The optimal medial osteotomy: a study of nasal bone thickness and fracture patterns.

The use of medial osteotomies as an adjunct in rhinoplasty represents an ongoing challenge to the surgeon. Despite previous descriptions, it remains difficult to obtain a consistent, aesthetically pleasing result. Nasal skin is thin and unforgiving in the region of the medial osteotomy, thus irregularities may be created. Also, bony collapse is possible with overmobilization of the osteotomy segment. The present study was undertaken to understand nasal bone thickness and osteotomy fracture tendencies to provide consistent and aesthetically pleasing results when performing medial osteotomy. Seventeen cadavers with known demographics were studied. Left heminoses were skeletonized to bone; 1-mm drill holes in a 3 x 3-mm grid were made from the midline up to the laterocephalic extent of the bony vault. On right hemi- noses, medial osteotomies were performed at either 0 or 15 degrees from the midline and combined with "low-to-low" lateral osteotomies with digital greenstick infracture. Soft tissue was removed to examine fracture patterns and narrowing. A transition in bone thickness was found both with increasing thickness from caudal to cephalic and lateral to medial, leading to a natural cleavage plane, evident in all 17 cadavers. Zero-degree osteotomies caused contour irregularities with rocker-like deformities in seven of eight noses. Fifteen-degree medial osteotomies produced narrowing without contour deformities in all cases (nine of nine), which was significantly different from the result with 0-degree osteotomies (p = 0.0004). Sharp, thin osteotomes were preferred to perform the osteotomies. The order of the osteotomies (medial, lateral) did not affect resultant narrowing or cause contour deformity. Fifteen-degree medial osteotomies followed the natural cleavage plane formed by bone thickness transition, whereas 0-degree osteotomies cut into much thicker bone, resulting in thick spicules of bone attached to the mobilized segment. When 15-degree medial osteotomies were combined with low-to-low lateral osteotomies with digital greenstick infracture, the resultant narrowing was sufficient and the greenstick reliable and controlled, without any evidence of contour deformity. The smooth contour is readily apparent clinically.