Prevalence and extent of Alveolar dehiscence and fenestration in Class I hyperdivergent subjects with different buccolingual inclinations of maxillary molar teeth: a CBCT study

Buccolingual position of teeth could affect the prevalence of alveolar bone defects. Presence of alveolar defects may have a deleterious effect on orthodontic treatment. The aim was to assess the prevalence and extent of dehiscence and fenestration in Class I hyperdivergent subjects and correlate it with buccolingual inclinations(BL) of maxillary first molar teeth. Methods: This retrospective study involved 80 CBCTs of class I hyperdivergent subjects divided into two groups - group A (n=33) buccolingual inclination >9º and group B (n=47) buccolingual inclination <9º. Prevalence and extent of alveolar bone dehiscence and fenestrations were measured in CBCTs using OSIRIX Lite software. Descriptive statistics, Mann Whitney U test and Spearman correlation were done for evaluating intergroup differences and correlation with Buccolingual inclination. Results: Overall prevalence of dehiscence and fenestration in maxillary first molars was 60.95% and 5% respectively. In the buccal alveolar bone, prevalence of dehiscence was highest in group A (84.6%) for 16 and in the lingual alveolar bone prevalence of dehiscence was highest in group B (71.4%) for 26 . On intergroup comparison, the extent of lingual alveolar bone dehiscence (26) in group B was significantly higher (p value <0.05) than in group A. No significant correlation between the extent of dehiscence and fenestration with buccolingual inclination of molar teeth was noted. Conclusion: Molar teeth with BL inclinations of more than 9º had higher prevalence of dehiscence on the buccal side and molar teeth with BL inclinations less than 9 degrees had more dehiscence on the lingual side. But no significant correlation of BL inclination with prevalence and extent of dehiscence and fenestration was noted

Effect of dental follicles in minimally invasive open-eruption technique of labially impacted maxillary central incisors / 华西口腔医学杂志

OBJECTIVES@#To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles.@*METHODS@#Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy.@*RESULTS@#A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05).@*CONCLUSIONS@#In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.

Alveolar bone loss with microarchitecture changes in aged rat / Pérdida ósea alveolar con alteraciones en la microarquitectura en ratas envejecidas

SUMMARY: The aim of the present study was to evaluate the changes of alveolar bone in aged rats. The mandibles of the 4- month and 22-month aged rats were scanned by micro-CT. After the reconstruction of the alveolar bone,the distance between the cemento enamel junction (CEJ) and the alveolar bone crest (ABC) was measured. The micro architectures of the inter-radicular alveolar bone were analyzed. The 22-month rats experienced the reduction in alveolar crest height in the buccal side and the lingual side, and significant increase in alveolar bone loss compared with the 4-month rats. The 22-month rats had a porous microarchitecture, the trabecular arrangement was obviously dissociated with the expanded inter-bone spaces of marrow, and the bone histomorphometry analysis showed the decreased bone volume/tissue volume and trabecular thickness in the 22-month rats. These results suggest that alveolar bone loss and alveolar trabecular bone deterioration might contribute to the weakening of molar support in the elderly.

RESUMEN: El objetivo del presente estudio fue evaluar los cambios del hueso alveolar en ratas envejecidas. Las mandíbulas de las ratas de 4 y 22 meses se escanearon mediante micro-TC. Después de la reconstrucción del hueso alveolar, se midió la distancia entre la unión cementoesmalte (CEJ) y la cresta ósea alveolar (ABC). Se analizaron las microarquitecturas del hueso alveolar interradicular. Las ratas de 22 meses experimentaron la reducción de la altura de la cresta alveolar. en el lado bucal y lingual, y un aumento significativo en la pérdida de hueso alveolar en comparación con las ratas de 4 meses. Las ratas de 22 meses tenían una microarquitectura porosa, la disposición trabecular estaba obviamente disociada con los espacios interóseos expandidos de la médula y el análisis de histomorfometría ósea mostró una disminución del volumen óseo / volumen tisular y del grosor trabecular en las ratas de 22 meses. Estos resultados sugieren que la pérdida ósea alveolar y el deterioro del hueso trabecular alveolar podrían contribuir al debilitamiento del soporte molar en los ancianos.

