Thickness of melanocytes in giant congenital melanocytic nevus for complete surgical excision: clinicopathological evaluation of 117 lesions according to the area and size.

BACKGROUND: Giant congenital melanocytic nevi (GCMN) are usually defined as nevi that exceed 20 cm in maximal diameter or 15% of the total body surface area. There have been reports of life-long malignant change risks arising from GCMN, leading to surgical excision of GCMN. This study aims to evaluate the thickness of melanocytes based on clinical factors in order to provide objective information for the complete resection of the lesion. METHODS: Overall, 75 patients diagnosed with GCMN between 2000 and 2021 were included, and their clinical records were collected retrospectively. 117 pathologic slides obtained during excision were reviewed to measure nevus thickness. Clinical factors were assessed with a generalized estimated equation model for association with nevus thickness. RESULTS: The thickness of nevus was significantly associated with the location and size. Nevus thickness was more superficial in the distal extremity than in the head and trunk (P = 0.003 [head]; P < 0.001 [trunk]; P = 0.091 [Proximal extremity]). Nevi sized 60 cm or more were significantly deeper than those measuring 20-29.9 cm (P = 0.035). An interaction between size and location existed (P < 0.001). Trunk and distal extremity lesions consistently exhibited uniform thickness regardless of lesion size, whereas head and proximal extremity lesions showed variations in thickness based on lesion size. CONCLUSION: GCMNs have differences in thickness according to location and size. Therefore, it is necessary to devise an approach optimized for each patient to treat GCMN. In the study, it was emphasized that the thickness of GCMN is correlated with clinical factors, specifically the location and size of the nevus. Consequently, these findings underscore the need for individualized treatment plans for effective surgical intervention.

Comparison of Speech Outcomes Between Speech Therapy Only and Double-Opposing Z-Plasty Combined With Speech Therapy in Patients With Submucous Cleft Palate.

The purpose of this study was to compare speech outcomes in patients with submucous cleft palate (SMCP) between speech therapy alone and double-opposing Z-plasty (DOZ) combined with speech therapy. The subjects were 67 patients with SMCP (overt type, 45 males, 22 females), who were divided into the observation group (n=18), the speech therapy group (n=24; duration, 17.8 mo), and the DOZ and speech therapy (DOZ-speech therapy) group (n=25; median age at DOZ, 5.3 years, duration, 18.6 mo). The median age at initial and final speech assessments were 3 and 5 years. After age, sex, syndromic status, duration of speech therapy, surgery timing, and speech outcomes were investigated, statistical analysis was performed. After tailored interventions, both isolated and non-isolated SMCP patients experienced significant improvements in speech outcomes, including nasal emission, hypernasality, compensatory articulation, and unintelligible speech. Since comparable improvements were observed, there were no significant differences in the final assessments regardless of initial speech issues between the speech therapy group and the DOZ-speech therapy group (all P>0.05). In the DOZ-speech therapy group, the rate of achieving "socially acceptable" speech was 92.3% in isolated cases and 90% in non-isolated cases. Multivariate analysis revealed that DOZ showed a tendency to reduce hypernasality, compensatory articulation, and "unintelligible" speech; syndromic or developmental conditions influenced outcomes in nasal emission and hypernasality; and initial hypernasality and compensatory articulation were correlated with outcomes. Therefore, DOZ surgery could be recommended to resolve hypernasality and compensatory articulation in SMCP patients before speech issues worsen.

Catch-Up Growth Pattern in Cleft Palate: A Longitudinal Study from Infancy to Adolescence.

