Clinical Anatomy Of The Chin Evaluated By 3-dimensional Tomography And Cadaveric Dissection And Aesthetic Concerns Of Chin Augmentation With Hyaluronic Acid Soft Tissue Filler In Chinese

Background:The chin is an important facial structure that directly affects the overall contour of the face.Soft tissue fillers have been widely used for the correction of chin volume loss due to congenital conditions and aging.Objectives:This study aimed to discuss anatomical concerns for chin filler injections and cosmetic concepts for the chin area,which may help to reduce the incidence of severe intravascular embolization complications and improve patient satisfaction.Methods&Materials:We scanned 40 cadaveric heads with a contrast agent using a 64-row spiral CT scanner.The scan was visualized by a Philips IntelliSpace workstation and analyzed by MIMICS software to measure and quantify the arterial data.Twenty of 40 cadavers were dissected to define the layers of tissue.We also measured the length of beautiful chins,as evaluated by 2 plastic surgeons,and the ratios of chins from"The 100 Most Beautiful/Handsome Faces in China" published by TCC Asia in 2020.Chin volume injections were performed on 23 Asian females and 15 Asian males.Demographic and imaging data were collected,and the facial aesthetic length was calculated.Patient and injection physician satisfaction was assessed using the Global Aesthetic Improvement Scale(GAIS).Results:In total,221 arteries passed through the sagittal plane of 40 specimens.The number of superficial arteries(163 of 221)was much greater than the number of deep arteries(58 of 221).The number of arteries gradually decreased with distance from the lower lip vermilion border plane,which formed the lower third of the face.The ideal chin height was equal to two-thirds of the length of the lower face,which is the distance from the subnasale to the menton,with no sex difference.The ideal length of the chin was equal to that of the nasal dorsum in males,and the ideal chin/nasal dorsum ratio was 0.9 in females.Clinical recruitment included 23 Asian women and 15 Asian men.All 38 patients received hyaluronic acid fillers for mental injection to correct congenital mental shortening.The average mental filler volume was 1.89±0.74ml for females and 2.68±1.28ml for males.All patients showed significant improvement in mental shape and contour immediately after injection.At 3 months of follow-up,most of the improvement was retained.Conclusion:This study introduces a safe and effective technique for administering chin filler injections that minimizes risks and improves patient satisfaction.