Ultrasound-based jawbone surface quality evaluation after alveolar ridge preservation.

BACKGROUND: Bone readiness for implant placement is typically evaluated by bone quality/density on 2-dimensional radiographs and cone beam computed tomography at an arbitrary time between 3 and 6 months after tooth extraction and alveolar ridge preservation (ARP). The aim of this study is to investigate if high-frequency ultrasound (US) can classify bone readiness in humans, using micro-CT as a reference standard to obtain bone mineral density (BMD) and bone volume fraction (BVTV) of healed sockets receiving ARP in humans. METHODS: A total of 27 bone cores were harvested during the implant surgery from 24 patients who received prior extraction with ARP. US images were taken immediately before the implant surgery at a site co-registered with the tissue biopsy collection location, made possible with a specially designed guide, and then classified into 3 tiers using B-mode image criteria (1) favorable, (2) questionable, and (3) unfavorable. Bone mineral density (hydroxyapatite) and BVTV were obtained from micro-CT as the gold standard. RESULTS: Hydroxyapatite and BVTV were evaluated within the projected US slice plane and thresholded to favorable (>2200 mg/cm3; >0.45 mm3/mm3), questionable (1500-2200 mg/cm3; 0.4-0.45 mm3/mm3), and unfavorable (<1500 mg/cm3; <0.4 mm3/mm3). The present US B-mode classification inversely scales with BMD. Regression analysis showed a significant relation between US classification and BMD as well as BVTV. T-test analysis demonstrated a significant correlation between US reader scores and the gold standard. When comparing Tier 1 with the combination of Tier 2 and 3, US achieved a significant group differentiation relative to mean BMD (p = 0.004, true positive 66.7%, false positive 0%, true negative 100%, false negative 33.3%, specificity 100%, sensitivity 66.7%, receiver operating characteristics area under the curve 0.86). Similar results were found between US-derived tiers and BVTV. CONCLUSION: Preliminary data suggest US could classify jawbone surface quality that correlates with BMD/BVTV and serve as the basis for future development of US-based socket healing evaluation after ARP.

Inferior alveolar nerve repositioning surgical techniques and outcomes - a systematic review.

Inferior alveolar nerve (IAN) lateralization (IANL) or transposition (IANT) are both techniques allowing for dental implant placement in posterior atrophic mandibles. The aim of this study was to systematically review the implant survival rate and the complications associated with IAN reposition techniques with simultaneous implant placement in atrophic posterior mandibles. This systematic review was conducted following PRISMA guidelines (Preferred Reporting Items for Systematic review and Meta-Analysis). The review was designed to answer the following PICO question: Is IAN repositioning (I) a safe and efficient technique (O) to treat patient looking for fixed dental rehabilitation of an atrophic posterior mandible (P). Thirty-three articles were reviewed, including a total of 899 patients, and approximately 950 IAN repositioning procedures. Dental implant survival rate ranged between 86.95% and 100% with a mean dental survival rate of 90.16%. Among the 269 patients who underwent IANT, there were 93% immediate neurosensory disturbance, and 15% persistent neurosensory disturbance. Among the 350 patients who underwent IANL, there were 93% immediate neurosensory disturbance, and 6% persistent neurosensory disturbance. IANT and IANL are reliable techniques allowing safe dental implant placement in atrophic posterior mandible with high patient satisfaction. IANL seems to cause less persistent neurosensory disturbances compared to IANT. The level of evidence is poor due to the high number of bias present in the included studies. IAN neurosensory disturbance assessment should be better homogenized in order to increase comparability.

Fratura idiopática de mandíbula atrófica / Idiopathic fracture of atrophic jaw / Fractura idiopática de mandíbula atrófica

Objetivo: Discorrer sobre o tratamento cirúrgico de uma fratura idiopática de mandíbula atrófica. Relato de caso: Idosa compareceu à emergência de um hospital referência em traumas na Paraíba relatando dificuldade ao se alimentar, impossibilidade de uso da prótese dentaria, sintomatologia dolorosa em região mandibular direita com processo infeccioso ativo, sem histórico de trauma direto em face. Ao exame tomográfico constatou-se fratura em mandíbula atrófica com presença de dente incluso na região. Diante do quadro, optou-se por iniciar antibioticoterapia empírica e planejou-se tratamento cirúrgico de reconstrução mandibular com sistema load-sharing, tendo auxílio de biomodelo para conformação prévia da placa. Conclusão: O correto planejamento e escolha do sistema de fixação são fundamentais para o sucesso do tratamento. O uso de biomodelo com pré modelagem de placa mostrou-se positivo por otimizar o tempo cirúrgico, reduzindo os riscos inerentes ao procedimento nesta faixa etária e a utilização de sistema capaz de suportar a carga sofrida na estrutura óssea comprometida nestes casos é mandatório... (AU)

Objective: to discuss the surgical treatment of an idiopathic fracture of the atrophic mandible. Case report: elderly woman attended the emergency department of the Emergency and Trauma Hospital Dom Luiz Gonzaga Fernandes, in Campina Grande, Brazil. The patient reported pain on eating and inability to use her denture as painful symptoms in the right mandibular region with active fistula, without any records of facial trauma. Tomographic examination revealed an atrophic mandibular fracture with an impacted tooth in the region. The following procedures were performed: antibiotic therapy, surgical fixation using a 2.4mm pre-molded plate, shaped using a biomodel, and fistulectomy. Conclusion: Thus, to plan accordingly aiming to minimize the surgical time and its associate damage and the use of appropriate fixation systems capable of supporting the load on the compromised bone are essential to a successful treatment, specially with elderly patients due their general health condition and preexistent comorbities... (AU)

