The Study On Plastic And Aesthetic Surgery Of Zygomatic Complex Protrusion And Related Anatomy

BackgroundBesides the development of the facial soft tissue ,the facial peripheria is mainly decided by the feature of the superior maxillary bone ,inferior maxillary bone and the zygomatic complex, among which the zygomatic complex is the most important factor.The abnormal development of the zygomatic complex not only result in the disproportion of the upper, middle and the below facial width, but also the lacking soft "S" curve of the lateral surface which lead to not good looking face and make the person depressed.Because of the different culture background and the different value of appreciate beauty, the western female are keen to owning abnormal protrusion malar surface, while the eastern female are on the opposite. People with the abnormal protrusion of the zygomatic bone complex are easily be seen among the Asia countries especially China, Korea, Japan and Mongolia et al. In our country, people in the Guangdong province, Hainan province and the Fujian province are much more easily getting an abnormal protrusion of the zygomatic complex. With the changing of the modern medical mode and the upgrading of the health conception, more and more people especially female with abnormal protrusion malar face are turning to diminution their malar faces through plastic surgery operation. Because of that the diminution operation of the protrusion zygomatic complex is becoming the hot spot in the plastic surgery field in China and other Asian countries. This has been a basic working content in the maxillofacial region plastic surgery of the Guangdong province.We make a summary of the difficulties and problems in the diminution zygomatic complex operation which focus on these five aspects, i, In order to guide the operation better, we should judge the abnormal protrusion of the zygomatic bone in a scientific way. ii, we should design the cutting bone line and the bone's moving direction after being cut in a reasonable way. iii, we should study how to design the operative route and make sure the safety of the temple cut. iv, we should study on how to solve the soft tissue of the middle and below face ptosis complication after operation, v: we should make clear that which method is better to fix the broken endsof fractured bone from inner side. How to value the stability of the fix method and whether there is an inner fix method that can be more efficient and convenient. To aim directly at those problems, we study the vitodynamics and anatomy of the zygomatic complex by means of autopsy anatomy and clinical patients' vitodynamics analysis to fulfillment the operation design and operative method of the diminution abnormal protrusion of the zygomatic bone complex sugery.ObjectiveIn order to design the temple cut method and its' site of the zygomatic complex diminution operation in a reasonable way, we probe into the study on the anatomy of zygomatic bone complex. At the same time consummate the method on judging the abnormal protrusion zygomatic complex and analyze the reason of the ptosed soft tissue after the diminution operation of zygomatic complex. Through the establishment of the three diamensions finite model of the zygomatic complex and analyze the stability of the fixed methods used in the clinic, we want to provide a better method on how to fix the bone during the operation.Method1. Study on the relative anatomy of the zygomatic complex of cadavers.a. Study on the anatomy of temple area. We select 14 male corpses and 2 female corpses to study the locations of the frontal branch and the arteria temporalis superficialis, the distance between the traga and the disk of temporomandibular joint.b. Study on the anatomy of the soft tissue of the malar area. We select 12 male corpses and 2 corpses to study the structural characteristics of the pars zygomatica muscles, quanliao fat pad and the ligamentum arcuatum so that we can analyze the reason of the soft tissue ptosed after the decoherent operation.c. Study on the measurement of the zygomatic complex. We select fourtyfive regular female skulls and twentyfour adult female patients which are decided by the experienced professional plastic surgeon as the normal proportion of zygomatic complex and abnormal protrusion zygomatic complex respectively. We chose eight indexes to measure the skulls and the three dimensional CT of the patients. Finally we use the discriminant analysis method to establish the discrimination equation.2. Study on biomechanics of zygomatic complex protrusion in vivo.a. The establishment of the three dimensional finite dim model of the zygomatic complex. Firstly we select the CT of the abnormal protrusion zygomatic complex patients as the targets and use the MIMCS software to establish the three dimensional finite dim models. Secondly we identify the direction of the muscle line of force and the size of the masseteric coherent area. Thirdly we establish the three dimensional finite dim model that we can use this to analyze the stress after operation. Finally we study the mechanics of the zygomatic complex under the conditions of jugomaxillary muscle pulling state and biting state.b. The application of the three dimensional finite dim model of the zygomatic complex in the diminution abnormal protrusion zygomatic complex operation. We analyze the mechanic characteristic of the cuting bone in the three dimensional finite dim model. We judge the better fixing way with good stability by means of comparing three different fix ways that are used popularly in the clinic in the model. Moreover, we've designed the brand-new fixation method with L-shaped steel plates.3. The discussion of the improved operation method of diminution the abnormal protrusion zygomatic complex in clinics. We design the convenient and efficient method of pars zygomatica soft tissue sling operation approach from the inner mouth according to the results of the zygomatic complex anatomy study and computer image study in order to prevent from the complication of the soft tissue droop after diminution abnormal protrusion zygomatic complex operation.Result1. When we make the tragion as a