Characterization of a natural model of adult mice with different rate of aging.

Aging is a heterogeneous process, so individuals of the same age may be aging at a different rate. A natural model of premature aging in mice have been proposed based on the poor response to the T-maze. Those that take longer to cross the intersection are known as Prematurely Aging Mice (PAM), while those that show an exceptional response are known as Exceptional non-PAM (E-NPAM), being the rest non-PAM (NPAM). Although many aspects of PAM and E-NPAM have been described, some aspects of their brain aging have not been studied. Similarly, it is known that PAM, NPAM and E-NPAM show a different rate of aging and longevity, but the differences between these three groups in behavior, immune function and oxidative-inflammatory state are unknown. The present study aims to deepen the study of brain aging in PAM and E-NPAM, and to study the differences in behavior, immunity, and oxidative-inflammatory state of peritoneal leukocytes between PAM, NPAM and E-NPAM. Results show deteriorated brains in PAM. Moreover, NPAM show an oxidative state similar to E-NPAM, an anxiety similar to PAM, and an intermediate immunity and lifespan between PAM and E-NPAM. In conclusion, immune function seems to be more associated with the longevity achieved.

Frailty and biological age. Which best describes our aging and longevity?

Frailty and Biological Age are two closely related concepts; however, frailty is a multisystem geriatric syndrome that applies to elderly subjects, whereas biological age is a gerontologic way to describe the rate of aging of each individual, which can be used from the beginning of the aging process, in adulthood. If frailty reaches less consensus on the definition, it is a term much more widely used than this of biological age, which shows a clearer definition but is scarcely employed in social and medical fields. In this review, we suggest that this Biological Age is the best to describe how we are aging and determine our longevity, and several examples support our proposal.

Prodromic Inflammatory-Oxidative Stress in Peritoneal Leukocytes of Triple-Transgenic Mice for Alzheimer's Disease.

Inflammatory-oxidative stress is known to be pivotal in the pathobiology of Alzheimer's disease (AD), but the involvement of this stress at the peripheral level in the disease's onset has been scarcely studied. This study investigated the pro-inflammatory profile and oxidative stress parameters in peritoneal leukocytes from female triple-transgenic mice for AD (3xTgAD) and non-transgenic mice (NTg). Peritoneal leukocytes were obtained at 2, 4, 6, 12, and 15 months of age. The concentrations of TNFα, INFγ, IL-1ß, IL-2, IL-6, IL-17, and IL-10 released in cultures without stimuli and mitogen concanavalin A and lipopolysaccharide presence were measured. The concentrations of reduced glutathione (GSH), oxidized glutathione (GSSG), lipid peroxidation, and Hsp70 were also analyzed in the peritoneal cells. Our results showed that although there was a lower release of pro-inflammatory cytokines by 3xTgAD mice, this response was uncontrolled and overstimulated, especially at a prodromal stage at 2 months of age. In addition, there were lower concentrations of GSH in leukocytes from 3xTgAD and higher amounts of lipid peroxides at 2 and 4 months, as well as, at 6 months, a lower concentration of Hsp70. In conclusion, 3xTgAD mice show a worse pro-inflammatory response and higher oxidative stress than NTg mice during the prodromal stages, potentially supporting the idea that Alzheimer's disease could be a consequence of peripheral alteration in the leukocyte inflammation-oxidation state.

Immunoneuroendocrine, Stress, Metabolic, and Behavioural Responses in High-Fat Diet-Induced Obesity.

Obesity has reached global epidemic proportions, and even though its effects are well-documented, studying the interactions among all influencing factors is crucial for a better understanding of its physiopathology. In a high-fat-diet-induced obesity animal model using C57BL/6J mice, behavioural responses were assessed through a battery of tests, while stress biomarkers and systemic inflammatory cytokines were measured using an Enzyme-Linked ImmunoSorbent Assay and a Bio-Plex Multiplex System. The peritoneal macrophage microbicide capacity was analysed via flow cytometry, and crown-like structures (CLSs) in white adipose tissue (WAT) were evaluated through staining techniques. Results indicated that obese mice exhibited increased body weight, hyperglycaemia, and hyperlipidaemia after 18 weeks on a high-fat diet, as well as worse physical conditions, poorer coordination and balance, and anxiety-like behaviour. Differences in corticosterone and noradrenaline concentrations were also found in obese animals, revealing a stress response and noradrenergic dysregulation, along with a weakened innate immune response characterized by a lower microbicide capacity, and the presence of an underlying inflammation evidenced by more CLSs in WAT. Altogether, these findings indicate that obesity deteriorates the entire stress, inflammatory, metabolic, sensorimotor and anxiety-like behavioural axis. This demonstrates that jointly evaluating all these aspects allows for a deeper and better exploration of this disease and its associated comorbidities, emphasizing the need for individualized and context-specific strategies for its management.

