Assessment of the osteogenic effect after maxillary sinus floor elevation and simultaneous implantation with or without bone grafts by analyzing trabecular bone parameters: a retrospective study

Abstract Objective: The aim of this population-based retrospective study was to compare the osteogenic effect of newly formed bone after maxillary sinus floor elevation (MSFE) and simultaneous implantation with or without bone grafts by quantitatively analyzing trabecular bone parameters. Methodology: A total of 100 patients with missing posterior maxillary teeth who required MSFE and implantation were included in this study. Patients were divided into two groups: the non-graft group (n=50) and the graft group (n=50). Radiographic parameters were measured using cone beam computed tomography (CBCT), and the quality of newly formed bone was analyzed by assessing trabecular bone parameters using CTAn (CTAnalyzer, SkyScan, Antwerp, Belgium) software. Results: In the selected regions of interest, the non-graft group showed greater bone volume/total volume (BV/TV), bone surface/total volume (BS/TV), trabecular number (Tb. N), and trabecular thickness (Tb. Th) than the graft group (p<0.001). The non-graft group showed lower trabecular separation (Tb. Sp) than the graft group (p<0.001). The incidence of perforation and bleeding was higher in the graft group than in the non-graft group (p<0.001), but infection did not significantly differ between groups (p>0.05). Compared to the graft group, the non-graft group showed lower postoperative bone height, gained bone height and apical bone height (p<0.001). Conclusion: MSFE with and without bone grafts can significantly improve bone formation. In MSFE, the use of bone grafts hinders the formation of good quality bone, whereas the absence of bone grafts can generate good bone quality and limited bone mass.

Histomorphometric Comparison of Bio-Oss vs. Osteodens in Maxillary Sinus Floor Elevation Procedures / Comparación histomorfométrica de Bio-Oss frente a Osteodens en procedimientos de elevación del suelo del seno maxilar

Introduction: The loss of dental elements can lead to excessive bone loss in the posterior maxillary segments, which can limit the placement of dental implants in that area, the pneumatization of the maxillary sinus and the absence of dental elements to keep the bone active are some of the main causes. Among the wide range of available grafting materials, bovine hydroxyapatite has been extensively studied and has shown excellent clinical and histological results. Materials and methods: A total of 17 maxillary sinus floor elevations were performed (n = 8 Osteodens, n = 9 Bio-Oss). After a healing period of 6 to 8 months, a block of the grafted area was obtained using trephines and analyzed by histomorphometry. Results: The percentage of neoformed bone tissue was higher for Bio-Oss (39.0% ± 11.1) compared to Osteodens (33.4% ± 8.3), while the remaining graft values were slightly lower in Bio-Oss compared to Osteodens (16.3% ± 11.2 and 20.8% ± 12.1, respectively). The proportion of connective tissue was similar in both groups (44.7% Bio-Oss and 45.8% Osteodens). Age, gender, and residual height of the sinus floor did not show statistically significant differences. Conclusions: In this study, both graft materials (Bio-Oss and Osteodens) showed no statistically significant differences in their ability to regenerate suitable bone tissue for implant placement after 6 months of healing. Further studies with a larger sample size are needed to validate these results.

Introducción: La pérdida de elementos dentarios puede provocar una excesiva pérdida ósea en los segmentos maxilares posteriores, lo que puede limitar la colocación de implantes dentarios en esa zona, la neumatización del seno maxilar y la ausencia de elementos dentarios que mantengan el hueso activo son algunas de las principales causas. Entre la amplia gama de materiales de injerto disponibles, la hidroxiapatita bovina ha sido ampliamente estudiada y ha mostrado excelentes resultados clínicos e histológicos. Materiales y métodos: Se realizaron un total de 17 elevaciones del suelo del seno maxilar (n = 8 Osteodens, n = 9 Bio-Oss). Tras un periodo de cicatrización de 6 a 8 meses, se obtuvo un bloque de la zona injertada mediante trépanos y se analizó mediante histomorfometría. Resultados: El porcentaje de tejido óseo neoformado fue mayor en Bio-Oss (39,0% ± 11,1) en comparación con Osteodens (33,4% ± 8,3), mientras que los valores del injerto remanente fueron ligeramente inferiores en Bio-Oss en comparación con Osteodens (16,3% ± 11,2 y 20,8% ± 12,1, respectivamente). La proporción de tejido conjuntivo fue similar en ambos grupos (44,7% Bio-Oss y 45,8% Osteodens). La edad, el sexo y la altura residual del piso sinusal no mostraron diferencias estadísticamente significativas. Conclusiones: En este estudio, ambos materiales de injerto (Bio-Oss y Osteodens) no mostraron diferencias estadísticamente significativas en su capacidad para regenerar tejido óseo adecuado para la colocación de implantes tras 6 meses de cicatrización. Se necesitan más estudios con un tamaño de muestra mayor para validar estos resultados.

