Evaluation of the root morphology of mandibular first premolars using cone-beam computed tomography in a peruvian population / Evaluación de la morfología radicular de primeros premolares mandibulares mediante tomografía computarizada de haz cónico en una población peruana

Introduction: The morphology of the root canal of the first premolars is not always the same and therefore a good knowledge of its dental anatomy is essential. Aim: To assess the morphology of roots and root canals of mandibular first premolars in a Peruvian population using cone-beam computed tomography (CBCT). Materials and Methods: This was a descriptive cross-sec-tional study. A total of 370 mandibular first premolars fulfilling the inclusion criteria were evaluated using CBCT, and the number of roots and root canals, the Vertucci's classification of root canal configuration, age, sex and side of the tooth were registered. Results: One and two roots were presented in 96.2% (n=356) and 3.8% (n=14), respectively, of the mandibular first premolars analyzed, and one canal was present in 67.6% (n=250) and two canals in 32.2% (n=119). A type I root canal configuration was found in 67.6% (n=250) of the cases followed by type V with 26.2% (n=97). A statistically significant association was found between the number of roots and canals (p<0.001) and age also had a significant influence on this variable (p=0.0043). Conclusions: The presence of one canal in mandibular first premolars is the most frequent, although there is a considerable prevalence of two in the population studied. The number of roots is associated with the number of canals, with age having a significant influence on these variables.

Introducción: La morfología del canal radicular de los primeros premolares no siempre es la misma y por ello es fundamental un buen conocimiento de su anatomía dental. Objetivo: Evaluar la morfología de las raíces y conductos radiculares de primeros premolares mandibulares en una población peruana mediante tomografía computarizada de haz cónico. Materiales y Métodos: Este fue un estudio transversal descriptivo. Se evaluaron mediante tomografías un total de 370 primeros premolares mandibulares que cumplían con los criterios de inclusión, y se registró el número de raíces y conductos radiculares, la clasificación de Vertucci de la configuración radicular, la edad, el sexo y el lado del diente. Se realizaron las pruebas de chi-cuadrado y una regresión logística binaria (p<0,05). Resultado: Se presentó una y dos raíces en el 96,2% (n=356) y 3,8% (n=14), respectivamente, de los primeros premolares mandibulares analizados, y un canal estuvo presente en el 67,6% (n=250) y dos canales en el 32,2% (n=119). Se encontró una configuración del conducto radicular tipo I en el 67,6% (n=250) de los casos seguido del tipo V con un 26,2% (n=97). Se encontró una asociación estadísticamente significativa entre el número de raíces y conductos (p<0.001) y la edad también influyó significativamente en esta variable (p=0.0043). Conclusión: La presencia de 1 canal en primeros premolares mandibulares es la más frecuente, aunque existe una prevalencia considerable de 2 en la población estudiada. El número de raíces está asociado al número de canales, teniendo la edad una influencia significativa en estas variables.

The interference of digital radiographic image acquisition and processing protocols in the diagnosis of incipient enamel carious lesions.

Background: This study aims to evaluate the diagnosis of proximal carious lesions through different parameters of execution and visualization of the images. Material and Methods: Proximal carious lesions were artificially induced in human teeth three different times (10, 20, and 30 hours) by in vitro demineralization. The teeth were radiographed with the Dürr digital system using three exposure times (0.10, 0.16, and 0.20s) and three different resolutions in the scanning of the phosphor plates (20-, 25- and 40-line pairs). After acquiring the images, they were submitted to VistaScan Fine, Caries 1, and Caries 2 software filters. Three radiologists analyzed the images in JPEG format. Results: The Pearson's chi-square test showed an association between longer demineralization time and the presence of injury according to the professional's classification. There was no statistically significant association among the other parameters, exposure time, resolution, and use of filters and the presence of a lesion. All parameters showed a greater sensitivity than specificity. The exposure time of 0.2s showed better accuracy, the resolutions 25 and 40lp showed equal results and better than 20lp and the Fine filter obtained better values than the Caries 1 and 2 filters. Conclusions: Despite the variation of parameters, exposure time, resolution, and use of filters, there were no statistically significant differences. For better diagnostic accuracy, it is recommended to use 0.2s of exposure time and a Fine filter, and scan the phosphor plates with 25lp. Key words:Orbital fracture, Etiology, Orbital trauma, Road traffic accidents, Trauma.

