Changes in Electrical Activity of the Masseter Muscle and Masticatory Force After the Use of the Masseter Nerve as Donor in Facial Reanimation Surgery

Introduction
The masseter nerve has been used as a donor nerve for facial reanimation procedures due to the multiple advantages it offers; it has been generally considered that sacrifice of the masseter nerve does not alter the masticatory apparatus; however, there are no objective studies to support this claim.
Objective
To evaluate the impact that the use of the masseter nerve in dynamic facial reconstruction has on the electrical activity of the masseter muscle and on bite force.
Materials and Methods
An observational and prospective longitudinal study was performed measuring bite force and electrical activity of the masseter muscles before and 3 months after dynamic facial reconstructive surgery using the masseter nerve. An occlusal analyzer and surface electromyography were employed for measurements.
Results
The study included 15 patients with unilateral facial paralysis, with a mean age of 24.06 ± 23.43. Seven patients were subjected to a masseter-buccal branch nerve transfer, whereas in eight patients, the masseter nerve was used as a donor nerve for gracilis free functional muscle transfer. Electrical activity of the masseter muscle was significantly reduced after surgery in both occlusal positions: from 140.86 ± 65.94 to 109.68 ± 68.04 ( p = 0.01) in maximum intercuspation and from 123.68 ± 75.64 to 82.64 ± 66.56 ( p = 0.01) in the rest position. However, bite force did not show any reduction, changing from 22.07 ± 15.66 to 15.56 ± 7.91 ( p = 0.1) after the procedure
Conclusion
Masseter nerve transfer causes a reduction in electromyographic signals of the masseter muscle; however, bite force is preserved and comparable to preoperative status.

Retrospective Analysis of Chilean and Mexican GI Stromal Tumor Registries: A Tale of Two Latin American Realities

Purpose: Like other malignancies, GI stromal tumors (GIST) are highly heterogeneous. This not only applies to histologic features and malignant potential, but also to geographic incidence rates. Several studies have reported GIST incidence and prevalence in Europe and North America. In contrast, GIST incidence rates in South America are largely unknown, and only a few studies have reported GIST prevalence in Latin America.

Patients and methods: Our study was part of a collaborative effort between Chile and Mexico, called Salud con Datos. We sought to determine GIST prevalence and patients’ clinical characteristics, including survival rates, through retrospective analysis.

Results: Overall, 624 patients were included in our study. Our results found significant differences between Mexican and Chilean registries, such as stage at diagnosis, primary tumor location, CD117-positive immunohistochemistry status, mitotic index, and tumor size. Overall survival (OS) times for Chilean and Mexican patients with GIST were 134 and 156 months, respectively. No statistically significant differences in OS were detected by sex, age, stage at diagnosis, or recurrence status in both cohorts. As expected, patients categorized as being at high risk of recurrence displayed a trend toward poorer progression-free survival in both registries.

Conclusion: To the best of our knowledge, this is the largest report from Latin America assessing the prevalence, clinical characteristics, postsurgery risk of recurrence, and outcomes of patients with GIST. Our data confirm surgery as the standard treatment of localized disease and confirm a poorer prognosis in patients with regional or distant disease. Finally, observed differences between registries could be a result of registration bias.

Astrocytic Tumors in Mexico: An Overview of Characteristics and Prognosis in an Open Reference Center for Low-Income Population.

Objective:
The authors aimed to analyze the current epidemiology of high- and low-grade gliomas, follow-up strategies, and prognosis in a national reference center of a developing country.

Materials and Methods:
Medical records of patients diagnosed with intracranial gliomas from January 2012 to January 2016 were reviewed. Data were classified by age, symptoms, Karnofsky functional scale (KFS), tumor location, extent of resection (EOR), histopathology, hospital stay, Glasgow outcome scale (GOS), adjuvant treatments, overall survival (OS), and mortality.