Objetivo: Discutir sobre el tratamiento quirúrgico de una fractura idiopática de la mandíbula atrófica. Caso clínico: Anciana compareció al servicio de urgencias del Hospital de Emergencia y Trauma de Campina Grande Dom Luiz Gonzaga Fernandes, PB, relatando dificultad para alimentarse, imposibilidad de uso de prótesis dental, sintomatología dolorosa en la región mandibular derecha con fístula activa, sin antecedentes de traumatismo directo en la cara. El examen tomográfico presentó una fractura mandibular atrófica con presencia de un diente incluido en la región. Como resultado se realizó antibioticoterapia, procedimiento de fijación quirúrgica con una placa de 2,4 mm premoldeada en biomodelo y fistulectomía. Conclusión: De esta forma, el correcto planeamiento para minimizar el tiempo quirúrgico y los daños asociados, principalmente en los ancianos por su estado general de salud y comorbilidades preexistentes, la utilización de sistemas de fijación adecuados capaces de soportar la carga sufrida en los huesos comprometidos, es fundamental para el éxito del tratamiento... (AU)

Intraoral scanning of the edentulous jaw without additional markers: An in vivo validation study on scanning precision and registration of an intraoral scan with a cone-beam computed tomography scan.

Purpose: A fully digital approach to oral prosthodontic rehabilitation requires the possibility of combining (i.e., registering) digital documentation from different sources. This becomes more complex in an edentulous jaw, as fixed dental markers to perform reliable registration are lacking. This validation study aimed to evaluate the reproducibility of 1) intraoral scanning and 2) soft tissue-based registration of an intraoral scan with a cone-beam computed tomography (CBCT) scan for a fully edentulous upper jaw. Materials and Methods: Two observers independently performed intraoral scans of the upper jaw in 14 fully edentulous patients. The palatal vault of both surface models was aligned, and the inter-observer variability was assessed by calculating the mean inter-surface distance at the level of the alveolar crest. Additionally, a CBCT scan of all patients was obtained and a soft tissue surface model was generated using patient-specific gray values. This CBCT soft tissue model was registered with the intraoral scans of both observers, and the intraclass correlation coefficient (ICC) was calculated to evaluate the reproducibility of the registration method. Results: The mean inter-observer deviation when performing an intraoral scan of the fully edentulous upper jaw was 0.10 ± 0.09 mm. The inter-observer agreement for the soft tissue-based registration method was excellent (ICC=0.94; 95% confidence interval, 0.81-0.98). Conclusion: Even when teeth are lacking, intraoral scanning of the jaw and soft tissue-based registration of an intraoral scan with a CBCT scan can be performed with a high degree of precision.

Dynamic and static computer-assisted implant surgery for completely edentulous patients. A proof of a concept.

OBJECTIVES: To assess the accuracy and patient reported outcome measures (PROMs) of the computer-guided "double factor" technique for treating fully edentulous patients. METHODS: A proof of concept prospective study was designed. Ten consecutive patients requiring full arch dental implant supported rehabilitation in a private practice were enrolled between October 2021 and March 2022. All patients were treated by means of an All-on-four®, and implants were planned and placed according to the "double factor" technique. This technique merges the static and dynamic computer-guided surgical approach in the same surgery. The primary outcome was the accuracy of implant placement, measured by overlapping post- and pre-operative cone-beam computerized tomography with the implant planning. Additionally, PROMs and patient quality of life after surgery were evaluated using different questionnaires. Descriptive and bivariate data analyses were performed. Statistical significance was considered for p < 0.05. RESULTS: A total of 48 implants were placed using the "double factor" technique, and 12 full-arch immediate loading prostheses were delivered. The mean angular deviation was 3.74° (standard deviation [SD]: 2). The total linear deviation at the apex and platform of the implant was 1.25 mm (SD: 0.55) and 1.42 mm (SD: 0.64), respectively. No statistically significant differences were found between tilted and axial implants, the upper and lower jaw, or the right and left side. High self-reported satisfaction was registered, and the Oral Health Impact Profile-14 (OHIP-14) score improved postoperatively (p = 0.002). CONCLUSIONS: The "double factor" technique is a valid and accurate treatment approach for fully edentulous patients. CLINICAL SIGNIFICANCE: The double factor technique merges the advantages of both the dynamic and static computer assisted surgery approaches, affording accurate and predictable results when treating fully edentulous patients in a minimally invasive manner.

Influence of diameter in the stress distribution of extra-short dental implants under axial and oblique load: a finite element analysis

Aim: This study evaluated the influence of a wide diameter on extra-short dental implant stress distribution as a retainer for single implant-supported crowns in the atrophic mandible posterior region under axial and oblique load. Methods: Four 3D digital casts of an atrophic mandible, with a single implant-retained crown with a 3:1 crown-to-implant ratio, were created for finite element analysis. The implant diameter used was either 4 mm (regular) or 6 mm (wide), both with 5 mm length. A 200 N axial or 30º oblique load was applied to the mandibular right first molar occlusal surface. The equivalent von Mises stress was recorded for the abutment and implant, minimum principal stress, and maximum shear stress for cortical and cancellous bone. Results: Oblique load increased the stress in all components when compared to axial load. Wide diameter implants showed a decrease of von Mises stress around 40% in both load directions at the implant, and an increase of at least 3.6% at the abutment. Wide diameter implants exhibited better results for cancellous bone in both angulations. However, in the cortical bone, the minimum principal stress was at least 66% greater for wide than regular diameter implants, and the maximum shear stress was more than 100% greater. Conclusion: Extra-short dental implants with wide diameter result in better biomechanical behavior for the implant, but the implications of a potential risk of overloading the cortical bone and bone loss over time, mainly under oblique load, should be investigated

Immediate flapless full-arch rehabilitation of edentulous jaws on 4 or 6 implants according to the prosthetic-driven planning and guided implant surgery: A retrospective study on clinical and radiographic outcomes up to 10 years of follow-up.