Association of mandibular canine impaction and anatomical factors: A multicentre retrospective panoramic study in Latin America.

INTRODUCTION: Mandibular canine impaction is infrequent in dental eruption anomalies and treatment is very challenging. The aim of this multicenter retrospective panoramic study in Latin America was to evaluate panoramic radiographic imaging characteristics of mandibular canine impaction (impaction area, mandibular base contact, transmigration, impaction height and sex) and their associations. MATERIAL AND METHODS: This cross-sectional study evaluated 212 digital panoramic radiographs from three radiological centres in Tingo Maria (Peru), Bogota and Tunja (Colombia). The study included children of both sexes with impacted mandibular canines. Mandibular alpha angle, contact with mandibular basal bone (MBB), impacted sector according to 10 sectors with an adaptation of the Ericson and Kurol method, presence of transmigration and the impacted height were measured and the relationship among these measures was analyzed. Fisher's exact test, Chi-square and binary logistic regression were used. (P<0.05). RESULTS: The mandibular canine impaction showed contact with the MBB (32.08%), dental transmigration (36.79%), mainly located at an apical (40.09%) and sub-apical (36.79%) level. Transmigration mainly occurred in sectors 6 (33.30%) and 10 (25.60%) (P<0.001). It was found that for each year of increase in age, the possibility of contact with the MBB decreased (ß=0.89, P=0.010), and as the alpha angle increased by one degree the probability of contact with the MBB decreased (ß=0.97, P=0.001) and the probability of transmigration increased (ß=1.05, P<0.001). CONCLUSIONS: One third of the impacted canines were in contact with the MBB, while another third presented dental transmigration and were mainly located apically and subapically of the incisor roots. These imaging features should be taken into account when planning orthodontic treatment.

Alveolar morphometry in young adults with and without agenesis of the upper lateral incisor: A retrospective study.

INTRODUCTION: We aimed to compare alveolar morphometry in young adults with agenesis of the upper lateral incisor versus the side without agenesis and versus matched controls. MATERIAL AND METHODS: In this observational retrospective study, cone beam computed tomography scans were obtained of 36 upper hemiarches from young adults aged 15 to 30 years. The hemiarches were distributed into three groups: group 1: 12 upper hemiarches presenting agenesis of the upper lateral incisor; group 2: 12 upper hemiarches from the opposite side without agenesis of the upper lateral incisor (control group 1); and group 3: 12 upper hemiarches without agenesis of the upper lateral incisor matched for age and sex with respect to the affected group (control group 2). A trained and calibrated investigator performed all the alveolar measurements at two different times, including sagittal, coronal and axial slices of each hemiarch. Paired Student's t-tests, Chi-square and repeated measures ANOVA with Bonferroni correction were used, (P<0.05). RESULTS: Apical mesial evaluation of group 1 (4.22±1.19mm) was significantly lower (P<0.001) than that of groups 2 (6.72±1.17mm) and 3 (7.58±1.67mm). Apical distal evaluation also showed differences (P<0.001) among the three groups, with the dimension being smaller in group 1 with agenesis (4.53±1.14mm), followed by group 2 without agenesis (6.23±1.55mm) and the healthy control group 3 (7.73±1.71mm). CONCLUSIONS: Lateral incisor agenesis significantly reduces the alveolar dimensions of the affected area. In cases of unilateral agenesis, the unaffected side also shows sequelae, with decreased dimensions compared to cases without agenesis. This condition should be taken into account when making therapeutic decisions regarding rehabilitation with implants or canine replacement.

Comparison of mesiodistal angulations of premolars and molars in anterior open bite subjects with different sagittal malocclusions: A retrospective study.

