- Email: [email protected]
Morphologic variations of sesamoid cartilages of the nose in Iranian cadavers
Vol. 114 No. 2 August 2012
Morphologic variations of sesamoid cartilages of the nose in Iranian cadavers Ali Ebrahimi, MD,a Mohammad Hosein Kalantar Motamedi, DDS,b and Nasrin Nejadsarvari, MD, MPHc Baqiyatallah University of Medical Sciences and Tehran University of Medical Sciences Imam Khomeini Hospital, Tehran, Iran
Background. Accessory cartilages are small nasal cartilages between the lateral crus and piriform aperture of the nose bilaterally. These cartilages are among the supporting structures of the nasal tip. Study Design. This prospective cross-sectional study was conducted on Iranian fresh cadavers for evaluation of ethnic differences. Seventy-two sesamoid cartilages in 41 cadavers (mean age 42 years) were dissected to evaluate anatomy and anthropometry of the sesamoid cartilages. Elevation of the dorsal nasal flap after a collumellar incision was done. After the separation of the lower lateral cartilages and sesamoid cartilages on each side, the anatomy and anthropometry of the cartilages were assessed. Results. In 12% (5) of the cadavers there were no sesamoid cartilages, and in 88% (36) of the cadavers there was 1 sesamoid on each side. The shape of the sesamoid cartilages was rectangular in 66% (27) and triangular in 22% (9). The mean length, width, and thickness were 3 mm, 2 mm, and 0.75 mm, respectively. Conclusions. This cartilage was single on each side of the nose and its shape was an irregular rectangle or triangle and has an important role in preserving nasal alar contour and tip projection. These findings confirm ethnic variations in the sesamoid nasal cartilages when this Iranian population is compared with other populations assessed in earlier reports. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:e22-e25)
In the human nose, sesamoid cartilages are small accessory cartilages found in the lateral space between the upper and lower lateral cartilages. Although the framework of the nasal tip is formed by lower lateral cartilages, sesamoid cartilages connect each lateral crus to the piriform aperture. Sesamoid bridges between the tail of the lateral crus and piriform aperture have a supportive role for preserving contour of the lateral crus and nasal tip. According to past reports, sesamoids are multiple.1 In rhinoplasty the alar cartilage is not dissected beyond the lateral tail. The present cadaveric nasal dissection is used to document for the first time the anatomy of accessory cartilages and to understand the correlation between the lateral cartilage sesamoid and piriform aperture in Iranian fresh cadavers. The aim was to understand anatomic variations of the accessory nasal cartilages.
a
Assistant Professor of Plastic Surgery, Trauma Research Center, Baqiyatallah University of Medical Sciences. b General Practitioner, Tehran University of Medical Sciences Imam Khomeini Hospital. c Professor, Oral and Maxillofacial Surgery, Trauma Research Center, Baqiyatallah University of Medical Sciences. Received for publication May 2, 2011; returned for revision Aug 23, 2011; accepted for publication Sep 20, 2011. © 2012 Mosby, Inc. All rights reserved. 2212-4403/$ - see front matter doi:10.1016/j.oooo.2011.09.020
e22
MATERIALS AND METHODS This prospective cross-sectional study was conducted by dissecting 72 sesamoid cartilages in 41 cadavers (mean age 42 years); 25 male (61%) and 16 female (39%) cadabers were studied; 5 cadavers were missing sesamoid cartilages bilaterally. The anatomy of the accessory nasal cartilages was evaluated in cadavers within 48 hours after death. A collumellar incision and open rhinoplasty approach was used for the elevation of the dorsal nasal flap to access the lateral and sesamoid cartilages. The identities of the cadavers were unknown, and the Ethics Committees of Baqiyatallah University of Medical Sciences and Tehran University of Medical Sciences Imam Khomeini Hospital, Tehran, approved the study. Anatomic variations of accessory cartilages were assessed by dissection of the lateral crus toward the piriform aperture using eye loupe N-3 magnification. We also measured anthropometry of these small cartilages, including length, width, and thickness, with a caliper. All variables were analyzed using student t test and chi-square tests. A P value of ⬍.05 was considered to be significant. During dissection, there were no asymmetric absence of the sesamoid cartilages.