OBJECTIVE: To characterize the patterns of somatic catch-up growth from infancy to adolescence in patients with cleft palate (CP). STUDY DESIGN: We assessed 474 nonsyndromic patients with isolated cleft palate (n = 69) and unilateral and bilateral cleft lip and palate (n = 271; n = 134) who underwent palatoplasty between 1988 and 2017 and had longitudinal physical growth data at birth (T0), cheiloplasty (T1), palatoplasty (T2), childhood (T3), and adolescence (T4). The z scores of weight (ZWT), height (ZHT), and body mass index (ZBMI) were compared among the CP types (isolated cleft palate, unilateral cleft lip and palate, and bilateral cleft lip and palate) and time points (T1, T2, T3, and T4). Subgroup analyses were performed to investigate the growth of patients with malnourishment (z score < -1) at T1 or T2. A generalized linear model was used to investigate the effects of gestational age and cardiac anomalies on the longitudinal changes in ZHT and ZBMI. RESULTS: Regardless of the time point, the overall ZHT, ZWT, and ZBMI approximated 0 in all CP types, indicating few differences from the mean values of noncleft children. Significant catch-up growth occurred in ZHT and ZWT from T1 to T4 for all CP types (all P < .05). Despite the recovery of ZHT and ZBMI in most patients with malnourishment, these values remain relatively low until adolescence. Patients who were born at preterm stage or had surgically repaired cardiac anomalies grew well. CONCLUSIONS: Even in infants with CP and malnutrition, preterm birth, or cardiac anomalies, rapid catch-up growth can occur prior to palatoplasty with the help of comprehensive cleft care.

Joint semiparametric kernel network regression.

Variable selection and graphical modeling play essential roles in highly correlated and high-dimensional (HCHD) data analysis. Variable selection methods have been developed under both parametric and nonparametric model settings. However, variable selection for nonadditive, nonparametric regression with high-dimensional variables is challenging due to complications in modeling unknown dependence structures among HCHD variables. Gaussian graphical models are a popular and useful tool for investigating the conditional dependence between variables via estimating sparse precision matrices. For a given class of interest, the estimated precision matrices can be mapped onto networks for visualization. However, the limitation of Gaussian graphical models is that they are only applicable to discretized response variables and for the case when p log ( p ) ≪ n $$ p\log (p)\ll n $$ , where p $$ p $$ is the number of variables and n $$ n $$ is the sample size. They are necessary to develop a joint method for variable selection and graphical modeling. To the best of our knowledge, the methods for simultaneously selecting variable selection and estimating networks among variables in the semiparametric regression settings are quite limited. Hence, in this paper, we develop a joint semiparametric kernel network regression method to solve this limitation and to provide a connection between them. Our approach is a unified and integrated method that can simultaneously identify important variables and build a network among those variables. We developed our approach under a semiparametric kernel machine regression framework, which can allow for nonlinear or nonadditive associations and complicated interactions among the variables. The advantages of our approach are that it can (1) simultaneously select variables and build a network among HCHD variables under a regression setting; (2) model unknown and complicated interactions among the variables and estimate the network among these variables; (3) allow for any form of semiparametric model, including non-additive, nonparametric model; and (4) provide an interpretable network that considers important variables and a response variable. We demonstrate our approach using a simulation study and real application on genetic pathway-based analysis.

The Effect of Epiphysiodesis on the Longitudinal Bone Growth of Hands or Feet in Children With Macrodactyly Based on Long-term Quantitative Analysis.

BACKGROUND: Treatment protocols for macrodactyly have not been elucidated due to its rarity and variety of clinical manifestations. This study aims to share our long-term clinical results of epiphysiodesis in children with macrodactyly. METHODS: A retrospective chart review was performed for 17 patients with isolated macrodactyly treated with epiphysiodesis over 20 years. Length and width of each phalanx in both the affected finger and the corresponding unaffected finger in the contralateral hand were measured. Results were presented in ratios of the affected to unaffected side for each phalanx. Measuring of length and width of phalanx was performed preoperatively and postoperatively at 6, 12, and 24 months, and the last follow-up session. Postoperative satisfaction scoring was done with visual analogue scale. RESULTS: The mean follow-up period was 7 years and 2 months. In the proximal phalanx, length ratio significantly decreased compared with preoperative state at after more than 24 months, in the middle phalanx after 6 months, in the distal phalanx after 12 months. When classified by the growth patterns, the progressive type showed significant decrease in length ratio at after 6 months, and the static type after 12 months. Patients were overall satisfied with the results. CONCLUSION: Epiphysiodesis effectively regulated longitudinal growth with different degree of control for different phalanges in the long-term follow-up.

