Editor’s Correspondence

T he nasal keystone region is an aptly named con-fluence of bone and cartilage at the junction of the upper and middle thirds of the nose. Its importance to the stability and structure of the nose is exemplified by the number of complications that may arise from poor surgical handling of this area. The keystone region consists of contributions from the paired nasal bones cephalically, paired upper lateral cartilages (ULCs) caudally, quadrangular cartilage anterior-inferiorly, and perpendicular plate of the ethmoid (PPE) posterior-inferiorly. We sought to review the anatomy of fresh-frozen ca-davers in regard to the keystone region, in concert with previous anatomical descriptions, to expand on the significance of this region for rhinoplasty. Methods. Dissections were performed on 11 fresh-frozen and thawed cadaver heads without evidence of prior traumatic, surgical, or positional deviation of the external nose. To expose the keystone, the soft-tissue envelope and the nasal septal mucosa were removed. After the cartilages and nasal bones had been adequately exposed, the periosteium and perichondrium were removed. Finally, the osseocartilaginous complex was removed from the skull en bloc by osteomies made along the maxillary crest, the frontal process of the maxilla, the nasofrontal su-ture and posteriorly through the PPE to the maxillary crest (Figure 1). After full dissection, the osseocartilagi-nous junctions were well demarcated and visible to the naked eye. Measurements were performed with surgical cali-pers. The measurements were made in 9 males and 2 females , all of whom were white. Patient ages at the time of death ranged from 27 to 90 years. Statistical analysis was performed, using a 2-tailed t test for continuous variables, comparing the length of mid-line overlap from the present study with the measurements obtained from a prior study by Kim et al. 1 These data were obtained through personal correspondence with the study's authors. Statistical calculations were performed with Microsoft Excel software (version 14.0; Mi-crosoft Corp). Results. A total of 5 separate measurements were made on each specimen (Table). (1) The dorsal articulation of the ULCs with the nasal bones (mean, 8.0 mm [range, 4.5-12.0 mm]) (Figure 1). (2) The unilateral length of the lateral articulations of the ULC with the nasal bones (mean, 11.3 mm [range, 6.0-18.0 mm]) (Figure 2). (3) The midline nasal bone overlap with the quadrangular cartilage (mean, 6.5 mm [range, 0.5-11.5 mm]). (4) The length of the quadrangular cartilage along the nasal dor-sum, from the junction with the …