Instalação de implante em região posterior de maxila através da técnica de Summers e osseodensificação: relato de caso / Implant installation in posterior maxilla using the Summers technique and osseodensification: a case report / Instalación de implantes en la región posterior del maxilar utilizando la técnica de Summers y la oseodensificación: informe de un caso

Este trabalho tem por objetivo relatar um caso em que foi realizada a técnica de Summers para elevação do seio maxilar, associada à realização de osseodensificação. Paciente do gênero masculino, 53 anos, apresentando ausência do dente 17, com altura reduzida na área edêntula. Foi realizada a elevação do seio maxilar pela técnica de Summers associada à osseodensificação da região para uma melhora da qualidade óssea. Foi instalado um implante cone morse SIN de 3.8 x 8.5 com torque de 45 newtons. No acompanhamento pós-operatório não houve qualquer sinal ou sintoma de complicação e o paciente foi reabilitada com uma prótese parafusada sobre implante.

This study aims to report a case in which the Summers technique was performed for maxillary sinus elevation, associated with osseodensification. Male patient, 53 years old, with missing tooth 17, with reduced height in the edentulous area. Maxillary sinus elevation was performed using the Summers technique associated with osseodensification of the region for an improvement in bone quality. A 3.8 x 8.5 SIN morse taper implant with a torque of 45 newtons was installed. In the postoperative follow-up, there were no signs or symptoms of complications and the patient was rehabilitated with a screw-retained implant prosthesis.

Este trabajo tiene como objetivo informar de un caso en el que se realizó la técnica de Summers para la elevación del seno maxilar, asociada a la osteodensificación. Paciente varón, de 53 años, que presenta ausencia del diente 17, con altura reducida en la zona edéntula. Se elevó el seno maxilar mediante la técnica de Summers asociada a la osteodensificación de la región para mejorar la calidad ósea. Se instaló un implante morse cónico de 3,8 x 8,5 SIN con un par de 45 newtons. En el seguimiento postoperatorio no hubo signos ni síntomas de complicación y el paciente fue rehabilitado con una prótesis atornillada sobre un implante.

Techniques of Maxillary Sinus Floor Elevation

Posterior maxillary region is often limited for standard implant placement because of reduced residual vertical bone height. An elevation of the maxillary sinus floor is one option in solving this problem. This article describes the various surgical techniques that can be used to enter the sinus cavity, elevating the sinus membrane and placing the bone grafts for placement of dental implants in the resorbed posterior maxillary region.

The anatomical limit and strategies for molar movement during orthodontic treatment / 口腔疾病防治

@#In many cases, tooth movement over a considerable distance is needed to meet the major goal of orthodontic treatment, which has always been to correct malocclusion and improve the facial profile in patients with skeletal malocclusion. However, tooth movement over a considerable distance also carries risks of dehiscence, fenestration, root exposure, and so forth. The reason lies in neglecting many limits for tooth movement, especially anatomical characteristics. This review focuses on structural limits for orthodontic molar movement, such as the alveolar cortex, the maxillary sinus floor, and the mandibular canal. In addition, we set the strategy in clinical orthodontics. For the alveolar cortex and the mandibular canal, orthodontists are recommended to move the root away from the cortical bone initially and formulate personalized molar movement plans according to clinical examination and cone-beam computed tomography (CBCT) and other imaging examinations. First, the molar root was controlled by torque away from the bone plate, and then, the molar movement amount and direction were controlled according to the personalized movement path. In regard to the maxillary sinus floor, light and continuous forces and scientific biomechanics are suitable for bodily tooth movement. In summary, better therapeutic efficacy and long-term stabilization could be achieved by circumventing the limits and risks caused by anatomical limitations and characteristics.

Effect of different thresholds on the accuracy of linear and volumetric analysis of native- and grafted-bone

Abstract The study aimed to evaluate the accuracy of Micro-CT in linear and volumetric measurements in native (NB) and grafted bone (GB) areas. A total of 111 biopsies of maxillary sinuses grafted with deproteinized bovine bone (DBB) in humans were evaluated. The linear measurements were performed to measure the length of the NB and GB. Furthermore, the amount of mineralized tissues at the NB and GB was performed. In the histomorphometry analysis the percentage of mineralized tissues at the NB and GB was obtained in two histological sections while the mineralized tissues were measure in the micro-CT varying the thresholds of the grayscale varying from 90-250 to 90-150 with 10 levels of variation between each one was applied. Then these data were correlated in order to check the higher r level between the histomorphometry and micro-CT thresholds intervals. The linear length of the NB was 2.44±0.91mm and 2.48±1.50mm, respectively, for micro-CT and histomorphometry (r =0.57), while the linear length of the GB was 3.63±1.66mm and 3.13±1.45mm, respectively, for micro-CT and histomorphometry (r =0.74) Histomorphometry showed 45.91±11.69% of bone in NB, and 49.57±5.59% of bone and biomaterial in the GB. The total volume of mineralized tissues that were closest to the histometric analysis were 43.75±15.39% in the NB (Threshold:90-240; r = 0.50) and 51.68±8.42% in the GB (Threshold:90-180; r =-0.028). The micro-CT analysis showed good accuracy in the linear analysis in both portions of the biopsies but for volumetric analysis just in NB.

