[Deforming endonasal mass during pregnancy]. / Deformierende endonasale Raumforderung während der Schwangerschaft.

This article presents the case of a 33-year-old woman who consulted the authors' ENT clinic in the 39th week of pregnancy with recurrent epistaxis. A livid endonasal mass was found on the left side, subtotally displacing the nose and leading to deformation of the external nose. External biopsy provided no indications of malignancy. Postpartum CT of the paranasal sinuses revealed a mass destroying the cartilaginous nasal septum. Endoscopic resection of the finding was performed with preservation of the clinically sound nasal septal cartilage. Histopathological examination revealed a capillary hemangioma, which was classified as granuloma gravidarum due to its occurrence during pregnancy.

The Caucasian Hump: Radiologic Study of the Osteocartilaginous Vault versus Surface Anatomy. Clinical Implications in Structured and Preservation Rhinoplasty.

BACKGROUND: The relation between the osteocartilaginous nasal vault and nasal hump characteristics has not been fully investigated. METHODS: Measurements were collected from computed tomographic nasal scans in the midsagittal plane in adult Caucasian patients seeking rhinoplasty because of nasal hump from January of 2015 to December of 2018. Measurements were compared to those of sex- and age-matched patients not seeking rhinoplasty (control group). Patients with other significant nasal deformities were excluded. The correlations between nasal hump length, height, and osteocartilaginous nasal vault measurements were assessed. Distances from the beginning of the nasal hump to the kyphion and ethmoidal points were measured as well. The location of the nasal hump apex in relation to the keystone area structures was detailed. RESULTS: The study included 134 Caucasian patients, with 67 presenting nasal hump. The mean patient age was 32.9 years and 69.6 percent were female patients. Nasal hump measured a mean 17 ± 2.7 mm in length and 1.8 mm (range, 1.1 to 3.8 mm) in height. Nasal hump length correlated with nose length and nasal bone length. Nasal hump height correlated with nose length and the angle over the kyphion. In 97 percent of patients, the nasal hump began caudal to the ethmoidal point, and in all patients, the kyphion was underneath the nasal hump. The nasal hump is not a symmetric structure and, in all patients, its apex was situated above the septal cartilage. CONCLUSIONS: The nasal hump characteristics are mainly attributable to the septal cartilage, and this should be the cornerstone of any dorsal hump reduction strategy. The caudal aspect of the nasal bones contributes to the nasal hump, whereas the posterior ethmoidal plate rarely does.

Using Ultrasound to Evaluate Nasal Septal Cartilage.

Importance: Having a noninvasive tool that quantifies the amount of remaining septal cartilage in the setting of prior septoplasty would be useful for surgical planning and patient counseling. Objective: The objective of this pilot study is to determine if endocavitary ultrasound can be used to evaluate the presence and thickness of septal cartilage in vivo. Design, Setting, and Participants: A small prospective observational study was designed to assess the feasibility of using intranasal ultrasound to verify the presence and measure the thickness of septal cartilage. Imaging was undertaken by the principle investigator using a protocol developed by the research team. Six healthy volunteers were enrolled including three subjects who have had prior septoplasty. Images and measurements of the nasal septum were obtained. Main Outcomes: Confirming the presence of the nasal septum was the main outcome with a secondary outcome of measurement of septum thickness. Results: The endonasal ultrasound probe was able to identify the septum and resected areas. The mean thickness of the septum in subjects without surgery was 1.0 mm and those with prior septoplasty was 0.8 mm. Student's t-test show a statistically significant difference in septum thickness between these two groups with a p-value of 0.0093. Conclusions and Relevance: This study demonstrates a novel method of determining the presence of septal cartilage after septoplasty surgery. This information may be useful for operative planning in revision rhinoplasty.

Finite Element Analysis of the Septal Cartilage L-Strut.

