facial deformities or asymmetries that would interfere with accurate assessment of fracture reduction.
• Patients with systemic diseases or conditions that contraindicate elective surgery or impair bone healing (e.g., uncontrolled diabetes, severe osteoporosis, active malignancy, and immunosuppression).
• Patients on medications affecting bone metabolism (e.g., long-term corticosteroids, bisphosphonates). Patients with active infections in the maxillofacial region.
• Pregnant or lactating women.
• Patients with psychiatric disorders or unrealistic expectations.
• Patients who are unable to undergo CT scans or follow post-operative instructions.