Lateral cephalometric analysis of the nasal morphology among Saudi adults

Abstract

Purpose: This study was designed to establish normal values for the nasal form and its relationship to the other cranial structures among male and female skeletal class I Saudi adults. The results of males and females were compared to each other and to the results of a previous study using the same analysis method.

Patients and methods: Sixty-two lateral cephalometric radiographs of Saudi subjects (32 females and 30 males) were retrospectively retrieved from the orthodontic clinical data. Their ages ranged from 20 to 24 years old. All of the cephalometric radiographs were traced manually.

Results: There were statistically significant differences between the Saudi males and females in the nasal length, nasolabial angle, horizontal distance from the nose tip to the incisal edge of the most prominent upper central incisor, and chin. The Saudi males had longer dorsa and increased vertical distances from the pronasale to the chin when compared to the females. The Saudi females had longer vertical distances from the pronasale to the upper lip and larger nasolabial angles when compared to the males. The Saudi males and females had longer noses, longer dorsa, more curved noses (larger supratip break angles), and increased horizontal distances between the nose tip and the chin when compared to a New Zealand sample. The New Zealand sample had increased nasolabial angles, increased nasal tip projection angles, noses significantly projected from the upper lip, the most prominent central incisors, and more prominent maxillae when compared to the Saudi sample.

Conclusion: There were significant differences between the Saudi males and females, as well as between the Saudi sample and the New Zealand sample. These results suggest that both gender and ethnicity must be taken into account when establishing normal values for the nasal form and its relationship to the other cranial structures.

Keywords: lateral cephalometry; nasal analysis; orthodontics; rhinoplasty.

Figure 1

Reference points and planes. Notes: STN: soft tissue nasion, the point of greatest concavity in the soft tissue profile between the glabella and pronasale. S: sella, the center of the pituitary fossa. N: nasion, the most anterior point of the nasofrontal suture in the midsagittal plane. Sn: subnasale, the point at which the nasal septum merges with the upper cutaneous lip in the midsagittal plane. PRN: pronasale, the most anterior point on the nose. VP: vertical plane, the perpendicular to the horizontal plane through the soft tissue nasion. STG: soft tissue glabella, the most prominent point in the midsagittal plane of the forehead. DNP: dorsal nose plane, constructed by laying a straight edge on the upper aspect of the nose. STP: supratip plane, the tangent to the supratip of the nose. Cm: columella point, the most anterior point on the columella of the nose. Ls: labrale superius, the most anterior point on the upper lip. HP: horizontal reference plane, constructed by drawing a line through the soft tissue nasion parallel to the line through the nasion 7 degrees up from the sella-nasion line. STPg: soft tissue pogonion, the most anterior point on the soft tissue of the chin. Is: incision superius, the incisal edge of the most prominent maxillary central incisor. The red line is the STP and the black line is the DNP.

Figure 2

Horizontal and vertical measurements. Notes: Sn: subnasale, the point at which the nasal septum merges with the upper cutaneous lip in the midsagittal plane. VP: vertical plane, the perpendicular to the horizontal plane through the soft tissue nasion. Ls: labrale superius, the most anterior point on the upper lip. HP: horizontal reference plane, constructed by drawing a line through the soft tissue nasion parallel to the line through the nasion 7 degrees up from the sella-nasion line. STPg: soft tissue pogonion, the most anterior point on the soft tissue of the chin. Is: incision superius, the incisal edge of the most prominent maxillary central incisor. 1PRN-Ls horizontal, 2PRN-Is horizontal, 3PRN-STPg horizontal, 4PRN-Ls vertical, 5PRN-Is vertical, 6PRN-STPg vertical, 7Sn-VP, 8STPg-VP.