The Applical Anatomy Of Zygoma And The Retrospective Study Of Zygomatic Complex Fractures

Zygomatic complex lies in the lateral side of midfacial region, which are the key structures of function and appearance. Zygoma connects with the adjac ient bones through zygomatic-temporal suture, zygomatic-maxillary suture, front o-zygomatic suture and zygomatico-buttress suture. With the development of so ciety, more traffic and sports or work related accidents appear , which lead to more midfacial fractures. Zygomatic complex fractures rank first or next to nas al fractures in midfacial region. As to the treatment principles, "function and a ppearance" become the contemporary principles, while "function first, appearanc e second" are the past ones. Because the anatomic features of zygoma are irre gular, reduction route and fixation points are the research hotspot in maxillofac ial region nowdays. Also, AIS is used in rating injury severity, we try to appl y the revised MTSS and RTSS to evaluate the midfacial trauma,then compare t he rating results and make sure that which is more suitable for midfacial fract ures. The objective of this study is to investigate the zygomatic morphologic c haracters, basic data are obtained from measurement of 108 dry skulls of the Chinese Han nationality, which are used to compare sex and side differences. Then we make a deep study of zygomatic complex fractures: incidence, etiolog y, clinical features,diagnosis,management and follow-up results.to study the class ifications of zyoma and zygomatic arch fracture,to investigate the reduction rou te, especially the coronal incision.Also,we make a study of AIS and make a pr eliminary changes to suit midfacial fractures.At last,a zygomatic complex reduct ion localizer are designd and applied in 4 patients who suffered from zygomati c complex fractures.The study consists of three parts:Part one.- The anthropologic study and anatomic measurements of zygomaPaper one The an thropologic study and anatomic measurements of zygomaObjective: To get the anatomic morphologic characters of zygoma for the reduction and fixation of zygomatic complex fractures.Methods: 108 dry skulls were measured in our study, certain data such as the arch length, chord length, height, width, angle, index, et al were included, furthmore ,we measured the bone thickness at 5mm and 10mm far away from zygomatic-temporal suture and frontal-zygomatic suture, which was used in rigid internal fixation.Results: The data of male skull were generally bigger than female.The width of malar prominence is 4/5 of head width. Angle measurement showed that the upper part of female zygoma protruded more than male ones. We measured the bone thickness at 5mm and 10mm far away from the both sutures,at 5mm and 10mm medial to zygomatic-temporal suture was 3.15mm and 3.79mm in male,3.06mm and 3.56mm in female;at 5mm and 10mm distal to zygomatic-temporal suture was 3.07mm and 3.45mm in male,2.98mm and 3.21mm in female; at 5mm and 10mm above frontal-zygomatic suture was 4.12mm and 4.08mm in male,3.93mm and 3.89mm in female; at 5mm and 10mm below frontal-zygomatic suture was 5.22mm and 5.78mm in male,4.92mm and 5.54mm in female;Conclusions:As to the zygomatic arch, the arch and chord length of male skull is longer than female,which show that the location of male zygoma is more protruding than female. Measurement of angle and index is to show the relationship of zygoma to skull,our results show the female zygoma is more square than male;the length of screw should not excel the thickness of bone concerned.According to the bone thickness, suitable Ti screws should be selected to avoid certain complications.Part two: The clinical study of zygomatic complex fractures Paper two A retrospective clinical study of 210 zygomatic complex fracturesObjective:To investigate the epidemiologic features of fractures of zygomat ic complex,mainly dealing with the etiology,clinical features,clssifications,diagnos is,managements,and complications.Methods:210 cases of zygomatic complex fractures from 1990 to 2002 ,which had intact data in our unit were collected and analysed.the incidence ,etiol ogy,reduction approaches,fixation types and complications were investigated.clini cal and radiographic examinations were taken before and after surgery.ResuItsrAs a result, of 210 patients,152 were performed primary, timely re duction and fixation; coronal incision of scalp was used in 108 patients, local small incision was performed in 44 patients(Gillies incisions 18 cases, microinc ision 17 cases, introral incision of vestibulum oris 5 cases,other kind of local i ncision 4 cases); Rigid internal fixation was used in 108 cases, rigid internal f ixation combined with transosseous used in 5 ones, the single application of tr ansosseous wire fixation was seen in 22 patients. According to the Knight-Nort h classification criteria, I 26 cases(11.4%),II 69 cases(30.1%),III 35 cases(15.3 %),IV 46 cases(20.1%),V 32 cases(13.2%),VI 21 cases(9.2%);The following-up time ranks from 6 months to 72months(average 22 months),the results showed