INTRODUCTION: Mesiodistal angulation of premolars and molars can be altered by forces of open bite malocclusion. The aim of this study was to compare the mesiodistal angulations of the posterior teeth in class I, II, and III individuals with anterior open bite (AOB) versus individuals with harmonious occlusion. METHODS: This comparative cross-sectional study used 299 lateral head radiographs of individuals with permanent dentition. There were 4 groups (harmonious occlusion [n=89], Class I open bite [OB] [n=75], Class II OB [n=66], and Class III OB [n=69]). Premolar (1UPM, 2UPM) and molar (1UM, 2UM) angulations were measured relative to the occlusal plane and the palatal or mandibular plane by a trained and calibrated evaluator. ANOVA and Scheffe tests were used for statistical analyses (P<0.05). RESULTS: The mesial angulation of the upper premolars showed greater angulation of between approximately 2° and 5° in the OB groups compared to the harmonious occlusion group (P<0.05). Only in the Class II OB group did the first and second upper molars show distal angulation in relation to the palatal plane (1UM 81.85°±5.42°; 2UM 75.32±7.4°) (P<0.05). The Class III OB group presented the greatest distal angulations of the lower premolars and molars (between 3° to 5° of difference, P<0.05) in relation to those of the harmonious occlusion group. CONCLUSIONS: The upper first premolars in all the AOB groups and the lower second premolars in the Class II OB group had greater mesioangulation. Additionally, the upper molars of the Class II OB group and the lower molars of the Class III OB group showed distoangulation compared with the molars in the group with harmonious occlusion.

Evaluación de Lesiones Periapicales Utilizando Tres Índices sobre Tomografía Computarizada Cone Beam

El uso de tomografía computarizada Cone Beam (CBCT) puede favorecer el diagnóstico temprano de periodontitis apical e influir en su pronóstico y tratamiento; sin embargo, no existe una estandarización entre los índices que determinan la presencia de lesiones periapicales en esta técnica radiológica. Es por tal motivo que, el objetivo de este estudio fue evaluar lesiones periapicales utilizando tres índices sobre CBCT. La población de estudio estuvo conformada por todas las CBCT realizadas en un centro radiológico peruano durante un año, se realizó un muestreo no probabilístico y se evaluaron 36 tomografías Cone Beam con los índices CBCT-PAI, COPI y CBCT-ERI; los datos recolectados fueron analizados estadísticamente y se determinó que el índice CBCT-PAI identificó 91,7 % lesiones periapicales; el índice COPI, 72,2 % y el índice CBCT-ERI, 88,9 %. Asimismo, se aplicó la prueba x2 de Pearson y se determinó un valor de p=0,05. Por lo tanto, se concluyó que el diagnóstico de lesiones periapicales sobre tomografía computarizada Cone Beam puede presentar resultados similares cuando se evalúa con cualquiera de los índices CBCT-PAI, COPI o CBCT-ERI.

The use of Cone Beam Computed Tomography (CBCT) can favor the early diagnosis of apical periodontitis and influence its prognosis and treatment; however, there is no standardization among the indexes that determine the presence of periapical lesions in this radiological technique. For this reason, the aim of this study was to evaluate periapical lesions using three indices on CBCT. The study population consisted of all the CBCT scans performed in a Peruvian radiological center for one year, a non-probabilistic sampling was performed and 36 Cone Beam tomography's were evaluated with the CBCT-PAI, COPI and CBCT-ERI indexes; the data collected were analyzed statistically and it was determined that the CBCT-PAI index identified 91.7 % periapical lesions; the COPI index, 72.2 % and the CBCT-ERI index, 88.9 %. Likewise, Pearson's x2 test was applied and a value of p=0.05 was determined. Therefore, it was concluded that the diagnosis of periapical lesions on Cone Beam computed tomography can present similar results when evaluated with any of the CBCT-PAI, COPI or CBCT-ERI indexes.

Conservative Treatment of Bilateral Impacted Mandibular Canines Traction.

