Comparison of high septal and low septal preservation techniques in rhinoplasty

Introduction and Aim The nose, located at the center and anterior-most part of the face, plays a crucial role in both determining facial characteristics and assessing facial aesthetics. Preservation rhinoplasty, one of the most popular rhinoplasty techniques in recent decades, encompasses modifications to the soft tissue, tip, and dorsum of the nose, with its most significant innovation being the approach to the nasal dorsum. Various techniques have been developed under the umbrella of preservation rhinoplasty, mainly categorized into interventions on the nasal dorsum and the nasal septum. Septal maneuvers involve making incisions at different levels of the septum to mobilize the dorsum and to lower the entire dorsum line (from supratip to radix) into the nasal cavity to varying extents, thereby flattening the nasal profile. Each technique (in this case, high and low septal) causes different degrees and patterns of reduction in the hump and supratip areas due to their unique surgical mechanisms. A detailed evaluation and understanding of these differences can assist surgeons in selecting the appropriate technique, leading to better surgical outcomes and decision-making processes. This study aims to compare the effects of the two most commonly used septal techniques in preservation rhinoplasty, "high septal" and "low septal," on the nasal dorsum via changes in the supratip and hump regions. Materials and Methods Medical records and photographs of patients aged 16-35 who underwent rhinoplasty between 2022 and 2024 at Bezmialem Vakif University Hospital were retrospectively reviewed. A total of 30 patients meeting the inclusion criteria were selected: 20 underwent the high septal technique, and 10 underwent the low septal technique. Standardized preoperative and 1-year postoperative lateral photographs were taken against a blue background, with the patient's head in the Frankfurt horizontal plane, at a 70 cm distance from the camera using a Redmi Note 10s with a 26 mm focal length lens. These images were then superimposed using Adobe Photoshop 2025. Using the vertical alar plane as a reference and placing the 0-degree meridian at the alar crease, the preoperative and postoperative positions of the supratip and hump were identified. Perpendicular lines were drawn from these points to the vertical alar plane, and the projection distances were measured metrically. Using the collected data, four parameters were established to evaluate the relationship between preoperative and postoperative nasal hump and supratip height changes for both techniques. The first parameter was the ratio of supratip change to hump change. The second parameter, a normalized ratio, was calculated as (supratip change / preoperative supratip value) divided by (hump change / preoperative hump value). The third parameter involved the assessment of postoperative nasal dorsum inclination, derived from the vertical alar plane–dorsum tangent and nasofacial angle variations. Finally, the fourth parameter measured the variation in supratip height differences across tertile levels, based on mean differences among patient groups categorized by increasing hump change.Statistical analyses were performed using IBM SPSS Statistics 26.0 and MS Excel 2024. A p-value < 0.05 was considered statistically significant. Results The first two parameters showed that the effect of hump reduction on supratip change differed between the two techniques. The average value for the supratip/hump ratio was 1.625 in the high septal group and 0.817 in the low septal group, with a statistically significant difference. A value greater than 1 in the high septal group indicated that supratip reduction exceeded the hump reduction, while a value below 1 in the low septal group suggested a less pronounced supratip response. For the normalized ratio, the average values were 1.098 for the high septal group and 0.560 for the low septal group, again showing a significant difference. Following this, angular comparisons were made to evaluate how these differences translated to postoperative nasal dorsum orientation. Three angles were measured: Angle 1 (vertical alar plane vs. dorsum tangent), Angle 2 (dorsum tangent vs. glabella-pogonion line), and Angle 3 (nasion-pronasale-glabella-pogonion or nasofacial angle). No statistically significant differences were found between groups initially. After removing two outlier patients (with angular values of 45.4° and 29.8°), a significant difference was observed in Angle 1, with the high septal group averaging 33.71° and the low septal group 37.04°. Angles 2 and 3 remained non-significant. For the fourth parameter, patients were divided into tertiles based on increasing hump change. In the high septal group, supratip increase was more pronounced between the first and second tertiles, but the rate of increase slowed from the second to third tertile, indicating a saturation point. In contrast, the low septal group showed a steady and accelerating supratip response, suggesting a more direct and potent relationship between hump reduction and supratip projection in these patients. Discussion The comparison of postoperative supratip height changes, assessed using Parameters 1 and 2, with changes in hump height, demonstrates how and to what extent the maneuvers performed during dorsal hump reduction affect the supratip region in these patients. In the high septal group, the average supratip decrease was 1.625 mm for a 1 mm hump reduction, whereas in the low septal group, the supratip decreased by 0.817 mm for the same hump reduction. In the high septal approach, the change in supratip height was proportionally greater than the amount of resection applied to the hump region. Conversely, in the low septal technique, the reduction in hump height translated into a more limited impact on the supratip. In high septal techniques, when the dorsum is leveled, the keystone area undergoes flexion due to the flexibility achieved by excising part of the underlying septal cartilage. Additionally, an