New-Onset Atrial Fibrillation Is a Red Flag to Microvascular Free Tissue Transfer Failure in Head and Neck Cancer Patients.

BACKGROUND: Postoperative new-onset atrial fibrillation (AF) has been shown to be associated with increased surgical morbidity and mortality following cancer ablation surgery. However, evidence of new-onset AF's impact on surgical outcomes in head and neck cancer patients undergoing tumor ablation and microvascular free tissue transfer remains scarce. This study aims to evaluate the association between AF and surgical outcomes in these patients. METHODS: We enrolled head and neck cancer patients who underwent tumor ablation reconstructed with microvascular free tissue transfer from the National Health Insurance Research Database (NHIRD). Patients were grouped into the following: (1) without AF, (2) new-onset AF, and (3) preexisting AF. The groups were matched by propensity score based on age, gender, cancer stage, and comorbidities. The primary outcome was postoperative complications, whereas all-cause mortality was the secondary outcome. RESULTS: In total, 26,817 patients were included in this study. After matching, we identified 2,176 (79.24%) patients without AF, 285 (10.37%) with preexisting AF, and 285 (10.37%) with new-onset AF. Our results demonstrated that the free flap failure rate was twofold escalated in patients with new-onset AF (9.8%) compared to those without AF (5.4%) or preexisting AF (5.3%; p = 0.01). However, we did not identify significant differences among other postoperative complications across groups. Additionally, we found that the risk of all-cause mortality was significantly elevated in patients with preexisting AF (p < 0.001) compared to those without AF or new-onset AF. CONCLUSION: Our study demonstrated that new-onset AF is associated with an increased risk of flap failure and could serve as a predictor. On the other hand, all-cause mortality in patients with preexisting AF was significantly elevated. Close postoperative monitoring in patients with new-onset and preexisting AF is crucial to identify any potential adverse effects.

Objective Comparison of Eyebrow Position after Internal and External Browpexy.

BACKGROUND: Several brow-lift techniques have been used to prevent brow ptosis after blepharoplasty. For example, both internal and external browpexies have been adopted worldwide. However, few studies have compared these two methods. The authors compared postoperative eyebrow position changes between upper eyelid skin excision, internal browpexy, and external browpexy. METHODS: The authors retrospectively reviewed the cases of 87 patients who underwent upper blepharoplasty performed by a single clinician at their institute between April of 2018 and June of 2020. Patients with routine outpatient photographs taken before and after surgery were enrolled in the study. ImageJ was used to measure brow height at eight points in each eye. Brow height changes were compared among the three groups. RESULTS: Routine photographs were available for 68 patients (133 eyes). Thirty-nine patients underwent internal browpexy (78 eyes), nine underwent external browpexy (17 eyes), and 20 underwent upper eyelid skin excisions (38 eyes). Three months after surgery, significant elevation was noted on the lateral side of the brow in the internal browpexy group and across the whole brow in the external browpexy group. In the upper eyelid skin excision group, whole brow ptosis was observed. Brow-lift outcomes were better in the external than in the internal browpexy group, whereas both browpexy groups showed better outcomes than the upper eyelid skin excision group. CONCLUSIONS: Within 3 months of surgery, both internal and external browpexy provided significant brow-lift effects, preventing brow ptosis caused by blepharoplasty with skin excision. External browpexy had better brow-lift outcomes than did internal browpexy. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Carbon Dioxide Laser Transconjunctival Lower Blepharoplasty: An Objective and Quantitative Comparison to Monopolar Electrosurgery.

