Defining the Zygomaticosphenoidal Angle as a Guide to Anatomic Zygomaticomaxillary Complex Fracture Reduction.

BACKGROUND: Alignment of the zygomaticosphenoid suture is fundamental to reduction of zygomaticomaxillary complex fractures. To prevent a rotational deformity, the correct angle of the zygoma relative to the cranial base must be restored. Clinically, this can be a challenge, especially when there is comminution of the zygomaticosphenoid suture. Defining a zygomaticosphenoidal angle would provide a reference for use with stereotactic navigation to achieve anatomic reduction. METHODS: A single-center retrospective analysis of 100 patients was designed to determine normative zygomaticosphenoidal angle values. An angle subtended by the midline and a best-fit line through the zygomaticosphenoid suture on axial computed tomography was measured bilaterally in patients with isolated mandibular or nasal fractures. The mean of this measurement for 3 vertically adjacent cuts was calculated with position of central cut determined by the equator of the globe and trigone of the sphenoid. Multivariate regression was completed to identify changes in zygomaticosphenoidal angle with age, sex, and race. RESULTS: The mean zygomaticosphenoidal angle was 47° (range 39°-55°). 97% of angles were within 2 standard deviations (8°) of mean. Regression analysis demonstrated no significant change in angle with age (P = 0.74) or sex (P = 0.89). For each angle, the variation across the 3 sample cuts was ≤4.5°. Patients demonstrated high fidelity in zygomaticosphenoidal angle bilaterally with mean difference of 3°. CONCLUSION: The zygomaticosphenoidal angle is a useful reference, in conjunction with stereotactic navigation, for reduction of zygomaticomaxillary complex fractures. Contralaterally obtained patient-specific data may be used to guide unilateral repair. Normative values may serve as reference in bilateral injury.

Establishing a Protocol for Closed Treatment of Mandibular Condyle Fractures with Dynamic Elastic Therapy.

Treatment of mandibular condyle fractures is controversial. Open treatment achieves anatomic reduction with occlusal stability and faster functional recovery but risks facial nerve injury and jeopardizes joint capsule circulation which can lead to bone resorption. Traditional closed treatment avoids these issues but requires prolonged fixation and risks subsequent facial asymmetry, occlusal disturbance, and ankylosis. Rather than wires, closed treatment with elastics allows for customizable management of a healing fracture with ability to alter vector and degree of traction to restore vertical height and occlusion with less discomfort and decreased risk for ankylosis. In this protocol, unilateral condylar fractures were treated with class II elastics ipsilateral to injury and class I contralaterally. Class III elastics were used contralaterally if additional traction was required and Class II elastics were placed bilaterally for bilateral fractures. Patients were sequentially advanced from fixating to guiding to supportive elastics by titrating elastic vector to any dental midline incongruency or chin deviation. Six patients were treated with this protocol with six-month follow-up. Fracture patterns included displaced and dislocated fractures as well as intracapsular and extracapsular condylar fractures. All patients at completion of the protocol had objective centric occlusion with no subjective malocclusion, chin deviation, facial asymmetry, or temporomandibular joint pain. These early data demonstrate a safe and efficacious innovative protocol for closed treatment of mandibular condylar fractures with dynamic elastic therapy.