Computed Tomography Analysis of Nasal Anatomy in Dorsal Preservation Rhinoplasty

Overview

Removing a strip of septum under the bridge and cutting the bone at the root are the distinctive steps of preservation rhinoplasty, and both approach the skull base. The study measured nasal bone thickness, the level of the bone to cartilage junction known as the K area, and distances from the bone cut line to the frontal sinus and skull base.

Sections of note

• Retrospective evaluation of 203 consecutive preoperative CT scans, January 2020 to June 2021, classified by age and gender.
• Measurements were nasal bone thickness at the inner corner of the eye, and distances from the transverse osteotomy line to the K area, the frontal sinus and the cribriform plate.
• Mean measurements were similar across all age groups from 18 to over 50.
• Mean nasal bone thickness differed significantly by gender, P equals 0.001.
• The distance from the osteotomy line to the K area also differed by gender, P equals 0.001.
• Distances to the frontal sinus and cribriform plate were similar in both genders.
• Nasal bone was thinner and the K area sat higher in women.
• The authors conclude men may need more removal of the ethmoid plate when lowering a hump, making them more prone to skull base complications.

What it means for a patient

• The anatomy determining the risk of preservation surgery differs measurably between men and women.
• The cribriform plate is part of the skull base, and injuring it can leak the fluid surrounding the brain.
• The authors recommend more caution during the septal excision step in men.
• This measures anatomy only; it reports no complications and no surgical outcomes.

Why this paper matters

Preservation techniques involve cuts close to the skull base, where the rare serious complication is a cerebrospinal fluid leak. This study measures the margin surgeons have and shows it varies by gender. Whether that difference changes complication rates has not been shown.

Terms

• Subdorsal septal resection: removing a strip of septum below the bridge so it can settle down.
• K area: the keystone junction where the nasal bones meet the septal cartilage.
• Transverse osteotomy: a bone cut across the root of the nose.
• Cribriform plate: the thin perforated bone of the skull base above the nose.
• Ethmoid perpendicular plate: the bone forming the upper rear part of the septum.