Assessment of nasal tip projection

Introduction The aim of this study was to compare Goode′s and Byrd′s method in objectively assessing nasal tip projection. Materials and methods This study included 20 patients from the ENT outpatient clinic, Cairo university hospital, who underwent augmentation tip rhinoplasty, closed technique, using Sheen graft, during the period from January 2008 until December 2011. Two objective methods, Goode′s method and Byrd′s method, were used to assess nasal tip projection preoperatively and postoperatively. Results There was statistically significant difference between the gain in projection by Goode′s method compared with Byrd′s method. The mean gain in projection was 11.6 using Goode′s method, whereas it was only 9.55 when measured by Byrd′s method. Goode′s method correlated more with patients′ and surgeon′s subjective assessment and satisfaction. Conclusion In our study, Goode′s method proved to be more accurate in representing the final outcome compared with Byrd′s method in the Egyptian population.


Introduction
Th e three main characteristics of the nasal tip are shape, rotation and projection. Predictably maintaining or changing these nasal tip characteristics remains a challenge; even for the most experienced facial plastic surgeon, projection is notably the most diffi cult to control [1].
In 1975, Sheen introduced a new concept in tip surgery in the form of adding a vertical tip graft to obtain more defi nition and projection [2]. Modifi cations were introduced to the principle, including the use of several layers of grafts and changing the shape or orientation of the tip graft [3].
As regards the Middle Eastern population, the need for increasing tip projection is particularly compelling. Th is can be explained by the quality of the lower lateral cartilages (LLC) and the overlying skin/soft tissue envelop [4].
Th e amount of nasal tip projection ( NTP) can be assessed using several methods that mainly depend on measurements made on the profi le photograph of the patient. Goode [5] proposed his method, which calculates the ratio between the nasal height and the nasal length. Byrd and Hobar [6] saw the best way was to measure the amount of nasal projection beyond the lateral facial profi le, which is determined by a line passing from the nasal root to the upper lip.
Th e amount of nasal projection anterior to that line, compared with the total height of the nose, represents a better magnitude of NTP.
In our study, we assessed and compared the reliability of both methods in objectively measuring NTP in the Egyptian population.

Materials and methods
This clinical study included 20 patients from Kasr AlAini, Cairo University Hospital, who underwent augmentation tip rhinoplasty using Sheen graft. All procedures were performed using the 'Closed Rhinoplasty Approach' by same surgeon. The nasal septal cartilage was the graft used for all patients.
Inclusion criterion was being a candidate for graft augmentation of the nasal tip with the objective of increasing tip projection.
Exclusion criteria included congenital anomalies and traumatic conditions aff ecting the nasal tip area.
Postoperative photography was started after 3 months and then repeated in each following visit. Standardized position shots were taken in each visit. Th e photographs at 9 months postoperatively were used for comparison and assessment of results. Th e follow-up period ranged from 9 to 35 months, with a mean of 14.3 months.

Assessement of nasal tip projection
Two methods were used to assess the NTP in the preoperative and postoperative photographs. Th e fi rst method was introduced by Goode [5], whereas the second was introduced by Byrd and Hobar [6].

Goode's method
Th is method depends on a ratio between the length of the nose (as determined by a line from the root to the tip) and its height (as determined by a line from the ala to the tip). To calculate the NTP using Goode's method, three points (R, A and T) were defi ned on the projected photo ( Fig. 1 and Table 1).
Calculation of the NTP: nasal height (Line Two) divided by the nasal length (Line One) and documented as a percentage. Normal value: 67 (±5).

Byrd's method
Th is method depends on the percentage of the nose that lies anterior to the upper lip line. To calculate the NTP by Byrd's method, four points and two lines have to be marked.
Th e four points included the previous three points used in Goode's method (R, A and T), in addition to a point marked on the most projecting point of the upper lip (L) ( Fig. 2 and Table 2).
Calculation of the NTP: Line Two (A) divided by Line Two and documented as percentage. Normal value: 55 (±5).
Values were documented in the patient's data-fl ow sheet.
Points (letters) and lines (numbers) used in the calculation of nasal tip projection by Goode's method. Simple measurements on two-dimensional photographs were used to assess the results of surgery in this study. More precision in measurement was attempted by applying measurements on large-scale photos projected on white board. As both Goode's and Byrd's methods depend on ratios, there was no worry about changing the scale and obtaining larger photos (Fig. 3).

Subjective assessment
Subjective assessment was performed on two levels, the patient's and the surgeon's impression. A fourpoint score was used for both the patient and surgeon to document their satisfaction with the end result of surgery. Th e scores were graded as follows:

Statistical analysis
All measurements were documented in the data-fl ow sheet of the patient. Statistical analysis of the results was then performed using the SPSS, version 15 (IBM corporation, Endicott, New York, USA). Tests used included the independent t-test, th e 2 -test and the one-way analysis of variance test.

Preoperative and postoperative tip projection
Preoperative NTP using Goode's method had a mean value of 58.50 ± 4.00 SD, and the postoperative measurement was 70.10 ± 2.93 SD. Th e mean increase in NTP was 14.00, and it was statistically signifi cant (P value = 0.00).
Preoperative NTP using Byrd's method had a mean value of 49.40 ± 2.79 SD, and the postoperative measurement was 58.95 ± 2.92 SD. Th e mean increase in NTP was 17.21 and it was statistically signifi cant (P value = 0.00).