Improvement of Immune Function and Redox State in Several Organs of Old and Prematurely Aging Female Mice After a Short Social Interaction With Adults.

Aging is associated with chronic oxidative stress, which contributes to the deterioration of the immune system, increasing morbidity and mortality. A positive social environment permits health maintenance and a slower rate of aging. Improvements in immune function and oxidative stress were shown in peritoneal leukocytes and organs of old mice and adult prematurely aging mice (PAM) after cohabitation with adults or exceptional non-prematurely aging mice (ENPAM), respectively, for 2 months, but adults and ENPAM experienced deterioration. This was solved by shortening the cohabitation time to 15 minutes per day for 2 months, where old mice and PAM maintained immune and redox state improvements in their peritoneal leukocytes, as well as a greater longevity, and adults and ENPAM did not show deterioration. However, it is unknown whether the positive effects of this short cohabitation are reflected in the immunity and redox state of the organs. The aim of the present study was to test whether a cohabitation of 15 minutes per day for 2 months maintains these positive effects in the organs of retired breeder female old mice and PAM and avoids the negative ones in adults and ENPAM. After cohabitation the animals were sacrificed, and the thymus and spleen were extracted to evaluate the immune function. The oxidative state was also analyzed in the spleen, liver, heart, lung, and kidney. The results show that after cohabitation, old mice and PAM improved their immunity and redox state, and adults and ENPAM showed no deterioration. This cohabitation can be suggested to improve health and slow down aging.

Influence of consumption of the food additive carrageenan on the gut microbiota and the intestinal homeostasis of mice.

The safety of the carrageenan (CGN) consumption as a food additive is under debate, with negative effects being associated with the products of hydrolysis of CGN. Moreover, there is an increasing need to integrate gut microbiome analysis in the scientific risk assessment of food additives. The objective of this study was to test the effects of CGN consumption on the gut microbiota and the intestinal homeostasis of young male and female mice. Female and male ICR-CD1 mice (8 weeks old) orally received 540 mg kg-1 day-1 of CGN, representing the maximum-level exposure assessment scenario surveyed for children, over the course of two weeks. Fecal material and peritoneal immune cells were analyzed to determine changes in the fecal microbiota, based on the analysis of bacterial 16S rRNA gene amplicon sequences and short-chain fatty acid (SCFA) concentrations, and some immune functions and redox parameters of peritoneal leukocytes. Non-significant microbiota taxonomical changes associated with CGN intake were found in the mouse stools, resulting the housing time in an increase in bacterial groups belonging to the Bacteroidota phylum. The PICRUSt2 functional predictions showed an overall increase in functional clusters of orthologous genes (COGs) involved in carbohydrate transport and metabolism. A significant increase in the cytotoxicity of fecal supernatants was observed in CGN-fed mice, which correlated with worsening of immune functions and oxidative parameters. The altered immunity and oxidative stress observed in young mice after the consumption of CGN, along with the fecal cytotoxicity shown towards intestinal epithelial cells, may be associated with the gut microbiota's capacity to degrade CGN. The characterization of the gut microbiota's ability to hydrolyze CGN should be included in the risk assessment of this food additive.

Intracellular cytokines in peritoneal leukocytes relate to lifespan in aging and long-lived female mice.

Peritoneal immune cell function is a reliable indicator of aging and longevity in mice and inflammaging is associated with a shorter lifespan. Nevertheless, it is unknown if the content of cytokines in these immune cells is linked to individual differences in lifespan. Therefore, this work aimed to investigate different peritoneal leukocyte populations and their content in intracellular pro-inflammatory (TNF and IL-6) and anti-inflammatory (IL-10) cytokines by flow cytometry in adult (10 months-old, n = 8) and old (18 months-old, n = 20) female Swiss/ICR mice. In addition, old mice were monitored longitudinally throughout their aging process, and the same markers were analyzed at the very old (24 months-old, n = 8) and long-lived (30 months-old, n = 4) ages. The longitudinal follow-up allowed us to relate the investigated parameters to individual lifespans. The results show that long-lived female mice exhibit an adult-like profile in most parameters investigated but also display specific immune adaptations, such as increased CD4+ and CD8+ T cells containing the pro-inflammatory TNF cytokine and CD4+ T cells and macrophages containing the anti-inflammatory cytokine IL-10. These adaptations may underlie their exceptional longevity. In addition, a negative correlation was obtained between the percentage of cytotoxic T cells, KLRG-1/CD4, large peritoneal macrophages, and the percentage of CD4+ T cells containing IL-6 and macrophages containing IL-10 in old age and lifespan, whereas a positive correlation was found between the CD4/CD8 ratio and the longevity of the animals at the same age. These results highlight the crucial role of peritoneal leukocytes in inflammaging and longevity.

