Late maxillary protraction in patients with unilateral cleft lip and palate: a retrospective study

This retrospective study assessed the dentoskeletal effect of late maxillary protraction (LMP; reverse-pull headgear, Class III elastics, and maxillary sutural loosening) in unilateral cleft lip and palate (UCLP) patients versus a control group of untreated UCLP patients.

Cephalograms taken at age 13 to 14 years (T1) and 17 to 18 years (T2) were used for this study. The study group comprised 18 patients (10 male and 8 female, mean age at start of LMP therapy = 13.4 [0.45] years). A control groups of 17 patients (8 male and 9 female, mean age = 13.5 [0.44] years) was used for comparison.

The repeated-measures analysis of variance showed statistically significant changes across time between groups for the following variables (mean difference [T2-T1] in the study group, 95% confidence interval): SNA (°) (1.95, 0.75 to 3.15), A ⊥ Na Perp (mm) (1.82, 0.86 to 2.77), CoA (mm) (2.92, 1.53 to 4.31), ANB (°) (3.13, 2.02 to 4.24), Wits (mm) (7.82, 5.01 to 10.54), Mx-Md Diff (mm) (0.62, -1.58 to 2.83), Occl P-SN (°) (-3.98, -5.99 to -1.98), overjet (mm) (8.82, 5.90 to 11.74), FMIA (°) (4.05, -0.05 to 8.15), and IMPA (°) (-5.77, -9.74 to -1.80). Late maxillary protraction created a slight open bite (0.66 mm). Trends for overeruption of mandibular incisors and an increase in lower face height (P = .07 for both) were noted in the study group.

Late maxillary protraction produced a combination of skeletal changes (protraction of maxilla, improvement in the maxillo-mandibular skeletal relationship) and dental compensations (counterclockwise rotation of occlusal plane, retroclination of mandibular incisors) in patients with UCLP. Late maxillary protraction was also associated with some unwanted tooth movements (open bite tendency, mandibular incisors overeruption).