BACKGROUND: The ability to simultaneously cut and perform hemostasis with low lateral thermal injury makes carbon dioxide laser a useful tool in blepharoplasty. Monopolar electrosurgery is another commonly used cutting tool that improves the quality of hemostasis and cutting speed. This study aimed to objectively and quantitatively assess the intraoperative and postoperative outcomes of transconjunctival lower blepharoplasty using either a carbon dioxide laser or monopolar electrosurgery. METHODS: Between August of 2018 and March of 2021, 78 patients who underwent transconjunctival lower blepharoplasty were assigned randomly to the carbon dioxide laser group or the monopolar electrosurgery group. Patient-related parameters were recorded. Periorbital bruises were assessed objectively and quantitatively using the ecchymosis evaluation score. Analyses were performed using the independent sample t test, the Mann-Whitney U test, the chi-square test, and the Fisher exact test. RESULTS: Sex, age, local anesthesia injection volume, and fat removal volume were not different between the groups. Patients' subjective intraoperative heat sensation was significantly higher in the monopolar electrosurgery group than in the carbon dioxide laser group. The carbon dioxide laser group had a significantly lower incidence of postoperative chemosis than the monopolar electrosurgery group. All patients had uncomplicated wound healing, except three (7.89%) patients in the monopolar electrosurgery group who developed conjunctival granuloma. Operation time, intraoperative pain sensation, intraoperative blood pressure, postoperative ecchymosis, conjunctivitis, and patients' aesthetic satisfaction did not differ between the groups. CONCLUSION: The authors' findings revealed that carbon dioxide laser is a useful technique for reducing intraoperative heat sensation and postoperative chemosis and may prevent conjunctival wound complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

International Microsurgery Club Webinar Series-Bridging the Knowledge Gap during the COVID-19 Pandemic.

BACKGROUND: The impact of the coronavirus disease 2019 (COVID-19) outbreak shut down most conferences. To minimalize the influence, virtual meetings sprang up subsequently. International Microsurgery Club (IMC), as one of the largest professionals-only online microsurgery education groups worldwide, began to host regular weekend webinars during the pandemic to fill the knowledge gap. This study aims to discuss how webinars have fundamentally changed the way knowledge is delivered and exchanged. METHODS: From February 29, 2020 to March 14, 2021, 103 IMC webinars were reviewed and analyzed in detail to determine the use, benefit, and effect. A comparison between webinars hosted by the different societies was made as well. A questionnaire survey focusing on attendees' behavior, attitude, and using habit about webinars was also made. RESULTS: As for the 103 IMC webinar events, the peak participants were 112.3 people in average. The members requesting to join IMC abruptly increased during the pandemic, and the group activity increased dramatically. From the questionnaire (n = 68), the satisfaction level was high (8.88 ± 1.18/10). The respondents were most satisfied with the good quality of the speakers (73.5%). Not only hosts our webinar series but IMC also serves as the platform that welcomes webinars from other societies to share their information. In September 2020, International Microsurgery Webinar League was established via the significant webinar hosts, with more than 300 recorded webinar talks connected successfully. CONCLUSION: As the knowledge revolution driven by COVID-19 will continue, IMC will keep playing an essential role in exploring new and emerging opportunities to improve knowledge dissemination worldwide beyond the space-time boundary.

A Combination of Three-Step Lower Blepharoplasty to Correct Four Types of Lower Eyelid Deformities in Asian People.

BACKGROUND: This study aimed to propose a novel four-type deformity and treatment-oriented classification of the lower eyelids that directs the therapeutic combination of three-step lower blepharoplasty for Asian populations. METHODS: We reviewed 183 patients who underwent a therapeutic combination of three steps of lower blepharoplasty after being diagnosed with four types of lower eyelid deformities between July 2018 and April 2021. The three-step lower blepharoplasty includes: (1) mid-face and lower eyelid augmentation, (2) transconjunctival eye bag removal, and (3) skin pinch removal. Consecutive digital images, detailed fat graft volume, fat removal amount, skin pinch removal amount, complications, and patient's satisfaction and aesthetic improvement score were recorded. RESULTS: The overall patient's satisfy score is 91. Aesthetic improvement score is 80.2 and 83.3 among lay persons and experts, respectively. The volume of the fat graft ranges from 2 to 3 mL per orbit according to the severity of the deformity. The amount of fat removed was 0.53 ± 0.36 and 0.61 ± 0.40 mL per orbit in types II and III patients, respectively. There is no lower lid malposition. Eleven patients had over-correction of fat grafting, and they need steroid injection; 20 patients had under-correction of fat grafting, and they need secondary fat grafting. Ten patients need secondary skin pinch excision due to post-op skin redundancy. Two patients had conjunctiva wound granuloma. CONCLUSIONS: The combination of three-step lower blepharoplasty according to the novel classification is a straightforward and effective method to correct lower eyelid deformities. The complication rate was low with high patient satisfaction. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Allogeneic Bone-Marrow Mesenchymal Stem Cell with Moldable Cryogel for Craniofacial Bone Regeneration.