Importance: Septoplasty is one of the most commonly performed operations in the head and neck. However, the reasons for septoplasty failure and the additional stress of performing a chondrotomy on the septal cartilage are not well understood. Design, Setting, and Participants: A finite element model of the nasal septum was created using a microcomputed tomography scan of the nasoseptal complex that was reconstructed into a three-dimensional model in silico. Testing included four common chondrotomy designs: traditional L-strut, double-cornered chondrotomy (DCC), curved L-strut, and the C-curve. Tip displacement was applied in a vector parallel to the caudal strut to simulate nasal tip palpation. Main Outcomes and Measures: With finite element analysis, the maximum principal stress (MPS), von Mises stress (VMS), harvested cartilage volume, and surface area were recorded. Results: The highest MPS for the L-strut, DCC, curved L-strut, and C-curve was identified at the corner of the chondrotomy. The MPS at the corner of the chondrotomy was reduced 44% when comparing the C-curve with the traditional L-strut. The VMS patterns showed compressive stress along the caudal septum in all models, but at the corner, the stresses were highest in the chondrotomies designed with sharp-angled corners. The VMS showed a 76% decrease when comparing the C-curve with the traditional L-strut. The stress across the anterior septal angle is also higher in models with sharp-angled corners. Cartilage harvest volumetric and surface area assessments did not show meaningful differences between shapes. Conclusions and Relevance: The highest area of stress is near the transition of the dorsal to caudal septum in all models. Stresses are relatively higher in chondrotomy shapes that contain sharp-angled corners. The relative reduction in MPS and VMS utilizing a C-curve instead of an L-strut may decrease the likelihood that the septum will deform or fail in this region. The volume and surface area of the C-curve are similar to that of the L-strut technique. Avoiding sharp-angled corners reduces the stresses at the corner of the chondrotomy and across the anterior septal angle. Using a C-curve may be an improved septoplasty design.

Comparison of Micro-Computed Tomography and Clinical Computed Tomography Protocols for Visualization of Nasal Cartilage Before Surgical Planning for Rhinoplasty.

IMPORTANCE: There is no imaging standard to model nasal cartilage for the planning of rhinoplasty procedures. Preoperative visualization of cartilage may improve objective evaluation of nasal deformities, surgical planning, and surgical reconstruction. OBJECTIVES: To evaluate the feasibility of visualizing nasal cartilage using high resolution micro-computed tomography (CT) compared with the criterion standard of pathologic findings in a cadaveric specimen and to evaluate its accuracy compared with various clinical CT protocols. DESIGN, SETTING, AND PARTICIPANTS: Anatomic study at the University of Washington using single human cadaveric nasal specimens performed from July 10, 2017, to March 30, 2018. INTERVENTIONS: A micro-CT acquisition with 60-micron resolution was obtained of a nasal specimen. The specimen was then scanned with 5 different clinical CT protocols to span both clinical care and machine limits. The specimen was then sectioned in 5-mm axial slices for pathologic analysis. MAIN OUTCOMES AND MEASURES: Micro-CT images were registered to pathologic specimen cross-sections using a graphite fiducial system. Cartilage substructures were manually segmented and analyzed. A library of matched images across the micro-CT and various clinical CT protocols was then developed. Region of interest analysis was performed for each of the cartilage structures and their boundaries on clinical CT protocols and micro-CT, with the outcome of mean (SD) density using Hounsfield units. RESULTS: A single human cadaveric nasal specimen was used to obtain the following results. Lower lateral cartilage, upper lateral cartilage, and septal cartilage were accurately delineated on the micro-CT images compared with pathologic findings. The mean absolute deviation from pathologic findings was 0.30 mm for septal cartilage thickness, 0.98 mm for maximal upper lateral cartilage length, and 1.40 mm for maximal lower lateral cartilage length. On clinical CT protocols, only septal cartilage was well discriminated from boundary. Higher radiation dose resulted in more accurate density measurements of cartilage, but it did not ultimately improve ability to discriminate cartilage. CONCLUSIONS AND RELEVANCE: The results of this anatomic study may represent a notable step toward advancing knowledge of the capabilities and pitfalls of nasal cartilage visualization on CT. Nasal cartilage visualization was feasible on the micro-CT compared with pathologic findings. Future research may further examine the barriers to accurately visualizing upper lateral cartilage and lower lateral cartilage, a prerequisite for clinical application. LEVEL OF EVIDENCE: NA.

Component Restoration in the Unilateral Intermediate Cleft Tip Rhinoplasty: Technique and Long-Term Outcomes.

