Comparison between computer guided lag screw fixation versus traditional lag screw fixation in open reduction and internal fixation of anterior mandibular fractures.

Two groups of patients with anterior mandibular fractures indicated for open reduction and internal fixation. First group will be subjected to computer guided lag screw fixation. Second group will be subjected to traditional lag screw fixation.

Eligible patients will be randomised in equal proportions between study group (computer guided lag screw fixation) and control group (conventional lag screw fixation).

A- Computer guided lag screw fixation group:

• Pre operative Computed tomography will be done for the patient.
• Computed tomography data will be imported into Computer aided surgical simulation software.
• Utilizing Computer aided surgical simulation software the fracture segments are virtually reduced and patient specific surgical guide is designed and sent to three dimension printer before operation.
• Intra operative: All cases will undergo surgery under general anaesthesia.
• Exposure of the fractured segments will be done using vestibular incision.
• Inter-maxillary fixation will be done
• The fractured segments will be reduced in normal anatomic position guided by occlusion.
• Fracture fragments will be fixed using lag screws utilizing patient specific surgical guide.
• Closure of the surgical incision.
• Post operative at first week Computed tomography will be done for the patient.
• Computed tomography data will be imported into computer aided surgical simulation software.
• Utilizing computer aided surgical simulation software the post operative computed tomography will be superimposed onto the pre operative planned simulation.

B- Conventional titanium plates:

• Pre operative Computed tomography will be done for the patient.
• Computed tomography data will be imported into Computer aided surgical simulation software.
• Utilizing Computer aided surgical simulation software the fracture segments are virtually reduced.
• Intra operative: All cases will undergo surgery under general anaesthesia.
• Exposure of the fractured segments will be done using vestibular incision.
• Inter-maxillary fixation will be done.
• The fractured segments will be reduced in normal anatomic position guided by occlusion.
• The fracture fragments will be fixed using lag screws.
• Closure of the surgical incision.
• Post operative at first week Computed tomography will be done for the patient.
• Computed tomography data will be imported into computer aided surgical simulation software.
• Utilizing computer aided surgical simulation software the post operative computed tomography will be superimposed onto the pre operative planned simulation.

Follow up for both groups:

Clinical evaluation will be performed at first week postoperative then patients will be recalled every week for one month. Final follow up visit will be at 3 months post operative.

Inclusion criteria:

• Patients with anterior mandibular fracture indicated for open reduction internal fixation alone or in combination with fracture elsewhere in the mandible or mid face.
• All ages and both sexes were included in this study.
• Patients should be free from any systemic disease that may affect normal healing of bone, and predictable outcome.
• Patients with good general condition allowing major surgical procedure under general anaesthesia .
• Patients with physical and psychological tolerance.

Exclusion criteria:

• Patients with comminuted fractures as it is not indicated for compression osteosynthesis like lag screws.
• Patients with high risk systemic diseases like uncontrolled diabetes mellitus. As uncontrolled diabetes mellitus has a negative impact on normal bone healing.
• Patients with old and/or mal-union fractures. As they will affect accuracy of reduction of the fractured segments.

Because the two interventions requires different pre operative preparation, both the participants and investigators can't be blinded.