Allogeneic bone-marrow mesenchymal stem cells (BMSCs) can promote bone regeneration and substitute for autologous BMSCs if autologous sources are unavailable, but the efficacy of bone regeneration by allogeneic BMSCs is still inconsistent. A Lewis rat cranium defect model was used to investigate the efficacy of bone regeneration between autologous and allogeneic BMSCs in gelatin-nanohydroxyapatite cryogel scaffolds. BMSCs from Wistar rats served as the allogeneic cell lineage. The full-thickness cranium defects were treated by either blank control, cryogel only, allogeneic BMSC-seeded cryogel, or autologous BMSC-seeded cryogel (n = 5). Bone regeneration was monitored by micro-computed tomography and examined histologically at week 12. In addition, we assessed the immune responses in vitro by mixed lymphocyte reaction (MLR) assay and CD4+ immunochemistry staining ex vivo. The MLR showed that allogeneic BSMCs elicited a weak immune response on day 14 that progressively attenuated by day 28. In vivo, the bone regeneration in allogeneic BMSCs was inferior at week 4, but progressively matched the autologous BMSCs by week 12. Our results suggest that allogeneic BMSCs can serve as an alternative source for bone regeneration.

Shock Index as a Predictor for Angiographic Hemostasis in Life-Threatening Traumatic Oronasal Bleeding.

The objective of this retrospective study was to identify predictors of angiographic hemostasis among patients with life-threatening traumatic oronasal bleeding (ONB) and determine the threshold for timely referral or intervention. The diagnosis of traumatic, life-threatening ONB was made if the patient suffered from craniofacial trauma presenting at triage with unstable hemodynamics or required a definitive airway due to ONB, without other major bleeding identified. There were 4404 craniofacial trauma patients between January 2015 and December 2019, of which 72 (1.6%) fulfilled the diagnosis of traumatic life-threatening ONB. Of these patients, 39 (54.2%) received trans-arterial embolization (TAE), 11 (15.3%) were treated with other methods, and 22 (30.5%) were excluded. Motor vehicle accidents were the most common cause of life-threatening ONB (52%), and the internal maxillary artery was the most commonly identified hemorrhaging artery requiring embolization (84%). Shock index (SI) was significantly higher in the angiographic hemostasis group (p < 0.001). The AUC-ROC was 0.87 (95% CI, 0.88-1.00) for SI to predict angiographic hemostasis. Early recognition and timely intervention are crucial in post-traumatic, life-threatening ONB management. Patients initially presenting with SI > 0.95 were more likely to receive TAE, with the TAE group having statistically higher SI than the non-TAE group whilst receiving significantly more packed red blood cells. Hence, for patients presenting with life-threatening traumatic ONB and a SI > 0.95, TAE should be considered if preliminary attempts at hemostasis have failed.

End-to-Side Anterior Interosseous Nerve Transfer: A Valuable Alternative for Traumatic High Ulnar Nerve Palsy.

