Cartilaginous histology of the cleft lip nose: proving the extrinsic etiology.

In an effort to prove the etiology of the cleft lip nasal deformity, 23 patients with unilateral cleft lip underwent biopsy through the midportion of the columella from mucosa to mucosa. This tissue "sandwich" contained an internal control of cleft and noncleft medial crus cartilage. With the use of special stains and examination under the microscope at low, medium, and high powers, sections were evaluated on the basis of presence of abnormal chondrocytes, number of binucleate chondrocytes, number of nucleated chondrocytes, number of lacunae, perichondrial thickness, and cartilage thickness. In each specimen examined, there were no significant differences between cleft and noncleft sides, proving histologically the previous subjective observation that the deformity is extrinsic, due to distortion of the lower lateral cartilage by abnormal vectors of force.