Reduction of bilateral parasymphysis fractures is challenging due to the following factors: fragmentation of the mandible into three segments and excessive muscular forces pulling the central fragment posteroinferiorly [1]. Proper reduction in such fractures is essential for restoring the sagittal projection and transverse dimension of the anterior mandible [2]. Here, we report a straightforward technique that aids in precise anatomical reduction and stabilization during fixation of the central fragment using a Carroll-Girard screw.

A 37-year-old man presented with pain and difficulty in mouth opening after falling from his bicycle 2 months ago. The patient expressed concerns regarding his severely retruded chin and loss of projection of the lower face. Clinical examination revealed bilateral step deformities in the parasymphysis region and tenderness over the left condylar region. Computed tomography imaging demonstrated a malunited bilateral parasymphysis fracture with an associated left subcondylar fracture (Fig. 1). Open reduction and internal fixation of the fractured segments were planned under general anesthesia to restore premorbid occlusion and function.

Restoration of skeletal form and occlusion in bilateral parasymphysis fractures is technically demanding due to the fragmented mandible and unfavorable muscular biodynamics [3]. Additionally, the complexities specific to this case included (1) malunion, preventing anatomical reduction by interdigitation of fracture fragments, and (2) absence of teeth in the anterior mandible, resulting in the loss of an occlusal guide for reduction.

Anatomic reduction of bilateral parasymphysis fractures is generally achieved using towel clips [4], bone forceps [5], wires [6], digital manipulation [7], or a combination of these methods [8]. However, these methods are associated with limitations. Towel clips and bone clamps engage only the buccal aspect, causing lingual splaying during reduction [9]. Digital manipulation is difficult due to excessive muscular forces [7]. Sargunam et al. [10] described the use of dental impression compound on the lingual aspect to prevent tipping of the mid-symphyseal fragment during fixation. Jaisani et al. [1] reported the reduction of bilateral parasymphysis fractures using a traction screw; however, this method can result in screw bending, and the screw handle is insufficiently ergonomic for applying traction in the desired plane. The use of a Carroll-Girard screw addresses these disadvantages by offering controlled traction in the correct direction and improving operator ergonomics by reducing wrist fatigue compared to other methods.

The Carroll-Girard screw was originally used for the reduction of zygomatic fractures in maxillofacial surgery [11,12]. Govind and Jelmini [13] have also reported the use of this instrument for reducing posteriorly displaced Markowitz type I fractures. This instrument features a wide horizontal handle and a T-bar screw, allowing rotation in any direction for precise manipulation of fracture fragments and anatomical reduction. The Carroll-Girard screw is simple to operate and maintains a three-dimensional force during fixation [11]. Though not conventionally used for reducing mandibular fractures, given the complexities associated with this particular fracture and the excessive pull of suprahyoid muscles, the Carroll-Girard screw was ideal for controlling and stabilizing the central fragment during fixation. It is straightforward and allows the application of traction force in the appropriate plane. In conclusion, the Carroll-Girard screw technique can effectively reduce and stabilize segmental mandibular fractures.