BACKGROUND: The intermediate cleft tip rhinoplasty is performed in childhood to address residual tip asymmetries during the most critical period of psychosocial development. The authors describe and evaluate long-term outcomes of that approach for the unilateral cleft lip and palate patient based on the concept of individual restoration of each abnormal anatomical component. METHODS: Photomorphometric analyses of unilateral cleft lip and palate patients (n = 50) who underwent intermediate cleft tip rhinoplasty using the component restoration technique were evaluated preoperatively (time 0) and postoperatively at less than 1 year (time 1), 1 to 3 years (time 2), and more than 3 years (time 3) and compared to age-matched unilateral cleft lip and palate control patients. Nasal relationships (alar symmetry, nasal tip protrusion-to-alar base width ratio, and height-to-width dimensions for the cleft and noncleft nostrils) were compared over time using a linear mixed-effect model. RESULTS: At time 0, both groups demonstrated similar nasal relationships, with the exception of a wider cleft-side nostril in relationship to height in the rhinoplasty group. The component restoration technique improved all four nasal relationships at all postoperative time points compared with time 0 in a statistically significant manner, whereas control patients did not demonstrate significant changes at the corresponding ages. Long-term differences at time 3 revealed a trend toward improved alar symmetry and cleft-side and non-cleft-side nostril dimensions, and a significant improvement in the nasal tip protrusion-to-alar base width ratio in intermediate cleft tip rhinoplasty-treated versus control patients (p = 0.002). CONCLUSION: The component restoration technique for the unilateral intermediate cleft tip rhinoplasty improves nasal relationships toward normal immediately and in a sustained manner for at least 3 years. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Combined Nasal Osteotomies With Caudal Transverse Osteotomy and Their Effect on Dorsal Geometry.

Background: Congenital, traumatic, or developmental bony vault deformities may require additional interventions rather than classical osteotomies to correct the surface structure or angulations of the nasal bones in rhinoplasty. Objectives: The aim of the study was to determine the effects of the additional osteotomies applied for the correction of the nasal vault asymmetries retrospectively. Methods: Twenty-one patients among 512 primary rhinoplasty cases between 2011 and 2016 with bony vault asymmetries were included in the study. Three patients had bilateral convex, 6 patients had unilateral convex, and 7 patients had unilateral concave surface deformities. Five patients had concave deformity on one side and convex deformity on the other side. Double-layer lateral osteotomies and caudal transverse osteotomies were conducted for the correction of the severe surface anatomy deformities of the nasal bones. The caudal transverse osteotomy was delicately performed with a special osteotome, which was designed to protect inner periosteum and mucosa of the nasal bone, and to prevent uncontrolled fracture formation with thinned edge. Results: Twenty patients (95.2%) had favorable results with restoration of a symmetric bony and cartilaginous nasal vault configuration. None of the bone fragments showed any rotation or malposition. One (4.8%) patient with a crooked nose had suboptimal dorsal geometry without requiring revisional surgery at the level of the cartilaginous nasal vault. Conclusions: The author described the morphology, clinical relevance, and correction methods of the nasal vault and the changes that occur in this area during rhinoplasty in patients with concave, convex, or combined three-dimensional nasal bone deformities. Level of Evidence: 4.

Cribriform Plate, Crista Galli, Olfactory Fossa and Septal Deviation.

OBJECTIVES: In the present study, we investigated the relationship between olfactory fossa, cribriform plate, crista galli and nasal Septal Deviation (SD). Keros classification of olfactory fossa was also performed. METHODS: This study was performed retrospectively. Computerized Tomography (CT) images of 200 adult subjects were observed. Unilateral nasal Septal Deviation (SD) cases were included into the study. On coronal CT scans, SD side and location, SD angle, cribriform plate width, olfactory fossa depth (Keros classification) and width, area of the olfactory fossa, crista galli length, width and pneumatization were evaluated. RESULTS: Anterior and anteroposterior deviations were detected mainly. In females, 64.0% and in males, 45.3% of the SDs were located anteriorly. In males, anteroposterior SDs (40.0%) were detected more than females. In anteroposterior SDs, SD angle was higher than anterior SDs. With higher SD angle, crista galli width and height decreased. Cribriform plate width, olfactory fossa height, width and area values of contralateral side were significantly higher than those of the ipsilateral side. For Keros classification, in male group, type 1 (53.3%) and in females, type 2 (57.6%) was detected at ipsilateral side. For contralateral side, type 2 Keros was detected in both genders. Complete crista galli pneumatization was observed in 4.0% and partial pneumatization was detected in 12.0%. In 84% of the patients, there is no Crista galli pneumatization. With the presence of pneumatized crista galli, contralateral Keros values decreased. Crista galli height and contralateral olfactory fossa width showed positive correlation. In older patients, cribriform plate width decreased. CONCLUSION: In our study, there was no Keros type 3 olfactory fossa. In males' contralateral side of SD; and in females both ipsilateral and contralateral side of SD, Keros type 2 olfactory fossa were detected. Therefore, during sinus surgery, surgeons should work carefully not to made intracranial penetration.