The Effectiveness of Releasing the Lower Lateral Cartilage Through Intranasal Z-plasty Incision on the Vestibular Web During Secondary Correction of Nasal Deformities in Complete Unilateral Cleft Lip and Palate.

The primary goal in the secondary correction of unilateral cleft lip nose deformity is to achieve symmetry of the nose and nostril. This study aimed to investigate the efficacy of freeing the lower lateral cartilage from the pyriform ligament through an intranasal Z-plasty incision on the vestibular web in adult patients with complete unilateral cleft lip and palate. Thirty-six patients with complete unilateral cleft lip and palate, who underwent open rhinoplasty between August 2014 and December 2021, were identified retrospectively. Five parameters for nose form and nostril symmetry were measured on basal views through 2-dimensional photographic analysis. The patients were divided into subgroups with or without septoplasty. Cleft-to-non-cleft ratios between the Z (13 patients) and non-Z groups (23 patients) were compared using the Mann-Whitney U test. The mean follow-up was 12.9 months (6-31 mo). In the Z group, there were significant differences between the preoperative and postoperative values for nostril angulation, regardless of septoplasty (all P <0.05). Despite septoplasty, significant differences in the postoperative changes in nostril angulation were found between the Z and non-Z groups (all P <0.05). Intranasal Z-plasty on the plica vestibularis is an effective technique for releasing the lower lateral cartilage, improving the nostril asymmetry in cleft lip nose deformity.

The Outcomes of Endoscopic Suturectomy in Syndromic Craniosynostosis.

OBJECTIVE: Endoscopic suturectomy is a widely practiced surgical option for infants with craniosynostosis. But the efficacy and safety of the procedure remain unclear in syndromic patients. This study aims to evaluate the efficacy and safety of endoscopic suturectomy for patients with syndromic craniosynostosis. METHODS: From January 2013 to December 2020, 242 patients underwent endoscopic suturectomy at our institution. The surgical outcome was determined to be favorable or unfavorable based upon the necessity of an additional cranial surgery upon the last follow-up. First, we analyzed the outcomes of 26 syndromic craniosynostosis patients who have followed up for over a year. Second, we compared the outcomes between the syndromic (N=12) and nonsyndromic (N=11) patients with bilateral coronal synostosis who have followed up for over a year. RESULTS: Twenty-three out of 26 syndromic craniosynostosis patients (88%) showed favorable outcomes without significant complications. In the analysis for bilateral coronal synostosis patients, 11 of 12 syndromic patients (92%) presented favorable outcomes, and all nonsyndromic patients showed favorable outcomes. No significant differences were observed in various anthropometric indices (cranial index, intracranial volume, anterior cranial height, anterior cranial base length, and cranial height-length index) and surgical outcomes between syndromic and nonsyndromic groups. CONCLUSIONS: Endoscopic suturectomy has the potential to be a surgical option for syndromic craniosynostosis. Even for patients with unfavorable outcomes, endoscopic suturectomy could serve as a bridge treatment for infants to counter cranial deformation before additional extensive surgery.

Characterization of Spheno-occipital Synchondrosis Fusion From Preadolescents to Young Adults Using Age and Cervical Vertebrae Maturation Index.

