Biomechanical Stability of Two Different Maxillofacial Screws in a Rabbit Model

Internal rigid fixation techniques are commonly used to treat maxillofacial fractures by stabilizing bone segments using titanium plates and screws. The current study aimed to compare the biomechanical stability of two maxillofacial screws with different tip designs in vivo.

Six male rabbits were randomly divided into two experimental periods of 0 and 4 weeks. Under general anesthesia, the screws were randomly placed in the tibia bone on both sides of each animal. The pullout test was conducted using a Sentam test device. Data were statistically analyzed using ANOVA.

The average insertion torque for non-self-tapping and self-tapping screws amounted to 4.2±1.7 and 4.8±1.4 Newton/centimeter, respectively (P-value >0.05). The calculated measures for the pullout test demonstrated a significant increase of secondary stability after 4 weeks in comparison to 0 week (P-value<0.001). However, the results among the two screws showed no statistically significant difference in each time point (P-value >0.05).

No significant differences were demonstrated among self-tapping or non-self-tapping maxillofacial screws.