Statement of Clinical Relevance Accessory cartilages are small nasal cartilages between the lateral crus and piriform aperture of the nose bilaterally and are supporting structures of the nasal tip. This cartilage has an important role in preserving nasal alar contour and tip projection.
OOOO Volume 114, Number 2
ORIGINAL ARTICLE Ebrahimi et al. e23
Table I. Anthropometry of sesamoid cartilage in Iranian fresh cadavers, mm Parameter Length
Width
Thickness
Fig. 1. In these cadaveric lower lateral cartilages, there are irregular rectangle sesamoids at the tail of the lateral crus.
RESULTS Forty-one cadavers were dissected for evaluation of sesamoid cartilages; in 12% (5) of the cadavers there was no sesamoid cartilage on either side of the nose at the tail of the lateral crus toward the piriform aperture; in 88% (36) there was 1 sesamoid on each side that leaned to the piriform aperture. The shape of the sesamoid was not symmetric in both sides; 66% (27) of cadavers had irregular rectangle (Figure 1) sesamoid cartilages and 22% (9) had irregular triangle sesamoid cartilages. The perichondria of the sesamoids were evaluated with the use of an eye loupe and were continuous with the lateral crus perichondria. There was no significant difference between men and women (P ⬎ .05). In 5 cadavers devoid of sesamoids bilaterally, the nasal tip was underprojected compared with cadavers that had sesamoids bilaterally; we measured ideal nasal length (0.67 ⫻ midfacial height) and tip projection (direct distance between alar-cheek junction to the tip) with a caliper before dissection. In cadavers with sesamoids, the ratio of ideal nasal length to tip projection was 1.0:0.68, whereas in cadavers without sesamoids, this ratio was nearly 1.0:0.51; this difference was significant (P ⬍ .05) and indicates underprojection of the nasal tip. The authors failed to find multiple sesamoid cartilages. In dissection of cadavers there was only 1 sesamoid cartilage bridged between the lateral crus and piriform aperture; this sesamoid cartilage was situated along the tail of lateral crus and provided support for the lateral crus. There was no significant difference between men and women regarding number or shape of sesamoids (P ⬎ .05). This cadaveric dissection failed to support the previously held opinion about the existence of multiple chain-like sesamoid cartilages. Sesamoid cartilage length measured in the midportion of the cartilage was 2- 5 mm (mean 3 mm), width was 1.5-3 mm (mean 2
Right
Left
P value
Male: 3.5 ⫾ 1/8 Female: 2.5 ⫾ 1.1 Mean: 3 mm ⫾ 0.2 Male: 2 ⫾ 1 Female: 1.8 ⫾ 0.9 Mean: 2 ⫾ 0.1 Male: 0.8 ⫾ 0.15 Female: 0.7 ⫾ 0.16 Mean: 0.75 ⫾ 0.1
Male: 3 ⫾ 1.2 Female: 2.8 ⫾ 0.9 Mean: 3 ⫾ 0.1 Male: 1.5 ⫾ 0.9 Female: 2 ⫾ 0.8 Mean: 1.9 ⫾ 0.2 Male: 0.8 ⫾ 0.14 Female: 0.8 ⫾ 0.11 Mean: 0.75 ⫾ 0.1
⬎.05 ⬎.05 ⬎.05
We used a caliper for measurement of sesamoids, and there was no difference between the sexes.
Fig. 2. shows shows mined tion.
Sesamoid cartilage with magnification; black arrow the length of the sesamoid cartilage; white arrow the width of the sesamoid cartilage. We also deterthickness of the sesamoid cartilage in the midpor-
mm), and thickness was 0.7-1 mm (mean 0.75 mm; Table I; Figure 2) During dissection, we found sesamoid cartilages that supported the lateral crus and preserved the position of the lateral crus at the piriform aperture. Sesamoid accessory cartilages were singular on each side and they supported the nasal tip. Sesamoid cartilages observed in this study exhibited asymmetry and variability.
