ABSTRACT
OBJECTIVE: The aim of the study was to evaluate cephalometrically the effects of distraction of the maxilla over a 1-year period by means of an internal distractor applied in a boxer dog. DESIGN: Internal distractors were placed bilaterally in the internal cavity of the maxillary sinus of a 2-year-old boxer dog after a Le Fort I osteotomy. Distraction was started 5 days after surgery and activations were continued for 14 days at a rate of 1 mm/day. Standardized lateral cephalograms were taken with an extemal source of 90 kV, 60 mS immediately pre-surgery, at day 1 after the start of the distraction (dp) and at day 5 dp, day 7 dp, day 10 dp, day 14 dp (end of distraction), at 14 days of consolidation period (cp), at 28 days cp and at 56 days cp (removal of the distractors). One year after the removal of the distractor, a final lateral cephalogram was taken. Cephalometric analysis was performed and superimpositions were used for the evaluation of the sagittal position of the maxilla. RESULTS: The linear measurements, as well as the superimposition showed evidence for a significantly advanced position of the maxilla, which was stable 1 year after removal of the distractor. CONCLUSION: The application of the internal maxillary distractor in a boxer dog resulted in a sagittal advancement of the midface that was still present after 1 year.