The purpose of this study was to characterize the spheno-occipital synchondrosis fusion (SOSF) from preadolescents to young adults. A total of 630 Korean subjects (308 men, 322 women; age range, 6-18 y) were divided into 26 groups according to sex and age. After 3-dimensional computed tomography (CT) images were reoriented using the Frankfort horizontal (FH) plane, mid-sagittal plane, and frontal plane via ON3D software (3DONS), the cervical vertebrae maturation index (CVMI) and SOSF stages were identified using 6-stage and 5-stage scoring systems, respectively. The distributions of stage in each group were statistically investigated. Women showed early appearance and a short range of onset (CVMI stage 2, SOSF stage 2), middle (CVMI stage 4, SOSF stage 3 and stage 4), and completion (CVMI stage 6, SOSF stage 5), indicating rapid skeletal maturation compared with men. In both males and females, there were strong positive correlations between age and CVMI stage (rs=0.902, rs=0.890), between age and SOSF stage (rs=0.887, rs=0.885), and between CVMI and SOSF stages (rs=0.955, rs=0.964) (all P<0.001). The mean ages at SOSF stage 3 and stage 4 (12.7~13.9 y in males and 11.0~12.5 y in females) could be used as indicators of the pubertal growth peak. Regression equations for SOSF stage (y), age (a), and CVMI stage (b) were as follows: y=1.355-(0.133×a)+(0.29007×b)+(0.041×a×b) for males (r2=0.9496); y=1.305-(0.158×a)+(0.455×b)+(0.036×a×b) for females (r2=0.9606). Ordinal logistic regression analyses with the proportional odds model showed that females had more advanced SOSF stages than males (odds ratio: 1.972; 95% CI: 1.063-3.658, P<0.05). Our findings may provide basic references for CVMI and SOSF from preadolescents to young adults.

Tumor invasion in the hyponychium is associated with distant metastasis and poor prognosis in subungual melanoma: A histologic landscape of 44 cases.

BACKGROUND: Subungual melanoma (SUM) has a poor prognosis because of delayed diagnosis. Its progression, consensus on surgical treatment, and correlation with clinical outcomes remain unclear. OBJECTIVE: We aimed to identify the pattern of dermal invasion in different locations of the nail apparatus and its relationship with prognosis. METHODS: In this retrospective review of surgically treated SUM patients between January 2011 and April 2019, the nail apparatus was divided into 5 anatomic subunits: the dorsal roof of proximal nail fold, ventral floor of proximal nail fold, germinal matrix, nail bed, and hyponychium. Invasions in the subunits were categorized using 3 criteria: no tumor, in situ tumor, or invasion. RESULTS: Among 44 cases of SUM, dermal invasion occurred mostly in the distal areas, with 11, 30, 18, 7, and 4 in the hyponychium, nail bed, germinal matrix, ventral floor of proximal nail fold, and dorsal roof of proximal nail fold, respectively. The patients with hyponychial invasion showed a significantly greater Breslow depth (P = .009), a higher rate of lymph node metastasis (P = .019), distant metastasis (P = .036), and shorter disease-free survival (P = .001). CONCLUSION: Hyponychial invasion is an important prognostic predictor of SUM, given its strong association with invasion depth, metastatic progression, and disease-free survival. Patients with invasion in the hyponychium should undergo more strict workup, treatment, and surveillance.

Functional Surgery for Subungual Melanoma: Surgical Tips Based on Histological Analysis of 21 Cadavers.

BACKGROUND: Amputation has been the standard treatment for subungual melanoma. Although there is growing attention toward a more conservative functional surgery, specific operative techniques are not yet available. OBJECTIVE: We aimed to provide objective measurements for use in functional surgery by analyzing the anatomy of the nail apparatus obtained from 21 cadavers. MATERIALS AND METHODS: Nailbed thickness was histologically measured in each subunit, and skin surface anatomy was evaluated to determine the proximal resection margin. Immunohistochemical staining was performed to analyze microvessel distribution according to the nail subunit. RESULTS: The nailbed thickness was the thinnest at the most proximal point of the nail matrix (thumbs, 1.10 ± 0.42 mm; big toes, 1.15 ± 0.37 mm) and the thickest at the hyponychium (thumbs, 2.86 ± 0.82 mm; big toes, 2.72 ± 0.84 mm). The distance from the eponychium to the skin surface closest to the bony cortex of extensor tendon insertion was 6.92 ± 5.13 mm in thumbs and 5.14 ± 1.59 mm in big toes. The median microvessel density was the highest at the hyponychium (25.74 vessels/mm2) and lowest at the germinal matrix (16.26 vessels/mm2) (p < .05). CONCLUSION: This histological study offers practical tips, including those to help decide the proximal and deep resection margins, in functional surgery.