Resumo Esse estudo tem como objetivo avaliar a acurácia da análise microtomográfica em mensurações lineares e volumétricas em osso nativo (ON) e enxertado (OE). Para isso, 111 biópsias removidas de seios maxilares de pacientes enxertados com osso bovino desproteinizado foram coletadas e avaliadas. As medidas lineares foram realizadas para medir o comprimento do ON e do OE. Além disso, foi realizada a mensuração da quantidade de tecidos mineralizados em ON e OE. Na análise histomorfométrica a porcentagem de tecidos mineralizados do ON e OE foi obtida em dois cortes histológicos enquanto os tecidos mineralizados foram medidos em microtomografias variando os thresholds da escala de cinza variando de 90-250 a 90-150 com 10 níveis de variação entre cada. Em seguida, esses dados foram correlacionados para verificar o maior nível de R entre os intervalos dos thresholds testados na análise microtomográfica em relação aos dados obtidos na histomorfometria. O comprimento linear do ON foi de 2,44±0,91mm e 2,48±1,50mm, respectivamente, para análises microtomográfica e histomorfométrica (r=0,57), enquanto o comprimento linear do OE foi de 3,63±1,66mm e 3,13±1,45mm, respectivamente, para para análises microtomográfica e histomorfométrica (r =0,74) A histomorfometria detectou 45,91±11,69% de osso na porção de ON e 49,57±5,59% de osso e biomaterial na porção de OE. O volume total de tecidos mineralizados detectados pela análise microtomográfica que apresentou valores mais próximos da análise histomorfométrica foi de 43,75±15,39% no ON (Thresholds:90-240; r = 0,50) e 51,68±8,42% no OE (Thresholds:90-180; r =- 0,028). A análise microtomográfica apresentou boa acurácia na análise linear em ambas as porções das biópsias, porém a mesma apresentou boa acurácia para análise volumétrica apenas em áreas de ON.

Expert consensus on the bone augmentation surgery for alveolar bone defects / 口腔疾病防治

@#Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.

Transcrestal sinus lift with simultaneous implant placement using osseodensification in posterior maxilla with residual bone height of 4-6 mm / Elevação de seio maxilar via crista do rebordo com instalação simultânea de implante utilizando osseodensificador em região posterior de maxila com altura do remanescente ósseo de 4 a 6 mm

Objective: The aim of this study was to evaluate the transcrestal sinus lift using Osseodensification technique with simultaneous implant placement. Material and Methods: In this case series 7 patients who needed implant placement in the atrophic posterior maxilla were enrolled. In all the cases the residual bone height between the sinus floor and the alveolar crest was 4-6 mm. Transcrestal sinus lift was performed using Osseodensification with simultaneous implant placement. Cone-beam computed tomography (CBCT) were obtained immediately postoperative and 6 months after operation. Implant stability using Osstell® were assessed at the time of implant placement and implant exposure (6 months). Results: The results showed that the mean bone height gain was 5.33±0.83mm at 6 months postoperatively. Mean bone density value was 818.43±109.63 HU. Mean ISQ value was 80.00±3.11 at 6 months postoperatively. The duration of surgical procedure (minutes) ranged between 25-38 minutes with an average of 30.86±4.10 minutes. Conclusion: The crestal maxillary sinus floor elevation using Osseodensification technique with simultaneous implant placement provide superior results regarding bone density and implant stability and less duration of surgical procedure. (AU)

Objetivo: O objetivo deste estudo foi avaliar a elevação de seio maxilar via crista do rebordo com a técnica de Osseodensificação com instalação simultânea de implante. Material e Métodos: Nesta série de casos, participaram 7 pacientes que necessitavam de implantes em região posterior de maxila atrófica. Em todos os casos a altura de remanescente ósseo entre o soalho do seio e a crista alveolar estava entre 4 a 6 mm. A elevação de seio maxilar via crista do rebordo foi realizada com osseodensificação com instalação simultânea de implante. As Tomografias Computadorizadas Cone Beam (TCCB) foram obtidas imediatamente após a cirurgia e 6 meses depois. A estabilidade dos implantes utilizando Osstell® foi avaliada no momento da instalação do implante e no momento da reabertura (6 meses). Resultados: Os resultados mostraram que a média de ganho de altura óssea foi de 5.33±0.83mm após 6 meses da cirurgia. A média da densidade óssea foi de 818.43±109.63 HU. A média de ISQ foi de 80.00±3.11 após 6 meses da cirurgia. A duração do procedimento cirúrgico (minutos) foi entre 25 a 38 minutos com uma média de 30.86±4.10 minutos. Conclusão: A elevação do soalho de seio maxilar via crista do rebordo com instalação simultânea de implante utilizando osseodensificador promove resultados superiores em relação à densidade óssea, estabilidade do implante e menor duração do tempo cirúrgico (AU)

