Automated artificial intelligence-based three-dimensional comparison of orthodontic treatment outcomes with and without piezocision surgery.

OBJECTIVE(S): This study aims to evaluate the influence of the piezocision surgery in the orthodontic biomechanics, as well as in the magnitude and direction of tooth movement in the mandibular arch using novel artificial intelligence (AI)-automated tools. MATERIALS AND METHODS: Nineteen patients, who had piezocision performed in the lower arch at the beginning of treatment with the goal of accelerating tooth movement, were compared to 19 patients who did not receive piezocision. Cone beam computed tomography (CBCT) and intraoral scans (IOS) were acquired before and after orthodontic treatment. AI-automated dental tools were used to segment and locate landmarks in dental crowns from IOS and root canals from CBCT scans to quantify 3D tooth movement. Differences in mesial-distal, buccolingual, intrusion and extrusion linear movements, as well as tooth long axis angulation and rotation were compared. RESULTS: The treatment time for the control and experimental groups were 13.2 ± 5.06 and 13 ± 5.52 months respectively (P = .176). Overall, anterior and posterior tooth movement presented similar 3D linear and angular changes in the groups. The piezocision group demonstrated greater (P = .01) mesial long axis angulation of lower right first premolar (4.4 ± 6°) compared with control group (0.02 ± 4.9°), while the mesial rotation was significantly smaller (P = .008) in the experimental group (0.5 ± 7.8°) than in the control (8.5 ± 9.8°) considering the same tooth. CONCLUSION: The open source-automated dental tools facilitated the clinicians' assessment of piezocision treatment outcomes. The piezocision surgery prior to the orthodontic treatment did not decrease the treatment time and did not influence in the orthodontic biomechanics, leading to similar tooth movements compared to conventional treatment.

Three-dimensional changes after maxillary molar distalization with a miniscrew-anchored cantilever.

OBJECTIVES: To evaluate the changes after maxillary molar distalization in Class II malocclusion using the miniscrew-anchored cantilever with an extension arm. MATERIALS AND METHODS: The sample included 20 patients (9 male, 11 female; mean age 13.21 ± 1.54 years) with Class II malocclusion, treated with the miniscrew-anchored cantilever. Lateral cephalograms and dental models obtained before (T1) and after molar distalization (T2) were evaluated using Dolphin software and 3D Slicer. Superimposition of digital dental models using regions of interest on the palate was performed to evaluate three-dimensional displacement of maxillary teeth. Intragroup change comparisons were performed using dependent t-test and Wilcoxon test (P < 0.05). RESULTS: The maxillary first molars were distalized to overcorrected Class I. The mean distalization time was 0.43 ± 0.13 years. Cephalometric analysis demonstrated significant distal movement of the maxillary first premolar (-1.21 mm, 95% confidence interval [CI]: -0.45, -1.96) and maxillary first (-3.38 mm, 95% CI: -2.88, -3.87) and second molars (-2.12 mm, 95% CI: -1.53, -2.71). Distal movements increased progressively from the incisors to the molars. The first molar showed small intrusion (-0.72 mm, 95% CI: 0.49, -1.34). In the digital model analysis, the first and second molars showed a crown distal rotation of 19.31° ± 5.71° and 10.17° ± 3.84°, respectively. The increase in maxillary intermolar distance, evaluated at the mesiobuccal cusps, was 2.63 ± 1.56 mm. CONCLUSIONS: The miniscrew-anchored cantilever was effective for maxillary molar distalization. Sagittal, lateral, and vertical movements were observed for all maxillary teeth. Distal movement was progressively greater from anterior to posterior teeth.

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.

A new instrument to clinically evaluate the anteroposterior relationship of the maxillary central incisors to the forehead.

BACKGROUND: To evaluate the reliability of a new instrument to clinically measure the anteroposterior relationship of the maxillary central incisors to the forehead. METHODS: An analytical cross-sectional study using a sample of 84 (67% female and 33% male) young adult participants was conducted. Measurements were performed according to Element II of the Andrews' Six Elements of Orofacial Harmony by assessing the horizontal distance between the facial axis point of the maxillary central incisor and the forehead's anterior limit line. The instrument tested was a transparent plastic template having a leveling meter, reference lines, and an embedded millimeter ruler. Two orthodontists evaluated the sample twice with a minimum of a two-week interval between evaluations. The reliability was evaluated using the intraclass correlation coefficient. Repeated-measures ANOVA was also performed. RESULTS: Good to excellent intra- and interexaminer agreement, with intraclass correlation coefficient values of 0.874 (95% confidence interval 0.800-0.921; P < 0.001) and 0.876 (95% confidence interval 0.739-0.948; P < 0.001), respectively, were calculated. There were no statistically significant differences between all the repeated measurements assessed (P = 0.820). CONCLUSIONS: The instrument showed good to excellent reliability for determining the anteroposterior relationship of the maxillary central incisors to the forehead and could be used to help orthodontists and maxillofacial surgeons indirectly evaluate the anteroposterior position of the maxilla.