Risk of Malignant Transformation Arising From Giant Congenital Melanocytic Nevi: A 20-year Single-center Study.

BACKGROUND: Although giant congenital melanocytic nevus (GCMN) is regarded as premalignant, the incidence and risk factors of malignant transformation are controversial. OBJECTIVE: This study aimed to share the authors' surgical experience with GCMNs and provide data on their demographics, malignant transformation, and prognosis. METHODS: This single-center, consecutive study included 152 patients with GCMN who visited this center from March 2000 to February 2020. Their medical documentation was reviewed retrospectively, and the nevi were classified according to the size as follows: Group 1, 10 to 19.9 cm (n = 45); Group 2, 20 to 39.9 cm (n = 62); and Group 3, ≥40 cm (n = 45). RESULTS: Seven malignancies were found (4.6%; 4 melanomas, 2 rhabdomyosarcomas [RMS], and 1 malignant peripheral nerve sheath tumor [MPNST]). The risk increased according to the nevus size (2.2% in Group 1, 3.2% in Group 2, and 8.9% in Group 3) but the difference was not statistically significant (p = .3305). CONCLUSION: Malignant transformation from GCMN cannot be ignored. It can include transformation into melanoma, RMS, and MPNST. Early surgical resection and regular follow-up should be performed in patients with nevi ≥10 cm.

Medial Plantar Fasciocutaneous Flap Reconstruction for Load-Bearing Foot Defects in Patients With Acral Melanoma.

BACKGROUND: Acral lentiginous melanoma (ALM) is a rare subtype of malignant melanoma that usually involves the weight-bearing plantar area. Plantar defect reconstruction has traditionally been performed with skin grafts or free flaps. This study examined the efficacy and safety of a medial plantar artery perforator flap (MPAPF) for plantar defect reconstruction after wide excision of an ALM. METHOD: Twenty-five patients who underwent reconstruction with a MPAPF between 2011 and 2021 were enrolled in this study. The defects were classified into 6 plantar zones. Demographic and clinical data were retrospectively analyzed. RESULTS: Reconstruction with medial plantar fasciocutaneous island flaps was performed in all cases, except for 4 patients who had lesions in forefoot, which required free medial plantar flaps. Defects in lateral and posterior heel were more likely to present with venous congestion and require longer healing times and revision surgery (P < 0.05). The average follow-up period was 49 months. Four and 5 patients developed local recurrence and distant metastasis, respectively. Four cases of hyperkeratosis and paresthesia were documented, but there were no cases of ulceration or wound dehiscence. None of the cases required secondary debulking procedures. CONCLUSIONS: The MPAPF is safe and effective for plantar defect reconstruction among patients with ALM. Meticulous dissection and adequate tunneling are needed, particularly for defects in the lateral and posterior heel, to minimize flap congestion and revision operations.

Feasibility of low-dose digital subtraction angiography protocols for the endovascular treatment of intracranial dural arteriovenous fistulas.

