Flexural strength of mini-implants developed for Herbst appliance skeletal anchorage. A study in Minipigs br1 cadavers.

OBJECTIVE The present study was designed to verify if mini-implant prototypes (MIP) developed for Herbst appliance anchorage are capable of withstanding orthopedic forces, and to determine whether the flexural strength of these MIP varies depending on the site of insertion (maxilla and mandible). METHODS Thirteen MIP were inserted in three minipig cadavers (six in the maxilla and seven in the mandible). The specimens were prepared and submitted to mechanical testing. The mean and standard deviation were calculated for each region. A two-way Student's t test was used to compare the strength between the sites. A one-way Student's t test was performed to test the hypothesis. Orthopedic forces above 1.0 kgf were considered. RESULTS The MIP supported flexural strength higher than 1.0 kgf (13.8 ± 2.3 Kg, in the posterior region of the maxilla and 20.5 ± 5.2 Kg in the anterior region of the mandible) with a significantly lower flexural strength in the anterior region of the mandible (p < 0.05). CONCLUSIONS The MIP are capable of withstanding orthopedic forces, and are more resistant in the anterior region of the mandible than in the posterior region of the maxilla in Minipigs br1 cadavers.