Objective: This study was to investigate the nasal musculature and its relationship with the deformities of the unilateral cleft lip nose.
Method: The anatomic and histological examination and comparison of the musculus depressor septi nasi (MDSN) were performed in 33 normal cadavers and 30 patients with unilateral cleft lip undergoing the operation for secondary nasal deformities.
Result: It was found that the MDSN in the cleft side of a unilateral cleft lip nose is lacking.
Conclusion: Because of the anatomic deficiency on the cleft side, the function of the normal side is pathologically increased. The functional imbalance between the normal and abnormal side may bring about dislocation and malformation of the base of nasal columella as well as the septal structures.