DISCUSSION The aim of this study was to document the anatomy and anthropometry of accessory sesamoid cartilages of the human nose in an Iranian population. The cartilage was situated between the lateral crus and piriform aperture and gave support for lower lateral cartilages and the nasal tip. This cartilage is situated between lateral crus and piriform aperture and is supportive for lower lateral cartilages and the nasal tip. Earlier anatomic studies
ORAL AND MAXILLOFACIAL SURGERY e24 Ebrahimi et al.
reported varying numbers of lesser alar and sesamoid cartilages.1-3 Our findings may represent ethnic variations in different populations; rhinoplasty is a common esthetic operation in Iran, and in a majority of patients we observe good tip projection during operation; this finding is in contrast to eastern Asian populations. The human nose is complex structurally, and this complexity results in variations in nasal shape and form.3 The framework of the nasal tip is formed by the medial, middle, and lateral crura of the lower lateral cartilages, and the accessory cartilages connect each lateral crus to the piriform aperture. All of these cartilages are bound together by a continuous perichondrum, which gives stability to the cartilages and causes them to act as a single structure and functional unit. Shape and position of this unit, the thickness of the overlying skin, and the fibrous attachment to the adjacent anatomic structures interrelate and determine the appearance of the tip.4-7 Anatomy The small alar cartilages are located between the lateral crura and the maxilla, below the inferior edge of the upper lateral cartilages in the intercartilage area. Although Dion et al. thought these small cartilages to be multiple,1 the results of the current study did not reveal similar results. The lesser alar and sesamoid cartilages found during dissection did not visually influence the external nasal shape.2-8 The study of the nasal profile shows that the shape, positioning, and thickness of the underlying structures vary among individuals. Understanding the variations may have practical application in rhinoplasty. A facial membrane encircling the piriform aperture was found in hemifacial cadaver dissection; this fascia incorporates the previously described sesamoid complex.9 This facial system surrounds the piriform aperture and provides a connection from maxillary bone to the lateral cartilage and the alar base. On macroscopic examination, sesamoid cartilage and dense fibrous tissue were observed between the lateral crus and the piriform aperture.9 Regarding the structure between the lateral crus and piriform aperture, definite fibrous attachmentas well as the cartilage was found in dissection of fresh cadavers.10 Janeke and Wright investigated this supporting structure using cadavers and named it the sesamoid complex.11 Gunther has shown that the lateral crus was connected to the accessory cartilage.12 Findings Accessory cartilage was found in 88% of cadavers at the end of the lateral crus in the piriform aperture in this study. Similar findings regarding the sesamoid cartilage
OOOO August 2012
have been reported by Seung et al. in Korean patients.13,14 In addition, accessory cartilages reported by Salaam et al. were at the end of lower lateral crus, which continued to the piriform aperture.15 The findings of the present study were similar. The accessory cartilage ring is a major factor in determining the vestibular valve and can be expressed superficially by significant concavity just beyond the lateral crus.16 The shape and position of the alar cartilages influenced the nasal tip shape and asymmetry.17 Because of supporting actions of sesamoid cartilages at the tail of lateral crus, we noticed nasal tip over projection in cadavers, these findings explain why Iranian nasal tips are different from those of eastern Asian people. In cadavers where we did not find sesamoids (12%), there was fibrous tissue between the tail of the lateral crus and piriform aperture during dissection, and (using eye-loop magnification) there was no remnant of sesamoid cartilage visualized. We found 3 important points about morphology and role of sesamoids in this cadaveric study: first, that single sesamoids were found on each side of the nose; second, that the morphology of sesamoid cartilages in the majority of cadavers was an irregular rectangle (66%); and third, the direct role of sesamoids in supporting lateral crus contouring and nasal tip projection. According to Byrd’s analysis, ideal nasal length is measured as 0.67 of midfacial height.18 The tip is the midline point on the dome projecting points of the lower lateral cartilages, and tip projection is two-thirds (0.67) of ideal nasal length; if tip projection is ⬍0.67, then ideal nasal length it is underprojected.18 When we used Byrd’s criteria for determining nasal tip projection in the 12% of cadavers missing sesamoid cartilage, the tip was underprojected. This finding is important in that it shows the direct role of sesamoids in preserving alar contour and tip projection.