OBJECTIVES: to retrospectively evaluate clinical and radiographic outcomes of immediate, flapless full-arch prostheses, supported by 4/6 implants according to prosthetic-driven planning and guided surgery. MATERIALS AND METHODS: The study involved 28 edentulous patients (20 female/8 males; average age 67.75 ± 8.627 years), 32 prostheses (17 all-on-4/15 all-on-6) and 164 implants. The Implants survival, prostheses success/survival, peri-implant marginal bone loss, incidence of biological and prosthetic complications were evaluated. Multiple linear regression analysis was performed to analyze the influence of implant and patient characteristics on marginal bone loss. RESULTS: Cumulative implant survival rate was 89.7% for all-on-four (seven failures) and 99.0% for all-on-six (one failure) after a mean follow-up of 6.46 ± 2.236 years (range 1-10 years). Cumulative prosthesis success rate was 51.5% (58.8% for all-on-four/ 43.8% for all-on-six). Prosthesis survival rate was 88.2% for all-on-four. No failure was registered in all-on-six. Mean value of marginal bone loss was 1.38 ± 0.1.28 mm at 5-year and 2.09 ± 0.56 mm at 10-year follow-up. No difference was found in the mean value of marginal bone resorption between all-on-four (1.56 ± 1.61 mm) and all-on-six (1.20 ± 0.85 mm) (p = 0.104) and between tilted (1.22 ± 1.29 mm) and axial implants (1.44 ± 1.27 mm) (p = 0.385) after 5-year follow-up. The incidence of biological complications was 1.0% in all-on-six (one mucositis) and 10.3% in all-on-four (two peri-implantitis). Prosthetic complications affected teeth of final rehabilitations with 3 detachments, 10 chippings or fractures, and 3 severe occlusal wears. CONCLUSIONS: Based on the results and within the limitations of the present study, the implant-supported hybrid prosthesis according to prosthetic-driven planning and guided surgery showed to be an efficient, safe, and effective approach to rehabilitate edentulous jaws.

Manejo odontológico integral de una paciente con disostosis cleidocraneal. Reporte caso / Integral dental management of a patient with cleidocraneal dysplasia. Case report

Introducción: la disostosis cleidocraneal (CCD) es una enfermedad genética rara que compromete el desarrollo óseo normal, causada por la alteración en el gen RUNX2 del cromosoma 6p (brazo corto). Sus consecuencias incluyen alteraciones óseas por anomalías en la osificación intramembranosa que, a su vez, conllevan a modificaciones en el desarrollo de huesos craneales, claviculares, a múltiples efectos sobre el número, erupción y recambio dental, y a dificultades funcionales, además de cambios en la conducta psicosocial por el deterioro en la calidad de vida. Objetivo: describir el manejo integral de una paciente con disostosis cleidocraneal, a través de la revisión de caso clínico y el reporte de hallazgos en su mejoramiento, como consecuencia de tratamientos quirúrgicos, rehabilitación y el apoyo interdisciplinario, aspecto de gran importancia para este tipo de pacientes. Caso clínico: paciente femenina de 31 años con diagnóstico de CCD que asistió a la Unidad Estomatológica de la Universidad de Cartagena ­ Colombia, y fue remitida desde Genética por presentar inconformidad funcional y dolor leve durante la masticación de los alimentos por movilidad dental severa en dientes antero-inferiores; además, manifestó permanencia de órganos dentarios deciduos, la cual fue tratada en fases. Al tratamiento se le dio un enfoque multidisciplinar, lo que mejoró, de forma sustancial, la autopercepción e interrelación de la paciente en la sociedad.

Background: Cleidocranial dysostosis (CCD) is a rare genetic disease that compromises normal bone development, caused by the alteration in the RUNX2 gene of chromosome 6p (short arm), which causes bone alterations due to abnormalities in intramembranous ossification that leads to alterations in the development of cranial and clavicular bones and multiple efects on the number, eruption and dental turnover, which leads to functional difculties, in addition to behavior and alterations in psychosocial behavior and the deterioration of their quality of life, Objective: To describe the comprehensive management of a patient with cranial Cleido dysostosis, through a clinical case review, reporting among the fndings the improvement of the patient through surgical treatments, rehabilitation and interdisciplinary support, of great importance for this type of patient. Clinical case: A 31-year-old female patient with a diagnosis of CCD, who attended the Stomatology Unit of the University of Cartagena - Colombia, referred by the treating geneticist, due to functional discomfort and mild pain during chewing food due to severe dental mobility. in anterior-inferior teeth, also showing permanence of deciduous dental organs, which was treated in phases in which a multidisciplinary approach was given to its management, which substantially improved its self-perception and its interrelation in society.

Efficacy of biologics for alveolar ridge preservation/reconstruction and implant site development: An American Academy of Periodontology best evidence systematic review.

