Cristina Bucchi’s research while affiliated with University of La Frontera and other places

Odontomas are benign tumors characterized by slow and limited growth with a rare recurrence. Odontomas are generally detected by radiographic findings in the radiopaque stage, where calcification of the tissues is observed. This article seeks to report the recurrence of a radiologically diagnosed odontoma to show the importance of radiographic controls after enucleation as a diagnostic and follow-up method. Case report: A female patient, 9 years old, attended dental care in 2020 due to malpositioned teeth. In the intraoral clinical examination, she presented stage II mixed dentition with crowding. A radiographic exam showed no associated lesions. The patient reported a history of odontoma removal and a supernumerary tooth in sextant II in 2016. Subsequently, she was referred to orthodontics, where permanent dentition with moderate anterior crowding in the maxilla and mandible was observed. The radiographic examination showed a radiopaque area compatible with odontoma, palatal to teeth 12 and 13. Conclusions: Although recurrence is rare, complete removal in the case of an odontoma is critical. This study demonstrates the importance of performing radiographic controls 5 years after enucleation of an odontoma, considering the stages of evolution.

Purpose: Obesity has become a growing public health issue worldwide. Studies have shown that eating rate is one of the most important factors to consider in the strategies to prevent and/or treat obesity. Eating rate can be reduced through different strategies, such as an increase in oro-sensory exposure, the modification of food texture, and an increase in the number of chewing cycles. The aim of this systematic review was to analyze the available evidence regarding the effect of chewing behavior modification on the parameters that contribute to obesity. Methods: A systematic search was done on the electronic databases Pubmed, Cochrane Central Register of Controlled Trials, and Scopus, using the terms “mastication”, “chewing”, “chewing speed”, “prolonged chewing“, “number of chews“, “masticatory cycles” “satiety” “satiety response” “appetite”, “appetite regulation“, “nutritional status” and “obesity”. Results: A total of 23 intervention studies were selected that intervened in the participants’ chewing behavior, either by reducing the eating rate, increasing oro-sensory exposure, food hardness or the number of chewing cycles. In most studies these interventions were effective at reducing food intake, subjective appetite and improving the plasma levels of satiety-related hormones and metabolites; moreover, they reduced body mass index in the long term. Conclusion: The currently available evidence seems to indicate that modifications to chewing behavior can bring with it a myriad of benefits for the treatment of obesity.

human amnion epithelial cells (hAECs) are pluripotent stem cells; they have the ability to differentiate into cells of the three embryonic layers, and are used in various regenerative therapies in medicine. This study aims to describe a protocol for the isolation of amnion epithelial cells (hAECs) from human placentas from cesarean delivery, as well as their characterization and culture conditions in vitro. hAECs were isolated from 20 cesarean delivery placentas with an optimized protocol. The cells were characterized by flow cytometry, light and fluorescence microscopy, and the proliferation of the cells was evaluated by MTT at 1, 3, 5 and 7 days with and without β-mercaptoethanol in the culture medium. Histological analysis of the amnion showed a practically complete detachment of the cells of the underlying membrane after the second digestion. The average number of cells obtained was 10.97 million cells per amnion. The hAECs perform a limited proliferation rate, which was not favored by the addition of β-mercaptoethanol in the culture. A spontaneous morphology change from epithelial to mesenchymal morphology is exhibited after the fourth passage. The epithelial cells of the amnion can be isolated with a simple and effective protocol, however, they present little proliferative capacity. Under the conditions of this study, the addition of β-mercaptoethanol does not favor the proliferation of the cells.

Previous studies have proposed that our ability to produce and use stone tools was the primary selective pressure explaining the evolution of the human hand. Derived traits in humans include a robust first metacarpal and longer thumbs relative to the other fingers. Along with other anatomical peculiarities, humans can exert forceful precision and have powerful grips, and can resist loads during tool production and use. Despite this biomechanical explanation for the morphology of the human hand, limited work has been done on the soft tissue and, therefore, the relationship between the hand bones and the muscles most heavily relied upon during tool-related behaviours still requires thorough investigation. For this purpose, we have dissected 23 forearms and hands of fresh human cadavers of known sex and age at death, and dissected all the muscles attached at the first metacarpal (the first dorsal interosseous, opponens pollicis, and abductor pollicis longus muscles). Variations in physiological cross-sectional area, muscle mass, and fibre length were compared with metacarpal anatomy. In no case bone traits were a significant predictor of muscle features. In contrast, sex and age predicted muscle architecture in several cases, thus substantially affecting the functional analysis based on linear measurements of this bone. The data, therefore, failed to provide a deductive framework for predicting muscle recruitment based on measurements of bone from the fossil record.