CONCLUSION Anatomic variation of accessory nasal cartilages were evaluated, revealing that sesamoid cartilage were present in 88% of the cadavers with no significant difference between male and female (P ⬎ .05). When present the sesamoid cartilage were single on each side. They were irregular rectangular or triangular in shape. The larger brim was situated near the lateral crus and the lesser brim near the piriform aperture. The anthropometry of these small cartilages was also described in this Iranian population. This cartilage has an important role in preserving nasal alar contour and tip projection. REFERENCES 1. Dion MC, Jefek BW, Tobin CE. The anatomy of the nose: external support. Arch Otolaryngol 1978;104:145-50. 2. Macho GA. Descriptive morphological features of the nose, an
OOOO Volume 114, Number 2
3. 4. 5. 6. 7.
8. 9. 10. 11. 12.
assessment of their importance for plastic reconstruction. J Forensic Sci 1989;34:902-11. Han SK, Lee DG, Kim JB, Kim WK. An anatomic study of nasal tip supporting structures. Ann Plast Surg 2004;52:134-9. Mccollough EG, Mangat D. Systematic approach to correction of nasal tip in rhinoplasty. Arch Otolaryngol 1981;107:12-6. Peck GC. The onlay graft for nasal tip projection. Plast Reconstr Surg 1983;71:27-39. Horton CE. Achieving more nasal tip projection. Plast Reconstr Surg 1975;56:211. Adams WP, Rohrich RJ, Hollier LH, Minoli J, Thornton LK, Gyimesi I. Anatomic basis and clinical implications for nasal tip support in open versus closed rhinoplasty. Plast Reconstr Surg 1999;103:255. Macho GA. An appraisal of plastic reconstruction of the external nose. J Forensic Sci 1989;20:1391-403. Rohrich RJ, Hoxworth RE, Thornton JF, Pessa JE. The pyriform ligament. Plast Reconstr Surg 2008;121:277-81. Daniel RK, Letourneau A. Rhinoplasty: nasal anatomy. Ann Plast Surg 1988;20:5-13. Janeke JB, Wright WK. Studies on the support of the nasal tip. Arch Otolaryngol 1971;93:458-64. Gunther JP. Tip rhinoplasty: a personal approach. Facial Plast Surg Clin North Am 1987;4:263-75.
ORIGINAL ARTICLE Ebrahimi et al. e25 13. Seung K, Dong G, Kim JB, Kim WK. An anatomic study of nasal tip supporting structures. Ann Plast Surg 2004;52: 134-39. 14. Guyuron B, Behmand RA. Nasal tip sutures. Plast Reconstr Surg 2003;112:1130-45. 15. Salaam A, Kashgarian M, Davilia J, Persing J. Anatomy of the Caucasian alar groove. Plast Reconstr Surg 2002;110:261-69. 16. Busca GP, Amasio ME, Staffieri A. The surgery of the tip of the nose. Acta Otorhinolaryngol Ital 2002;22:7-29. Review. 17. Hatzis GP, Sherry SD, Hogan GM, Finn RA. Observations of the marginal incision and lateral crura alar cartilage asymmetry in rhinoplasty: a fixed cadaver study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:432-7. 18. Byrd HS, Hobar PC. Rhinoplasty: a practical guide for surgical planning. Plast Reconstr Surg 1993;91:642.