BACKGROUND: The use of biologics may be indicated for alveolar ridge preservation (ARP) and reconstruction (ARR), and implant site development (ISD). The present systematic review aimed to analyze the effect of autologous blood-derived products (ABPs), enamel matrix derivative (EMD), recombinant human platelet-derived growth factor-BB (rhPDGF-BB), and recombinant human bone morphogenetic protein-2 (rhBMP-2), on the outcomes of ARP/ARR and ISD therapy (i.e., alveolar ridge augmentation [ARA] and maxillary sinus floor augmentation [MSFA]). METHODS: An electronic search for eligible articles published from January 2000 to October 2021 was conducted. Randomized clinical trials evaluating the efficacy of ABPs, EMD, rhBMP-2, and rhPDGF-BB for ARP/ARR and ISD were included according to pre-established eligibility criteria. Data on linear and volumetric dimensional changes, histomorphometric findings, and a variety of secondary outcomes (i.e., clinical, implant-related, digital imaging, safety, and patient-reported outcome measures [PROMs]) were extracted and critically analyzed. Risk of bias assessment of the selected investigations was also conducted. RESULTS: A total of 39 articles were included and analyzed qualitatively. Due to the high level of heterogeneity across studies, quantitative analyses were not feasible. Most studies in the topic of ARP/ARR revealed that the use of biologics rendered similar results compared with conventional protocols. However, when juxtaposed to unassisted healing or socket filling using collagen sponges, the application of biologics did contribute to attenuate post-extraction alveolar ridge atrophy in most investigations. Additionally, histomorphometric outcomes were positively influenced by the application of biologics. The use of biologics in ARA interventions did not yield superior clinical or radiographic outcomes compared with control therapies. Nevertheless, ABPs enhanced new bone formation and reduced the likelihood of early wound dehiscence. The use of biologics in MSFA interventions did not translate into superior clinical or radiographic outcomes. It was observed, though, that the use of some biologics may promote bone formation during earlier stages of healing. Only four clinical investigations evaluated PROMs and reported a modest beneficial impact of the use of biologics on pain and swelling. No severe adverse events in association with the use of the biologics evaluated in this systematic review were noted. CONCLUSIONS: Outcomes of therapy after post-extraction ARP/ARR and ARA in edentulous ridges were comparable among different therapeutic modalities evaluated in this systematic review. Nevertheless, the use of biologics (i.e., PRF, EMD, rhPDGF-BB, and rhBMP-2) in combination with a bone graft material generally results into superior histomorphometric outcomes and faster wound healing compared with control groups.

Zygomatic implants in intra-sinus versus extra-maxillary approaches for prosthetic rehabilitation in severely atrophic maxillae: finite element analysis / Implantes cigomáticos en abordajes intra sinusal versus extra maxilar para rehabilitación protésica en maxilares severamente atróficos: análisis de elementos finitos

Objetive: To compare the stresses and deformations generated on the surrounding bone of the zygomatic implants when using an intra sinusal and extra-maxillary approach, through the finite element method. Material and Methods: Computer aided designs (CADs) were constructed using SolidWorks Software of a skull with bone resorption to be rehabilitated through a fixed hybrid prosthesis using two zygomatic and two conventional straight implants. For the boundary conditions (load conditions), symmetry in the sagittal plane was assumed and that all the materials were isotropic, homogeneous and linearly elastic. Two zygomatic implantation techniques were simulated: intra sinusal (Is) and extra maxillary (Em). Vertical and lateral loads of 150 N and 50 N were applied to the finite element models to obtain Von Mises equivalent stress and strain (displacement). Results: The average measurement of the Von Mises stress (MPa) recorded were as follows: Approach of the implant body (Is: 0.24- Em: 0.28,) effort of implant body with vertical load: Is: 0.69 - Em: 0.96; effort of peri-implant surface under horizontal load: Is: 2.11 - Em: 0.94. Average displacement under vertical load of peri-implant surface Is: 0.35 - Em: 0.40, and of implant body Is: 1.34 - Em: 2.04. Average total deformation in approach Is: 2.23 mm - Em: 0.80mm, and average total deformation in the implant body under horizontal load was Is: 0.14 - Em: 0.21. Conclusion: The results of this study indicate that despite the differences that occurred in both stress and strain (displacement) between the intra-sinus and extra-maxillary approaches, the static strength of the bone, which is approximately 150 MPa in tension and 250 MPa in compression was not exceeded. Considering the limitations of finite element analysis, there seems to be no biomechanical reason to choose one approach over the other.

Objetivo: Comparar por el método de elementos finitos los esfuerzos y deformaciones generados sobre el hueso circundante de implantes cigomáticos tratados con un abordaje intra sinusal y extra maxilar. Material y Métodos: Se construyeron los diseños asistidos por computadora (CAD) utilizando el Software SolidWorks de un cráneo con una reabsorción ósea para ser rehabilitado, a través de una prótesis híbrida fija, mediante dos implantes cigomáticos y dos rectos convencionales. Para las condiciones de frontera (condiciones de carga) se asumió simetría en el plano sagital y que todos los materiales eran isotrópicos, homogéneos y linealmente elásticos. Se simularon dos técnicas de implantación cigomática: una intra sinusal (Is) y otra extra maxilar (Em). Se aplicaron cargas verticales y laterales de 150 N y 50 N a los modelos de elementos finitos para obtener el esfuerzo equivalente de Von mises y la deformación (desplazamiento). Resultados: La medición promedio del esfuerzo de Von Mises (MPa) registró: abordaje del cuerpo de implante (Is: 0.24-Em: 0.28) esfuerzo del cuerpo de implante con carga vertical: (Is:0.69 ­ Em: 0.96); esfuerzo de la superficie peri implantar ante carga horizontal (lateral):( Is:2.11 ­ Em:0.94). Desplazamiento promedio ante carga vertical de la superficie peri implantar (Is:0.35 ­ Em:0.40) y del cuerpo del implante (Is:1.34 ­ Em:2.04). Deformación total promedio en mm en abordaje (Is: 2.23 ­ Em:0.80) y deformación total promedio en el cuerpo del implante ante carga horizontal (Is:0.14 ­ Em:0.21). Conclusión: Los resultados de este estudio indican que a pesar de las diferencias que se presentaron tanto en el esfuerzo como en la deformación (desplazamiento) entre los abordajes intra sinusal y extra maxilar, la resistencia estática del hueso, que es de aproximadamente 150 MPa en tensión y 250 MPa en compresión no se superó. Considerando las limitaciones de los AEF, parece no haber razones biomecánicas para elegir uno u otro enfoque.