The objectives of the treatment of impacted canines differ according to the characteristics of dental malocclusion. Traction of the tooth is a conservative and viable alternative, which allows for maintaining stability and occlusal function. The following case report describes the treatment of an 11.6-year-old female patient, who presented bilateral impaction of mandibular canines in contact with the midline, mixed dentition in the inter-transitional period, class I angle malocclusion, with light crowding teeth. The treatment comprised three phases. The first phase, verticalization of the mandibular canines in mixed dentition, was performed to pull the impacted bilateral mandibular canines towards the dental arch to achieve their verticalization, maintaining the molar relationship, and the position of the upper and lower incisors. In the second phase, osteogenic rest was planned to relieve post-traction stress while awaiting the replacement of the mixed dentition. Finally, the third phase in permanent dentition was to align and level canines within the arch after extraction of the deciduous canines. For the viability of the permanent mandibular canines in the dental arch, orthosurgical traction was implemented, with a traction system with closed nickel-titanium coil springs with a transitory rigid dental-mucous-supported anchorage device, which allowed control and protection of the adjacent teeth and movements with helical forces of a controlled three-dimensional range. The results of the treatment were adequate, achieving consolidated molar and canine relationships, overjet, overbite, and optimal facial balance.

Postoperative chronic pain in arthroplasty papillon-lefèvre syndrome: 17-year dental follow-up: case report / Síndrome de papillon-lefèvre: seguimiento dental de 17 años: reporte de caso

Introduction: The present report describes the case of a 12-year-old patient with 17-year follow-up who was previously diagnosed with Papillon-Lefèvre Syndrome (PLS), which is a rare autosomal recessive irregularity in the cathepsin C gene (CTSC) characterized by palmoplantar hyperkeratosis and premature loss of primary and permanent teeth. Case Report: A specific mutation in the c.203 T > G gene inducing loss of function leading to PLS was detected, as was a mutation in the HLA-DRB1*11 allele, which is associated with this syndrome. There is no consanguinity of the parents, and the siblings are entirely healthy. Early identification of the main characteristics of this syndrome is imperative. Accurate diagnosis by genetic analysis allows differential diagnoses and timely comprehensive dental treatment. Conclusions: Additionally, it allows consultation with a dermatologist to maintain or improve the quality of life of patients with this condition due to progressive worsening and severity of the main physical manifestations. Keywords: Papillon-Lefevre Disease; Keratoderma, Palmo-plantar; Cathepsin C; Periodontitis; Skin Diseases, Genetic; Case reports

Introducción: El presente reporte describe el caso de un paciente de 12 años de edad con 17 años de seguimiento a quien previamente se le diagnosticó Síndrome de Papillon-Lefèvre (PLS), el cual es una rara irregularidad autosómica recesiva en el gen de la catepsina C (CTSC) caracterizada por hiperqueratosis palmoplantar y pérdida prematura de dientes primarios y permanentes. Reporte de Caso: Se detectó una mutación específica en el gen c.203 T > G que induce pérdida de función que conduce a PLS, así como una mutación en el alelo HLA-DRB1*11, que se asocia a este síndrome. No presenta consanguinidad de los padres, padres y hermanos totalmente sanos. La identificación temprana de las principales características de este síndrome es imperativa. El diagnóstico certero por análisis genético permite diagnósticos diferenciales y tratamientos odontológicos integrales oportunos. Conclusiones: Adicionalmente, permite la consulta con un dermatólogo para mantener o mejorar la calidad de vida de los pacientes con esta condición debido al progresivo empeoramiento y severidad de las principales manifestaciones físicas.

Association of breastfeeding duration with the development of non-nutritive habits, and transversal and vertical occlusal alterations in preschool children: A cross-sectional study.