X axis and make parallel of it from the B spot outside of eyebrow, we find the ramus frontalis arteriae temporalis is always behind the frontal branch of the superficialis cranial nerve and the angle of it is as the same as the ramus frontalis arteriae temporalis superficialis's, we also find that the most far distance between the arteria temporalis superficialis and the suprema frontal branch of cranial nerve ,the distance between the anterior border disk of temporomandibular joint and the articular tubercle insertion is about 22.32±9.16 mm and 3.40±0.75mm respectively. We can avoid the injury of blood vessel and nerve if we make a cut at the hair line that is parallel the TE line. We can also avoid the injury of the articular disc when we choose the site in the articular tubercle insertion at least far away from it about 5mm as the cut bone site.2. We find that the distance between the start M spot and the T spot of the greater zygomatic muscle is 51.30±3.31mm, we also find that the angle of the greater and lesser zygomatic muscle to the X axis is43.16±5.72°. The greater and lesser zygomatic muscle are almost cover the most forward protrusion part of the zygomatic complex, the average length of them is 53.53±4.36mm and 46.30～61.38mm respectively. There are two structural characteristics that differentiate the subcutaneous fat of quanliao from others of the face. Firstly the depth of the subcutaneous fat of quanliao is very special which the thickest site is located between the foramen infraorbitale and the angulus oculi lateralis perpendicular. Secondly the zygomatic ligaments are the most important ligament that sustain the soft tissue of quanliao and started from the rear of the greater zygomatic muscle origin and are mainly distributed into the inferior border of ansa capitis and the area covered by zygomatic muscles and the relationship between it and the subcutaneous fat of quanliao and the muscles is very close.3. We establish a discriminant equation that can be used to judge whether the zygomatic complex of the patient is abnormal protrusion or not in the clinic according to the experiment measurement data in which we select forty five normal adult human skulls and twenty four adult female patients' skulls CT who have abnormal protrusion zygomatic complex and select eight anatomay indexes that are very closely related to the quanliao.4. We establish the model of zygomatic complex combined with jugomaxillary muscle pulling mode has five characteristics these are i ,the deck and the special part of the model can be randomly cut, moved and deleted, ii, we can mimicking the condition of the operation and also analyze the vitodynamics of the zygomatic complex after the operation, iii, we can add different load units to analyze the new mechanics model, iv, the model is also the basic element of study the morphology of the zygomatic complex, because it can provide the data of the frame structure for analyze the change of the facial soft tissue after the zygomatic complex has been changed, v, we divide the sclerotin of the model into ten parts according to the extent of the gray scale of the finite dim, that is the density but not into the os integumentale and cancellated bone.5. We study on the mechanics of zygomatic complex by means of three dimensional finite models, compare the cut bone method and evaluate the stability of the inner fix method. We find there is no significant difference of the stress and offset between the slope cut bones and "L" cut bone. Both of their mechanics stability are the same. We also find the maximum stress and the average stress of the new cut bone method "L" style are less than the ole method.6. Through our follow-up visit from three to six months after operation, we find there is no patient in the new operation method group showed sag midface or deepen nasolabial groove, while twelve patients in the regular operation method has showed deepen nasolabial groove.7. Questions need to be solved in the future. Because of the number of the clinic patients are limited in our study so we need to fulfill the study in the future. At the same time we need to find more useful indexes that can be used to judge the patient in clinics. There are several questions in our study that can not be solved, for example we did not study the fix method through using adhesive material. Et, al.ConclusionIn this research we discuss and solve the hard problems in the diminution operation of quanliao by means of three diamensional finite dim technique and anatomic technique. We not only provide improved proposal to reduce the complication in the clinic but also provide the efficient judging indexes that can be used to distinguish the patient with abnormal protrusion zygomatic complex and at the same time we evaluate the vitodynamical stability of the bone cutting and fixing method in the operation and introduce a new operation method that can efficiently reduce the complication of sagging midface after the operation.There are four obviously new ideas brought by this research that aimed at clinic application, Firstly our study provide a reasonable design on how to set the cut bone site, angle and method that can avoid the injury of the blood vessel and nerve. Secondly we provide several indexes that can correctly judge whether a person has an abnormal protrusion zygomatic bone or not in clinics according to the discriminant analysis used in this study. Thirdly we design a new suspl-operation approach from the inner mouth that can reduce the complication after the diminution operation of zygomatic complex. Fourthly we establish the three diamensional finite dim model of zygomatic complex and evaluate the vitodynamical stability of the bone cutting and fixing. In a conclusion our research aims directly at the urgent demands of the person with abnormal protrusion zygomatic complex that are widely spread into Guangdong province and other places of our country. From our research we improved the traditional method and fulfillment the elementary study of the zygomatic complex that can facilitate the future study on new material which used as a fixing substance in the diminution zygomatic complex operation.