BACKGROUND: Among neurointerventional procedures, the embolization of complex shunt lesions usually requires more radiation dose. We aimed to evaluate the procedural outcome and safety in using low-dose DSA protocols for intracranial dural arteriovenous fistula (AVF) embolization treatment. METHODS: Between January 2014 and July 2018, 55 patients with dural AVFs who underwent endovascular treatment were included in the study. The low-dose group (n = 27) included from January 2016 used various low-dose DSA protocols made by modifying the thickness of the copper filter or the detector entrance dose. We compared radiation dose metrics, such as air-kerma, kerma-air product (KAP), and fluoroscopy time, as well as clinical and imaging outcomes with the conventional-dose group (n = 28) included before January 2016. RESULTS: The total KAP was 40.1% lower in the low-dose group (87.9 vs. 146.7 Gy cm2, p = 0.002). The average number of DSA runs (25.1 vs. 25.5, p = 0.86) and fluoroscopy times (77.4 vs. 69.7 min, p = 0.48) were similar between the groups. An immediate favorable occlusion rate (total or near total occlusion) was achieved in 41 (74.5%) patients. Ten patients (18.2%) underwent additional procedures due to residual (n = 6) and/or recurrent (n = 5) lesions. At a median of 10 months follow-up, 45 patients (86.5%) had achieved favorable occlusion. Treatment outcomes showed no significant between-group differences. There was one case (1.8%) of procedure-related complications in the low-dose group. All but one patient showed favorable clinical outcomes (modified Rankin score ≤ 2). CONCLUSION: The low-dose protocols were feasible by showing significant radiation dose reduction and acceptable procedural outcome.

Prediction of postoperative pain and analgesic requirements using surgical pleth index: a observational study.

The aim of this study was to evaluate the performance of surgical pleth index (SPI) measured before arousal from general anaesthesia for prediction of immediate postoperative pain and postoperative opioid requirement during postoperative 48 h. After obtaining ethical approval and written informed consent, we enrolled 51 patients undergoing liver resection under isoflurane based general anaesthesia using laryngeal mask airway in this prospective observational study. Data relating to SPI values were recorded every 30 s for the last 3 min of surgery (bispectral index < 60 at all times). Postoperative pain intensity was assessed using a 0-10 numerical rating scale (NRS) every 10 min in the recovery room. The relationships between SPI with postoperative pain score and opioid requirement were analysed. A receiver-operating characteristic curve (ROC) was used to evaluate the performance of SPI to predict NRS ≥ 5. SPI value was significantly associated with the highest pain score in the recovery room (r = 0.63, p < 0.001). An SPI value of 60, which showed the highest sensitivity and specificity, was defined post hoc as the cut-off for moderate-severe pain (NRS ≥ 5). When compared the patients who showed SPI value over 60 or not, there was significant difference in the amount of fentanyl consumption during postoperative 48 h (1093 ± 406 µg vs. 766 ± 369 µg, p = 0.014; SPI ≥ 60 vs. SPI < 60). SPI measured before arousal after inhalation anaesthesia was associated with immediate postoperative pain and postoperative opioid consumption.

A physiometer for simultaneous measurement of whole blood viscosity and its determinants: hematocrit and red blood cell deformability.

In this study, a microfluidic-based physiometer capable of measuring whole blood viscosity, hematocrit, and red blood cell (RBC) deformability on a chip is introduced. The physiometer consists of two major parts: a hydrodynamic component for whole blood viscosity measurement and an electronic component for hematocrit and RBC deformability measurement. In the hydrodynamic component, the whole blood is infused with phosphate buffered saline as a reference fluid for estimation of the whole blood viscosity. At a given flow rate, ten sets of whole blood viscosity readings are successfully obtained over a wide range of shear rates; this is achieved via a series of geometrically optimized microchannel arrays. In the electronic component, analysis of the whole blood impedance spectrum under flowing conditions reveals the electrical characteristics of the blood: the cytoplasm resistance (Rcytoplsm), plasma resistance (Rplasma), and RBC membrane capacitance (constant phase element). The hematocrit is estimated from Rcytoplsm and Rplasma, while the RBC deformation index is determined from the membrane capacitance change of the RBC. Each unique function is experimentally demonstrated and compared to the corresponding gold standard method. The whole blood viscosity measured using the physiometer is 0.8 ± 1.4% in normalized difference compared to that using a rotational cone-and-plate viscometer. For the hematocrit measurement, the coefficient of variation for the physiometer ranges from 0.3 to 1.2% which is lower than the one obtained from centrifugation. In the deformability measurement, there is a strong linear correlation (R2 = 0.97) between the deformation index acquired by image processing and the change in the membrane capacitance acquired by using the physiometer. The effects of the hematocrit and RBC deformability on the whole blood viscosity are also demonstrated. For simultaneous and reliable measurement on a chip, a physiometer equipped with a temperature-control system is prepared. Lab-made software enables the measurement of the three target indices and the temperature control in an automated manner. By using this system, the temperature is controlled to 36.9 ± 0.2 °C which greatly matches with the target temperature (37.0 °C) and it is varied from 25 °C to 43 °C. The developed physiometer is potentially applicable for a comprehensive analysis of biophysical indices in whole blood.