BACKGROUND: The prognosis of high ulnar nerve injury is poor despite nerve repair or grafting. Anterior interosseous nerve (AIN) transfers provide a satisfactory recovery. However, the efficacy of end-to-side (ETS) AIN transfer and optimal timing in Sunderland grade IV/V of high ulnar nerve injury is lacking. OBJECTIVE: The goals were to compare the outcomes of high ulnar nerve injury managed with ETS AIN transfers with those managed with conventional procedures (nerve repair or graft only) and identify differences between early and delayed transfers. METHODS: Patients with isolated high ulnar nerve injury (Sunderland grade IV/V) from 2010 to 2017 were recruited. Patients with conventional treatments and AIN transfers were designated as the control and AIN groups, respectively. Early transfer was defined as the AIN transfer performed within 8 weeks postinjury. Outcomes were measured and analyzed by the British Medical Research Council (BMRC) score, grip strength, and pinch strength. RESULTS: A total of 24 patients with high ulnar nerve injury (Sunderland grade IV/V) were included. There were 11 and 13 patients in the control and AIN groups, respectively. In univariate analysis, both early and delayed AIN transfers demonstrated significantly better motor recovery among BMRC score and strength of grip and pinch at 12 months (P < 0.05). No statistical significance was found between early and delayed transfer. In multivariate analysis, both early and delayed transfers were regarded as strong and independent factors for motor recovery of ulnar nerve. Compared with the control, early [odds ratio (OR), 1.83; P < 0.001] and delayed (OR, 1.59; P < 0.001) transfers showed significant improvement with regard to BMRC scores. The pinch strength in early (OR, 31.68; P < 0.001) and delayed (OR, 26.45; P < 0.001) transfers was also significantly better. CONCLUSION: The ETS AIN transfer, in either early or delayed fashion, significantly improved intrinsic motor recovery in high ulnar nerve injuries classified as Sunderland grade IV/V. The early transfer group demonstrated a trend toward better functional recovery with less downtime.

Osteogenic potential of induced pluripotent stem cells from human adipose-derived stem cells.

BACKGROUND: Bone regeneration is a crucial and challenging issue in clinical practice. Bone tissue engineering (BTE) with an optimal cell source may provide an ideal strategy for the reconstruction of bone defects. This study examined whether induced pluripotent stem cells (iPSCs) derived from adipose-derived stem cells (ASCs) could act as an osteogenic substitute and whether these ASC-iPSCs yield more new bone formation than ASCs in hydrogel scaffolds. METHODS: ASC-iPSCs were reprogrammed from ASCs through a retroviral system. ASCs were harvested and isolated from adipose tissue of humans. An aliquot of cell suspension (1 × 106 cells/mL) was seeded directly onto the nHAP-gelatin cryogel scaffolds. Nude mice back implantation of cell-seeded scaffolds was designed for in vivo comparison of osteogenic potentials between ASCs and ASC-iPSCs. Samples were harvested 4 and 8 weeks after implantation for further analysis based on histology and RT-PCR. RESULTS: ASC-iPSCs were successfully obtained from human adipose-derived stem cells. PCR results also showed that specific genes of iPSCs with the ability to cause the differentiation of cells into the three germ layers were expressed. In our in vivo experiments, iPSCs were subcutaneously injected into nude mice to induce teratoma formation. The morphology of the three germ layers was confirmed by histological staining. ASC is an essential cell source for BTE with benefits of high volume and less-invasive acquisition. With additional transforming Yamanaka factors, ASC-iPSCs showed higher osteogenic differentiation and elevated expression of collagen type I (Col I), osteocalcin (OCN), alkaline phosphate (ALP), and runt-related transcription factor 2 (RunX-2). CONCLUSIONS: This report suggests that ASC-iPSCs could be a superior cell source in BTE with better osteogenic differentiation efficacy for future clinical applications.

The Effectiveness of an International Cleft Mission Model in Asia: An Update.

BACKGROUND: Cleft lip/palate is a congenital craniofacial anomaly affecting patients physically and psychosocially and has contributed to the global burden of surgical disease, especially in underprivileged areas. For 20 years, Noordhoff Craniofacial Foundation (NCF) and the Chang Gung Craniofacial Center (CGCFC) have carried out missions to these areas. Rather than implementing short-term missions that lack proper follow-up care, the team has provided an effective, long-term, and multidisciplinary approach for the treatment of patients with cleft lip/palate. In this study, we evaluate the sustainability and effectiveness of the cleft mission model implemented by NCF and CGCFC. METHODS: Data from the years 1998-2017 were retrieved from the NCF database. All local centers were evaluated by a 3-stage categorization, levels 1 to 3, based on 4 criteria: (1) capacity to carry out independent missions, (2) diversity of cleft-care professionals, (3) diversity of surgical service offered, and (4) collaboration with local hospitals. Support and training of personnel were provided based on deficiency in these criteria. Noordhoff Craniofacial Foundation made close collaborations and partnerships with several organizations that shared its mission for comprehensive cleft care in developing countries. RESULTS: In all, 19 partner cleft teams in 9 different countries were established. In coordination with these teams, NCF and CGCFC have treated 1846 patients across 78 mission trips. To date, 158 personnel from 19 different countries have been successfully trained to provide cleft care in local centers. Most partner cleft teams centers have progressively reached category level 3, including those in the Philippines, Cambodia, and Mongolia. CONCLUSIONS: In order to establish and maintain sustainable cleft care in developing regions, commitment and compassion toward those who lack essential resources are necessary. Noordhoff Craniofacial Foundation and CGCFC have achieved a successful and practicable model through seeding medical personnel in order to provide effective and sustainable cleft care to the regions in need.