Lateral window maxillary sinus lift surgery: case report / Cirurgia de levantamento de seio maxilar pela técnica da janela lateral: relato de caso

ABSTRACT The loss in height of the alveolar bone crest after tooth extraction makes rehabilitation of the posterior maxilla challenging due to low bone density and atrophy, in addition to pneumatization of the maxillary sinus. Maxillary sinus lift surgery prior to implant placement makes implant-supported rehabilitation feasible. This study aimed to describe a case report of maxillary sinus surgery using the side window technique prior to rehabilitation with a prosthesis supported by dental implants, highlighting the importance of planning to minimize intraoperative complications. This is a clinical case report of a 59-year-old male patient who was assisted at a private higher education institution complaining of edentulous spaces and the desire for rehabilitation with implants. He underwent rehabilitation planning, including the surgical treatment of maxillary sinus lifting using the side window technique. Bone gain was confirmed using cone beam computed tomography six months after the surgical approach to the maxillary sinus. The planning of rehabilitation of the posterior maxilla and careful sinus lift surgery using the side window technique is a predictable therapeutic option for clinical cases with bone gain in height of the posterior region of the maxilla prior to the installation of dental implants. The clinical case presented demonstrated success in the gain of bone volume in the posterior region of the maxilla, without postoperative complications, and the patient was still satisfied with the proposed treatment, awaiting complete implant-supported rehabilitation.

RESUMO A perda em altura da crista óssea alveolar pós extração dentária torna a reabilitação da maxila posterior desafiadora devido à baixa densidade e atrofia ósseas, além da pneumatização do seio maxilar. A cirurgia sinusal previamente à instalação de implantes viabiliza a reabilitação implantossuportada. Esse estudo teve como objetivo apresentar um relato de caso clínico submetido à cirurgia de levantamento de seio maxilar pela técnica da janela lateral previamente à reabilitação com prótese suportada por implantes dentários, destacando a importância do planejamento para minimizar complicações transoperatórias. Esse é um relato de caso clínico de um paciente do sexo masculino, 59 anos de idade, assistido em uma Instituição de Ensino Superior Privada, com queixa de espaços edêntulos e desejo de reabilitação com implantes. Foi submetido ao planejamento reabilitador incluindo o tratamento cirúrgico de levantamento de seio maxilar bilateral pela técnica da janela lateral. O ganho ósseo foi confirmado pela tomografia computadorizada de feixe cônico após seis meses da abordagem cirúrgica do seio maxilar bilateralmente. O planejamento reabilitador da região posterior da maxila e a execução da cirurgia de levantamento de seio pela técnica da janela lateral de maneira criteriosa consiste em uma opção terapêutica previsível para os casos clínicos com necessidade de ganho ósseo em altura previamente à instalação de implantes dentários. O caso clínico apresentado demonstrou sucesso no ganho de volume ósseo na região posterior de maxila, sem complicações pós-operatórias e o paciente segue satisfeito com o tratamento proposto, aguardando conclusão da reabilitação implantossuportada.

Posterior rehabilitation using 3D-printed dental implants and synthetic regenerative biomaterials / Reabilitação posterior com implantes impressos e biomateriais sintéticos

Aim: To describe through a clinical case report the surgical sequence of rehabilitation with 3D-printed implants associated with maxillary sinus floor lift with synthetic regenerative materials, including biphasic bioceramic. Case Report: Patient had an agenesis of the upper left premolars (#12 and #13), a vertical bone deficiency caused by maxillary sinus' pneumatization, and a horizontal alveolar resorption around the missing teeth area. During the surgical procedures, incisions, detachment, and osteotomy were performed in the lateral region of the maxillary sinus. The sinus membrane was detached and lifted 10 mm. Then, a thick poly(dioxanone)-based synthetic resorbable membrane (Plenum) was inserted and adapted inside the sinus to protect the sinus membrane. After the osteotomies with sub-instrumentation, 3D-printed implants (Plenum) were installed in the #12 area (3.5mm x 11.5 mm; 30N) and #13 area (4.0mm x 10mm; 20N). The maxillary sinus was entirely filled with a biphasic bioceramic, HA/ß-TCP (70:30) 500-1000 µm (Plenum) and covered by the same synthetic resorbable membrane. Connective tissue graft from the palatal area was positioned internally to the flap and stabilized with sutures to improve the vestibular tissue architecture. The entire surgical wound was sutured, and the tissues stabilized. No complications occurred in the postoperative period. Conclusion: The use of synthetic regenerative memberane and 3D-printed implants seems to be a promising option in areas of deficient bone remnants (AU)