In this study we analyse the relationship between strength and the entheseal area of the opponens pollicis (OP) and abductor pollicis longus (APL) muscles, two muscles of the hand whose main function is to oppose the thumb and move the thumb anteriorly, respectively. We were interested in this link for two reasons: (1) to determine if muscular strength is related to entheseal size, and (2) to evaluate the predictive power of enthesis, age, sex and body size on muscular strength. With the latter objective we attempt to discuss whether it is reasonable to infer behaviour from entheses in the archaeological record. To figure out if the recruitment of muscles leaves a distinctive mark on the bone is a key component for understanding human hand evolution. This is because manipulative activities, like tool-related behaviours, could contribute to the anatomical changes in the hand of our lineage as well as explain the high dexterity we have. The ability of entheses to provide information on activity patterns has a long history of debate. Briefly, there are studies concluding that manual labour has an effect on entheseal morphology, and others stating that entheseal anatomy is strongly dependant on the biological profile of individuals (e.g. age and body size) which makes them poor behavioural indicators.

Background: This study evaluated the effectiveness of a regenerative endodontic approach to regenerate the pulp tissue in mature teeth of ferret. The presence of odontoblast-like cells in the newly-formed tissue of teeth treated with or without preameloblast-conditioned medium was evaluated based on morphological criteria. Materials and methods: Twenty-four canines from six ferrets were treated. The pulp was removed, and the apical foramen was enlarged. After inducing the formation of a blood clot, a collagen sponge with or without preameloblast-conditioned medium was placed underneath the cementoenamel junction. The samples were analyzed at the eighth week of follow-up. Results: Vascularized connective tissue was observed in 50% of teeth, without differences between groups. The tissue occupied the apical third of the root canals. Odontoblast-like cells were not observed in any group. Conclusion: Revitalization of mature teeth is possible, at least in the apical third of the root canal. Further experimental research is needed to produce more reliable outcomes.

Previous studies have proposed that our ability to produce and use stone tools has been the primary selective pressure explaining the evolution of the human hand. Derived traits in the human hand include a robust thumb metacarpal, particularly at the head and the base, and a moderate trapeziometacarpal joint curvature in both radioulnar and dorsovolar aspects. Along with other anatomical peculiarities, humans can exert forceful precision and power grips, and resist load during tool production and use. Despite that this is a biomechanical explanation for the morphology of the human hand, limited work had been done using soft tissue and therefore, the relationship between the muscles most strongly recruited during tool production/use and the derived traits in the hand bones remains to be thoroughly investigated. We have dissected 15 forearms of wet human cadavers of known sex and age at death. An estimate of the force magnitude was calculated by means of the physiological cross-sectional area (PCSA) of the muscles that arise and insert on the first metacarpal (first dorsal interosseous, opponens pollicis and abductor pollicis longus muscles). Variation in PCSA, muscle mass and fiber length was compared with metacarpal morphology. The bones were documented using photogrammetry and the 3D models were analyzed by applying geometric morphometrics. For comparison purposes, analogous information from non-human primates available at the literature and digital databases were studied. We aim to relate muscle architecture and the functionally influenced bony variables, and provide some light into the question of whether the evolution of the first metacarpal was related to its musculature.

The mandibular incisive canal (MIC) is a continuation of the mandibular canal, anterior to the mental foramen, containing the neurovascular bundle of the teeth in anterior mandibular segment. The aim of this study was to calculate the prevalence and analyze the morphometric parameters of MIC in a Chilean population through digital panoramic radiographs. A cross-sectional study was performed using 500 digital panoramic radiographies of adult individuals. The prevalence of MIC was set in different sexes, age groups and proximity to teeth; in addition to the morphometric parameters of length, width (diameter) and distances of MIC to dental element and the mandibular base. General MIC prevalence was 53 % (265 cases), 49.9 % in women and 57 % in men. In the age groups, prevalence was higher in men, MIC was predominantly associated to first premolars (98.2 % - women; 90 % - men), however a relevant number (42.6 % women; 55.1 % - men) was close to the canines. The MIC length ranged from 2.6 to 18 mm (median - 5 to 8 mm), the width of 0.8 to 5.4 mm (median - 2 to 3 mm), the distance to other elements from 0.6 to 12 , 5 mm (medians - 5 to 7 mm) and the margin of the mandible from 4.1 to 16.7 mm (median - 8 to 10 mm). The length decreases in older age groups regardless of sex. Width and distance the mandibular base was larger in men compared to women.