Effect of a diabetes-specific formula in non-diabetic inpatients with stroke: a randomized controlled trial.

BACKGROUND/OBJECTIVES: In patients with acute stroke, the presence of hyperglycaemia has been associated with higher morbidity and less neurological recovery. The aim of the study was to evaluate the impact of a diabetes specific enteral nutrition (EN) formula on glycaemia, comorbidities and mortality in patients admitted with a first episode of stroke who received complete EN. METHODS: This was a prospective randomised controlled trial. Patients with acute stroke did not have diagnosis of diabetes mellitus and required nasogastric tube feeding. This study has been registered with code NCT03422900. The patients were randomised into two arms: an isocaloric isoprotein formula (control group (CG), 27 patients) vs a diabetes-specific formula (low glycaemic index carbohydrates, fibre (80% soluble) and higher lipid content) (experimental group (EG), 25 patients). Pre-EN blood glucose, hyperglycaemia during EN treatment, HbA1c, insulin use, oral route recovery, length of stay (LOS) and mortality at 30 days were collected. The complications of enteral nutrition during admission were collected as well. RESULTS: 52 patients were included, 50% females, with an age of 77.44(11.48) years; 34 (65.4%) had ischaemic stroke, with a Rankin score of 0(0-2), and a National Institute of Health Stroke Scale (NIHSS) of 19 (15-22). In CG, there were more cases of hyperglycaemia on the 5th day post-NE (13(65%) vs7(35%), p < 0.01). CG showed an OR of 7.58(1.49-39.16) (p = 0.02) for the development of hyperglycaemia. There were no differences in LOS between groups (12(8.5) days vs 14(23) days, p = 0.19) or in the death rate (10(37%) vs 10(40%), p = 0.8), although differences were found in terms of oral route recovery (EG: 11(44%) patients vs CG: 5(18.5%) patients, p = 0.04) (OR (EG): 5.53(1.25-24.47); p = 0.02). CONCLUSIONS: The use of a diabetes-specific enteral formula in non-diabetic patients admitted with acute stroke reduced the risk of developing hyperglycaemia and improved the rate of oral route recovery. Registered under ClinicalTrials.gov Identifier no. NCT03422900.

Predictive Models of Life Span in Old Female Mice Based on Immune, Redox, and Behavioral Parameters.

The development of mathematical models capable of predicting the lifespan of animals is growing. However, there are no studies that compare the predictive power of different sets of parameters depending on the age of the animals. The aim of the present study is to test whether mathematical models for life span prediction developed in adult female mice based on immune, redox, and behavioral parameters can predict life span in old animals and to develop new models in old mice. For this purpose, 29 variables, including parameters of immune function, redox state, and behavioral ones, were evaluated in old female Swiss mice (80 ± 4 weeks). Life span was registered when they died naturally. Firstly, we observed that the models developed in adults were not able to accurately predict the life span of old mice. Therefore, the immunity (adjusted R2 = 73.6%), redox (adjusted R2 = 46.5%), immunity-redox (adjusted R2 = 96.4%), and behavioral (adjusted R2 = 67.9%) models were developed in old age. Finally, the models were validated in another batch of mice. The developed models in old mice show certain similarities to those in adults but include different immune, redox, and behavioral markers, which highlights the importance of age in the prediction of life span.

The immunity and redox clocks in mice, markers of lifespan.