Reprint requests: Dr. Motamedi Giti 19667 Tehran Iran [email protected]
Morphologic variations of sesamoid cartilages of the nose in Iranian cadavers Ali Ebrahimi, MD,a Mohammad Hosein Kalantar Motamedi, DDS,b and Nasrin Nejadsarvari, MD, MPHc Baqiyatallah University of Medical Sciences and Tehran University of Medical Sciences Imam Khomeini Hospital, Tehran, Iran
Background. Accessory cartilages are small nasal cartilages between the lateral crus and piriform aperture of the nose bilaterally. These cartilages are among the supporting structures of the nasal tip. Study Design. This prospective cross-sectional study was conducted on Iranian fresh cadavers for evaluation of ethnic differences. Seventy-two sesamoid cartilages in 41 cadavers (mean age 42 years) were dissected to evaluate anatomy and anthropometry of the sesamoid cartilages. Elevation of the dorsal nasal flap after a collumellar incision was done. After the separation of the lower lateral cartilages and sesamoid cartilages on each side, the anatomy and anthropometry of the cartilages were assessed. Results. In 12% (5) of the cadavers there were no sesamoid cartilages, and in 88% (36) of the cadavers there was 1 sesamoid on each side. The shape of the sesamoid cartilages was rectangular in 66% (27) and triangular in 22% (9). The mean length, width, and thickness were 3 mm, 2 mm, and 0.75 mm, respectively. Conclusions. This cartilage was single on each side of the nose and its shape was an irregular rectangle or triangle and has an important role in preserving nasal alar contour and tip projection. These findings confirm ethnic variations in the sesamoid nasal cartilages when this Iranian population is compared with other populations assessed in earlier reports. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:e22-e25)
In the human nose, sesamoid cartilages are small accessory cartilages found in the lateral space between the upper and lower lateral cartilages. Although the framework of the nasal tip is formed by lower lateral cartilages, sesamoid cartilages connect each lateral crus to the piriform aperture. Sesamoid bridges between the tail of the lateral crus and piriform aperture have a supportive role for preserving contour of the lateral crus and nasal tip. According to past reports, sesamoids are multiple.1 In rhinoplasty the alar cartilage is not dissected beyond the lateral tail. The present cadaveric nasal dissection is used to document for the first time the anatomy of accessory cartilages and to understand the correlation between the lateral cartilage sesamoid and piriform aperture in Iranian fresh cadavers. The aim was to understand anatomic variations of the accessory nasal cartilages.
a
Assistant Professor of Plastic Surgery, Trauma Research Center, Baqiyatallah University of Medical Sciences. b General Practitioner, Tehran University of Medical Sciences Imam Khomeini Hospital. c Professor, Oral and Maxillofacial Surgery, Trauma Research Center, Baqiyatallah University of Medical Sciences. Received for publication May 2, 2011; returned for revision Aug 23, 2011; accepted for publication Sep 20, 2011. © 2012 Mosby, Inc. All rights reserved. 2212-4403/$ - see front matter doi:10.1016/j.oooo.2011.09.020
e22
MATERIALS AND METHODS This prospective cross-sectional study was conducted by dissecting 72 sesamoid cartilages in 41 cadavers (mean age 42 years); 25 male (61%) and 16 female (39%) cadabers were studied; 5 cadavers were missing sesamoid cartilages bilaterally. The anatomy of the accessory nasal cartilages was evaluated in cadavers within 48 hours after death. A collumellar incision and open rhinoplasty approach was used for the elevation of the dorsal nasal flap to access the lateral and sesamoid cartilages. The identities of the cadavers were unknown, and the Ethics Committees of Baqiyatallah University of Medical Sciences and Tehran University of Medical Sciences Imam Khomeini Hospital, Tehran, approved the study. Anatomic variations of accessory cartilages were assessed by dissection of the lateral crus toward the piriform aperture using eye loupe N-3 magnification. We also measured anthropometry of these small cartilages, including length, width, and thickness, with a caliper. All variables were analyzed using student t test and chi-square tests. A P value of ⬍.05 was considered to be significant. During dissection, there were no asymmetric absence of the sesamoid cartilages.