Objetivo: Descrever por meio de um relato de caso clínico a sequência cirúrgica de reabilitação com implantes obtidos por impressão 3D associados à elevação do assoalho do seio maxilar com materiais regenerativos sintéticos, incluindo uma biocerâmica bifásica. Relato de Caso: Paciente apresentava agenesia dos pré-molares superiores esquerdos (24 e 25), deficiência óssea vertical causada pela pneumatização do seio maxilar e reabsorção alveolar horizontal ao redor da área dos dentes ausentes. Durante os procedimentos cirúrgicos foram realizados incisões, descolamento e osteotomia na região lateral do seio maxilar. A membrana sinusal foi descolada e elevada 10 mm. Em seguida, uma membrana reabsorvível sintética à base de poli(dioxanona) espessa (Plenum) foi inserida e adaptada dentro do seio para proteger a membrana do seio. Após as osteotomias com subinstrumentação, implantes impressos em 3D (Plenum) foram instalados na área do 24 (3,5mm x 11,5mm; 30N) e na área do 25 (4,0mm x 10mm; 20N). O seio maxilar foi inteiramente preenchido com biocerâmica bifásica, HA/ß-TCP (70:30)500-1000 µm (Plenum) e recoberto pela mesma membrana sintética reabsorvível. O tecido conjuntivo da região palatina foi posicionado internamente ao retalho e estabilizado com suturas para melhorar a arquitetura do tecido vestibular. Toda a ferida cirúrgica foi suturada e os tecidos estabilizados. Não ocorreram complicações no pós-operatório. Conclusão:A utilização de biomateriais regenerativos sintéticos e implantes impressos parece ser uma opção promissora em áreas de remanescentes ósseos deficientes.(AU)

Short vs standard implants associated with sinus floor elevation: a randomized controlled trial / Implantes curtos versus implantes convencionais associados à elevação do seixo maxilar: um ensaio clínico randomizado

Objective: the present equivalence two-arm parallel randomized controlled trial aimed to compare survival and marginal bone loss (MBL) of short implants (≤6 mm) and standard implants (≥8.5 mm) associated with sinus floor elevation (SFE). Methods: adult patients with partial edentulism with occlusal stability in the sinus area and intermediate bone height were selected in this double-blind trial (patient and outcome assessment). Patients were randomly allocated into two groups: standard length implants with SFE (control) or short implants (test). Clinical and radiographic assessments were made at the time of implant placement, 6 months, and annually thereafter up to 2 years after loading. The inter-examiner agreement was analyzed using intraclass correlation coefficient (ICC). One-way ANOVA, Kaplan-Meier, and Log-rank tests were used to compare implant survival (primary outcome) and MBL (secondary outcome) (P<0.05). Results: eight short implants and six standard implants were placed (mean age of patients was 47 ±12.5 years). The implant survival rates were 87.5% for short (one 5 mm implant failed at 7 months) and 100% for standard implants with no statistically significant difference between groups (P=0.4). The mean MBL after 1 year was 0.30 ±0.62 mm for short and 0.21 ±0.36 mm for standard implants (P=0.123). The inter-examiner agreement was set in 0.831. Conclusion: survival of short implants and standard implants associated with SFE was similar after two years of clinical service. Trial registration: Registered on 27-03-2018 at ClinicalTrials.gov (NCT03479333). Funding: This study was partially funded by Capes Finance Code 001 and #88881.187933/2018-01. TPC is partially funded by National Council for Scientific and Technological Development (CNPq - Brazil). The funders had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript.(AU)

Objetivo: o presente ensaio clínico randomizado de dois braços de equivalência comparou a taxa de sobrevivência e a perda óssea marginal de implantes curtos (≤ 6 mm) e implantes convencionais (≥ 8.5 mm) associados à elevação do seio maxilar. Métodos: edêntulos parciais adultos, com estabilidade oclusal e altura óssea intermediária na região do seio maxilar, foram selecionados neste estudo duplo-cego e alocados randomicamente em dois grupos: implante de comprimento convencional associado à elevação do seio maxilar (controle) ou implante curto (teste). Avaliações clínicas e radiográficas foram realizadas logo após a instalação do implante, seis meses e anualmente por até dois anos. A concordância interexaminador foi avaliada através do coeficiente de correlação intraclasse. Os testes ANOVA de uma via, Kaplan-Meier e Log-rank foram utilizados para comparar a sobrevivência do implante e a perda óssea marginal (P<0.05). Resultados: oito implantes curtos e seis implantes de comprimento convencional foram instalados em onze pacientes (média de idade dos pacientes: 47 ± 12.5 anos). As taxas de sobrevivência dos implantes foram de 87,5% para implantes curtos (um implante de 5 mm falhou aos sete meses), e 100% para implantes convencionais, sem diferença estatisticamente significativa entre os grupos (P=0.4). A perda óssea marginal média após um ano foi de 0.30 ±0.62 mm para implantes curtos e 0.21 ±0.36 mm para implantes convencionais (P=0.123). A concordância interexaminador foi de 0.831. Conclusão: a taxa de sobrevivência de implantes curtos e convencionais associados ao seio maxilar foi semelhante após dois anos de acompanhamento. Registro do estudo: Registrado em 27-03-2018 no ClinicalTrials.gov (NCT03479333).(AU)

