Surgical anatomy for Asian rhinoplasty: Part III

This article, which comprises the third part of a series on surgical anatomy for Asian rhinoplasty, addresses the lower one-third of the nose, including the alar cartilage and tip-supporting structures, known as distal mobile framework. As discussed in earlier parts of this series, diversity in surgical anatomy results in different surgical techniques in Asian rhinoplasty compared to rhinoplasty in Caucasian patients. Nasal tip structures are especially important due to their crucial importance for changing the nasal shape in Asians. This article, along with the previous ones, will provide both basic and advanced knowledge of practical surgical anatomy for Asian rhinoplasty.

Surgical importance of the posterior auricular ligament when harvesting ear cartilage in rhinoplasty

Background@#Ear cartilage is a preferred graft material in rhinoplasty. However, after harvest, instability of the auricular framework may arise as a form of donor site morbidity. In the harvest of ear cartilage, the posterior auricular ligament (PAL) is usually sacrificed in order to obtain as much cartilage as possible. Since damage to the PAL may cause auricular instability, we studied the periauricular anatomy using cadavers and evaluated auricular stability during surgery. @*Methods@#Six ears from hemifacial cadavers were studied to clarify the exact anatomy of the PAL. Then, the recoil force of the auricle was serially measured to evaluate the stability of the auricular framework in 30 patients during surgery: before making the skin incision (M1), before and after cutting the PAL (M2, M3), and after harvesting the cymba concha (M4). The differences in force observed after cutting the PAL (ΔM2–M3) and after harvesting the cymba concha (ΔM3–M4) were statistically analyzed. @*Results@#In the cadaveric study, the PAL was identified between the superficial and deep mastoid fasciae and connected the caudal aspect of the cymba concha to the deep mastoid fascia. During surgery, the PAL accounted for 16.20% of the total auricular recoil force. The recoil force decreased by 13.61 N and 11.25 N after cutting the PAL and harvesting the cymba concha, respectively. These decreases were statistically significant (P<0.05). @*Conclusions@#The results suggest that the PAL is a supporting structure of the auricle. Therefore, to preserve auricular stability, minimizing damage to the PAL while harvesting the ear cartilage may be helpful.

Deviated nose: Physiological and pathological changes of the nasal cavity

Deviated nose is highly challenging in rhinoplasty since the surgeon should consider both aesthetic and functional aspects of the nose. Deviated nose correction is surgically complex, and a thorough understanding of the mechanical and physiological changes of intranasal structures, including the septum and turbinates, is necessary for functional improvement.

Cadaveric study of deep temporal fascia for autologous rhinoplasty grafts: Dimensions of the temporal compartment in Asians

Background@#Due to the anatomical complexity of the deep temporal fascia (DTF), practical guidelines for its safe harvest are lacking. However, since the upper temporal compartment (UTC) contains no vital structures, it may provide safe access for DTF harvest. This study aimed to identify the anatomical structures of the temporal compartment in Asian cadavers and to measure their dimensions to enable safe DTF harvest. @*Methods@#The anatomical structures surrounding the temporal compartment were identified in 27 hemifaces from 15 Korean cadavers. After dissection, digital images were acquired and craniometric landmarks were placed upon them to identify the boundaries of the temporal compartment. The horizontal and vertical lengths of the temporal compartment were measured and their surface areas were computationally assessed. Subsequently, differences in the results by sex were evaluated. @*Results@#The five-layer anatomical structure of the UTC was clearly visualized. The UTC was bounded by the temporal septa superiorly and inferiorly, the innominate fascia laterally, and the DTF medially. No vital structures were present within the UTC. The vertical and horizontal lengths of the UTC were 6.41±0.67 cm and 10.44±0.83 cm, respectively, and the surface area of the UTC was 48.52±5.65 cm2. No statistically significant differences were observed in any dimensions between male and female patients. @*Conclusions@#During rhinoplasty, DTF can be harvested as an autologous graft material from the UTC. An anatomical understanding of the UTC will aid in the safe and simple harvest of a sufficient amount of DTF.

Surgical anatomy for Asian rhinoplasty: Part II

Surgical anatomy for Asian rhinoplasty Part I reviewed layered anatomy with neurovascular system of the nose. Part II discusses upper two-thirds of nose which consists of nasal bony and cartilaginous structures. Nasal physiology is mentioned briefly since there are several key structures that are important in nasal function. Following Part III will cover lower one-third of nose including in-depth anatomic structures which are important for advanced Asian rhinoplasty.

