Abstract
Introduction: Cleft lip and palate patients have often hypoplasia of midfacial area. Orthognathic surgery is often necessary to achieve good facial aesthetics and functional occlusion.
The aim of this study is to evaluate maxillary stability after Le Fort I osteotomy in cleft lip and palate patients. Methods: Five patients, two women and three men, 17-22 years old with unilateral cleft lip and palate underwent comprehensive orthodontic and surgery treatment.
The orthodontic treatment was performed at the Department of Orthodontics and Cleft Anomalies, University Hospital Královské Vinohrady and Le Fort I osteotomy at the Department of Maxillofacial Surgery in Masaryk Hospital, Ústí nad Labem. Maxillary stability after orthognathic surgery were measured at cephalograms, which were taken before (T1), first day after the surgery (T2) and 20 months after the procedure on average (T3).
The position of maxilla was determined by measuring the SNA angle and horizontal and vertical position of the A point. Frankfort horizontal plane (FH) and line perpendicular to the FH from Porion point (Y), which were drawn on each cephalogram.
Vertical dimension was measured as a distance between A point and FH (AX) and horizontal dimension as a distance between A point and the perpendicular line to FH (AY). All values were measured twice in four weeks interval by one evaluator and average values were used to eliminate measurement errors.
Results: The SNA angle increased of 5.6° on average in all five patients after surgery, horizontal shift of the point A was 10.7 mm. The relapse was 4.7° in SNA angle and -7.1 mm in point A with major differences among patients.
Vertical position of A point was changed by -3,4 mm on average after surgery. In some patients AX distance has grown, in some cases has shortened.
Vertical position of A point has changed with high interindividual changes during period after surgery. Conclusion: The maxillary advancement Le Fort I in cleft lip and palate patients is not stable; relapse can be expected.
The relapse rate is individual, probably caused by tissue retraction in the original scars or newly formed scar tissue, or by tension of surrounding soft tissues. However, the final occlusion is satisfactory in long-term period according to our experience.
More detailed research should be done to determine causes and to investigate the extent of relapse.