Reliability and accuracy of dynamic navigation for zygomatic implant placement.

OBJECTIVES: To assess the accuracy of a real-time dynamic navigation system applied in zygomatic implant (ZI) surgery and summarize device-related negative events and their management. MATERIAL AND METHODS: Patients who presented with severely maxillary atrophy or maxillary defects and received dynamic navigation-supported ZI surgery were included. The deviations of entry, exit, and angle were measured after image data fusion. A linear mixed-effects model was used. Statistical significance was defined as p < .05. Device-related negative events and their management were also recorded and analyzed. RESULTS: Two hundred and thirty-one zygomatic implants (ZIs) with navigation-guided placement were planned in 74 consecutive patients between Jan 2015 and Aug 2020. Among them, 71 patients with 221 ZIs received navigation-guided surgery finally. The deviations in entry, exit, and angle were 1.57 ± 0.71 mm, 2.1 ± 0.94 mm and 2.68 ± 1.25 degrees, respectively. Significant differences were found in entry and exit deviation according to the number of ZIs in the zygomata (p = .03 and .00, respectively). Patients with atrophic maxillary or maxillary defects showed a significant difference in exit deviation (p = .01). A total of 28 device-related negative events occurred, and one resulted in 2 ZI failures due to implant malposition. The overall survival rate of ZIs was 98.64%, and the mean follow-up time was 24.11 months (Standard Deviation [SD]: 12.62). CONCLUSIONS: The navigation-supported ZI implantation is an accurate and reliable surgical approach. However, relevant technical negative events in the navigation process are worthy of attention.

[Application evaluation of prefabricated rigid connecting bar in implants immediate impression preparation of edentulous jaw].

OBJECTIVE: To compare the operation complexity and accuracy of traditional splint impression technique and impression technique with prefabricated rigid connecting bar system for full-arch implants-supported fixed protheses in vitro. METHODS: Standard mandibular edentulous model with six implant analogs was prepared. The implants were placed at the bone level and multiunit abutments screwed into the implants. Two impression techniques were performed: the traditional splint impression technique was used in the control group, and the rigid connecting bar system was used in the test group. In the control group, impression copings were screwed into the multiunit abutments and connected with autopolymerizing acrylic resin. Open tray impression was fabricated with custom tray and polyether. In the test group, cylinders were screwed into the multiunit abutments. Prefabricated rigid bars with suitable length were selected and connected to the cylinders with small amount of autopolymerizing acrylic resin, and open tray impression was obtained. Impression procedures were repeated 6 times in each group. The working time of the two impression methods were recorded and compared. Analogs were screws into the impressions and gypsum casts were poured. The gypsum casts and the standard model were transferred to stereolithography (STL) files with model scanner. Comparative analysis of the STL files of the gypsum casts and the standard model was carried out and the root mean square (RMS) error value of the gypsum casts of the control and test groups compared with the standard model was recorded. The trueness of the two impression techniques was compared. RESULTS: The work time in the test group was significantly lower than that in the control group and the difference was statistically significant [(984.5±63.3) s vs. (1 478.3±156.2) s, P < 0.05]. Compared with the standard model, the RMS error value of the implant abutments in the test group was (16.9±5.5) µm. The RMS value in the control group was (20.2±8.0) µm. The difference between the two groups was not significant (P>0.05). CONCLUSION: The prefabricated rigid connecting bar can save the chair-side work time in implants immediate loading of edentulous jaw and simplify the impression process. The impression accuracy is not significantly different from the traditional impression technology. The impression technique with prefabricated rigid connecting bar system is worthy of clinical application.

The association between sleep disturbances and tooth loss among post-stroke patients / Prevalência de edentulismo e distúrbios de sono após acidente vascular cerebral

ABSTRACT Background: Loss of teeth has been associated with neurological and sleep disorders. It is considered to be a predictor of stroke and leads to modifications of airway patency and predisposition to obstructive sleep apnea. Objective: To investigate sleep quality, risk of obstructive sleep apnea and excessive sleepiness among post-stroke patients with tooth loss attending the Neurovascular Clinic of the Federal University of São Paulo. Methods: The prevalence rates of different types of stroke were assessed among 130 patients with different degrees of tooth loss, along with the presence of sleep disturbances, risk of obstructive sleep apnea and excessive daytime sleepiness. Results: The prevalence of ischemic stroke was 94.6%, with either no significant disability or slight disability. Our sample had poor sleep quality, and a high risk of obstructive sleep apnea, but without excessive daytime sleepiness. Half of our sample had lost between 9 and 31 teeth, and more than 25% had edentulism. The majority used full removable dental prostheses, and more than half of these individuals slept without removing the prosthesis. Conclusions: We found high prevalence of poor sleep quality and high risk of obstructive sleep apnea among post-stroke patients with tooth loss. This indicates the need for further studies on treating and preventing sleep disturbances in stroke patients with tooth loss.