extirpation of eyeballs in 2 cases,infection due to Ti plate in 2 cases, infection of wire in 3 cases, sequester in 1 case, numbness of infraorbital region in 2 cases, asymmetry in 22cases.ConcIusions:Traffic accidents are the major cause of fractures of zygomati c complex;there have been an change in the management principle.introsseous wire have been replaced by rigid internal fixation.Paper three The clinical study of zygomatic arch fracturesObjective: The aim of the study is to set up a system to evaluate the symmetry of bilateral zygomatic arch. To analyse the epidemiology, especially on the classifications and management of fractureS of zygomatic arch.Methods: 148 cases of zygomatic arch fractures were investigated in a retrospective study especially on the classification and treatment of zygomatic arch fractures.Results: In clinical rearch of zygomatic arch fractures,112 cases were treated by surgery, while conservative treatment in 36 cases.A new classification with four types were brought forth to meet clinical need.According to the new four-type classification, 12 sides belonged class A,34 sides belonged to class B,72 sides belonged to classC,and 56 sides belonged to class D;In the surgical 112 cases, RIF were used in 50 patients,wire fixation in 29 cases,Kirschner wires in 5 cases,the rest were not fixed.Conclusions: The new classification are preferred in clinical managements,Also the treatment principles have changed a lot in recent years,open reduction and rigid internal fixation are more preferred than before.Paper four The clinical use of scalp coronal incision on zygomatic complex fracturesObjective: To study the clinical application of scalp coronal incision on zygomatic complex fractures.MethodsrA retrospective study was conducted on 83 patients, especially on the indications and complications of scalp coronal incision of 69 zygomatic complex fractures. We studied the indications,complications of the scalp incision.Also explored the relationship between cliniacal procedures and complications.Results:The incision knife had something to do with the scar of scalp,also ,the drainage types were concerned with the complications. In the early period s after operation, 5 patients suffered from hematoma,2 patients had infections, 24 patients reported immediate postoperative anesthesia and paresthesia affecting the supraorbital region.5 cases met the symptoms of nerve injury: difficult to wrinkle forehead or shut up belpharon. After a follow-up of 3-5 years,6 cases suffered from a scar width over 0.5cm,paresthesia was seen in 2 cases(parietal region and temporal region),depression of temporal fossa in 2 cases, 1 patient h ad palsy of temporal branch of facial nerve: difficult to wrinkle forehead.Conclusions: Scalp coronal incision has lots of advantages. Clinically,the incision can give better exposure than other incisions; Cosmetically, the scars are acceptable to most patients because the incision is hidden under hair cover.However, complications offen can be seen in patients.Certain changes should be made to avoid complications.Paper five Study of Maxillofacial Trauma Severity Score On Evaluation of Severity of Midfacial TraumaObjective:A new trauma severity score system is propsed in this study to evaluate the severity of the midfacial trauma.Methods: 202 cases of midfacial trauma(=30 days before hospitalization) were selected. They were evaluated with ISS and RFISS respectively. The results of ISS/RFISS were compared and analyzed with SPSS software.Results: RFISS could accurately differentiate between single and multiple facial injury. It also could differentiate the injury severity of traffic group and other group.Although MTSS were more sensitive, it disobeyed the foundmental principles of AIS-ISS,and magnified the factual severity.Conclusions: RFISS is more meaningful for evaluating different sites of facial injury than ISS. RFISS can be used to evaluate midfacial injury objectively and accurately.Function loss should not be included in the injury severity scale.Part three: The design and clinical applicance of localizer on zygomatic complex fracturesPaper six The design and clinical applicance of localizer on zygomatic complex fracturesObjective:To design a localizer on zygomatic complex fractures and use it in pre-diagnosis,guiding reduction in operation and post-operative evaluation of zygomatic fractures.Methods:The localizer on zygomatic complex fractures was designed to measure the projection of zygoma,zygomatic arch and width of the midface.Then it was used in 4 patients with zygomatic complex fractures to evaluate the clinical effects.Results:Localizer on zygomatic complex fractures could be used for the measurements of the eminence of the zygoma and zygomatic arch for symmetric treatment result.Conclusions: It is an instrument for measuring the deformity of zygomatic fractures, it can be used for diagnosis of the soft tissue and bone deformity of the zygomatic area before operation,reduction guidance in operation,evaluation of the zygomatic complex symmetry during and after operation.