Importance of local and systemic factors in preventing implant displacement in the mandibular body: a scoping review of existing literature.

BACKGROUND: The aim of this research was to analyse the current literature on displaced dental implants in the mandibular body, including local and systemic variables related to their cause, and to identify the most frequent location. METHODS: The study conducted a search of three databases (Pubmed, Scopus, and Web of Science) using specific index terms such as 'dental implant', 'displacement', 'dislocation', 'displaced', and 'mandible'. The analysis focused on the direction of displacement and the characteristics of the bone tissue (bone quality, density, and quantity) in cases where dental implants were displaced. RESULTS: A total of 371 articles were obtained. Thirteen of these articles were selected and read in full. To define bone quality, the Lekholm and Zarb classification, modified by Rosas et al., was used. The type II-B bone, which is characterized by thick cortical bone surrounding cancellous bone with extremely wide medullary spaces, presented the largest number of complications. Twenty-two cases were found in which the displacement direction was horizontal. Of these, four were displaced vestibularly, fourteen lingually, and four remained in the center. Additionally, 24 cases presented vertical displacement, with 12 displaced towards the inferior border of the mandible, 9 towards the middle or adjacent to the inferior dental nerve canal, and 3 above the inferior dental nerve canal. CONCLUSION: The accidental displacement of implants within the mandibular body is associated with various risk factors, including the characteristics of the bony trabeculum and the size of the medullary spaces. It is reasonable to suggest that only an adequate pre-surgical diagnostic evaluation, with the help of high-resolution tomographic images that allow a previous evaluation of these structures, will help to have better control over the other factors, thus minimizing the risk of displacement.

Jawbone quality classification in dental implant planning and placement studies. A scoping review.

Aim: Cone beam computed tomography has become an attractive method for implant planning. However, in most cases, not all the information is taken advantage of and often the radiographic evaluation of bone quality is based on subjective assessment by the individual clinician. Therefore, the aim of this study was to examine classifications of bone tissue characteristics and methods for assessing them in dental implant planning and placement studies. Materials and Methods: Three databases (Pubmed, Scopus, Web of Science) were searched using specific index terms: "Bone quality, bone quantity, bone density, cone-beam CT and cone-beam computed tomography". Three reviewers selected titles and analyzed abstracts according to inclusion and exclusion criteria. Some descriptions of bone tissue characteristics (bone quality, density, and quantity) used before or during dental implant placement were selected and categorized. Results: The search yielded 442 titles. A total of 32 articles were selected and read in full text. Seventeen articles were considered relevant. Different classification systems were found to evaluate bone tissue characteristics as well as different examination protocols. Thirteen publications included in this review reported on bone quality and quantity using the Lekholm and Zarb classification. However, only four studies implemented and/or proposed modifications of the Lekholm and Zarb system. Four other publications described bone quality according to different classification systems such as Misch, University of California Los Angeles (UCLA), or Trisi and Rao. The assessment methods were often briefly described (or not described at all in one publication). Of the articles analyzed, five presented observer performance, whereas three presented diagnostic accuracy of the assessment method. Conclusion: Currently, there are different classification systems applied to dental implant planning and placement, particularly regarding whether bone quality or quantity affects treatment outcomes. However, most authors have not validated the diagnostic accuracy and reproducibility of the classification used. Therefore, it is necessary to develop a classification system consistent with characteristics of bone tissue, taking into consideration an adequate description of bone tissue assessment methods, their diagnostic accuracy, and observer performance.

Resonance Frequency Analysis Mapping During Implant Healing Using a Nanostructured Hydroxyapatite Surface.

Aim: Stability measured by resonance frequency analysis (RFA) is an important factor to be considered in the success of dental implant treatments, which can be evaluated from the implant stability quotient (ISQ). The aim of the present case series was to map the RFA during healing of implants with nanostructured hydroxyapatite surface to describe the behavior of ISQ values related to individual factors. Materials and Methods: Twenty-three implants were placed in eight patients by conventional surgical protocol, and ISQ values were monitored from the day of implant placement until week 20. To obtain the ISQ values, an Osstell device was used and the placed implants were grouped in proportional amounts to describe the ISQ behavior considering the length (≤10 or >10 mm), the diameter (3.5 or 4.3 mm), the insertion torque (<40 N-cm or ≥40 N-cm), and the placement area (maxilla or mandible). Results: All the implants assessed decreased their values in the first 3 weeks after placement. Subsequently, the ISQ values increased by amounts similar to those obtained at the time of the placement and even more. Implants with length >10 mm, diameter 4.3 mm, and insertion torque ≥40 N-cm showed the highest ISQ values. Conclusions: A decrease in the ISQ values of dental implants with nanostructured hydroxyapatite surface was evidenced between weeks 2 and 3 considering length, diameter, insertion torque, and maxillary or mandibular placement site.