Biocompatibility and Efficiency of Biodegradable Magnesium-Based Plates and Screws in the Facial Fracture Model of Beagles.

PURPOSE: A biodegradable magnesium alloy system has been developed as a substitute for conventional plates and screws made of titanium or absorbable polymer. However, previous studies were limited to small animal experiments using screws or wires. In the present study, we preliminarily evaluated the biocompatibility and effectiveness of human standard-size biodegradable magnesium-based plates and screws in facial fractures of beagles. MATERIALS AND METHODS: Fracture lines were created bilaterally in the zygomatic arches of 6 beagles. They were fixed in situ with plates and screws made of magnesium alloy mixed with calcium and zinc (experimental group) or absorbable polymer (control group). Laboratory testing, radiologic imaging, histologic analysis, and mechanical testing were performed 4 weeks postoperatively. RESULTS: Inflammatory reactions were not significantly increased in any animal. Mechanical testing showed greater ultimate load and structural stiffness in the experimental group. In the histologic analysis, the void area and bone regeneration area were increased in the experimental, and the implant area and soft tissue area were increased in the control group. Radiologically, 3-dimensional micro-computed tomography showed no differences in the bone gap area between the 2 groups. A temporary increase in hydrogen gas around the magnesium implants regressed spontaneously and did not affect bone healing significantly. CONCLUSIONS: Magnesium-based biodegradable plates and screws showed good biocompatibility and offered considerable stability for fixating facial bone fractures in the early bone-healing process. These results show the possibilities for the future development of magnesium alloy plates and screws for craniomaxillofacial fixation in humans.

Prospective Study on the Intraoperative Blood Loss in Patients with Cleft Palate Undergoing Furlow's Double Opposing Z-Palatoplasty.

BACKGROUND: Blood loss during cleft palate surgery has been investigated in previous research, but there is no report regarding blood loss when performing Furlow's double opposing Z-plasty (DOZ). In the present study, we evaluated intraoperative blood loss in patients with cleft palate who underwent the DOZ procedure. MATERIALS AND METHODS: Intraoperative blood loss was prospectively investigated in 59 patients undergoing palatoplasty with DOZ by a single surgeon between August 2012 and July 2013. Demographic factors and clinical status, including cleft type and palatal gap, were recorded. Blood loss was evaluated by measuring the change in weight of a suction bottle, suction line, and gauze balls. RESULTS: Mean blood loss was 16.61 ± 10.33 mL, which accounted for 5% of total blood volume. Male sex, older age, severe cleft type, larger palatal gap, relaxed incision, and increased operative time contributed to greater blood loss. The amount of intraoperative bleeding could be predicted by the following equation: Blood loss = -5.64 + 6.18 (male patients) + 7.58 (severe type cleft) + 0.88 X age (months) + 0.84 X palatal gap (mm). CONCLUSIONS: We found that the DOZ technique causes mild blood loss, but bleeding amount tended to increase in older male patients with a severe cleft and a larger palatal gap. The use of relaxed incisions during palatoplasty and prolonged operation times also contributed to greater blood loss.

Nerve Regeneration and Functional Recovery With Neurorrhaphy Performed at the Early Distraction Osteogenesis: An Experimental Study.