The Caucasian Nasal Septum: An In Vivo Computed Tomography Study.

BACKGROUND: The nasal septum is composed of cartilaginous and bony components and an understanding of each component volume is essential in both functional and cosmetic surgery. OBJECTIVES: We sought to radiographically measure septal dimensions on cross sectional computer tomography (CT) images, establishing average parameters for normal anatomy among a single, Caucasian population group. METHODS: One hundred and fifty consecutive sinus CT scan images were examined and 100 cases with appropriate sagittal views were included in the study. On each septum, the sagittal CT images were assessed and 14 points were identified and 23 lengths measured and tabulated. Trigonometric formulae were used to accurately calculate surface areas of 11 resulting triangles which constituted the components of the nasal septum. RESULTS: Measurements from 100 patients were included, with a mean age of 50.2 years, constituting 47 males and 53 females. Our surface area mapping established the following areas for both males and females respectively (mm2): quadrangular cartilage 1148 and 981; vomer 894 and 741; perpendicular plate of ethmoid bone 1244 and 1006; and total surface area 3287 and 2728. Our only statistically significant comparison in the series was found in the female series when age and reducing quadrilateral cartilage size were compared, highlighting reducing size with age (P = 0.04). CONCLUSIONS: The study presents the largest published data series representing nasal septal measurements on CT images in a living Caucasian population. Our data demonstrates that septal size remains constant after adolescence, throughout our age-varied series (18-79 years), except in the female population where the quadrilateral cartilage reduces in size with age.

Bony/Cartilaginous Mismatch: A Radiologic Investigation into the Cause of Tension Nose Deformity.

BACKGROUND: Tension nose deformity is believed to be caused by an "oversized" septal quadrangular cartilage. Prior studies have shown that quadrangular cartilage size is relatively consistent in populations. The authors hypothesize that the tension nose deformity is actually caused by an external extrusion of a normal sized septal cartilage from an undersized bony septal encasement. METHODS: A retrospective case-control study of sagittal computed tomographic scans was conducted, measuring the perimeter and surface area of the quadrangular cartilage and bony septal aperture in tension nose cases and controls. Statistical analysis was performed. RESULTS: Of 23 patients enrolled in the study, 12 patients were sorted into the tension nose group, and 11 patients were considered controls. Both groups had similar perimeter and surface area of their quadrangular cartilage, without statistical difference between the two groups. However, the tension nose group had a statistically significant reduction in bony septal aperture perimeter compared with controls (p < 0.01) and a larger externally extruded septum compared with their internal septal size. They also had a substantially higher rate of septal deviation than controls. CONCLUSIONS: The results of this study suggest that a mismatch between a small bony septal aperture and a normal sized septal quadrangular cartilage may be responsible for caudal, upper lip, and dorsal fullness seen with the tension nose deformity caused by external extrusion of cartilage. Septal deviation may co-occur as a buckling phenomenon in a limited bony space. Surgical strategies to match the entire quadrangular cartilage size to the bony framework are suggested. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

MRI and Additive Manufacturing of Nasal Alar Constructs for Patient-specific Reconstruction.

Surgical reconstruction of cartilaginous defects remains a major challenge. In the current study, we aimed to identify an imaging strategy for the development of patient-specific constructs that aid in the reconstruction of nasal deformities. Magnetic Resonance Imaging (MRI) was performed on a human cadaver head to find the optimal MRI sequence for nasal cartilage. This sequence was subsequently used on a volunteer. Images of both were assessed by three independent researchers to determine measurement error and total segmentation time. Three dimensionally (3D) reconstructed alar cartilage was then additively manufactured. Validity was assessed by comparing manually segmented MR images to the gold standard (micro-CT). Manual segmentation allowed delineation of the nasal cartilages. Inter- and intra-observer agreement was acceptable in the cadaver (coefficient of variation 4.6-12.5%), but less in the volunteer (coefficient of variation 0.6-21.9%). Segmentation times did not differ between observers (cadaver P = 0.36; volunteer P = 0.6). The lateral crus of the alar cartilage was consistently identified by all observers, whereas part of the medial crus was consistently missed. This study suggests that MRI is a feasible imaging modality for the development of 3D alar constructs for patient-specific reconstruction.

Keystone Perforator Island Flap as an Alternative Reconstructive Option for Partial Thickness Alar Defects Up to 1.5 Centimeters.