Effect of fibrin-rich plasma and collagen sponge on healing of the palatal mucosa.

Background: The purpose was to evaluate the variation in thickness and early healing of the donor area of the palate with the placement of a collagen sponge and the use of fibrin-rich plasma (L-PRF). Material and Methods: Thirty patients who required mucogingival surgery treatment were selected and distributed into 2 groups. After obtaining the free palate graft, L-PRF was placed in Group A, and a collagen sponge was placed in Group B. The healing process of the palate was evaluated at 24 hours and 7, 14, 21 and 28 days postsurgery. The thickness of the donor area (palate) was evaluated using an acrylic splint. These measurements were made before and 4 months after surgery. Results: In the collagen sponge group, less gain of the palatal mucosa was observed, with a mean difference of 0.1 ± 0.8 mm (CI: -0.341-0.518) (p=0.691), whereas in the fibrin-rich plasma group, a mean difference of 0.0 ± 0.5 mm (CI: -0.229-0.229) (p=0.934) was found; however, when comparing the gain of the palatal mucosa in both groups, no significant difference was observed (p=0.932). The healing index at 24 hours indicated the presence of clots, on Day 28 vascularisation and total epithelialisation (100.0%), and finally, the collagen sponge group on Day 14 presented 93.3% partial vascularisation of connective tissue and 33.3% L-PRF (p=0.001). Conclusions: There was no statistically significant difference in the thickness of the palatal mucosa after the use of L-PRF and the collagen sponge. Key words:Palate thickness, connective tissue graft, fibrin-rich plasma, collagen sponge, palate healing.

Impact of Puppet Theater on Oral Health Knowledge and Oral Hygiene in Preschoolers from a Peruvian Educational Institution: A Quasi-experimental Study.

Aim: The puppet theater, due to its artistic and educational characteristics, could allow children to develop oral health self-care in an attractive and fun way. The aim of this study was to evaluate the impact of puppet theater on oral health knowledge and oral hygiene in preschoolers from a Peruvian public school. Materials and Methods: An analytical, longitudinal, and quasi-experimental study was conducted in 132 preschoolers divided into three age-matched groups (3, 4, and 5 years old) from August to November 2019 in a Peruvian public school. At 4 weeks and 4 months after performing the puppet theater, a validated questionnaire of five closed questions was used to evaluate oral health knowledge, and the Greene-Vermillion index [only bacterial plaque index (BPI) part] was used to evaluate oral hygiene, considering good (0-0.6), fair (0.7-1.8), and poor (1.9-3.0). The theater sessions were held every week for the first month and every 2 weeks for the following 3 months. To analyze the levels in the BPI, the Wilcoxon and Friedman test was used to compare related measures, and to compare the knowledge for each question of the questionnaire, the McNemar and Cochran's Q tests were used, considering a P-value less than 0.05. Results: The BPI in relation to age (3, 4, and 5 years), before and after 4 months of performing the puppet theater, was 1.9 [confidence interval (CI): 1.7-2.0], 1.8 (CI: 1.6-1.9), and 1.8 (CI: 1.7-2.0), decreasing to 0.9 (CI: 0.8-1.0), 0.8 (CI: 0.7-0.9), and 0.9 (CI: 0.8-1.00), respectively. In relation to gender (men and women), it was 1.8 (CI: 1.7-2.0) and 1.8 (CI: 1.7-1.9), decreasing to 0.9 (CI: 0.8-1.0) and 0.8 (CI: 0.8-0.9), respectively. In relation to origin (urban or rural), it was 1.8 (CI: 1.7-1.9) and 1.8 (CI: 1.4-2.2), decreasing to 0.9 (CI: 0.8-0.9) and 0.8 (CI: 0.7-0.9), respectively. The level of BPI and oral health knowledge improved significantly (P < 0.001) over time in all preschoolers, except in those who came from the rural area (P > 0.05). Conclusion: The application of the puppet theater positively influenced the preschoolers in such a way that it significantly improved their oral health knowledge and oral hygiene at 4 weeks and 4 months, in both genders of 3, 4, and 5 years of age, and in those whose origin was the urban area. However, no significant improvements in oral health knowledge and oral hygiene were observed in those preschoolers whose origin was the rural area.

Evaluation of Buccal Bone Wall Thickness of Anterosuperior Teeth and Nasopalatine Duct Morphology in Cone Beam Computed Tomography of Patients Living at Different Altitudes: A Two-Year Retrospective Study.