Thermosensitive Injectable Hydrogel for Simultaneous Intraperitoneal Delivery of Doxorubicin and Prevention of Peritoneal Adhesion.

To improve intraperitoneal chemotherapy and to prevent postsurgical peritoneal adhesion, we aimed to develop a drug delivery strategy for controlled release of a chemotherapeutic drug from the intraperitoneally injected thermosensitive poly(N-isopropylacrylamide)-based hydrogel (HACPN), which is also endowed with peritoneal anti-adhesion properties. Anticancer drug doxorubicin (DOX) was loaded into the hydrogel (HACPN-DOX) to investigate the chemotherapeutic and adhesion barrier effects in vivo. A burst release followed by sustained release of DOX from HACPN-DOX was found due to gradual degradation of the hydrogel. Cell culture studies demonstrated the cytotoxicity of released DOX toward CT-26 mouse colon carcinoma cells in vitro. Using peritoneal carcinomatosis animal model in BALB/c mice with intraperitoneally injected CT-26 cells, animals treated with HACPN-DOX revealed the best antitumor efficacy judging from tumor weight and volume, survival rate, and bioluminescence signal intensity when compared with treatment with free DOX at the same drug dosage. HACPN (or HACPN-DOX) also significantly reduced the risk of postoperative peritoneal adhesion, which was generated by sidewall defect-cecum abrasion in tumor-bearing BALB/c mice, from gross and histology analyses. This study could create a paradigm to combine controlled drug release with barrier function in a single drug-loaded injectable hydrogel to enhance the intraperitoneal chemotherapeutic efficacy while simultaneously preventing postsurgical adhesion.

Prediction of traumatic carotid-cavernous sinus fistula via noncontrast computed tomography by fracture pattern and abnormality of venous system.

BACKGROUND: Traumatic carotid-cavernous sinus fistula (tCCF) is infrequent but with high morbidity if delayed diagnosed or managed. Because of the lack of screening criteria and requirement of advanced and invasive radiological examinations, diagnosis is often delayed or underdiagnosed. METHODS: A matched case-control study with univariate and multivariate analyses was conducted to predict tCCFs. Forty-six patients diagnosed with tCCFs were included and matched with 138 patients of craniofacial trauma without tCCF as control at a ratio of 1:3. RESULTS: The diagnostic diameter of superior ophthalmic vein (SOV) in tCCF was 4 mm with area under curve of 0.89. In multivariate analysis, engorgement of SOV and cavernous sinus (odds ratio [OR], 35.39; 95% confidence interval [CI], 13.56-104.84; p < 0.001) and lateral impact (ipsilateral temporal and sphenoid sinus fractures) (OR, 3.96; 95% CI, 1.10-14.91; p = 0.028) were identified significant, whereas basilar skull fracture (OR, 1.58; 95% CI, 0.53-4.75; p = 0.300) and injuries to ocular nerves (cranial nerves III, IV, and VI) (OR, 1.77; 95% CI, 0.38-7.88; p = 0.055) were insignificant. CONCLUSION: Presence of SOV or cavernous sinus engorgement on noncontrast computed tomography and lateral impact were demonstrated as independent predictors to tCCF and warrant further radiological evaluation. Injury to ocular nerves is not predictive but as an essential differential diagnosis with reversible outcome. LEVEL OF EVIDENCE: Diagnostic, level III.

Injectable thermosensitive hydrogel containing hyaluronic acid and chitosan as a barrier for prevention of postoperative peritoneal adhesion.

