Latex Injection And Clinical Application Study Of The Pedicled Middle Temporal Fascial Fat Flap

PURPOSE: This study is to explore the soft tissue layers and vascular distribution of temporal region by latex injection and anatomic study on fresh skull specimens in order to determine the anatomic details of pedicled middle temporal fascial fat flap;and evaluate the effectiveness,stability and safety of pedicled middle temporal fascial fat flap in temporomandibular joint surgery via radiological investigation and clinical follow-up.MATERIAL AND METHODS:(1)5 fresh skull specimens were processed with latex injection via the external carotid artery,external jugular vein and internal jugular vein.After the injection,the specimens were dissected and the tissue layers and distribution of middle temporal vessels were recorded.(2)135 cases with various temporomandibular joint diseases from January2012 to December 2017 were reviewed.All cases were surgically treated by the Department of Oral Surgery of Shanghai Jiao Tong University School of Medicine affiliated Ninth People’s Hospital and pedicled middle temporal fascial fat flaps were applied.The thickness of the soft tissue flap between the condyle(or graft)and the glenoid fossa on the immediate postoperative radiological data was measured to evaluate the instant effectiveness.For those who were radiologically followed for more than 1year,the thickness of the flaps at 1 year postoperatively were measured and recorded to evaluate the long-term stability.Clinical or phone follow-ups were carried out to record major complications including infection,temporomandibular joint ankylosis,alopecia and temporal region hollowing,with the purpose of evaluating the safety of the flap.RESULTS: 5 skull specimens were injected with latex successfully,and after dissection,an independent fascia,the middle temporal fascia was found between the superficial and deep temporal fascia,and a flap containing middle temporal fascia and fat tissue could be harvested.Middle temporal artery,the major supply of middle temporal fascia,deep temporal fascia and partial temporalis muscle,originated from superficial temporal artery at the level of zygomatic arch and traveled into the deep temporal fascia.Included 135 cases(170 joints)were classified into four groups: 22 cases(24 joints)with terminal stage of temporomandibular joint internal derangement or osteoarthropathy;8 cases(14 joints)with idiopathic condylar resorption;63 cases(90 joints)with temporomandibular joint ankylosis;42 cases(42 joints)with temporomandibular joint and skull base tumor or tumorous lesion.Radiological examination was taken within a week after surgery,showing a soft tissue with mixed texture separating the condyle(or graft)and glenoid fossa,with an average thickness of(4.21+1.24)mm.67 out of 135cases(80 joints)were radiologically followed for at least 1 year,and the thickness of the flap at 1 week and 1 year postoperatively were(5.45+2.3)mm and(5.04+2.14)mm,respectively,leading to an approximate shrinkage rate of 8%.Clinical follow-up showed no severe complication.CONCLUSION: The pedicled middle temporal fascial flap comes from an independent tissue layer with independent pedicles of middle temporal vessels.It can be applied widely in temporomandibular joint reconstruction surgery,with advantages of low probability of infection,low impact on donor site aesthetics and long-term stability.