Distraction osteogenesis is widely used in many clinical situations, but distraction in cases accompanying nerve injury has been avoided due to concern of unfavorable effect on nerve regeneration by traction. This study evaluated the feasibility of early distraction lengthening after neurorrhaphy. Thirty-six rats were evenly distributed into 3 groups (12 rats in each group); neurorrhaphy and distraction (group I), neurorrhaphy and osteotomy without distraction (group II), and only distraction without neurorrhaphy (group III), respectively. After osteotomy on the right tibia, distraction started after 1 week and was continued for 40 days with 0.25 mm per day. Histological evaluation was carried out to identify nerve regeneration at 4, 8, and 12 weeks after surgery. Walking tract analysis was performed to assess the functional recovery preoperatively and 1, 4, 8, and 12 weeks postoperatively. Histologically, axon number ratio was significantly impaired in group I (0.48 ± 0.14) and group II (0.53 ± 0.13) compared with group III (0.88 ± 0.04) at 4 weeks (P = 0.020). There was no significant difference at both 8 and 12 weeks. Walking tract analysis showed significant differences between groups I and III (-40.5 ± 4.3), and groups II and III (-35.5 ± 5.0) at 1 week (P = 0.001), but no difference was observed at 8 and 12 weeks. Distraction osteogenesis in early stage after nerve repair is safe and effective, when performed at a rate of 0.25 mm per day in rats.

One-Stage Treatment for Adult Patients With Crouzonoid Appearance by Orthognathic and Face Contouring Surgery.

Crouzon syndrome is a rare genetic disorder with autosomal-dominant inheritance that shows a triad of hallmark characteristics: craniosynostosis, exophthalmos, and midface retrusion. General treatment protocol for patients with Crouzon syndrome has already been established, but there is no standard treatment strategy for adult patients with Crouzonoid appearance. The authors present clinical patients of 1-stage orthognathic and face contouring surgery to achieve functional and aesthetic improvement.One-stage surgery was performed in adult patients with Crouzonoid appearance without a history of facial surgery. Orthognathic 2-jaw surgery was first performed to treat class III malocclusion. Face contouring surgery was conducted next to improve the aesthetic appearance using midface augmentation with onlay rib bone graft, advancement genioplasty, augmentation rhinoplasty, and ancillary procedures such as neck lift, fat graft, or fillers.Five patients (2 men, 3 women) were enrolled in this study. The mean age at the time of surgery was 19.0 years. No specific surgery-related complications such as infection, nerve injury, or recurred malocclusion were observed during the 3.5 years of follow-up. Normal class I occlusion was reached in all patients. The frontonasal angle, nasolabial angle, and labiomental angle improved from 125.1° to 135.1° (P > 0.05), 60.9° to 86.3° (P = 0.018), and 146.3° to 125.0° (P = 0.018), respectively. The Global Aesthetic Improvement Scale score was 4.75 and 5.00 in frontal and profile views, respectively.One-stage orthognathic and face contouring surgery may be an effective surgical option with good postoperative functional and aesthetic improvement in adult patients with Crouzonoid appearance.

Micro-Viscometer for Measuring Shear-Varying Blood Viscosity over a Wide-Ranging Shear Rate.

In this study, a micro-viscometer is developed for measuring shear-varying blood viscosity over a wide-ranging shear rate. The micro-viscometer consists of 10 microfluidic channel arrays, each of which has a different micro-channel width. The proposed design enables the retrieval of 10 different shear rates from a single flow rate, thereby enabling the measurement of shear-varying blood viscosity with a fixed flow rate condition. For this purpose, an optimal design that guarantees accurate viscosity measurement is selected from a parametric study. The functionality of the micro-viscometer is verified by both numerical and experimental studies. The proposed micro-viscometer shows 6.8% (numerical) and 5.3% (experimental) in relative error when compared to the result from a standard rotational viscometer. Moreover, a reliability test is performed by repeated measurement (N = 7), and the result shows 2.69 ± 2.19% for the mean relative error. Accurate viscosity measurements are performed on blood samples with variations in the hematocrit (35%, 45%, and 55%), which significantly influences blood viscosity. Since the blood viscosity correlated with various physical parameters of the blood, the micro-viscometer is anticipated to be a significant advancement for realization of blood on a chip.