Peritoneal adhesion is one of the common complications after abdominal surgery. Injectable thermosensitive hydrogel could serve as an ideal barrier to prevent this postoperative tissue adhesion. In this study, poly(N-isopropylacrylamide) (PNIPAm) was grafted to chitosan (CS) and the polymer was further conjugated with hyaluronic acid (HA) to form thermosensitive HA-CS-PNIPAm hydrogel. Aqueous solutions of PNIPAm and HA-CS-PNIPAm at 10%(w/v) are both free-flowing and injectable at room temperature and exhibit sol-gel phase transition around 31°C; however, HA-CS-PNIPAm shows less volume shrinkage after gelation and higher complex modulus than PNIPAm. Cell culture studies indicate both injectable hydrogel show barrier effects to reduce fibroblasts penetration while induce little cytotoxicity in vitro. From a sidewall defect-bowel abrasion model in rats, significant reduction of postoperative peritoneal adhesion was found for peritoneal defects treated with HA-CS-PNIPAm compared with those treated with PNIPAm and untreated controls from gross and histological evaluation. Furthermore, HA-CS-PNIPAm did not interfere with normal peritoneal tissue healing and did not elicit acute toxicity from blood analysis and tissue biopsy examination. By taking advantage of the easy handling and placement properties of HA-CS-PNIPAm during application, this copolymer hydrogel would be a potentially ideal injectable anti-adhesion barrier after abdominal surgeries.

Quantitative Determination of Zygomaticomaxillary Complex Position Based on Computed Tomographic Imaging.

BACKGROUND: The zygomaticomaxillary complex (ZMC) is frequently involved in craniofacial fractures. We propose an objective approach for defining the ZMC position on skeletal and soft tissue by using Amira to process 3-dimensional (3D) facial computed tomography (CT) images. AIM AND OBJECTIVES: In this study, we aim to propose 1 anthropometric system, facilitated based on CT images, which can be used in quantitative analysis of ZMC position and examine the symmetry of skeletal and soft tissue of the ZMC with high reliability and validity. METHODS: Twenty Taiwanese trauma patients with pure mandibular fracture but bilateral intact ZMCs were recruited to participate in this study. The head position was adjusted in 3D planes during the examinations. The distances between the zygion and nasion and maxillozygion and nasion were defined as the x plane. The y plane was defined as the distance between the maxillozygion to the vertex and orbitale to the vertex. The distance between the maxillozygion and opisthocranion was defined as the z plane. RESULTS: The results indicated that the intrasubject variability was 0.7 to 1.6 and 0.1 to 1.8 mm in skeletal and soft tissue, respectively. The intersubject variability ranged from 3.1 to 9.2 and 1.8 to 9.3 mm in skeletal and soft tissue, respectively. The proposed anthropometric system demonstrated high validity and reliability in ZMC measurements. No significant difference was observed among bilateral ZMCs, indicating the feasibility of the mirroring technique during surgical processes. CONCLUSIONS: We conclude that the anthropometric system for processing 3D facial CT images facilitated by Amira has potential implication in the assessment and reconstruction of the ZMC in both skeletal and soft tissue.

Systematic Analysis of the Risk Factors Affecting the Recurrence of Traumatic Carotid-Cavernous Sinus Fistula.

OBJECTIVE: The current therapies for traumatic carotid-cavernous sinus fistula (tCCF) yield a variable rate of recurrence and produce different results. We analyzed factors among traumatic head injury to identify the risk factors in recurrent tCCFs. METHODS: We retrospectively reviewed patients who were diagnosed with tCCFs from January 2004 to December 2014 in a tertiary referral center. The factors that were analyzed included age, sex, associated injury, clinical presentation, interval from injury to interventions, interventions for tCCFs, and pathologic characters of tCCFs under digital subtraction angiography. RESULTS: A total of 55 patients with 56 tCCFs (1 bilateral tCCF) were included. Thirty-nine patients (40 tCCFs) were treated successfully in single session of a procedure, whereas 16 patients (16 tCCFs) experienced a recurrence of tCCF. In multivariate analysis, we found that the involvement of C2 or C4 segments (Debrun classification) of intracavernous internal carotid artery is an independent risk factor (hazard ratio [HR] 2.95, 95% confidence interval [95% CI] 1.34-6.52; P < 0.01) for the recurrence of tCCFs. Endovascular coil embolization demonstrated superior efficacy in successful interventions of tCCFs compared with detachable balloons (HR 2.63, 95% CI 1.06-6.57; P < 0.05) and other modalities (HR 3.06, 95% CI: 1.27-7.37; P < 0.05). CONCLUSIONS: A detachable coil is a favorable approach in the management of tCCFs when considering the rate of recurrence. In addition, the involvement of C2 or C4 segments (Debrun classification) served as an independent risk factor of the recurrence of tCCFs.