BACKGROUND: Breastfeeding has multiple nutritional, immunological and psychological benefits, as well as a positive influence on the development of the stomatognathic system. OBJECTIVES: The present study attempted to determine the relationship between the duration of breastfeeding and the development of non-nutritive habits, and transversal and vertical occlusal alterations in preschool children. MATERIAL AND METHODS: This cross-sectional study involved 155 preschoolers aged 2-5 years from 3 public schools in Lima, Peru. The sample was divided into 2 groups with regard to the duration of breastfeeding: group A (n = 50) included infants that had been breastfed for up to 6 months; and group B (n = 105) included infants that had been breastfed for 6-12 months. Two trained and calibrated dentists evaluated each group, and clinically determined the presence or absence of transversal or vertical occlusal alterations. Likewise, the children's parents or caregivers were consulted to determine the development of non-nutritive habits. RESULTS: A significant association was found between breastfeeding duration and the development of the oral breathing habit; groups A and B showed a prevalence of 30.0% and 16.2%, respectively (p = 0.048). Likewise, breastfeeding duration affected the appearance of oral breathing (OR (odds ratio) = 0.84; 95% CI (confidence interval): 0.74-0.96; p = 0.011). Furthermore, the use of a bottle for more than 24 months significantly influenced the appearance of oral habits (OR = 3.55; 95% CI: 1.20-10.55; p = 0.022) and open bite (OR = 12.12; 95% CI: 1.16-126.31; p = 0.037). CONCLUSIONS: Breastfeeding duration of 6-12 months was shown to be a protective factor in preventing the appearance of oral breathing. Posterior crossbite (PCB), open bite and deep bite seemed not to be influenced by breastfeeding duration. However, the use of a bottle for more than 24 months significantly influenced the appearance of anterior open bite.

Sagittal Position of the Upper Incisor in Relation to the Forehead in Peruvian Individuals with Different Skeletal Relationships.

AIM: The aim of this study was to determine the sagittal position of the upper incisor considering Andrews' analysis based on the position of the forehead in Peruvian individuals with different skeletal relationships. MATERIALS AND METHODS: This retrospective, cross-sectional study included 212 lateral head radiographs of Peruvian individuals (males: 85, mean age 21.38 ± 6.88, and females: 127, mean age 21.18 ± 6.95), with different skeletal relationships (Class I group = 96, Class II group = 57, Class III group = 59). The values of the ANB, SNA, SNB angles as well as the forehead anterior limit line (FALL) and goal anterior limit line (GALL) points were identified in the radiographs, and then a vertical line was drawn in each point to determine if the upper incisor was positioned forward (protruded), backward (retruded) or within (adequate) these lines. Two trained and calibrated investigators performed all the measurements. The Chi-square test was used to evaluate associations. A p-value < 0.05 was considered statistically significant. RESULTS: Overall, the sagittal position of the upper incisor showed a significant association with the sagittal skeletal relationship (p = 0.001). The upper incisors showed an adequate position (41.7%), protruded position (56.10%), and retruded position (42.40%), for Class I, II, and III skeletal relationships, respectively, as highest percentages in each Class. Statistical significance was found for females only (p = 0.005). CONCLUSION: Skeletal Class I mainly showed an adequate position of the upper central incisor, whereas for Class II a protruded position was most frequently found, and Class III presented a retruded position. CLINICAL SIGNIFICANCE: Andrews' analysis based on the position of the forehead in Peruvian individuals is a valuable tool for orthodontic diagnosis. How to cite this article: Bazán-Mendoza JR, Arias-Modesto PB, Ruíz-Mora GA, et al. Sagittal Position of the Upper Incisor in Relation to the Forehead in Peruvian Individuals with Different Skeletal Relationships. J Contemp Dent Pract 2023;24(11):821-825.

Root morphology of lateral incisors adjacent to impacted maxillary canines: A cone-beam computed tomography retrospective cross-sectional study.