Feasibility of a polydioxanone plate as an adjuvant material in rhinoplasty in Asians

BACKGROUND: Nasal framework-supporting procedures such as septal extension grafts, derotation grafts, and columellar strut grafts are usually required in rhinoplasty in Asian patients because the skin envelope is tight, but the nasal framework is small and weak. Autologous materials are preferred, but they have some limitations related to the amount that can be harvested and the frequency of use. Therefore, synthetic materials have been used to overcome these limitations. METHODS: A total of 114 patients who received a polydioxanone (PDS) plate as an adjuvant material in rhinoplasty from September 2016 to August 2017 were retrospectively investigated. The PDS plate was used as to support the weak framework and to correct the contour of the alar cartilages. The PDS plate was used for reinforcement of columellar struts and septal L-struts, alar cartilage push-down grafts, fixation of septal extension grafts, and correction of alar contour deformities RESULTS: Primary and secondary rhinoplasty was performed in 103 and 11 patients, respectively. Clinically, no significant inflammation occurred, but decreased projection of the tip was observed in seven patients and relapse of a short nose was noted in five patients. CONCLUSIONS: PDS plates have been used in the United States and Europe for more than 10 years to provide a scaffold for the nasal framework. These plates can provide reinforcement to columellar struts, L-struts, and septal extension grafts. In addition, they can assist in deformity correction. Therefore, PDS plates can be considered a good adjuvant material for Asian patients with weak and small nasal cartilage.

Surgical anatomy for Asian rhinoplasty

Surgical anatomy is an important and fundamental aspect for all surgical procedures. Anatomy provides a surgeon with the basic and in-depth knowledge that is required and mandatory when performing an operation. Although this subject might be tedious and routine, it is compulsory and should not be overlooked or neglected to avoid any possible postoperative complications. An aggressive and hasty operation without anatomic considerations might cause adverse effects that are irreversible even though a surgical anatomy of the nose is quite simple.

The Effect of a Condylar Repositioning Plate on Condylar Position and Relapse in Two-Jaw Surgery

BACKGROUND: Numerous condylar repositioning methods have been reported. However, most of them are 2-dimensional or are complex procedures that require a longer operation time and a highly trained surgeon. This study aims to introduce a new technique using a condylar repositioning plate and a centric relation splint to achieve a centric relationship. METHODS: We evaluated 387 patients who had undergone surgery for skeletal jaw deformities. During the operation, a centric relation splint, intermediate splint, final centric occlusion splint, and condylar repositioning plate along with an L-type mini-plate for LeFort I osteotomy or a bicortical screw for bilateral sagittal split ramus osteotomy were utilized for rigid fixation. The evaluation included: a physical examination to detect preoperative and postoperative temporomandibular joint dysfunction, 3-dimensional computed tomography and oblique transcranial temporomandibular joint radiography to measure 3-dimensional condylar head movement, and posteroanterior and lateral cephalometric radiography to measure the preoperative and postoperative movement of the bony segment and relapse rate. RESULTS: A 0.3% relapse rate was observed in the coronal plane, and a 2.8% relapse rate in the sagittal plane, which is indistinguishable from the dental relapse rate in orthodontic treatment. The condylar repositioning plate could not fully prevent movement of the condylar head, but the relapse rate was minimal, implying that the movement of the condylar head was within tolerable limits. CONCLUSIONS: Our condylar repositioning method using a centric relation splint and mini-plate in orthognathic surgery was found to be simple and effective for patients suffering from skeletal jaw deformities.

Effect of Amniotic Fluid Stem Cells and Amniotic Fluid Cells on the Wound Healing Process in a White Rat Model

BACKGROUND: Amniotic-fluid-derived stem cells and amniocytes have recently been determined to have wound healing effects, but their mechanism is not yet clearly understood. In this study, the effects of amniotic fluid stem cells and amniocytes on wound healing were investigated through animal experiments. METHODS: On the back of Sprague-Dawley rats, four circular full-thickness skin wounds 2 cm in diameter were created. The wounds were classified into the following four types: a control group using Tegaderm disc wound dressings and experimental groups using collagen discs, amniotic fluid stem cell discs, and amniocyte discs. The wounds were assessed through macroscopic histological examination and immunohistochemistry over a period of time. RESULTS: The amniotic fluid stem cell and amniocyte groups showed higher wound healing rates compared with the control group; histologically, the inflammatory cell invasion disappeared more quickly in these groups, and there was more significant angiogenesis. In particular, these groups had significant promotion of epithelial cell reproduction, collagen fiber formation, and angiogenesis during the initial 10 days of the wound healing process. The potency of transforming growth factor-beta and fibronectin in the experimental group was much greater than that in the control group in the early stage of the wound healing process. In later stages, however, no significant difference was observed. CONCLUSIONS: The amniotic fluid stem cells and amniocytes were confirmed to have accelerated the inflammatory stage to contribute to an enhanced cure rate and shortened wound healing period. Therefore, they hold promise as wound treatment agents.