Statement of Clinical Relevance Accessory cartilages are small nasal cartilages between the lateral crus and piriform aperture of the nose bilaterally and are supporting structures of the nasal tip. This cartilage has an important role in preserving nasal alar contour and tip projection.
OOOO Volume 114, Number 2
ORIGINAL ARTICLE Ebrahimi et al. e23
Table I. Anthropometry of sesamoid cartilage in Iranian fresh cadavers, mm Parameter Length
Width
Thickness
Fig. 1. In these cadaveric lower lateral cartilages, there are irregular rectangle sesamoids at the tail of the lateral crus.
RESULTS Forty-one cadavers were dissected for evaluation of sesamoid cartilages; in 12% (5) of the cadavers there was no sesamoid cartilage on either side of the nose at the tail of the lateral crus toward the piriform aperture; in 88% (36) there was 1 sesamoid on each side that leaned to the piriform aperture. The shape of the sesamoid was not symmetric in both sides; 66% (27) of cadavers had irregular rectangle (Figure 1) sesamoid cartilages and 22% (9) had irregular triangle sesamoid cartilages. The perichondria of the sesamoids were evaluated with the use of an eye loupe and were continuous with the lateral crus perichondria. There was no significant difference between men and women (P ⬎ .05). In 5 cadavers devoid of sesamoids bilaterally, the nasal tip was underprojected compared with cadavers that had sesamoids bilaterally; we measured ideal nasal length (0.67 ⫻ midfacial height) and tip projection (direct distance between alar-cheek junction to the tip) with a caliper before dissection. In cadavers with sesamoids, the ratio of ideal nasal length to tip projection was 1.0:0.68, whereas in cadavers without sesamoids, this ratio was nearly 1.0:0.51; this difference was significant (P ⬍ .05) and indicates underprojection of the nasal tip. The authors failed to find multiple sesamoid cartilages. In dissection of cadavers there was only 1 sesamoid cartilage bridged between the lateral crus and piriform aperture; this sesamoid cartilage was situated along the tail of lateral crus and provided support for the lateral crus. There was no significant difference between men and women regarding number or shape of sesamoids (P ⬎ .05). This cadaveric dissection failed to support the previously held opinion about the existence of multiple chain-like sesamoid cartilages. Sesamoid cartilage length measured in the midportion of the cartilage was 2- 5 mm (mean 3 mm), width was 1.5-3 mm (mean 2
Right
Left
P value
Male: 3.5 ⫾ 1/8 Female: 2.5 ⫾ 1.1 Mean: 3 mm ⫾ 0.2 Male: 2 ⫾ 1 Female: 1.8 ⫾ 0.9 Mean: 2 ⫾ 0.1 Male: 0.8 ⫾ 0.15 Female: 0.7 ⫾ 0.16 Mean: 0.75 ⫾ 0.1
Male: 3 ⫾ 1.2 Female: 2.8 ⫾ 0.9 Mean: 3 ⫾ 0.1 Male: 1.5 ⫾ 0.9 Female: 2 ⫾ 0.8 Mean: 1.9 ⫾ 0.2 Male: 0.8 ⫾ 0.14 Female: 0.8 ⫾ 0.11 Mean: 0.75 ⫾ 0.1
⬎.05 ⬎.05 ⬎.05
We used a caliper for measurement of sesamoids, and there was no difference between the sexes.
Fig. 2. shows shows mined tion.
Sesamoid cartilage with magnification; black arrow the length of the sesamoid cartilage; white arrow the width of the sesamoid cartilage. We also deterthickness of the sesamoid cartilage in the midpor-
mm), and thickness was 0.7-1 mm (mean 0.75 mm; Table I; Figure 2) During dissection, we found sesamoid cartilages that supported the lateral crus and preserved the position of the lateral crus at the piriform aperture. Sesamoid accessory cartilages were singular on each side and they supported the nasal tip. Sesamoid cartilages observed in this study exhibited asymmetry and variability.
