Introduction:Tip support mechanisms play a central role in tip stability and positioning. Different studies were published to demonstrate the most crucial factor in nasal tip support mechanisms. Historically it was thought that fibrous connection between the upper and lower lateral cartilages play a vital role in the nasal tip support mechanism. 1Anderson 2 described the tripod theory of tip support and assumed that this tripod (lateral and medial crura) is supposed to be the major support of nasal tip, while Farrior, 3 demonstrated that the lateral crus has a scroll relationship overlapping the upper lateral cartilage and this is important in maintaining the nasal tip support and projection. Six minor mechanisms for tip support were defined including; ligamentous sling spanning the domes of alar cartilages, dorsal portion of cartilaginous nasal septum, sesamoid complex, attachment of alar cartilage to the overlying skin and musculature, nasal spine and finally membranous portion of nasal septum.
4The shape of the nose tip is determined by the size, shape, and consistency of the underlying lower lateral cartilagesKeskinGhavami et al. 5 stated that the lower lateral cartilages together with the ligamentous attachments between these paired structures are critical in supporting the nasal tip, while Xavier 6 mentioned that the scroll area is mandatory and should be preserved to prevent weakening of tip support.Quatela and Pearson 7 mentioned that the medial crural foot plates play an important role in nasal tip support and projection, while Shomouelian et al. 8 added that disruption of the scroll area attachment in addition to the attachment of the medial crura to the caudal septum could result in loss of the nasal tip support. In aging nose, to best address the patient’s wishes, surgeon must possess a sound understanding of the atrophic changes associated with the aging nose, including tip ptosis, increased nasal bulbosity, long nose and altered nasal airflow patterns. 9Surgical emphasis is placed on conservative structured reduction to address functional concerns.
Over-resection risks destabilizing the nasal tip and altering the patient’s concrete self-image. 10Facial skeleton and overlying soft tissue undergo a gradual transformation throughout the aging process, and there are several consistent age associated changes of the three-layered structure, consisting of skin and subcutaneous tissues, bony and cartilaginous support and mucosa. 11Macroscopic changes affecting the nasal tip include; downward migration of the lateral crura of the lower lateral cartilages and an unfurling of the scroll area, leading to drooping of the nasal tip.
12 In addition, maxillary alveolar bone resorption causes posterior displacement of the pyriform aperture and divergence of the medial crura, reducing tip projection further and exaggerating the already acute nasolabial angle. 13Microscopically, there is a reduction in dermal collagen synthesis and an increase in the number of disorganized elastic fibers, resulting in thinner, less elastic skin, particularly over the dorsum and columella; meanwhile, despite an overall reduction in sebum production, the size of sebaceous glands in the nasal tip increases, making it heavy and bulbous. 14In spite of all the previous data regarding the aging nasal tip and its support, the main factor in determining the major tip support mechanisms is still debatable.
Also there is no previous study compared the age related histological changes that occur in different components of nasal cartilages and also the age related histological changes that occur in fibrous attachments of major nasal tip support. The aim of this study was to evaluate the age related cellular and architectural changes of nasal tip support mechanisms namely cartilages and soft tissue attachments in correlation to its anthropometric measurements specifically nasolabial angle (NLA) and projection.The demands of rhinoplasty in the aging patient are no different. Regardless of patient age, the principles of structure rhinoplasty remain constant: Augmentation is requiredChung V, Rao N and Toriumi DM. Rhinoplasty in the Aging Patient in Master Techniques in Facial Rejuvenation (Second Edition).
2018, 333-346.Patients and Methods:This prospective study was conducted on eighty patients undergoing aesthetic rhinoplasty operations in the period between June 2015 and January 2018. Patients selected to be include in the study had the criteria of being adult above 18 years old seeking cosmetic rhinoplasty with no history of previous nasal or septal surgeries. Patients with intra-nasal pathology or history of previous nasal trauma were excluded.