Subjective assessment of surgical outcome: overall result
Patient's and surgeon's assessments of operation outcome are shown in Tables 3 and 4.

Assessment of surgical outcome: gain in the nasal tip projection
Assessment of the diff erence in the mean value of gain of NTP classifi ed by patient's and surgeon's satisfaction score using either Goode's or Byrd's method of measurement revealed no statistically signifi cant diff erence. Th e P value was 0.68 and 0.09 for subjective assessment, and 0.69 and 0.20 for objective assessment, respectively (Table 5).
Th ree representative cases from our study are shown below with their satisfaction scores and NTP measurements using both Goode's and Byrd's methods.   The patient who underwent tip augmentation. Patient satisfaction score: 3; Goode's: before, 53.3; after, 67.5. Byrd's: before, 50.0; after, 55.5. as both methods show an increase in values from a hypoprojection state to a normoprojection outcome. Figure 5 shows a patient with an excellent satisfaction score (3). Her Goode's index increased from hypoprojection to normoprojection state, correlating with both patient's and surgeon's satisfaction scores. However, her Byrd's indices did not match with the subjective assessments. It calculated a normoprojection index preoperatively and hyperprojection index postoperatively, which correlated neither to patient's nor to surgeon's assessment and satisfaction. Figure 6 shows a patient with a Bad satisfaction score (0). Th is is in correlation with the high postoperative Goode's index denoting hyperprojection, which matched our subjective assessment. However, using Byrd's method postoperatively gave an index within normal, which again shows its inaccuracy in matching both patient's and surgeon's satisfaction. Th is patient was rescheduled for surgery.

Discussion
Normal tip projection represents an important objective and a strong challenge for surgeons performing rhinoplasty. Th is has been stressed on by world renowned surgeons, who exerted much time and eff ort in this interesting fi eld.
Th e diffi culty in achieving adequate tip projection is both an objective and subjective challenge. Th is challenge varies on the basis of the ethnic features of the population. Although Caucasian noses are considered a model, Middle Eastern noses represent a greater challenge [7].
Th ere are several surgical ways to increase tip projection. Th ese include transdomal suturing, placement of columellar struts, footplate approximation, nasal spine augmentation and grafting. Th e multitude of surgical One-way analysis of variance test for the difference in mean value of the gain in nasal tip projection classi ed by patient's and surgeon's assessment scores.
techniques is the best proof that the challenge has not been solved [8].
In 1972, he presented his triangular nasal tip graft at a meeting of the California Surgical society and then he published his experience with his newly designed graft in 1975. He therefore pioneered the concept of closed tip grafts. He considered the introduction of the tip graft as one of the most important conceptual milestones in his experience [9].
Nasal tip underprojection is a common fi nding in Egyptians seeking rhinoplasty for diff erent reasons. Th is might be due to certain anatomical features that c haracterize the population and account for defi cient tip projection. Th ose features include thick heavy skin, weak fl oppy L LC and lack of cartilage defi nition.
Daniel [10]  Th e lack of correlation between NTP measurement and facial attractiveness may explain the limited satisfaction of some patients included in this study despite the obvious gain in projection documented by measurement.
Devcic et al. [11] tried to correlate between diff erent nasal projection quantifying ratios and facial attractiveness. Th ey measured NTP ratios in 300 digital portraits of women aged 18-25 years.
Th e results of their study showed that none of the ratios correlated with facial attractiveness. However, Goode's ratio had the strongest correlation with facial attractiveness.
In light of our results, when we compared the patient's and surgeon's satisfaction scores with their postoperative NTP values using both Goode's and Byrd's methods, we deduce that, in the Egyptian population, Goode's method is more accurate in representing the fi nal overall outcome compared with Byrd's method.
Subjective assessment scores deal with the overall satisfaction (of the patient and surgeon) with the result of surgery, which in turn addressed several aspects of deformity apart from the NTP. Second, the diff erence in the threshold of satisfaction among patients renders their results relative rather than absolute. Finally, there may be a lack of correlation between NTP and facial attractiveness.

Conclusion
Nasal tip underprojection is a rather common problem in Egyptians seeking advice for rhinoplasty, due to ethnic features of the LLC and the overlying skin. Tip augmentation using autogenous cartilage represents the standard of care in modern rhinoplasty and is considered as the cornerstone in increasing tip projection.
Quantitative measurement of NTP after surgery includes simple measurements on two-dimensional photographs. Th e two methods designed by Goode and Byrd are the two methods mostly used in the assessment of NTP.
Th ere was signifi cant diff erence between the gain in projection using the Sheen graft between Goode's and Byrd's method. In the Egyptian population, Goode's method proved to be more accurate in representing the fi nal outcome compared with Byrd's method. Th is was apparent when correlating the postoperative values of both methods with patient's and surgeon's overall satisfaction.
Larger sample sizes, elimination of multiple variables and more advanced quantitative assessment modalities may alter these results and recommendations.