INTRODUCTION: The ala is a unique landmark of the nose disposing aesthetic and functional properties. The head and neck area is the main site of appearance of nonmelanoma skin cancer. One third of them are located in the nose with an alar preponderance compared with other nasal subunits. Correction of alar defects is a challenging reconstructive task. The keystone perforator island flap (KPIF) was introduced as an alternative in nasal reconstruction by senior authors. In the present case series, KPIFs' application is introduced into the alar subunit as an alternative, versatile, and reproducible reconstructive option, even for the novice plastic surgeon. MATERIALS AND METHODS: From April 2014 to September 2015, patients presenting with partial thickness alar defects (≤1.5 cm) secondary to tumor extirpation sustained reconstruction with different types of KPIF. RESULTS: A total of 31 patients (mean age of 72 years) were treated with various types of KPIF. The mean diameter of the defect was 1.14 cm. The vast majority of reconstructions concerned a type IV KPIF (18/31 or 58.1%). Sometimes an upward alar retraction was noted. A minimal rim wedge excision was performed (≤0.3 mm) using counterbalancing correcting sutures. All flaps survived without any sign of venous congestion, whereas the rim healed uneventfully. The mean follow-up period was 6.5 months. CONCLUSIONS: KPIF was introduced as a single-stage alternative reconstructive option for partial thickness alar defects, completing author's experience with this flap into such a challenging and aesthetically critical anatomic area.

A Finite Element Model to Simulate Formation of the Inverted-V Deformity.

IMPORTANCE: Computational modeling can be used to mimic the forces acting on the nasal framework that lead to the inverted-V deformity (IVD) after surgery and potentially determine long-range outcomes. OBJECTIVE: To demonstrate the use of the finite element method (FEM) to predict the formation of the IVD after separation of the upper lateral cartilages (ULCs) from the nasal septum. DESIGN, SETTING, AND PARTICIPANTS: A computer model of a nose was derived from human computed tomographic data. The septum and upper and lower lateral cartilages were designed to fit within the soft-tissue envelope using computer-aided design software. Mechanical properties were obtained from the literature. The 3 simulations created included (1) partial fusion of the ULCs to the septum, (2) separation of the ULCs from the septum, and (3) a fully connected model to serve as a control. Forces caused by wound healing were prescribed at the junction of the disarticulated ULCs and septum. Using FEM software, equilibrium stress and strain were calculated. Displacement of the soft tissue along the nasal dorsum was measured and evaluated for evidence of morphologic change consistent with the IVD. MAIN OUTCOME AND MEASURES: Morphologic changes on the computer models in response to each simulation. RESULTS: When a posteroinferior force vector was applied along the nasal dorsum, the areas of highest stress were along the medial edge of the ULCs and at the junction of the ULCs and the nasal bones. With full detachment of ULCs and the dorsal septum, the characteristic IVD was observed. Both separation FEMs produced a peak depression of 0.3 mm along the nasal dorsum. CONCLUSIONS AND RELEVANCE: The FEM can be used to simulate the long-term structural complications of a surgical maneuver in rhinoplasty, such as the IVD. When applied to other rhinoplasty maneuvers, the use of FEMs may be useful to simulate the long-term outcomes, particularly when long-term clinical results are not available. In the future, use of FEMs may simulate rhinoplasty results beyond simply morphing the outer contours of the nose and allow estimation of potentially long-term clinical outcomes that may not be readily apparent. LEVEL OF EVIDENCE: NA.

Ultrasound screening: Status of markers and efficacy of screening for structural abnormalities.

Aneuploidy is a major cause of perinatal morbidity and mortality and can have a significant impact on expecting parents and their families. With early screening and diagnosis it is important to be able to educate parents regarding the potential impact of the diagnosis. This knowledge allows parents the opportunity to consider management options early in the pregnancy, permitting more time to mentally and emotionally prepare both for the course of the pregnancy, and after the birth of the child should the pregnancy continue. Prenatal screening provides pregnant women a non-invasive risk assessment for the most common aneuploidies. Those who are considered "high-risk" then have the option for additional diagnostic (invasive) testing. Prior to the 1980s, prenatal screening consisted of risk assessment through maternal age; however, with the advent of maternal serum biochemical analysis and ultrasound, the field of prenatal screening developed significantly. As biochemical and sonographic advances continued into the 1990s, the emphasis shifted to risk assessment in the first trimester, with the combination of maternal serum analytes and sonographic evaluation of the nuchal translucency.(1) Within the last decade, the introduction of non-invasive screening (NIPT/S) has shown great impact on the expansion and evolving practice of prenatal screening. Although in many places the standard for prenatal testing continues to include maternal serum analytes and sonographic evaluation, the role of each marker alone and in combination remains important. In the era of increasingly available screening tests, especially with NIPT/(NIPS), this article attempts to review the current role of ultrasound in prenatal care and elucidate the role of ultrasound markers in prenatal screening.