DISCUSSION The aim of this study was to document the anatomy and anthropometry of accessory sesamoid cartilages of the human nose in an Iranian population. The cartilage was situated between the lateral crus and piriform aperture and gave support for lower lateral cartilages and the nasal tip. This cartilage is situated between lateral crus and piriform aperture and is supportive for lower lateral cartilages and the nasal tip. Earlier anatomic studies
ORAL AND MAXILLOFACIAL SURGERY e24 Ebrahimi et al.
reported varying numbers of lesser alar and sesamoid cartilages.1-3 Our findings may represent ethnic variations in different populations; rhinoplasty is a common esthetic operation in Iran, and in a majority of patients we observe good tip projection during operation; this finding is in contrast to eastern Asian populations. The human nose is complex structurally, and this complexity results in variations in nasal shape and form.3 The framework of the nasal tip is formed by the medial, middle, and lateral crura of the lower lateral cartilages, and the accessory cartilages connect each lateral crus to the piriform aperture. All of these cartilages are bound together by a continuous perichondrum, which gives stability to the cartilages and causes them to act as a single structure and functional unit. Shape and position of this unit, the thickness of the overlying skin, and the fibrous attachment to the adjacent anatomic structures interrelate and determine the appearance of the tip.4-7 Anatomy The small alar cartilages are located between the lateral crura and the maxilla, below the inferior edge of the upper lateral cartilages in the intercartilage area. Although Dion et al. thought these small cartilages to be multiple,1 the results of the current study did not reveal similar results. The lesser alar and sesamoid cartilages found during dissection did not visually influence the external nasal shape.2-8 The study of the nasal profile shows that the shape, positioning, and thickness of the underlying structures vary among individuals. Understanding the variations may have practical application in rhinoplasty. A facial membrane encircling the piriform aperture was found in hemifacial cadaver dissection; this fascia incorporates the previously described sesamoid complex.9 This facial system surrounds the piriform aperture and provides a connection from maxillary bone to the lateral cartilage and the alar base. On macroscopic examination, sesamoid cartilage and dense fibrous tissue were observed between the lateral crus and the piriform aperture.9 Regarding the structure between the lateral crus and piriform aperture, definite fibrous attachmentas well as the cartilage was found in dissection of fresh cadavers.10 Janeke and Wright investigated this supporting structure using cadavers and named it the sesamoid complex.11 Gunther has shown that the lateral crus was connected to the accessory cartilage.12 Findings Accessory cartilage was found in 88% of cadavers at the end of the lateral crus in the piriform aperture in this study. Similar findings regarding the sesamoid cartilage
OOOO August 2012
have been reported by Seung et al. in Korean patients.13,14 In addition, accessory cartilages reported by Salaam et al. were at the end of lower lateral crus, which continued to the piriform aperture.15 The findings of the present study were similar. The accessory cartilage ring is a major factor in determining the vestibular valve and can be expressed superficially by significant concavity just beyond the lateral crus.16 The shape and position of the alar cartilages influenced the nasal tip shape and asymmetry.17 Because of supporting actions of sesamoid cartilages at the tail of lateral crus, we noticed nasal tip over projection in cadavers, these findings explain why Iranian nasal tips are different from those of eastern Asian people. In cadavers where we did not find sesamoids (12%), there was fibrous tissue between the tail of the lateral crus and piriform aperture during dissection, and (using eye-loop magnification) there was no remnant of sesamoid cartilage visualized. We found 3 important points about morphology and role of sesamoids in this cadaveric study: first, that single sesamoids were found on each side of the nose; second, that the morphology of sesamoid cartilages in the majority of cadavers was an irregular rectangle (66%); and third, the direct role of sesamoids in supporting lateral crus contouring and nasal tip projection. According to Byrd’s analysis, ideal nasal length is measured as 0.67 of midfacial height.18 The tip is the midline point on the dome projecting points of the lower lateral cartilages, and tip projection is two-thirds (0.67) of ideal nasal length; if tip projection is ⬍0.67, then ideal nasal length it is underprojected.18 When we used Byrd’s criteria for determining nasal tip projection in the 12% of cadavers missing sesamoid cartilage, the tip was underprojected. This finding is important in that it shows the direct role of sesamoids in preserving alar contour and tip projection.