Retrospective study on the merits of bone grafts and the influence of implant protrusion length after osteotome sinus elevation surgery / 华西口腔医学杂志

OBJECTIVES@#This study aims to evaluate the endo-sinus bone remodeling of dental implants placed via osteotome sinus floor elevation (OSFE) after 6 months and using different implant protrusion lengths and bone grafts through cone beam computed tomography (CBCT).@*METHODS@#Ninety-six patients with 124 implants were included and assigned into four groups. Group 1: implant protrusion length4 mm with bone graft; group 3: implant protrusion length4 mm without bone graft. Apical bone gain (ABG), cortical bone gain (CBG), bone density gain (BDG), and marginal bone loss (MBL) were observed and analyzed at baseline and 6 months after implant surgery.@*RESULTS@#The CBG in grafted groups 1 and 2 was higher than that in non-grafted groups. The ABG and BDG were higher in non-grafted groups 3 and 4 than in grafted groups, and the levels in group 3 were higher than those in group 4. The CBG in grafted group 2 was higher than that in group 1. No significant difference was observed in MBL analysis.@*CONCLUSIONS@#The BDG of IPL4 mm implant when bone grafts were not applied. No relevance was observed between IPL and CBG. Bone grafts can accelerate endo-sinus bone remodeling by increasing CBG and dissipating the influence of IPL on BDG.

A study of the maxillary sinus lateral wall thickness using cone-beam CT / 口腔疾病防治

Objective@#To investigate the relationship between the thickness of the lateral wall of the maxillary sinus and patient age and sex at different tooth sites to provide a reference for sinus floor elevations.@*Methods @#Cone-beam CT（CBCT） imaging data were collected from 222 patients admitted to the Department of Stomatology, the First Hospital of Shanxi Medical University, from March 2020 to October 2020. The thicknesses of the maxillary sinus lateral wall of the first premolar, second premolar, first molar and second molar were observed and measured on the coronal plane of CBCT images, and the relationship between the maxillary sinus lateral wall thickness and patient sex was analyzed. The patients were divided into the following groups according to their age: ①the young group (18~29 years old), ②the middle-aged group (30~59 years old), and ③the elderly group (≥ 60 years old). The difference in the maxillary sinus lateral wall thickness was compared among these three age groups@*Results@#The mean thicknesses of the maxillary sinus lateral wall at the first premolar, second premolar, first molar and second molar were （1.61 ± 0.58） mm, （1.68 ± 0.66） mm, （2.00 ± 0.76） mm and （1.71 ± 0.71） mm, respectively. The maximum thickness of the lateral wall was located at the first molar (P< 0.05). The thickness of the maxillary sinus lateral wall in the young group was significantly thicker than that in the middle-aged group and the elderly group at the first premolar and first molar (P < 0.05). The thickness of the maxillary sinus lateral wall in males was significantly thicker than that in females at the second molar [(1.78 ± 0.80) mm vs. (1.63 ± 0.62) mm, P=0.029].@*Conclusion@#The mean thickness of the lateral wall changes at different reference points. The maxillary sinus lateral wall is the thickest at M1. The thickness of the maxillary sinus lateral wall decreased with age, and the thickness of the lateral wall was higher in males than in females.

The new bone formation in human maxillary sinuses using two bone substitutes with different resorption types associated or not with autogenous bone graft: a comparative histomorphometric, immunohistochemical and randomized clinical study

Abstract Objective The aim of this study is to evaluate the new bone and connective tissue formation and the biomaterial remaining after maxillary sinus bone augmentation using 5 different bone substitutes. The osteocalcin immunolabeling was performed to demonstrate their calcification and the possibility of receiving dental implants. Methodology 40 patients underwent maxillary sinus bone augmentation and were divided in 5 groups: Group 1 with 8 maxillary sinuses were grafted with autogenous bone graft (AB); Group 2 with 8 maxillary sinuses grafted with bioactive glass (BG); Group 3 with 8 maxillary sinuses grafted with bioactive glass added to autogenous bone graft (BG + AB) 1:1; Group 4 with 8 maxillary sinuses grafted with Bio-Oss (BO) and Group 5 with 8 maxillary sinuses grafted with Bio-Oss added to autogenous bone graft (BO + AB) 1:1. Results In group AB, 37.8% of bone was formed in the pristine bone region, 38.1% in the intermediate and 44.5% in the apical region. In group BG, 43.6% was formed in the pristine bone, 37% in the intermediate and 49.3% in the apical region. In group BG + AB 1:1, 39.0% was formed in the pristine bone region, 34.8% in the intermediate and 36.8% in apical region. In group BO, 33.4% was formed in the pristine bone, 32.5% in the intermediate and 34.3% in the apical region. In group BO + AB 1:1, 32.8% was formed in the pristine bone, 36.1% in intermediate and 27.8% in the apical regions. The immunolabeling for osteocalcin showed an intensive staining for all groups, which could demonstrate the calcification of the bone formed. Conclusion This study showed that the groups evaluated formed a suitable lamellar bone in the maxillary sinus reconstruction after six months of bone healing, thus being indicated to receive dental implants.

