Infection rate following mandibular distraction with internal and external devices in infants

Background: Internal and external devices may be utilized in mandibular distraction osteogenesis (MDO) for the correction of symptomatic micrognathia in infants and children. Purpose: To compare the rate and severity of infection between internal and external MDO devices. Study design, setting, sample: Retrospective cohort study utilizing an institutional database of patients who underwent MDO. Independent variable: Use of internal versus external MDO hardware. Main outcome variables: Rate of post-operative surgical site infections (minor and major). Covariates: Patient age, device type, laterality, infection, and treatment were documented. Analysis: Chi-Square and Fisher Exact Tests were used where appropriate for categorical variables and two-tailed T-tests were used for continuous variables. Significance was set at p < 0.05. Results: Between 2010 and 2022, 36 infants (ages 7 days-12 months) underwent bilateral MDO. Thirteen cases utilized internal hardware (n = 26 surgical sites) and 23 cases utilized external hardware (n = 46 surgical sites). Fifteen patients developed post-operative infections (41.7 %), 11 of which were minor infections and 4 were major infections. Seven patients with internal devices (53.8 %) and 8 patients with external devices (34.8 %) developed an infection (p = 0.27). Minor infections occurred in 4 patients with internal hardware (30.8 %) and 7 patients with external hardware (30.4 %; p = 1.00). Major infections occurred in 3 patients with internal hardware (23.1 %) and 1 patient with external hardware (4.3 %; p = 0.25). There were 19 surgical site infections (26.4 %), 14 of which were minor infections and 5 of which were major infections. Ten internal devices (38.6 %) and 9 external devices (19.6 %) were complicated by infection (p = 0.08). Minor infections occurred in 6 internal devices (23.1 %) and 8 external devices (17.4 %; p = 0.56). Major infections occurred in 4 internal devices (15.4 %) and 1 external device (2.2 %; p = 0.05). Conclusion: No significant difference was found in overall postoperative infection rate with internal and external MDO. A lower rate of major infection was observed in external devices.