The correlation between surface electromyography and bite force of mastication muscles in Asian young adults.

BACKGROUND: Mastication function is related to mandible movement, muscle strength, and bite force. No standard device for measuring bite force has been developed. A linear relationship between electromyographic activity and bite force has been reported by several investigators, but data on the reliability of this relationship remain limited in Asian young adults. AIM AND OBJECTIVES: The purpose of this study was to develop a clinically applicable, reliable, quantitative, and noninvasive system to measure the kinetic mastication function and observe the correlation between surface electromyography (sEMG) and bite force. MATERIALS AND METHODS: The study group consisted of 41 young healthy adults (24 men and 17 women). Surface electromyography was used to evaluate bilateral temporalis and masseter muscle activities, and an occlusal bite force system was used concurrently to measure the bite force during maximal voluntary biting. Bilateral symmetry was compared, and the correlation between EMG and bite force was calculated. RESULTS: The sEMG signals were 107.7±55.0 µV and 106.0±56.0 µV (P=0.699) on right and left temporalis muscles and 183.7±86.2 µV and 194.8±94.3 µV (P=0.121) on right and left masseter muscles, respectively. The bite force was 5.0±3.2 kg on the right side and 5.7±4.0 kg on the left side (P=0.974). A positive correlation between sEMG and bite force was observed. The correlation coefficient between the temporalis muscle and bite force was 0.512, and that between the masseter muscle and bite force was 0.360. CONCLUSION: No significant difference between the bilateral electromyographic activities of the temporalis and masseter muscles and bilateral bite force was observed in young healthy adults in Taiwan. A positive correlation between sEMG signals and bite force was noted. By combining sEMG and bite force, we developed a clinically applicable, quantitative, reliable, and noninvasive system for evaluating mastication function by using characteristics of biofeedback.

Single buccal sulcus approach with fluoroscan assistance for the management of simple zygomatic fractures.

BACKGROUND: Zygomatic fractures are associated with functional and aesthetic problems. The purpose of this study was to evaluate the adequacy of management and the surgical satisfaction of patients with simple zygomatic fractures treated through a single buccal sulcus approach and fluoroscan assistance. METHODS: Between 2008 and 2012, 42 patients with simple zygomatic fractures were included in the study. The surgical procedure was performed through a single buccal sulcus incision. The fracture sites were aligned under direct vision and fluoroscan assistance and stabilized with rigid internal fixation. The adequacy of reduction was evaluated based on postoperative plain radiographic films and computed tomographic scans using mirror image analyses. The satisfaction of functional and aesthetic results was also evaluated subjectively using a visual analog scale during follow-up. RESULTS: Twenty-nine male and thirteen female patients with a mean age of 33.2 years were evaluated. Motorcycle crashes (78.6%) were the most common mechanism of trauma. Based on follow-up imaging studies, 2 patients had inadequate reduction of zygomatic body, and there was a slight depression of the zygomatic arch in one patient. Ninety-three percent (39/42) of patients had satisfactory results, although one patient complained of malar asymmetry and another felt a depression in the arch area. Two patients complained of persistent hypesthesia during follow-up at 6 months. CONCLUSIONS: Our results suggest that a single buccal sulcus approach without lower eyelid or lateral eyebrow incision in the repair of simple fractures of the zygoma can be achieved with high patient satisfaction if the reduction and fixation are adequate and stable.