Results:
Astrocytomas accounted for 28.2% of the intracranial tumors and 53.5% were male. Headache was the most common symptom, while sensory disturbance was the least frequent. The right cerebral hemisphere was involved in 56.5% of cases and frontal lobe in 31.3%. Gross total resection (GTR) was achieved in 18.1% cases, 35.3% subtotal resection, and 46.4% biopsy. Regarding the astrocytomas, 43.3% were low grade and 56.4% high grade. Low-grade tumors had the highest frequency in the fourth decade of life, while Grade III and IV in the fifth and seventh decades of life, respectively. In high-grade lesions, there was a slight male predominance (~1.4:1). The initial KFS was regularly 80 for low-grade gliomas and 60 for high-grade. By 1-month postdischarge, the score decreased by 10 points. About half of the patients (47.5%) received adjuvant therapy after surgery. From the Glasgow Outcome Scale (GOS), the majority had a form of disability and 30-month OS was above 88% for Grade I-II and 0% for Grade III and IV.

Conclusions:
Astrocytic tumors were the most frequently noted intra-axial tumors. Age, histological grade, and EOR are important prognostic factors. These results are similar to other reports; however, increased variability was noted when treatment-related factors were considered. Additional studies are necessary to identify the factors related to these treatment results.

Incidence of unintended pregnancy among female sex workers in low-income and middle-income countries: a systematic review and meta-analysis.

To determine the incidence of unintended pregnancy among female sex workers (FSWs) in low-income and middle-income countries (LMICs).We searched MEDLINE, PsychInfo, Embase and Popline for papers published in English between January 2000 and January 2016, and Web of Science and Proquest for conference abstracts. Meta-analysis was performed on the primary outcomes using random effects models, with subgroup analysis used to explore heterogeneity.Eligible studies targeted FSWs aged 15-49 years living or working in an LMIC.Studies were eligible if they provided data on one of two primary outcomes: incidence of unintended pregnancy and incidence of pregnancy where intention is undefined. Secondary outcomes were also extracted when they were reported in included studies: incidence of induced abortion; incidence of birth; and correlates/predictors of pregnancy or unintended pregnancy.Twenty-five eligible studies were identified from 3866 articles. Methodological quality was low overall. Unintended pregnancy incidence showed high heterogeneity (I²>95%), ranging from 7.2 to 59.6 per 100 person-years across 10 studies. Study design and duration were found to account for heterogeneity. On subgroup analysis, the three cohort studies in which no intervention was introduced had a pooled incidence of 27.1 per 100 person-years (95% CI 24.4 to 29.8; I2=0%). Incidence of pregnancy (intention undefined) was also highly heterogeneous, ranging from 2.0 to 23.4 per 100 person-years (15 studies).Of the many studies examining FSWs’ sexual and reproductive health in LMICs, very few measured pregnancy and fewer assessed pregnancy intention. Incidence varied widely, likely due to differences in study design, duration and baseline population risk, but was high in most studies, representing a considerable concern for this key population. Evidence-based approaches that place greater importance on unintended pregnancy prevention need to be incorporated into existing sexual and reproductive health programmes for FSWs.CRD42016029185.

Competency-Based Education in Low Resource Settings: Development of a Novel Surgical Training Program.

BACKGROUND:
The unmet burden of surgical disease represents a major global health concern, and a lack of trained providers is a critical component of the inadequacy of surgical care worldwide. Competency-based training has been advanced in high-income countries, improving technical skills and decreasing training time, but it is poorly understood how this model might be applied to low- and middle-income countries. We describe the development of a competency-based program to accelerate specialty training of in-country providers in cleft surgery techniques.

METHODS:
The program was designed and piloted among eight trainees at five international cleft lip and palate surgical mission sites in Latin America and Africa. A competency-based evaluation form, designed for the program, was utilized to grade general technical and procedure-specific competencies, and pre- and post-training scores were analyzed using a paired t test.

RESULTS:
Trainees demonstrated improvement in average procedure-specific competency scores for both lip repairs (60.4-71.0%, p < 0.01) and palate (50.6-66.0%, p < 0.01). General technical competency scores also improved (63.6-72.0%, p < 0.01). Among the procedural competencies assessed, surgical markings showed the greatest improvement (19.0 and 22.8% for lip and palate, respectively), followed by nasal floor/mucosal approximation (15.0%) and hard palate dissection (17.1%).

CONCLUSION:
Surgical delivery models in LMICs are varied, and trade-offs often exist between goals of case throughput, quality and training. Pilot program results show that procedure-specific and general technical competencies can be improved over a relatively short time and demonstrate the feasibility of incorporating such a training program into surgical outreach missions.