Immune function and redox markers are used for estimating the aging rate, namely biological age (BA). However, it is unknown if this BA and its changes can be reflected in longevity. Thus, we must quantify BA in experimental animals. In peritoneal immune cells of 202 female mice (ICR/CD1) in different ages, 10 immune and 6 redox parameters were evaluated to construct two mathematical models for BA quantification in mice by multiple linear regression. Immune and redox parameters were selected as independent variables and chronological age as dependent, developing two models: the Immunity and the Redox Clocks, reaching both an adjusted R2 of 80.9% and a standard error of 6.38 and 8.57 weeks, respectively. Both models were validated in a different group of healthy mice obtaining a Pearson's correlation coefficient of 0.844 and 0.800 (p < 0.001) between chronological and BA. Furthermore, they were applied to adult prematurely aging mice, which showed a higher BA than non-prematurely aging mice. Moreover, after positive and negative lifestyle interventions, mice showed a lower and higher BA, respectively, than their age-matched controls. In conclusion, the Immunity and Redox Clocks allow BA quantification in mice and both the ImmunolAge and RedoxAge in mice relate to lifespan.

Development of novel antimicrobial acrylic denture modified with copper nanoparticles.

PURPOSE: This study aimed to synthesize heat-cured poly(methyl methacrylate) (PMMA) acrylic formulated with copper nanoparticles (nCu) for producing dentures with antimicrobial properties and ability to prevent denture stomatitis (DS). METHODS: nCu/PMMA nanocomposites were prepared through in situ formation of nCu into methyl methacrylate (MMA). The fabricated material was characterized using scanning electron microscopy, spectroscopy (energy-dispersive X-ray, attenuated total reflectance-Fourier-transform infrared, and X-ray photoelectron spectroscopy), X-ray diffraction analysis, and mechanical flexural tests (ISO 20795-1:2008). Antimicrobial activity against Candida albicans and oral bacteria was determined. MTS assay (ISO 10993-5:2009) and copper release experiments were conducted to assess cytotoxicity. In the clinical trial, participants wearing nCu/PMMA (n=25) and PMMA (n=25) dentures were compared; specifically, DS incidence and severity and Candida species proliferation were assessed for 12 months. Data were analyzed using analysis of variance with Tukey's post hoc test (α=0.05). RESULTS: nCu/PMMA nanocomposite loaded with 0.045% nCu exhibited the maximum antimicrobial activity against C. albicans and other oral bacteria without producing cytotoxicity in the wearer. nCu/PMMA dentures retained their mechanical and aesthetic properties as well as inhibited the growth of Candida species on both denture surface and patient palate. DS incidence and severity were lower in the nCu/PMMA denture group than in the PMMA denture group. CONCLUSIONS: PMMA acrylic produced with copper nanotechnology is antimicrobial, biocompatible, and aesthetic and can reduce DS incidence. Thus, this material may act as a novel preventive alternative for oral infections associated with denture use.

Components of the Glutathione Cycle as Markers of Biological Age: An Approach to Clinical Application in Aging.

The oxidative-inflammatory theory of aging states that aging is the result of the establishment of a chronic oxidative-inflammatory stress situation in which the immune system is implicated. Among the redox parameters, those involved in the glutathione cycle have been suggested as essential in aging. Thus, the first objective of this study was to determine if several components of the glutathione cycle (glutathione reductase (GR) and glutathione peroxidase (GPx) activities, and concentrations of oxidized glutathione (GSSG) and reduced glutathione (GSH)) in leukocytes) are associated with the biological age (ImmunolAge) estimated using the Immunity Clock in 190 men and women. The second objective was to identify the best blood fraction (whole blood, blood cells, erythrocytes, or plasma) to quantify these components and correlate them with the estimated ImmunolAge. The results show that the oxidative state of peripheral leukocytes correlates with their functionality, supporting the idea that this is the basis of immunosenescence. In blood, the correlations are more significant in the fraction of blood cells with respect to ImmunolAge (positive correlations with GSSG concentration and the GSSG/GSH ratio, and negative correlations with GPx and GR activities). Therefore, blood cells are proposed as the most effective sample to estimate the biological age of individuals in clinical settings.

Positive effects of pulsed electromagnetic fields on behavior, immune function, and oxidative and inflammatory state in old mice.