Platelet-Rich Plasma: Quantitative Assessment of Growth Factor Levels and Comparative Analysis of Activated and Inactivated Groups

BACKGROUND: Platelet-rich plasma (PRP) has more concentrated platelets than normal plasma (approximately 150-400x10(3) cell/dL). Platelets excrete several growth factors and cytokines that are associated with the healing and regeneration process. However, even though PRP is widely used, the mechanism or actual effect is presently unclear. Therefore, this study was performed to investigate the levels of growth factors and platelet concentration rate. METHODS: Autologous blood for preparing PRP was obtained from healthy subjects aged 25 to 35 years. The samples were divided into 4 experimental groups (inactivated whole blood, inactivated PRP, activated whole blood with thrombin and calcium chloride, and activated PRP). The platelet counts in the blood were analyzed and the growth factors were quantitatively measured. A statistical analysis was performed by using Dunn's multiple comparison test. RESULTS: In the blood cell analysis, the platelet count of the PRP group was approximately 4.25 times higher than that of the whole blood group. In the quantitative analysis of growth factors, the platelet-derived growth factor (PDGF)-AB, PDGF-BB, and transforming growth factor-beta of the inactivated and activated PRP groups were higher than those of the inactivated and activated whole blood groups (P<0.05). CONCLUSIONS: In this study, the platelet count and the levels of PDGF-AB and PDGF-BB in the PRP were determined. Further, more research is required on the bioactivity level of the growth factors secreted during the process of PRP preparation and the potency of growth factors that can be exerted physiologically in vivo.

Applying Method of Arch Bar in Maxillofacial Surgery without Orthodontic Treatment

Temporomandibular joint(TMJ) and dental occlusion are important in functional aspect as well as in cosmetic aspect for craniofacial surgery such as orthognathic and traumatic surgery. During these operations, appropriate maxillomandibular fixation(MMF) is especially necessary to conserve or reconstruct, dynamic TMJ and functional occlusion. Arch bar is one of the most popular method to gain proper MMF. Seventeen patients including 5 patients with mandibular fracture, 12 patients with orthognathic surgery(6 patients had relatively normal occlusion, however 6 patients had facial anomalies such as hemifacial microsomia with irregular occlusal plane.) were joined in this study. Arch bar was contoured on the dental cast, which was prepared for model surgery, prior to apply it on the facial anomaly patient. On using pre-contoured arch bar, patients felt better during the procedure and surgeons saved time. Moreover, well-contoured arch bar promises precise transmission of force on the bone, which implies surgeons do not need to worry about the occlusion while fixing bony structures. Authors suggest how to apply arch bar to satisfy basic theories about dental row and occlusion based on the experience. In addition, it is proposed to contour arch bar on the dental impression prior to apply it on the patient who has irregular and complex occlusal plane.

Difference of Gene Expression in Venous Malformation

PURPOSE: Venous malformation(VM) which often causes pain and discomfort is the most common type of vascular malformations. Although it is presented with disfigured appearance and associated soft tissue or skeletal hypertrophy, the molecular bases of VMs are poorly understood. Differentially expressed genes(DEGs) of VMs were investigated to illuminate the molecular mechanism of the disease entity. METHODS: Gene expressions of VM patients' subcutaneous tissue were studied in comparison with normal persons' by GeneFishing(TM) technique using the annealing control primers (ACPs) to identify DEGs. Candidate genes were sequenced and screened by basic local alignment search tool (BLAST) afterwards. RESULTS: Among seventy DEGs identified, forty DEGs which had shown significantly different expression pattern were sequenced. Twenty eight out of 40 were up- regulated while 12 were down-regulated. BLAST searches revealed that 37 were known genes and 3 were unknown genes. Many genes were involved in the differentiation and remodeling of smooth muscle cells, opposed to the previous hypothesis that a lot of angiogenetic genes would be involved. Furthermore, several transcription factors and related genes, as well as cell signaling and metabolism regulators, were up regulated. CONCLUSION: It suggests that analysis of DEGs in VMs provide basic knowledge about its pathophysiology. and new therapeutic approaches.