INTRODUCTION: To compare the root morphology of the maxillary lateral incisors (MLIs) adjacent to an impacted (IMC) versus non-impacted maxillary canine (non-IMC). MATERIALS AND METHODS: This cross-sectional study included cone beam computed tomography (CBCT) images derived from 154 subjects (with unilateral/bilateral impacted maxillary canines or without canine impaction). Each MLI was considered as a unit of analysis. Thus, the study group included 122 MLIs adjacent to impacted maxillary canine (IMCG) and the control group included 122 MLIs adjacent to a non-impacted maxillary canine (CG). Groups were matched by age, sex and evaluation side. Root length, root dilaceration angle and root convergence angle were evaluated in both the coronal and sagittal planes. Comparisons between groups were made with Student's t-test and the chi-square test with Bonferroni correction (P<0.008, P<0.01, respectively). RESULTS: The root measurements of the MLIs showed some significant differences between the groups. The coronal root length was 0.52mm shorter but not highly significant (P=0.032), the coronal root dilaceration angle was 7.51° smaller (P<0.001), and the coronal root convergence angle was 1.28° greater (P<0.001) in the IMCG compared to the CG. The orientation of root dilaceration in the MLIs showed significant differences between the groups: it was mostly distopalatal in the GC (87.5%), to a lesser extent in the IMCG (58.9%) and also mesiopalatal in the IMCG (22.3%), (P=0.001). CONCLUSIONS: The root morphology of MLIs adjacent to an IMC showed a tendency of shorter length, smaller root dilaceration and greater root convergence in the coronal section than MLIs adjacent to a non-IMC.

Influence of dentofacial characteristics on the appearance of self-reported bullying: A review.

Bullying is a social problem that affects children and adolescents in particular. It deteriorates the selfesteem of its victims, decreases their quality of life and generates future psychological problems. The aim of this review was to determine the influence of dentofacial characteristics on the appearance of selfreported bullying through a literature review. A systematic search was carried out in the databases of international scientific literature on health sciences, including MEDLINE via PubMed, Scopus, LILACS, and SciELO. Up to October 10, 2020, a total of 348 articles were identified, but only 36 were ultimately selected for the review. Specific keywords in English were used in the search: "dentofacial features"; "soft tissue"; and "malocclusion". It was found that the appearance of bullying was associated with altered facial profiles, namely the presence of different classes of malocclusion, with class II or class III malocclusion being the most impactful. Altered dentofacial characteristics can make an individual the target of harassment, leading to low quality of life, emotional instability, low self-esteem, and the lack of confidence with regard to dentofacial appearance as well as poor long-term social and academic performance. There is a need to develop preventive measures that would be applied by both parents and authorities, with disseminating information on bullying in schools as well as on adequate oral hygiene and the importance of going to the dentist. Traditional and cybernetic bullying share similarities. While working out strategies against bullying, it is essential to raise awareness among victims and bullies, families, and society, and to determine how bullying is perceived by children and teenagers.

Effect of the application of software on the volumetric and cross-sectional assessment of the oropharyngeal airway of patients with and without an open bite: A CBCT study.

BACKGROUND: Using different software to evaluate the airways, with different thresholds, but within the range for airway recognition, could yield different measurements in the same patient with or without craniofacial disharmony. OBJECTIVES: The aim of the present study was to compare the volume and the most constricted area (MCA) of the oropharynx in individuals with or without an open bite by using 2 software programs meant for cone-beam computed tomography (CBCT). MATERIAL AND METHODS: This comparative study included 60 cases selected from 137 CBCT scans obtained from individuals with the presence or absence of an open bite. Each group included adults of both genders - in total 30 women and 30 men - with a mean age of 27.57 ±11.85 years in the open bite group and 26.23 ±6.78 years in the control group. The oropharyngeal volume and MCA were measured with 2 three-dimensional (3D) software packages: Planmeca Romexis®; and Nemotec NemoStudio®. Two calibrated orthodontists trained in the use of the software made the measurements. Data was analyzed using Student's t tests for independent and paired samples (p < 0.05). RESULTS: In general, the oropharynx volume measurements obtained with the NemoStudio software were significantly higher than those obtained with Romexis (19,007.17 ±8005.79 mm3 and 17,823.47 ±7148.62 mm3, respectively) (p = 0.020). However, when the groups were analyzed separately, the measurements of the group with an open bite did not differ according to the software used (p = 0.352). The measurements of the MCA of the oropharynx were significantly higher when obtained with the NemoStudio software (MD (mean difference) = 19.02 mm2) (p = 0.005). In contrast, no difference in the MCA results for the 2 software packages was found in the open bite group (p = 0.728). CONCLUSIONS: The volumetric and cross-sectional measurements of the oropharyngeal airway, particularly in individuals without an open bite, were affected by the software used.