The establishment of chronic oxidative and inflammatory stress with aging leads to the deterioration of the nervous and immune systems and, consequently, to the loss of health. The aim of this work was to study the effect of exposure to low-frequency pulsed electromagnetic fields (PEMFs) produced by the NEURALTER® system (15 min/day for 4 weeks) in the behavior, immune functions, and oxidative and inflammatory state of old mice. Female old CD1 mice were divided into three groups: control group, handling control group and Neuralter group. Then, behavioral tests were performed, and peritoneal leukocytes were extracted to analyze function, oxidative and inflammatory parameters. In peritoneal leukocytes from old mice, the effects in vitro of 15 min with NEURALTER® were studied on function and oxidative parameters. The results show that after this type of treatment, old mice had greater coordination and locomotion, better immune function, and an oxidative-inflammatory state. Similarly, the immune function and oxidative state of leukocytes showed an improvement when these cells were exposed directly to the NEURALTER® system. In conclusion, the exposure to low-frequency PEMFs produced by the NEURALTER® system has beneficial effects on health in aging. In addition, this effect is direct, at least in part, on immune cells.

In Response to a Punctual Stress Male and Female Tyrosine Hydroxylase Haploinsufficient Mice Show a Deteriorated Behavior, Immunity, and Redox State.

An inadequate stress response is associated with impaired neuroimmunoendocrine communication, increasing morbidity and mortality. Since catecholamines (CA) constitute one of the acute stress response pathways, female mice with an haploinsufficiency of the tyrosine hydroxylase gene (TH-HZ), the main limiting enzyme in CA synthesis, show low CA amounts, exhibiting an impairment of homeostatic systems. The aim of this study was to investigate the effect of a punctual stress in TH-HZ mice, determining the differences with wild-type (WT) mice and those due to sex by restraint with a clamp for 10 min. After restraint, a behavioral battery was performed, and several immune functions, redox state parameters, and CA amounts were evaluated in peritoneal leukocytes. Results show that this punctual stress impaired WT behavior and improved female WT immunity and oxidative stress, whereas in TH-HZ mice, all parameters were impaired. In addition, different responses to stress due to sex were observed, with males having a worse response. In conclusion, this study confirms that a correct CA synthesis is necessary to deal with stress, and that when a positive stress (eustress) occurs, individuals may improve their immune function and oxidative state. Furthermore, it shows that the response to the same stressor is different according to sex.

[Touch, a crucial sense in social interactions to improve homeostasis in aging and promote healthy longevity]. / El tacto, un sentido crucial en las interacciones sociales para mejorar la homeostasis en el envejecimiento y promover una longevidad saludable.

Aging is associated with the generalized deterioration of the organism, being of great relevance experienced by homeostatic systems such as the nervous, immune, and endocrine systems, which increases the risk of morbidity and mortality. Among the lifestyle strategies that have been researched to improve these systems and achieve greater healthy longevity, this review will focus on the social environment. In order to verify the effectiveness of these both in the improvement of homeostasis and in life expectancy, the research carried out with experimental animals that have allowed this to be done will be discussed. In addition, as it has been observed that physical contact is crucial for the positive outcomes of social interaction on homeostatic systems and longevity to occur, we will focus on that mechanism, as well as some of the possible molecular pathways underlying the effects found.

Sex differences in neuroimmunoendocrine communication. Involvement on longevity.

Endocrine, nervous, and immune systems work coordinately to maintain the global homeostasis of the organism. They show sex differences in their functions that, in turn, contribute to sex differences beyond reproductive function. Females display a better control of the energetic metabolism and improved neuroprotection and have more antioxidant defenses and a better inflammatory status than males, which is associated with a more robust immune response than that of males. These differences are present from the early stages of life, being more relevant in adulthood and influencing the aging trajectory in each sex and may contribute to the different life lifespan between sexes.

Skin-to-Skin Contact: Crucial for Improving Behavior, Immunity, and Redox State after Short Cohabitation of Chronologically Old Mice and Prematurely Aging Mice with Adult Mice.

(1) Background: Aging is characterized by a deterioration of the homeostatic systems, namely the nervous and immune systems. The rate of aging can be modified by lifestyle factors such as social interactions. Recently, improvements in behavior, immune function, and oxidative state were observed in adult prematurely aging mice (PAM) and chronologically old mice after cohabitation with exceptional non-PAM (E-NPAM) and adult mice, respectively, for 2 months. However, the cause of this positive effect is not known. The objective of the present work was to study whether skin-to-skin contact promotes these improvements both in chronologically old mice and in adult PAM. (2) Methods: Old and adult CD1 female mice were used as well as adult PAM and E-NPAM. After cohabitation for 15 min/day for 2 months (two old mice or PAM with five adult mice or E-NPAM, respectively, with both non- and skin-to-skin contact), several behavioral tests were performed and functions and oxidative stress parameters in peritoneal leukocytes were analyzed. (3) Results: This social interaction improved behavioral responses, immune functions, redox state, and longevity, but only if the animals had skin-to-skin contact. (4) Conclusions: Physical contact seems to be crucial to experiencing the positive effects of social interaction.