Complicaciones quirúrgicas de la elevación de seno maxilar en implantología / Surgical Complications Associated to Maxillary Sinus Floor Elevation in Implantology

RESUMEN La elevación de piso de seno maxilar ha sido sumamente documentada en implantología como una técnica segura y predecible en el procedimiento de ganancia vertical ósea, en el maxilar posterior atrófico. Sin embargo, conjuntamente se han reportado complicaciones en este procedimiento, las cuales podrían poner en peligro los resultados de la regeneración, y por consiguiente la colocación del implante. El propósito de esta revisión de literatura es exponer y analizar diferentes complicaciones que pueden presentarse en la elevación de piso de seno maxilar.

ABSTRACT Maxillary sinus floor elevation has been extensively documented as a safe and predictable procedure for gaining vertical bone height in the atrophic posterior maxilla. Even though, complications have been reported, which can potentially jeopardize the outcome of the regeneration and implant therapy. Therefore, the purpose of this literature review is to present, debate and analyze the different complications that can occur during a sinus floor elevation.

Clinical guidelines for maxillary sinus floor elevation with sinus membrane lesions / 口腔疾病防治

@#Maxillary sinus membrane lesions have been broadly detected before implant surgery in the posterior maxilla region, resulting in uncertainty regarding maxillary sinus floor elevation surgery. In this context, we composed this commentary article based on the current literature and the clinical experience of our department. We discuss the common lesion types shown by CBCT including membrane pathological thickening, polyps/cystic lesions and air-liquid level in the sinus. Maxillary sinus floor elevation surgery can be conducted in patients with membrane thickening of 2-5 mm or with polyps/cysts of less than half of the sinus height (because the above symptoms have little influence on the outcome of surgery). Membrane thickening of more than 5 mm with ostium obstruction, antrochoanalpolyps, mucoceles and cysts of more than half of the sinus height should be carefully treated. Different treatments can be performed such as conducting elevation surgery while retaining the cyst, removing the cyst before surgery or removing the cyst during surgery based on the cyst type and size, inflammation, patency of the ostium, etc. Antibiotics-anti-inflammatory-aspiration, surgical debridement and oral lesions eliminations are generally used for treating post-operative sinusitis. Presurgical radiographic evaluation is the key to diagnosing and treating these membrane lesions. We highly advocate collaboration between our dentists and otolaryngologists on this issue.

Retrospective study on transcrestal sinus floor elevation with simultaneous implantation of short implants / 华西口腔医学杂志

OBJECTIVE@#To explore the changes in bone height of the maxillary sinus floor at different sinus ridge heights after transcrestal sinus floor elevation (tSFE) with the simultaneous implantation of short implants.@*METHODS@#A total of 74 Bicon short implants were implanted into 37 patients during the same period of maxillary sinus elevation. The residual bone height (RBH)<4 mm group has 43 sites, and the RBH≥4 mm group has 31 sites. After 5 years of follow-up observation, the implant survival rate and the change in bone height achieved in the maxillary sinus over time were measured and analyzed via clinical examination and X-ray imaging.@*RESULTS@#In the 74 implantation sites, the elevation height of the sinus floor was (6.64±1.32) mm and the bone height of the sinus floor was (3.35±1.29) mm 5 years after loading. No statistical difference was observed in the bone resorption of the implant neck between the RBH<4 mm and RBH≥4 mm groups. Meanwhile, a statistical difference was noted in the bone height obtained in the maxillary sinus between the two groups.@*CONCLUSIONS@#When RBH in the maxillary posterior tooth area was <4 mm, the simultaneous implantation of Bicon short implants with tSFE can achieve a high implant survival rate and bone gain in the maxillary sinus, but does not increase the absorption of the alveolar ridge bone.

Effect of anatomical parameters of maxillary sinus on the outcomes of transcrestal sinus lift / 华西口腔医学杂志

OBJECTIVE@#To investigate the effect of three anatomical parameters (maxillary sinus width, maxillary sinus angle, and residual bone height) on the outcomes of transcrestal sinus lift with simultaneous implant placement.@*METHODS@#A total of 60 maxillary sinuses in 42 patients were included in this study. All patients were treated with transcrestal sinus lift procedure associated with simultaneous implant placement using a composite graft material of autogenous bone and Bio-Oss. For each patient, beam computed tomography (CBCT) scans were performed preoperatively, immediately after surgery, and 6 months after surgery. The parameters were measured on the preoperative and postoperative CBCT images. The correlation of three anatomical parameters with graft resorption was analyzed using Pearson's correlation test.@*RESULTS@#The average residual bone height was (4.46±1.55) mm. The average width of maxillary sinus was (13.86±2.71) mm. The average sinus angle was 78.09°±10.27°. A significant positive correlation was observed between maxillary sinus width and graft resorption (P<0.01). A positive association was also found between sinus angle and graft resorption (P<0.01).@*CONCLUSIONS@#The findings show that graft bone resorption in elevated sinus has a positive correlation with the sinus width and sinus angle.