Effects of botulinum toxin in patients with myofascial pain related to temporomandibular joint disorders: A systematic review.

Botulinum toxin is used as an alternative for the treatment of chronic refractory myofascial pain derived from temporomandibular disorders (TMDs). It is important to establish the benefits of botulinum toxin in this type of symptomatology. The aim of the study was to conduct a systematic review in order to evaluate the effects of botulinum toxin in patients with myofascial pain related to temporomandibular disorders. The search was carried out systematically, without limitations of language or year of publication, until February 2021. The databases searched included PubMed, Web of Science, Scopus, The Cochrane Library, and Latin American and Carribean Health Sciences Literature (LILACS). Partial gray literature was searched using Google Scholar, ClinicalTrials.gov, OpenGrey, and the reference lists of selected articles. Randomized controlled clinical trials evaluating the effects of botulinum toxin in the treatment of myofascial pain were included. The risk of bias was assessed with the Cochrane RoB 2.0 tool, and the The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to determine the certainty of the scientific evidence. A total of 900 studies were retrieved, out of which only 8 randomized clinical trials were selected. From these 8 studies, the data of a total of 314 patients, predominantly women, between the ages of 18 to 75 years was obtained. After the assessment of the studies with the RoB 2.0 tool, 7 studies showed some concerns regarding the reported results and only one was at a low risk of overall bias. The analysis of the studies has shown that low doses of botulinum toxin are effective in the treatment of refractory myofascial pain associated with temporomandibular disorders. The studies presented mediumto low-certainty evidence..

Accuracy of computer-assisted surgery in immediate implant placement: An experimental study.

Purpose: Computer-guided surgery has been increased in recent years. Nonetheless, few data are available on the validation of this technique for immediate implant placement. The purpose of this in vitro study was to evaluate the accuracy of computer-guided surgery in immediate implant placement. Materials and Methods: Cone-beam computed tomography scans (CBCTs) and virtual models were obtained of eight fresh pigs hemi-mandibles to perform the digital planning of implants placement. Fifteen implants were simulated, and surgical guides were designed to transfer the digital planning to the surgical procedure. Postsurgical CBCTs were performed to compare the position of the planned implants versus the real implant position. Paired t-test and the intra-class correlation coefficient (ICC) were used to assess the mean differences and correlations in each outcome variable evaluated twice by one experienced researcher. Furthermore, variations were compared with the results reported in the scientific literature using a one-sample t-test P < 0.05. Results: The measurements of the outcome variables (implants position at the neck and apex level and the angular deviation) showed significant reproducibility (mean difference-0.01 mm, 0.07 mm, and 0.30°, respectively, P > 0.05). The ICC values ranged from 0.888 to 0.949. Furthermore, the mean deviation was 1.43 mm at the implant neck, 2.19 mm at the apex, and 6.81° for the angular deviation. Similarly, significant differences (P < 0.05) were found at the neck and angular deviation when comparing the results with values reported in the literature. Conclusions: Although some variations were observed, they did not have a clinically significant impact. Therefore, computer-guided surgery could be satisfactorily used in immediate implants placement.

Revolution in modern teaching in dentistry since the appearance of the COVID-19 pandemic: A review.