Plasma acylcarnitines and gut-derived aromatic amino acids as sex-specific hub metabolites of the human aging metabolome.

Aging biology entails a cell/tissue deregulated metabolism that affects all levels of biological organization. Therefore, the application of "omic" techniques that are closer to phenotype, such as metabolomics, to the study of the aging process should be a turning point in the definition of cellular processes involved. The main objective of the present study was to describe the changes in plasma metabolome associated with biological aging and the role of sex in the metabolic regulation during aging. A high-throughput untargeted metabolomic analysis was applied in plasma samples to detect hub metabolites and biomarkers of aging incorporating a sex/gender perspective. A cohort of 1030 healthy human adults (45.9% females, and 54.1% males) from 50 to 98 years of age was used. Results were validated using two independent cohorts (1: n = 146, 53% females, 30-100 years old; 2: n = 68, 70% females, 19-107 years old). Metabolites related to lipid and aromatic amino acid (AAA) metabolisms arose as the main metabolic pathways affected by age, with a high influence of sex. Globally, we describe changes in bioenergetic pathways that point to a decrease in mitochondrial ß-oxidation and an accumulation of unsaturated fatty acids and acylcarnitines that could be responsible for the increment of oxidative damage and inflammation characteristic of this physiological process. Furthermore, we describe for the first time the importance of gut-derived AAA catabolites in the aging process describing novel biomarkers that could contribute to better understand this physiological process but also age-related diseases.

Complicaciones de la técnica anestésica mandibular Spix en la clínica odontológica de la Universidad Andrés Bello / Incidence of complications of mandibular anesthetic Spix techniques in the Andrés Bello University dental clinic

Objetivo: Determinar la incidencia de complicaciones de la técnica anestésica Spix en procedimientos odontológicos a pacientes atendidos en la clínica de la Universidad Andrés Bello (UNAB). Material y Métodos: Se analizó a 37 pacientes que fueron atendidos por alumnos de cuarto y quinto año de la clínica odontológica, a los cuales se le realizó la técnica anestésica Spix para realizar el procedimiento odontológico. Se consignó mediante la observación la presencia de formación de hematomas intraorales en el sitio de punción, rotura de la aguja, cantidad de tubos de solución anestésica inyectados, presencia de dolor a la inyección de solución anestésico y la presencia o no de parálisis facial. Mediante la recolección de datos y posterior encuesta a los participantes se consignó la presencia de trismus al día siguiente de la atención y parestesia persistente al día siguiente de la atención. Resultados: De 37 pacientes estudiados que recibieron la técnica anestésica Spix, 6 presentaron hematoma intraoral (16,2%), ninguno reportó rotura de la aguja, 1 presentó parálisis facial (2,7%), 1 presentó parestesia persistente al día siguiente (2,7%), 12 presentaron trismus posterior a la inyección (32,4%). El rango de dolor reportado fue entre 1 y 4 según la escala EVA. Conclusión: Hay una baja incidencia de las complicaciones asociadas a la técnica anestésica Spix en la clínica odontológica de la UNAB, siendo el trismus la complicación más frecuente. Se necesita un mayor número de muestra para entender mejor esta realidad.

Objective: To determine the incidence of complications of the Spix anesthetic technique in the dental procedures of patients attended at the Andrés Bello University dental clinic. Material and Methods: 37 patients who were cared for by fourth- and fifth-year students from the dental clinic of the Andrés Bello University were analyzed, who underwent the Spix anesthetic technique to perform the dental procedure. The presence of intraoral hematoma formation at the puncture site, needle breakage, number of injected anesthesia tubes, presence of pain upon injection of anesthetic and the presence or not of facial paralysis were recorded. Through data collection and subsequent survey of the participants, the presence of trismus was recorded the day after care. Results. Of the 37 cases of patients studied who received the Spix anesthetic technique, 6 had intraoral hematoma (16.2%), no needle break was reported, 1 had facial paralysis (2.7%), 1 had persistent paresthesia at the next day (2.7%), 12 presented trismus after the injection (32.4%), the pain range was between 1 and 4 according to the VAS scale. Conclusion. There is a low incidence of complications associated with the Spix anesthetic technique in the Andrés Bello University dental clinic, trismus being the most frequent (32.4%). A larger sample number should be needed to better understand this reality.