Radiography study on osteotome sinus floor elevation with placed implant simultaneously with no graft augmentation / 北京大学学报(医学版)

OBJECTIVE@#To investigate the change of endo-sinus bone height and bone volume in osteotome sinus floor elevation (OSFE) without bone graft but placing implants simultaneously by using cone beam computed tomography (CBCT) and three dimensional analysis, and to find the impacting factors on endo-sinus bone augmentation.@*METHODS@#OSFE was performed in 38 edentulous patients with missing teeth at posterior maxillary region, and 44 implants were placed and referred for OSFE using no graft materials. CBCT was performed pre-surgery and 9－68 months post-surgery when the patients encountered another implant surgery. The gained bone height at mesial, distal, buccal and palatal sites around the implant in sinus were measured, volumetric measurements of the endo-sinus gained bone volume (ESGBV) in the elevated region were calculated by Mimics software. Univariate analysis and multiple linear regression were performed to investigate the impacting factors on the gained bone height and ESGBV. Marginal bone loss was recorded according to the periapical radiography after implant restoration.@*RESULTS@#The mean residual bone height (RBH) pre-surgery was (3.41±1.23) mm, the mean protruded length (PL) into sinus of implant post-surgery was (3.41±1.28) mm, the mean endo-sinus gained bone height was (2.44±1.23) mm at distal sites, (2.88±1.20) mm at mesial sites, (2.83±1.22) mm at buccal sites and (2.96±1.16) mm at palatal sites, the mean endo-sinus gained bone height at distal sites was significantly lower than the other three sites (P < 0.05). The average endo-sinus gained bone height was (2.78±1.13) mm. The mean ESGBV was (122.15± 73.27) mm3. Univariate analysis showed the more RBH, the less bone height gained in sinus, which existed at buccal, lingual, mesial and distal sites (P < 0.001), and the more RBH, the smaller ESGBV gained (P=0.012). The ESGBV was significantly higher in the subjects whose bone generation period was more than 24 months than those whose bone generation period less than 24 months (P=0.034). The more PL, the more bone height and ESGBV gained (P=0.008). Multivariate analysis showed after adjusting factors of gender, age, smoking, width of sinus floor, thickness of sinus membrane pre-surgery, diameter and length of the implant, PL and bone generation period was positively correlated with mean endo-sinus gained bone height and ESGBV, while RBH negatively correlated with mean endo-sinus gained bone height. During the follow-up, the mean marginal bone loss was 0 (0－1.41) mm and all the implants loaded successfully.@*CONCLUSION@#OSFE without bone graft but with placed implant simultaneously can increase endo-sinus gained bone height and ESGBV. RBH, PL and bone generation period are the significant factors impacting endo-sinus bone augmentation.

The role of the membrane of the maxillary sinus in space osteogenesis under the sinus floor after elevation of the sinus floor / 口腔疾病防治

@#With the continuous development of maxillary sinus floor elevation technology, the osteogenesis mechanism of maxillary sinus floor elevation has always been a concern of scholars. The membrane of the maxillary sinus is an indispensable physiological structure in the process of space osteogenesis under the sinus floor after elevation of the sinus floor. In recent years, the role of the maxillary sinus floor mucosa in sinus floor space osteogenesis has been a research hotspot. Recent studies have found that the maxillary sinus floor membrane plays a role as a natural biological barrier membrane in the process of sinus floor space osteogenesis after maxillary sinus floor elevation; in addition, it has the ability to undergo osteogenesis. It has also been found that maxillary sinus membrane stem cells (MSMSCs) derived from the maxillary sinus floor membrane have characteristics of mesenchymal stem cells, which can differentiate into osteoblasts and participate in sinus floor space osteogenesis after maxillary sinus floor elevation. New studies have also found that small RNAs such as microRNAs, long noncoding RNAs and circular RNAs can regulate the osteogenic differentiation of MSMSCs, which may be important biological targets for promoting osteogenesis in the sinus floor space. In this paper, the relationship between the maxillary sinus floor mucosa and bone formation after maxillary sinus floor elevation, the barrier and osteogenic function of the maxillary sinus floor mucosa, the sources of osteoblasts involved in osteogenesis of the sinus floor space, and the molecular regulatory mechanisms of stem cells derived from maxillary sinus mucosa will be elucidated step by step.