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..

Dentigerous cyst and the importance of early detection. report of a pediatric case.

Dentigerous cysts are a common cystic pathology that develop between the first and third decade of life and are mainly associated with impacted or erupted mandibular third molars followed by maxillary canines and maxillary third molars. These kinds of cysts are the result of the proliferation of enamel epithelium after its formation, the pathogenesis of which is not clear. Few of these cysts have been reported in pediatric patients. The following case report presents the rare occurrence of a dentigerous cyst in a 6-year-old boy and describes the treatment administered.

Los quistes dentígeros son una patología quística común que se desarrolla entre la primera y la tercera década de la vida, y se asocian principalmente con terceros molares mandibulares incluidos o erupcionados, seguidos de caninos superiores y terceros molares superiores. Este tipo de quistes son el resultado de la proliferación del epitelio del esmalte después de su formación, cuya patogenia no está clara. Se han informado pocos de estos quistes en pacientes pediátricos. El siguiente reporte de caso presenta la rara ocurrencia de un quiste dentígero en un niño de 6 años y describe el tratamiento administrado.

Effects of exposure parameters on detecting clear and unclear mandibular canals using two digital intra-oral sensors - An experimental study.

Aim: To evaluate the effects of exposure parameters (tube current and voltage) to detect clear and unclear mandibular canals (MCs) using a complementary metal-oxide semiconductor (CMOS) or photo-stimulable phosphor plate (PSP) sensors. Methods: A total of 24 dry half-mandibles were divided into two groups with clear (n = 16) and unclear (n = 8) MCs. The retro-alveolar parallel technique was performed in the six-molar region of the mandibles using direct and indirect digital intra-oral sensors. Six combinations of tube voltage (kV) (60 kV, 66 kV, and 70 kV) and tube current (mA) (2 mA, 5 mA, and 8 mA) were applied, and 144 images of each group were obtained with each CMOS and PSP sensor. Images were processed using Image J software. To evaluate diagnostic accuracy, two square images of the first-molar region were obtained from each image, one with the MC inside and the other without the MC (a total of 576 images were observed). Three radiologists diagnosed the presence or absence of MCs. The diagnostic accuracy of each exposure parameter was compared with the area under the curve (Az) in receiver-operating characteristic analysis. Results: The Az values for clear MCs were higher than those for unclear MCs (P < 0.001). There were no significant differences when the tube current was modified. For unclear MCs, the Az increased when higher tube voltages were used, showing a significant difference using the PSP sensor (p = 0.004). There was no significant difference for clear MCs. Conclusions: Lower exposure parameters should be used for clear MCs, while higher tube voltage values should be used for unclear MCs.

Incisor root length in individuals with and without anterior open bite: a comparative CBCT study.

OBJECTIVE: This study aimed to compare the root length of maxillary and mandibular incisors between individuals with open bite versus matched individuals with adequate overbite. METHODS: This comparative, matched and retrospective study included 48 cone beam computed tomographies (CBCTs) obtained at a university radiological center. Scans belonged to 24 individuals with open bite (overbite ≤ 0 mm) and 24 individuals with adequate overbite (controls). Both groups were matched by age, sex, malocclusion classification and skeletal characteristics (ANB and FMA angles). Root length of each maxillary and mandibular incisor was measured in millimeters (mm) in a sagittal section from a perpendicular line to the enamel cement junction until the root apex (384 length measurements were made). The means of root length in both groups were compared using t-tests. In addition, correlations between variables were evaluated with the Pearson correlation coefficient (α = 0.05). RESULTS: In both groups, the root length of the upper central incisors was approximately 12 mm and the root length of the maxillary lateral incisors was approximately 13 mm (p˃ 0.05). Likewise, the root length of lower central incisors in both groups measured approximately 12 mm (p˃ 0.05). However, the mandibular lateral incisor roots of open bite patients were significantly longer than in the normal overbite patients (approximately 1 mm, p= 0.012 right side, p= 0.001 left side). CONCLUSIONS: Root length of maxillary incisors and central mandibular incisor is similar in individuals with or without open bite, but the mandibular lateral incisor roots in open bite patients were significantly longer than in the normal overbite patients.

Patient Specific Classification of Dental Root Canal and Crown Shape.

This paper proposes machine learning approaches to support dentistry researchers in the context of integrating imaging modalities to analyze the morphology of tooth crowns and roots. One of the challenges to jointly analyze crowns and roots with precision is that two different image modalities are needed. Precision in dentistry is mainly driven by dental crown surfaces characteristics, but information on tooth root shape and position is of great value for successful root canal preparation, pulp regeneration, planning of orthodontic movement, restorative and implant dentistry. An innovative approach is to use image processing and machine learning to combine crown surfaces, obtained by intraoral scanners, with three dimensional volumetric images of the jaws and teeth root canals, obtained by cone beam computed tomography. In this paper, we propose a patient specific classification of dental root canal and crown shape analysis workflow that is widely applicable.