RESUMO Antecedentes: A perda de dentes tem sido associada a distúrbios neurológicos e do sono. É considerada um preditor de acidente vascular cerebral (AVC), com modificações na permeabilidade das vias aéreas e predisposição à apneia obstrutiva do sono. Objetivo: Investigar a qualidade do sono, o risco de apneia obstrutiva do sono e a sonolência excessiva em pacientes pós-AVC com perda dentária, atendidos na Clínica Neurovascular da Universidade Federal de São Paulo. Métodos: O estudo avaliou a prevalência de diferentes tipos de AVC em 130 pacientes com diferentes graus de perda dentária e a presença de distúrbios do sono, risco de apneia obstrutiva do sono e sonolência excessiva. Resultados: A prevalência de AVC isquêmico foi de 94,6%, sem deficiência significativa ou deficiência leve. Nossa amostra tinha má qualidade de sono e alto risco de apneia obstrutiva do sono, sem sonolência diurna excessiva. Metade de nossa amostra perdeu entre nove e 31 dentes, e mais de 25% tiveram edentulismo. A maioria usava próteses dentárias totalmente removíveis e, desses pacientes, mais da metade dormia com elas. Conclusões: Encontramos alta prevalência de má qualidade do sono e alto risco de apneia obstrutiva do sono em pacientes pós-AVC com perda dentária. Isso indica a necessidade de mais estudos sobre o tratamento e a prevenção de distúrbios do sono em pacientes com AVC e perda dentária.

Application evaluation of prefabricated rigid connecting bar in implants immediate impression preparation of edentulous jaw / 北京大学学报(医学版)

OBJECTIVE@#To compare the operation complexity and accuracy of traditional splint impression technique and impression technique with prefabricated rigid connecting bar system for full-arch implants-supported fixed protheses in vitro.@*METHODS@#Standard mandibular edentulous model with six implant analogs was prepared. The implants were placed at the bone level and multiunit abutments screwed into the implants. Two impression techniques were performed: the traditional splint impression technique was used in the control group, and the rigid connecting bar system was used in the test group. In the control group, impression copings were screwed into the multiunit abutments and connected with autopolymerizing acrylic resin. Open tray impression was fabricated with custom tray and polyether. In the test group, cylinders were screwed into the multiunit abutments. Prefabricated rigid bars with suitable length were selected and connected to the cylinders with small amount of autopolymerizing acrylic resin, and open tray impression was obtained. Impression procedures were repeated 6 times in each group. The working time of the two impression methods were recorded and compared. Analogs were screws into the impressions and gypsum casts were poured. The gypsum casts and the standard model were transferred to stereolithography (STL) files with model scanner. Comparative analysis of the STL files of the gypsum casts and the standard model was carried out and the root mean square (RMS) error value of the gypsum casts of the control and test groups compared with the standard model was recorded. The trueness of the two impression techniques was compared.@*RESULTS@#The work time in the test group was significantly lower than that in the control group and the difference was statistically significant [(984.5±63.3) s vs. (1 478.3±156.2) s, P < 0.05]. Compared with the standard model, the RMS error value of the implant abutments in the test group was (16.9±5.5) μm. The RMS value in the control group was (20.2±8.0) μm. The difference between the two groups was not significant (P>0.05).@*CONCLUSION@#The prefabricated rigid connecting bar can save the chair-side work time in implants immediate loading of edentulous jaw and simplify the impression process. The impression accuracy is not significantly different from the traditional impression technology. The impression technique with prefabricated rigid connecting bar system is worthy of clinical application.

Rehabilitation of atrophic posterior partial edentulous maxilla with TTPHIL ALL TILT® technique: 3 year follow-up case report / Reabilitação de maxila atrófica posterior parcialmente desdentada com técnica TTPHIL ALL TILT®: relato de caso de acompanhamento de 3 anos

Maxillary sinus pneumatisation pose a grave clinical challenge for implant fixed rehabilitation in posterior maxilla owing to diminished bone volume. This necessitates sinus lift and grafting which increase the duration and cost and possible surgical complications. Pterygoid implant has a greater short term osseointegration and is a proven treatment method for rehabilitation of highly resorbed posterior maxilla. To overcome the limitations of sinus grafting techniques, the current case report describes the use of flapless, tilted and pterygoid implant for restoration of partially edentulous atrophic maxilla eliminating grafting (AU).

A pneumatização do seio maxilar representa um grande desafio clínico para a reabilitação fixa por implante na região posterior da maxila devido ao volume ósseo diminuído. Isso requer elevação do seio e enxerto, fatores que aumentam a duração, o custo e as possíveis complicações cirúrgicas. O implante pterigóide tem uma osseointegração maior em curto prazo e é um método de tratamento comprovado para reabilitação de maxila posterior altamente reabsorvida. Para superar as limitações das técnicas de enxerto de seio, o relato de caso atual descreve o uso de implante sem retalho, inclinado e pterigóide para restauração de maxila atrófica parcialmente edêntula eliminando o enxerto.(AU)

Comportamiento de las enfermedades bucodentales en el Hospital Referal Maliana de Timor Leste / Behavior of oral and dental diseases at Referal Maliana Hospital, Timor Leste

