Long-Term Effect of Maxillary Distraction Osteogenesis (DO) on Nasal Index in Adult Patients with Cleft Lip and Palate Deformities.

Purpose: To test the hypothesis that there is no immediate and long-term effects of maxillary distraction osteogenesis (DO) on nasal index among adult subjects with cleft lip and palate deformities.

Materials And Methods: Twelve adult subjects in the age range of 17-20 years with complete unilateral cleft lip and palate underwent advancement of maxilla by DO. The immediate and long-term effects of maxillary DO on nasal index were evaluated from extra-oral full face frontal photographs recorded prior to DO (T0), at the end of active DO (T1) and at least 2-years after the DO (T2). The ANOVA, Post Hoc test (Bonferroni) and Pearson correlation coefficients were used. The probability value (P value) 0.05 was considered as statistically significant.

Results: SNM angle and Ptm-M distance increased significantly by DO (P < 0.001). The nasal index increased significantly (P < 0.01) by 13.85 % from T0 value of 85.15 ± 4.49 to 99.02 ± 11.16 % at the end of active distraction (T1) and by 12.69 to 97.84 ± 9.14 % at the end of long-term follow-up (T2). The correlation between sagittal maxillary advancement and nasal index was statistically significant (P < 0.001). For each millimeter of maxillary advancement, the nasal index increased by 1.38 % and 1.8 % at the end of active distraction and long-term follow-up respectively.

Conclusion: The advancement of maxilla by distraction osteogenesis among subjects with cleft lip and palate deformities increased nasal index significantly.