The Application Anatomy Study Of Lower Part Of Nose In Plastic Surgery

BackgroundNose is the important part of face and rhinoplasty is one of the oldest surgery. With the development of society and living standards, people pay more and more attention to the aesthetic of countenance. People are no longer satisfied with the general improvement and rough change of the face, many are demand more and perfect personal feature. Over the past 20 years the domestic cosmetic surgery developed rapidly. This job required for detailed information of the alar cartilage by the clinical application anatomy.We can solve the problem of collapse of the nasal dorsum by nose augmentation in clinic. But the existence of a large number of blunt tip and bulb tip require surgeon to improve the shape.Many scholars at home and abroad have do anthropometry studies among different genders and different races. They found there are many differences in the nose between Asians and other races. Asians often have bulb tip, wide nose, and lack of protrusion of tip. However, the lack of specificity in these studies, and the evaluation of the nasal aesthetic standard is not clear.In addition, domestic and foreign scholars have studied on the layer of nasal soft tissue thickness, blood vessels and nerves. The studies of the anatomy are in greater detail. However, nasal subunit of soft tissue anatomy of the fine, detailed enough to describe in detail, the lack of internal anatomical study of alar cartilage. It has the form of nasal tip support and the deep structure of cartilage has established a relationship, but the research is not adequate, the lack of alar cartilage study the various parts of the fine.ObjectiveTo measure the morphological indicators of the lower part of nose by anthropometry methods.To study the morphological characteristics of the lower part of nose. To seek aesthetic evaluation methods and standards for nose. To learn the relationship between internal structure and external structure in lower part of nose by observation and autopsy.MethodsThis study is divided into tow parts. In the first step, we do the anthropometry of the lower part of nose. In the second step, we do the anatomical study on formalin-fixed specimens of seven cases of adult head.First, measurement of the lower part of nose data of 165 students, whose age range from 19 to 30 years old, and the students are all Han nationality which is consist of 78 male and 87 female. They all meet the following conditions:①good health and normal facial features, non-nasal disease ;②no hump nose, aquiline nose, saddle nose and nasal deformities, such as obvious;③no nasal trauma history, surgical history. The persons sit in chairs when they were measured. The first plane is located in Frankfort, natural head-up, lip close. A total of four indicators are tip lobular width, nose width, tip protrusion and the length of nasal columella. First of all, we calculate four nasal index, tip lobule width / nose width, the length of lower part of tip lobule / tip lobule width, the length of lower part of tip lobule / tip protrusion, tip protrusion /nose width, in accordance with tip lobular width, the length of lower part of tip lobule, tip protrusion, nose width. Then study their differences by the two-sample t-test.Second, we do anatomical study. First of all, we observe the shape of tip of the nose, nasal alar and nasal columella, and measured the indicators of external nose. The measuring targets are tip lobular width, the length of lower part of tip lobule, tip protrusion, nose width. Then we dissected the nose of corpse. The upper incision on the level of inner canthal, the lower is parallel to the end of nose, the side incision along both sides of the nose and nasolabial groove. We cut the nasal skin, fascia, muscle fiber layer, the deep fat layer, the periosteum and perichondrium layer by layer to observe the changes between various layers. The location, morphology and adjacent relationship of nasal cartilage is observed. Different segments of the alar cartilage are distinguished followed by form. The measurement indicators are the distance between the top, the middle of the foot length, foot medial column length, the width of pyriform aperture. The internal and external indicators are compared and we analyzed the relationship between nasal alar cartilage and the form of lower part of nose.ResultsIn the first portion, four indicators of 165 cases are observed, in which included 78 man and 87 women. The results as follows, tip lobular width (male21.81±2.36, female20.49±2.00) , nose width (male40.19±3.19, female36.03±2.77) , tip protrusion (male19.58±2.32, femal 18.26±2.24) and the length of nasal columella (male11.73±2.32, female 11.11±2.26).And then the four nasal index are calculated, tip lobule width / nose width(male0.54±0.06, female0.57±0.07), the length of lower part of tip lobule / tip lobule width(male0.36±0.11,female0.35±0.11), the length of lower part of tip lobule / tip protrusion(male0.40±0.10, female0.39±0.10), tip protrusion /nose width(male0.49±0.07, female0.51±0.08). We found there are significant difference in the four indicators and tip lobule width / nose width between male and female by the two-sample t-test. The differences between the ethnic were compared and aesthetic standards of evaluation were discussed.In the second portion, we did detailed observation and description of the form of nasal cartilage. We found that the size of tip is closely related to separation distance of alar cartilage and the separation angle. The length of lower part of tip lobule and the form of tip are related to middle crura of alar cartilage. The length of nasal columella is related to the length of columella segment of medial crura. Nose width is related to the width of pyriform aperture. Tip support is mainly depend on the middle and the medial crura of nasal cartilage.ConclutionFirst, nose width of Han is longer than Caucasian, shorter than Melanoderm. Tip protrusion and tip protrusion/nose width of Han is more than Caucasian and Melanoderm. The vertex angle of the basis nasi of Han is the biggest. The vertex angle of the basis nasi of the Melanoderm is the second and the vertex angle of the basis nasi of Caucasian is the smallest.Second, there are significant differences in tip lobular width, nose width, tip protrusion and the length of lower part of tip lobule, but there is no difference between men and women in nasal index, the same standard aesthetic evaluation can be used. Nasal index is more important than nasal indicator in aesthetic evaluation.Third, alar cartilage is the important supporting structure of lower part of nose, each part of which is closely related to the form of lower part of nose.