RESUMEN Introducción: la salud bucodental es un indicador clave de salud, bienestar y calidad de vida. Las enfermedades bucodentales como caries, periodontopatías, cáncer bucal pueden prevenirse y tratarse en sus etapas iniciales. Objetivo: determinar el comportamiento de las enfermedades bucodentales en la población que asistió a la consulta de estomatología del Hospital Referal Maliana, distrito Bobonaro, Timor Leste durante 2017-2018. Métodos: estudio observacional descriptivo de corte transversal en 480 pacientes afectados con alguna patología bucodentaria, seleccionados por muestreo intencional no probabilístico. Resultados: predominó el sexo masculino (51,9 %), el grupo de edad más afectado fue 10-19 años (40,4 %), las patologías más diagnosticadas fueron las caries (79,1 %) en edades entre 0 y 39 años, gingivitis (58,6 %) en jóvenes, y desdentamiento parcial (49,4 %) en todas las edades. Prevaleció la higiene bucal deficiente (83,8 %) en ambos sexos y consumo de mama malus (64,8 %) más observado en mujeres. Conclusiones: la población timorense estudiada es mayormente masculina, predominó el grupo de edad de 10 a 19 años; las enfermedades bucodentales más frecuentes fueron las caries en menores de 40 años, gingivitis en jóvenes, y edentulismo parcial en todas las edades. Los principales factores de riesgo asociados fueron la higiene bucal deficiente para ambos sexos y masticación de la mama malus (nuez de Areca o de betel) en las féminas, lo que evidencia una alta probabilidad de que incremente y confirma la severidad de las enfermedades bucodentales como problema de salud en esta población.

ABSTRACT Introduction: oral-dental health is a key indicator of wellbeing and quality of life. Oral-dental diseases as caries, periodontopathies and oral cancer can be prevented and treated at early stages. Objective: to determine the behavior of oral-dental diseases in the population attending the dentistry office at Referal Maliana Hospital, Bobonaro district, Timor Leste during 2017-2018. Methods: observational, descriptive and cross-sectional study in 480 patients who suffered from some of the oral-dental pathologies chosen by non-probabilistic intentional sampling. Results: male sex prevailed (51,9 %), the age bracket most affected was 10-19 years old (40,4 %), dental caries was the pathology having the highest diagnosis (79,1 %) between 0 and 39 years old, gingivitis (58,6 %) in young patients and partially-toothless patients in all ages. Deficient oral hygiene prevailed in both sexes (83,8 %) and mama malus consumption (64,8 %) more observed in women. Conclusions: the East Timorese population studied was mainly male, the predominant age group was 10-19 years; the most frequent oral-dental diseases were caries in younger than 40 years old, gingivitis in young population and partial edentulous in all ages. The main risk factors associated were deficient oral-dental hygiene for both sexes and the mastication of mama malus (Areca Nut or Betel Quid) in female population, which evidences a high probability of a continuous increasing and confirms the severity of the oral-dental diseases as a health problem in this population.

Dispositivos intraorais no tratamento da apneia obstrutiva do sono em pacientes desdentados: uma revisão sistematizada de literatura / Intraoral devices in the treatment of obstructive sleep apnea in edentulous patients: a systematized literature review

Objetivo: elucidar aspectos envolvidos no uso dos dispositivos intraorais para apneia obstrutiva do sono em indivíduos desdentados totais, como a eficácia dos dispositivos, o conforto e retenção/estabilidade. Metodologia: essa revisão seguiu o checklist do PRISMA, no qual foram incluídos estudos clínicos em inglês, sem restrição de tempo, em que foram utilizados dispositivos para apneia obstrutiva do sono em pacientes desdentados bimaxilares. As buscas foram realizadas nas bases de dados PubMed / MEDLINE, Cochrane e SCOPUS até março de 2021. Resultados: Após as diferentes etapas do processo de seleção dos artigos, foram selecionados 6 estudos para esta revisão, sendo 5 relatos de caso e 1 ensaio clínico. Os estudos relataram uma redução no índice apneia-hipopneia. Em três estudos houve redução expressiva, proporcionando a redução no grau de apneia, de severa para moderada e moderada para leve. A protrusão alcançada com os dispositivos foi adequada para o efeito desejado, em todos os dispositivos. Os estudos não reportam deslocamento do dispositivo e apenas um relata desconforto temporário. Conclusão: Os dispositivos intraorais foram eficazes no tratamento da apneia obstrutiva do sono em pacientes desdentados e os usuários não tiveram queixas quanto ao conforto e estáveis... (AU)

Objective: to elucidate aspects involved in the use of intraoral devices for obstructive sleep apnea in complete edentulous patients, such as the effectiveness of these devices, comfort and retention/stability. Methodology: this review followed the PRISMA checklist, included clinical studies in English, without publication restrictions, in which intraoral devices were used for obstructive sleep apnea in edentulous bimaxillary patients. The search was carried out in PubMed/MEDLINE, Cochrane and SCOPUS databases, until March 2021. Results: After the different stages of the article selection process, 6 studies were selected for this review, 5 case reports and 1 clinical trial. The studies reported a reduction in the apnea-hypopnea index. In three studies there was a significant reduction in the degree of apnea, from severe to moderate and moderate to mild. The protrusion achieved with the devices was adequate for the desired effect, in all devices. Studies did not report displacement of the device and only one reports temporary discomfort. Conclusion: Intraoral devices were effective in treating obstructive sleep apnea in edentulous patients and users had no complaints about comfort and stability... (AU)

Factors associated with edentulism in individuals with chronic kidney disease undergoing hemodialysis: a cross-sectional study / Fatores associados ao edentulismo em indivíduos com doença renal crônica em hemodiálise: um estudo transversa