impaction effect is created as the dorsum is lowered into the space formed after the removal of a subdorsal cartilage strip. Opening the keystone area during reduction of convex dorsa alters the angulation and results in a geometrically longer dorsum. As a result, the upper lateral cartilages (ULCs) extend toward the scroll area, increasing projection, and the overlapping excess cartilage over the cephalic segment of the lower lateral cartilage is excised during surgery. Therefore, in addition to the decrease obtained by removing the subdorsal cartilage under the hump and supratip, the excision of the caudal ULC may also contribute to this excessive supratip reduction. Moreover, during removal of this caudal surplus, an excision at the W-point may also be performed, and since the W-point is shifted cranially, the region corresponding to the supratip is also moved cranially, resulting in a decrease in supratip projection. Although literature recommends avoiding excessive cartilage resection in the supratip region during high septal techniques due to the risk of saddle deformity, there is no study explaining the mechanical basis for this. Our study highlights that due to this mechanical structure of the high septal technique, preserving supratip height during surgery and planning subdorsal excision with the expectation of greater supratip reduction are important for better supratip control. In low septal techniques, two main forces act on the quadrangular cartilage: impaction and the rotational force applied during repositioning. This rotation elevates the caudal septum and causes fullness in the supratip region. The fact that the supratip region decreases less than the hump area in low septal techniques and that the change in supratip height is lower than the change in hump height is attributed to the effects of these forces. To avoid supratip fullness or a pollybeak deformity in low septal techniques, it would be beneficial to perform septal base resections with these mechanical dynamics in mind. Literature suggests that removing less cartilage near the anterior nasal spine (ANS) during inferior strip excision in low septal techniques helps provide enough rotation and creates a higher cartilage prominence at the ANS area for proper septal positioning. However, our study found that because low septal techniques risk creating supratip fullness, the rotational movement must be controlled, and insufficient excision near the ANS should be avoided. If an adequate amount is not removed, supratip height may remain high, preventing the achievement of desired dorsal proportions. These dorsum alterations caused by high and low septal techniques are also supported by the evaluation of Parameter 3. After excluding outliers, analysis of nasal dorsum inclination using the vertical alar plane and dorsum tangent (Angle 1) showed that the high septal group had significantly lower angles, while the low septal group had higher angle values. This corresponds with greater supratip reduction in high septal cases and less reduction in low septal cases. As with Angle 2 and 3 measurement methods, angular assessments using nasofacial or external facial cephalometric landmarks fail to accurately reflect the true dorsum inclination. Parameter 4 was used to assess the correlation between postoperative supratip changes and hump height. In the high septal group, supratip reduction did not increase proportionally with hump height; instead, the rate of increase slowed and reached a plateau. In other words, the tendency for supratip depression (saddling) gradually decreased, and supratip control became relatively easier as the hump size increased. This may be interpreted as delayed adaptation of surrounding supratip soft tissues creating a recoil effect that slows supratip descent. From a geometric perspective, as the hump enlarges, the ratio of arc length to hump height increases. Although the theoretical amount of ULC that needs to be excised should increase, the relative overflow into the supratip area appears to decrease, as seen in Parameter 4. This may be due to increased horizontal splaying and bulging tendencies of the ULCs surpassing their tendency to protrude into the scroll area as the hump height increases. This helps explain the literature's recommendation of the ballerina maneuver, especially in low septal and some high-hump high septal cases, to counteract ULC splaying and bulging. It emphasizes the importance of LKA dissection and tension reduction in the ULCs (ballerina maneuver) in high-hump patients. When evaluating Parameter 4 in the low septal technique, supratip reduction increased proportionally with hump size and did so at an accelerating rate. In other words, as the hump enlarges, the tendency of the technique to create supratip fullness decreases. Considering that supratip projection is primarily obtained via rotation, this suggests that with larger humps, the impaction effect used to reduce the hump surpasses the rotational effect. In low septal techniques, counteracting soft tissue forces applied to the rotated quadrangular cartilage may lead to hump relapse. However, our analysis indicates that the rotational effect relatively decreases as hump size increases, making low septal techniques more feasible for larger humps. In conclusion, the disadvantages inherent to both techniques decrease in noses with larger humps. Therefore, dorsal preservation techniques are also suitable for high-projection noses. Conclusion Although several publications discuss the high and low septal preservation techniques individually, no prior studies have directly compared their effects on the nasal dorsum. By evaluating the changes in the hump and supratip regions for both techniques, this study provides valuable insights into the mechanics of these modern preservation concepts. The findings emphasize the importance of considering preoperative nasal contour, hump, and supratip ratios—not just dorsal projection and septal deviation—when selecting the appropriate preservation rhinoplasty technique for optimal postoperative outcomes.