Reducing cone beam CT scan height as a method of radiation reduction for photorealistic three-dimensional orthognathic planning.

OBJECTIVES: To determine the superimposition accuracy of full-face stereophotographic images with 22 cm and 13 cm cone beam computed tomography (CBCT) scans. MATERIAL AND METHODS: 22 cm CBCT scans and corresponding stereophotographic images (3 dMD) for 30 subjects requiring orthognathic surgery were randomly selected. A 13 cm CBCT scan was generated from the 22 cm scan for each subject. All scans and images were converted into STL format. For each subject, the 22 cm and 13 cm CBCT scans were imported into CAD/CAM software and each superimposed with the corresponding 3 dMD image. A one-sample t-test was used to test the null hypothesis that the difference in the 90th percentile of the mean absolute distance between the two 3dMD images when aligned on the 22 cm and the 13 cm CBCT scans was not clinically significant (<0.5 mm). RESULTS: The 90th percentile of the mean absolute distance between the two 3 dMD surfaces using the 22 cm and 13 cm CBCT scans was significantly less than 0.5 mm (p < 0.001; 0.2 ± 0.2 mm; 95% CI, 0.16-0.30 mm). CONCLUSIONS: There is no difference in the accuracy of superimposition of a stereophotogrammetry image with a 22 cm CBCT scan or a 13 cm CBCT scan. It should now be possible to use a 13 cm CBCT scan and a full-face stereophotogrammetry image during 3D orthognathic planning to reduce radiation exposure.

Are gender differences in external noses caused by differences in nasal septal growth?

BACKGROUND: The nasal septum plays an important role in nasal growth, but there have been few reports on the relationship between the septum and nasal growth. The authors investigated the relationship between septa and external noses using computed tomography during the growth period. METHODS: One hundred and ninety-eight patients under the age of 21 were enrolled in this study between 2008 and 2012. The authors evaluated a total of 9 measurement items (five for nasal bones and septa, and four for external noses). RESULTS: In the final age group, most measurement items were significantly larger in males than in females. However, there was no remarkable difference between male and female growth processes. Nasal bridge length and nasal height were significantly correlated with the nasal bone or septum in almost all age groups. The relative proportion of the cartilaginous septum decreased significantly with age, and was negatively correlated with the perpendicular plate in all age groups. CONCLUSIONS: Nasal septa and external noses were both larger in males than in females at the beginning of the study period, although not significantly. The differences became significant throughout the study due to differential increases between the sexes during the monitored growth spurts.

Nasal tip support: a finite element analysis of the role of the caudal septum during tip depression.

OBJECTIVES/HYPOTHESIS: Although minor and major tip support mechanisms have been described in detail, no quantitative models exist to provide support for the relative contributions of the structural properties of the major alar cartilage, the fibrous attachments to surrounding structures, and the rigid support structures in an objective manner. STUDY DESIGN: The finite element method was used to compute the stress distribution in the nose during simple tip compression, and then identify the specific anatomic structures that resist deformation and thus contribute to tip support. Additionally, the impact of caudal septal resection on nasal tip support was examined. METHODS: The computer models consisted of three tissue components with anatomically correct geometries for skin and bone derived from computed tomographic data. Septum, upper lateral cartilages, and major alar cartilages were fitted within the model using three-dimensional computer-aided design software. Five-millimeter nasal tip compression was performed on the models with caudal septal resection (3 and 5 mm) and without resection to simulate palpation, then the resulting spatial distribution of stress and displacement was calculated. RESULTS: The von Mises stress in the normal model was primarily concentrated along the medial crural angle. As caudal septum length was reduced, stress was redistributed to adjacent soft tissue and bone, resulting in less force acting on the septum. In all models, displacement was greatest near the intermediate crura. CONCLUSIONS: These models are the first step in the comprehensive mechanical analysis of nasal tip dynamics. Our model supports the concept of the caudal septum and major alar cartilage providing the majority of critical load-bearing support.