AIM: To evaluate the buccal bone wall thickness of anterosuperior teeth and the dimension and morphology of the nasopalatine duct in cone beam computed tomography (CBCT) of patients treated in two cities at different altitudes. MATERIALS AND METHODS: In this retrospective analytical study, 79 CBCT scans were selected from a total of 347 in Juliaca, Peru (3824 m a.s.l.) and 171 CBCT scans were selected from a total of 622 in Lima, Peru (154 m a.s.l.). The buccal bone wall thickness of anterosuperior teeth was measured at 1 mm, 3 mm, and 5 mm from the alveolar crest. For the nasopalatine duct, its length and diameter were measured, and its anatomical shape was determined in coronal view. Descriptive statistical data such as mean and standard deviation were used, and Mann-Whitney U test was used for bivariate analysis. RESULTS: When comparing the CBCT scans from both cities, significant differences were observed in buccal bone wall thickness at 3 mm and 5 mm from the alveolar crest (P < 0.01 and P < 0.01, respectively); for men, at 1 mm and 3 mm (P = 0.04 and P = 0.04); for the age group from 33 to 47 years, at 3 mm and 5 mm (P < 0.01 and P < 0.01); and for the age group from 48 to 77 years, at 1 mm (P = 0.02). Regarding the nasopalatine duct, significant differences were observed in women in relation to length and nasal opening diameter (P < 0.01 and P < 0.01) and for men, in length (P < 0.01); for the age group from 18 to 32 years, in all three levels (P < 0.01); for the age group from 33 to 47 years, in length and diameter of the oral opening (P < 0.01 and P < 0.01); and for the age group from 48 to 77 years, in length and diameter of the nasal opening (P < 0.01 and P < 0.01). The most frequent nasopalatine duct shape was a single canal with more than 66% of cases, according to sex and age group. CONCLUSION: Patients living at different altitudes presented significant differences in buccal bone wall thickness according to sex and age; however, there were no differences related to dental inclination. Significant differences were found in the length and diameter of the nasopalatine duct at the nasal opening. In addition, the most frequent shape of the nasopalatine duct was the simple canal.

Muerte materna incidental en un accidente por relámpago: Reporte de caso / Incidental maternal death due to lightning injury: a case report

Resumen Los relámpagos se presentan con una frecuencia mayor a 50 veces por segundo a nivel mundial; sin embargo, las descargas directas suceden rara vez y son responsables del 5% de los eventos fatales. El mecanismo de lesión inicial es la parálisis de los centros vitales, lo que ocasiona apnea, fibrilación auricular o paro cardíaco. En mujeres embarazadas, el accidente por rayo puede producir complicaciones graves, dependiendo del punto de entrada en el cuerpo y su efecto indirecto sobre el feto, produciendo trastornos de la conducción en el sistema cardíaco y daño a nivel del sistema nervioso central. En la literatura mundial, solo catorce casos de embarazo y traumatismo por relámpago han sido reportados, sobreviviendo en todos la madre, con un único reporte de muerte fetal. Se presenta un caso de accidente por relámpago en una mujer embarazada en la semana 23 de gestación, cuyo tipo de lesión fue por contacto directo en el abdomen, y quien ingresó con compromiso neurológico, taquicardia materna y bradicardia fetal. El deceso materno ocurrió por infarto agudo extenso del miocardio y la formación de un émbolo intracavitario en el ventrículo izquierdo, con la consecuente muerte del binomio. Se describe su frecuencia, el mecanismo de lesión, las manifestaciones clínicas y el manejo actual. MÉD.UIS.2019;32(1):21-6

Abstract Lightning occurs with a frequency rate of more than 50 times per second worldwide. Nevertheless, direct lightning strikes are not common, and they are responsible for about 5% of all lightning injury fatalities. The initial mechanism of injury is the paralysis of the vital centers, which causes apnea, atrial fibrillation and cardiac arrest. In pregnant women, lightning can produce severe complications which depend on the point of entrance and its indirect effect on the fetus, affecting the cardiac conduction system and the central nervous system. We report a case of a lightning accident by direct strike on a 23-week pregnant woman, who's type of injury was by direct contact on the abdomen. She arrives to the emergency room with neurologic symptoms, maternal tachycardia and fetal bradycardia. The mother died due to myocardial infarction and the presence of an intracavitary embolus in the left ventricle, with the consequent maternal-fetal death. The incidence and injury mechanisms, as well as the clinical features and clinical management are described. MÉD.UIS.2019;32(1):21-6.