CONCLUSION Anatomic variation of accessory nasal cartilages were evaluated, revealing that sesamoid cartilage were present in 88% of the cadavers with no significant difference between male and female (P ⬎ .05). When present the sesamoid cartilage were single on each side. They were irregular rectangular or triangular in shape. The larger brim was situated near the lateral crus and the lesser brim near the piriform aperture. The anthropometry of these small cartilages was also described in this Iranian population. This cartilage has an important role in preserving nasal alar contour and tip projection. REFERENCES 1. Dion MC, Jefek BW, Tobin CE. The anatomy of the nose: external support. Arch Otolaryngol 1978;104:145-50. 2. Macho GA. Descriptive morphological features of the nose, an
OOOO Volume 114, Number 2
3. 4. 5. 6. 7.
8. 9. 10. 11. 12.
assessment of their importance for plastic reconstruction. J Forensic Sci 1989;34:902-11. Han SK, Lee DG, Kim JB, Kim WK. An anatomic study of nasal tip supporting structures. Ann Plast Surg 2004;52:134-9. Mccollough EG, Mangat D. Systematic approach to correction of nasal tip in rhinoplasty. Arch Otolaryngol 1981;107:12-6. Peck GC. The onlay graft for nasal tip projection. Plast Reconstr Surg 1983;71:27-39. Horton CE. Achieving more nasal tip projection. Plast Reconstr Surg 1975;56:211. Adams WP, Rohrich RJ, Hollier LH, Minoli J, Thornton LK, Gyimesi I. Anatomic basis and clinical implications for nasal tip support in open versus closed rhinoplasty. Plast Reconstr Surg 1999;103:255. Macho GA. An appraisal of plastic reconstruction of the external nose. J Forensic Sci 1989;20:1391-403. Rohrich RJ, Hoxworth RE, Thornton JF, Pessa JE. The pyriform ligament. Plast Reconstr Surg 2008;121:277-81. Daniel RK, Letourneau A. Rhinoplasty: nasal anatomy. Ann Plast Surg 1988;20:5-13. Janeke JB, Wright WK. Studies on the support of the nasal tip. Arch Otolaryngol 1971;93:458-64. Gunther JP. Tip rhinoplasty: a personal approach. Facial Plast Surg Clin North Am 1987;4:263-75.
ORIGINAL ARTICLE Ebrahimi et al. e25 13. Seung K, Dong G, Kim JB, Kim WK. An anatomic study of nasal tip supporting structures. Ann Plast Surg 2004;52: 134-39. 14. Guyuron B, Behmand RA. Nasal tip sutures. Plast Reconstr Surg 2003;112:1130-45. 15. Salaam A, Kashgarian M, Davilia J, Persing J. Anatomy of the Caucasian alar groove. Plast Reconstr Surg 2002;110:261-69. 16. Busca GP, Amasio ME, Staffieri A. The surgery of the tip of the nose. Acta Otorhinolaryngol Ital 2002;22:7-29. Review. 17. Hatzis GP, Sherry SD, Hogan GM, Finn RA. Observations of the marginal incision and lateral crura alar cartilage asymmetry in rhinoplasty: a fixed cadaver study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;97:432-7. 18. Byrd HS, Hobar PC. Rhinoplasty: a practical guide for surgical planning. Plast Reconstr Surg 1993;91:642.
Reprint requests: Dr. Motamedi Giti 19667 Tehran Iran [email protected]