Dentistry schools have attempted to overcome the challenges imposed by the coronavirus disease 2019 (COVID-19) pandemic through teaching via the Internet with the use of virtual platforms, designed to simulate face-to-face interaction and counteract the social isolation affecting the integral development of students. This review searched the main health databases, including MEDLINE via PubMed, Scopus and LILACS, and selected 31 articles to proceed with the research. During the pandemic, platforms such as Facebook, Instagram, YouTube, Zoom, Google Meet, and other similar tools allowed teachers to develop dynamic slides and dental models to simulate procedures, which played an important role in the course of mainly theoretical classes. In addition, applications such as WhatsApp allowed the rapid acquisition and sharing of useful information on a specific topic. While virtual resources facilitate the learning process through generating interest as well as providing accurate, necessary, valuable, and easily accessible information, which is constantly updated, the disadvantages of remote learning include the lack of instruments, infrastructure and materials, apart from supervision, to promote personal development and progressive evolution to directly treat patients. Another issue with regard to virtual learning is whether within a short period of time students can achieve a comparable level of practical skills as in the case of the conventional learning. In conclusion, the current pandemic has changed not only the use of technology in education, but also educational strategies for the future.

Comparison and reproducibility of three methods for maxillary digital dental model registration in open bite patients.

OBJECTIVE: To compare and assess the reproducibility of 3 methods for registration of maxillary digital dental models in patients with anterior open bite. Settings and sample population Digital dental models of 16 children with an anterior open bite in the mixed dentition were obtained before (T1) and after 12 months of treatment with bonded spurs (T2). METHODS: Landmarks were placed on all T2 models and 3 registration methods (R1, R2 and R3) were independently performed by 2 observers. R1 was based on 10 landmarks placed on posterior teeth. R2 was based on 5 landmarks on the palate (2 anterior, 2 posterior and 1 central). R3 used regions of interest around the 5 palatal landmarks used in R2. The differences between the registration methods were calculated by comparing the mean differences and standard deviations between the corresponding x, y and z coordinates of 6 corresponding landmarks in the T2 registered models. Repeated measures analysis of variance followed by post-hoc Bonferroni tests were used for comparisons (P < .05). The agreement between methods and the intra and interobserver reproducibility were assessed with Bland-Altman tests and intraclass correlation coefficients (ICC). RESULTS: Comparisons of R2 with R3 methods showed greater agreement, mean differences ≤0.50 mm for all landmarks, than comparisons of R1 with R2, and R1 with R3, mean differences >0.50 mm for most of the y and z coordinates (P < .05). The R1 and R3 methods presented excellent intra and interobserver reproducibility and R2 method had moderate interobserver reproducibility. CONCLUSIONS: Longitudinal assessments of open bite treatment using digital dental models could consider the posterior teeth and/or the palate as references. The R1 and R3 methods showed adequate reproducibility and yield different quantitative results. The choice will depend on the posterior teeth changes and dental models' characteristics.

Association between internal carotid artery calcifications detected as incidental findings and clinical characteristics associated with atherosclerosis: A dental volumetric tomography study.

PURPOSE: To evaluate the presence of calcifications in the internal carotid artery (ICA) in cone-beam computed tomography (CBCT), and to verify the association of these findings with sex, age, dental condition, and risk factors associated with vascular disorders. METHODS: The CBCT scans used in this study were obtained from the database of a private dental clinic requested for the planning of rehabilitation with dental implants. The selection criteria were patients aged 40 years and above. Out of a pool of 1176 CBCT examinations, a total of 284 scans of adult patients were evaluated by two blinded observers. Data were collected from patients' medical records. RESULTS: ICA calcifications were present in 63.0% of the examinations. Most calcifications were in the intracranial pathway (166). Despite being present in a smaller number 57 (C1), extracranial calcifications were more severe. Spearman's ρ coefficients (rS) indicated that the number of missing teeth was directly associated with the presence of calcifications (p = 0.042) and severity (p = 0.020). The age variable also had a direct relationship with the presence of calcifications (p ≤ 0.0001), increasing its frequency and severity over the years. In addition, hypertension (p = 0.036) and use of antihypertensive drugs (p = 0.015) were directly associated. CONCLUSIONS: There is a high occurrence of ICA calcifications in CBCT as incidental findings in adult patients, and it is directly associated with age, number of missing teeth and hypertension.