Impact of three miniplate configurations on mental nerve integrity in parasymphyseal mandibular fractures: a blinded randomized trial.

OBJECTIVES

To assess the mental nerve's functional integrity after parasymphyseal mandibular fracture fixation using three different miniplates configurations.

METHODOLOGY: A total of 36 patients with unilateral parasymphyseal fractures were included in the study. Patients were randomly allocated into three groups based on the fixation modality configuration. Clinical evaluations were carried out in conjunction with radiographic assessments of mean bone density at the fracture line. Electrophysiological objective nerve testing was conducted 1 month postoperatively to assess the amplitude, onset latency, and conduction velocity of the mental nerve.

RESULT: Physiological nerve testing intergroup analysis demonstrated no statistically significant differences in latency or amplitude, while conduction velocity showed a trend toward intergroup variation without reaching statistical significance (P = 0.072). Comparing the degree of agreement of nerve conduction parameters between the affected ipsilateral and healthy contralateral sides reported high levels of ICCs for all 3 miniplates configurations. Radiographic analysis revealed significantly greater bone density at the fracture site in the 3D-Interlocking group compared with twin fork and conventional miniplates (P < 0.001).

CONCLUSION

Fixation of parasymphyseal mandibular fractures using 3D-Interlocking or Twin-Fork miniplates yielded a slightly enhanced mental nerve conduction profile and integrity preservation when compared to the conventional miniplate configuration. Furthermore, the 3D-Interlocking plate demonstrated improved stability and healing of the fracture line. These findings support the use of 3D-Interlocking or Twin-Fork miniplates as preferable alternatives to conventional miniplates in the mental foramen region.

TRIAL REGISTRATION: Trial was retrospectively registered at clinicaltrials.gov [NCT07058597/ 2025-07-01].