Effect of Systemic Oxytocin Administration on the Healing of Mandibular Fractures.

BACKGROUND

It has been determined that oxytocin (OT), a hormone primarily involved in childbirth and lactation, has anabolic effects on bone metabolism.

PURPOSE: The purpose of the study was to measure and compare radiographic and clinical fracture healing between the OT-treated and control groups.

STUDY DESIGN, SETTING, AND SAMPLE: This is an in vivo animal study using a mandibular fracture model in 42, 6-month-old male Wistar rats. The fracture line was created and fixed using mini plates and screws.

PREDICTOR VARIABLES: The predictor variable was OT exposure. The animals were randomly assigned to OT or control groups (C). The animals were sacrificed on days 10 (OT-10, C-10), 20 (OT-10, C-10), and 30, (OT-30, C-30) to evaluate the effect of OT on fracture healing at different stages. Thus, two groups and six subgroups were formed.

OUTCOME VARIABLES: The outcome variable was fracture healing measured using gray values (GV), fracture healing scores (FHS), and the ratio of new bone area to total fracture area (NB/TF.) For an objective assessment of radiographic images, the average GV of the region can be calculated. FHS is a scoring system that evaluates bone healing. NB/TF is the ratio used to evaluate new bone formation.

COVARIATES: None.

ANALYSES: The differences between groups were analyzed using the independent samples test or the Mann-Whitney U test, depending on the distributional characteristics of the data. Comparisons between the control and experimental groups at each time point were performed using the independent samples test. Additionally, Pearson's or Spearman's correlation tests were used according to the distribution of the variables (P < .05).

RESULTS

Compared to the C groups, OT groups consistently showed higher recovery outcomes. Although no significant difference was observed on day 10, on day 20, OT-20 subgroup demonstrated significantly higher GV (OT-20 = 1.35 ± 0.39, C-20 = 0.77 ± 0.24) (P = .011 < 0.05), FHS values (OT-20 = 7.83 ± 0.75, C-20 = 5.67 ± 1.21) (P = .004 < 0.05), and NB/TF ratios (OT-20 = 80.19 ± 4.93, C-20 = 31.40 ± 3.87) (P = .001 < 0.05). On day 30, OT-30 maintained this superiority, showing significantly higher GV, FHS, and NB/TF values compared to C-30 (all P < .05).

CONCLUSIONS

In this study, the groups treated with OT showed higher mean healing scores. Oxytocin improved the healing of mandibular bone fractures.