Patients were admitted to the study after being instructed properly about it and signing a written consent for approval and the independent ethics committee of the university approved the study protocol. Patients were divided into 2 groups according to age; Group 1: includes 40 patients with age range 19-39 years. Group 2: includes 40 patients with age range ? 40years.
All patients had full medical history taken in addition to general and local nasal examination to evaluate the deformity. Standard endonasal examination by nasal speculum to detect excessive hypertrophied inferior turbinates, any intra nasal masses and anterior end enlargement of middle turbinate.For all patients, full face photographs: frontal, lateral, oblique lateral and basal views were used in preoperative assessment. Two anthropometric measurements were documented; NLA and tip projection. Tip projection was evaluated by measuring the ratio of the nasal length to tip projection while the nasolabial angle was measured by drawing a straight line through the most anterior and posterior points of the nostrils as seen on the lateral view. This line with a perpendicular line to the natural horizontal facial plane forms the nasolabial angle.All patients were operated upon using open rhinoplasty technique done according to patient’s needs independent of this study.
Six tissue (3 cartilage and 3 fibrous attachment) samples were taken through the usual steps of rhinoplasty procedure. They were preserved in Formalin 10% for 3 days, then in Ethanol 70% for 1 day, then in Ethanol 90% for 6 hours, then in Ethanol 100% for another 6 hours. After that they were put in Zylone for 6 hours, then in Paraffin at temperature 60 c for 4 hours to make a main block, then small blocks of 5 micron thickness were done followed by its fixation for 2 hours and the its staining with H;E, Mallory and safranin stains.The cartilage Samples were as follows; Sample (1): harvested from the lower lateral cartilage (LLC) during cephalic trimming measuring at least 1 x0.
5 cm. Sample (2): harvested from the upper lateral cartilage (ULC) during removal of the cartilaginous hump measuring at least 0.5 x 0.5 cm.
Sample (3): harvested from the septal cartilage (SC) either dorsal during removal of cartilaginous hump or caudal during septoplasty measuring at least 1 x 0.5 cm.The Fibrous attachment samples were as follows; Sample (1): Attachment in-between the dome of lower lateral cartilages (Interdomal attachment; IDA) was harvested measuring at least 0.
5 x0.5 cm. Sample (2): Attachment in-between upper and lower lateral cartilages (inter-cartilaginous attachment; ICA) was dissected and harvested following cephalic trimming of the lower lateral cartilage measuring at least 0.5 x 0.5 cm. Sample (3): Attachment in-between the caudal septum and the medial crural foot-plate (septo-crural attachment; SCA) was dissected and harvested measuring at least 0.5 x 0.5 cm.
Each cartilage specimen was sectioned in 5-?m sections and stained with hematoxylin-eosin (H;E) to examine chondrocytes cellularity, clusters nests formation and chondrocytes necrosis, Mallory stain to detect perichondrial fibrosis and organization and safranin O stain to highlight the concentration distribution of proteoglycan content. A modified Mankin scale (MM) 15 were used to score each nasal cartilage sample. Scored features for H;E staining including irregular perichondrium, organization, cellularity, chondrocyte clusters, perichondrium fibrosis, chondrocyte necrosis, and fibrinoid degeneration, with a maximum possible score of 16. Each sample will have a cumulative score for all H;E staining features.All fibrous attachments samples were collected and examined by image analyzer (Leica Q500 MC Program, Cambridge, UK) for quantitative assessment. Briefly, microscopic images (x400) in ten consecutive fields will be digitalized to assess area percentage of elastic fibers, amount of collagen fibers, number of cells, type of cells and vascularity.
16Correlation were analyzed using Statistical Program for Social Science (SPSS), Version 20.0, NY: IBM Corp. Quantitative data were expressed as mean± standard deviation (SD). Qualitative data were expressed as frequency and percentage.
The following tests were done: ANOVA test with post hoc Tukey’s test, Pearson’s correlation coefficient (r) test was used for correlating data. The confidence interval was set to 95% and the margin of error accepted was set to 5%. So, the p-value was considered significant as the following: P-value