Introduction: Chronic kidney disease (CKD) is a progres-sive condition characterized by structural or functional abnormalities of the kidney. CKD may be associated with several oral alterations, such as higher prevalence rate of dental caries, periodontal disease, xerostomia, candidiasis and burning mouth. The aim of the study was to identify risk factors associated with edentulism in adults with CKD undergoing hemodialysis. Methods: A cross-sec-tional study was conducted with 650 individuals aged 18 to 90 years undergoing hemodialysis in southeastern Brazil. Oral clinical examination and administration of a questionnaire addressing demographic characteristics and dental history were performed. The study received approval from the Human Research Ethics Committee of UFMG. Findings: A total of 183 participants were eden-tulous (28.2%). Individuals with less schooling (OR = 3.99; 95% CI: 2.34-6.79), those who had not been to a dentist in the previous six months (OR = 2.49; 95% CI: 1.52-4.08), those who rated their own smile as excellent or good (OR = 2.00; 95% CI: 1.35-2.97) and those with some mucosal alteration (OR = 4.17; 95% CI: 2.83-6.13) had a greater chance of belonging to the edentulous group. Discussion: The present findings can contribute to the establishment of public health policies aimed at guiding dental care programs for individuals with chronic kidney disease that take into account the specific needs of this population. Conclusion: Edentulism was associated with low schooling, a lack of dental care in the previous six months, a positive self-perception of one's smile and alterations in the oral mucosa.

Introdução: A doença renal crônica (DRC) é uma condição caracterizada por anormalidades estruturais ou funcionais do rim. A DRC pode estar associada a diversas alterações bucais, como maior prevalência de cárie dentária, doença periodontal, xerostomia, candidíase e queimação bucal. O objetivo deste estudo foi identificar os fatores de risco associados ao edentulismo em indivíduos com DRC em tratamento com hemodiálise. Materiais e Métodos: Foi realizado um estudo transversal com 650 indivíduos de 18 a 90 anos em hemodiálise no sudeste do Brasil. Foi realizado exame clínico oral e aplicação de questionário abordando características demográficas e histórico odontológico. O estudo foi aprovado pelo Comitê de Ética em Pesquisa em Seres Humanos da UFMG. Resultados: Um total de 183 participantes eram edêntulos (28,2%). Indivíduos com menor escolaridade (OR = 3,99; IC 95%: 2,34-6,79), aqueles que não foram ao dentista nos últimos seis meses (OR = 2,49; IC 95%: 1,52-4,08), aqueles que avaliaram o seu próprio sorriso como excelente ou bom (OR = 2,00; IC 95%: 1,35-2,97) e aqueles com alguma alteração de mucosa (OR = 4,17; IC 95%: 2,83-6,13) tiveram maior chance de pertencer ao grupo de edêntulos. Discussão: Os presentes achados podem contribuir para o estabelecimento de políticas públicas de saúde voltadas a nortear programas de atenção odontológica à pessoa com doença renal crônica que atendam às necessidades específicas dessa população. Conclusão: O edentulismo esteve associado à baixa escolaridade, falta de atendimento odontológico nos últimos seis meses, sorriso autoavaliado positivo e alterações mucosas.

Effect of total edentulism on the internal bone structure of mandibular condyle: a preliminary study.

OBJECTIVE: The aim of this study was to assess the internal structure of the mandibular condyles in patients with total edentulism by applying fractal analysis on cone-beam computed tomography (CBCT) images and compare with dentate subjects. METHODS: A total of 136 mandibular condyles were assessed. All CBCT images were prepared with 0.25-mm slice thickness and maximum magnification. A 64 × 64 pixel region of interest (ROI) within the trabecular bone in the center of the condyle was selected. Fractal analysis was performed using White and Rudolph's box-counting method. RESULTS: Control and study groups were age and gender-matched. The mean fractal dimension (FD) value of the study group was significantly lower compared to the control group (p < 0.01). In the study group, the mean FD value of the females was significantly lower than males (p = 0.01). For the control group, there was no significant difference between the genders for FD (p = 0.11). There was no significant difference between the age subgroups of the female study group and the male control group for FD (p = 0.22, p = 0.33). The mean FD value of the younger age subgroup was significantly higher compared to the older age subgroup in the female control and male study group (p = 0.03, p = 0.01). CONCLUSION: The internal bone structure of mandibular condyles in edentulous patients was found to be affected by edentulism. Fractal analysis can be used as an effective method for assessing temporomandibular joint health.

Reliability of Linear and Curvilinear Measurements on Cone-Beam Computed Tomography Images for the Evaluation of Implant Sites and Jaw Pathologies

ABSTRACT Objective: To evaluate the intra-examiner and inter-examiner reliability of linear and curvilinear measurements for the complete assessment of implant sites and jaw pathologies using Cone-Beam Computed Tomography (CBCT). Material and Methods: Fifty cone-beam computed tomographic images of patients were retrieved from the archives of Dentomaxillofacial Radiology. CBCT images taken for implant planning and evaluation of intrabony jaw pathologies (benign cyst/tumor) were included. Two expert oral and maxillofacial radiologists analyzed the images independently and made the measurements. The images for implant planning were analyzed for width, the height of the edentulous site, and the qualitative analysis of bone in the region. Jaw pathologies were assessed for linear dimensions and curvilinear measurements. Results: The inter-observer measurement error for implant site analysis ranged from 0.12 to 0.42 mm with almost perfect agreement (ICC: 0.94 to 1). The inter-observer measurement error for jaw pathology was 0.09 to 0.25 mm (ICC: 0.98-1). Curvilinear measurements showed perfect agreement between the observers. The intraobserver reliability for the various parameters used for the assessment of the implant site and jaw pathologies indicated almost perfect agreement. Conclusion: Reliability between the radiologists is high for various measurements on CBCT images taken for implant planning and jaw pathologies.