Prosthetically driven alveolar reconstructions: a retrospective study

Abstract This study aims to evaluate the post-extraction alveolar bone reconstruction amongst 12 patients exhibiting loss of buccal bone plate in a tooth of the anterior region of the maxilla using the prosthetically-driven alveolar reconstruction technique (PDAR). In PDAR, a partial fixed provisional prosthesis (PFPP [conventional or adhesive]) with a specially designed pontic maintains the clot in a mechanically stable position during alveolar regeneration. Moreover, the pontic design, in hourglass shape and located in the subgingival area, also prevents gingival margins from collapsing. Gingival recession was evaluated through the 6-month healing period. Cone beam computed tomography (CBCT) was performed 1 month before and 8 months after PDAR treatment. For the primary outcome, in the panoramic imaging, the central area of bone defect in each tooth was selected for linear measurements. Measurements of the vertical buccal bone gain and the gain in thickness in the alveolar bone crest were obtained 8 months after PDAR. Descriptive statistics and intraclass correlation coefficient analysis were conducted. After treatment, all patients showed bone formation (a mean vertical gain of 7.1±3.7 mm, associated with a horizontal mean gain of 4.5±1.4 mm in the alveolar bone crest). The intraclass correlation coefficient for the measurements performed using CBCT was 0.999. No gingival recession, greater than 1 mm, was observed. Lower-morbidity procedures without the use of biomaterials may be a useful in post-extraction alveolar ridge regeneration and/or preservation. PDAR promoted alveolar bone formation without flaps, grafts and membranes.

Resumo Este estudo teve como objetivo avaliar a reconstrução do osso alveolar após extração em 12 pacientes com perda da tábua óssea vestibular em dentes na região anterior da maxila usando a técnica da reconstrução alveolar proteticamente guiada (RAPG). Na RAPG, uma prótese parcial fixa provisória (PPFP [convencional ou adesiva]) com um pôntico com design específico mantém o coágulo numa posição mecanicamente estável. Além disso, o design do pôntico, com formato de ampulheta e localizado na área subgengival, também previne o colapso das margens gengivais. A recessão gengival foi avaliada durante o período de cicatrização de 6 meses. Tomografias computadorizadas cone beam (TCCB) foram feitas 1 mês antes e 8 meses após o tratamento com a RAPG. Para o desfecho primário, nas imagens panorâmicas, a área central do defeito ósseo em cada dente foi selecionada para as medições lineares. As medições do ganho vertical ósseo vestibular e do ganho em espessura na crista óssea alveolar foram realizadas. A análise estística descritiva e a análise do coeficiente de correlação intraclasse forma realizados. Após o tratamento, todos os pacientes apresentaram formação óssea (ganho vertical médio de 7,1±3,7 mm, associado a ganho horizontal médio de 4,5±1,4 mm na crista óssea alveolar). O coeficiente de correlação intraclasse foi de 0,999. Nenhuma retração gengival acima de 1 mm foi observada. Procedimentos com baixa morbidade sem o uso de biomateriais podem ser úteis na regeneração/preservação do rebordo após as extrações. A RAPG promove a formação do osso alveolar sem o uso de retalhos, enxertos e membranas.

Reabilitação de maxila atrófica com implantes zigomáticos: relato de caso / Rehabilitation of atrophic maxilla with zygomatic implants: case report

Introdução: maxilas severamente atrofiadas representam um desafio às reabilitações implantossuportadas. A reconstrução maxilar com enxertos ósseos para permitir a reabilitação com implantes osseointegrados é um tratamento com boa previsibilidade e alto índice de sucesso. No entanto, a morbidade causada pela necessidade de regiões doadoras e grande quantidade de osso dificulta a aceitação dos pacientes, podendo, inclusive, ser contraindicada dependendo da condição sistêmica. Objetivos: revisar a literatura, discutir as indicações, as complicações, a previsibilidade das reabilitações com implantes zigomáticos, assim como relatar um caso. Relato de caso: os implantes zigomáticos surgiram como uma alternativa para a reabilitação de pacientes maxilectomizados, decorrente da exérese de tumores, perdas ósseas decorrentes de infecções ou traumas, e casos de atrofia óssea severa, como abordado no caso em questão, em que a paciente apresentava edentulismo total em maxila e não gostaria mais de utilizar a prótese convencional, optando pela prótese sobre implante. Considerações finais: a reabilitação com implantes zigomáticos pode apresentar complicações, como o mau posicionamento dos implantes, comprometendo a reabilitação; todavia, apesar das restrições da técnica, a literatura mostra que os implantes zigomáticos, quando bem indicados, representam uma boa alternativa para a reabilitação de maxilas severamente atrofiadas.(AU)

Introduction: severely atrophied jaws pose a challenge to implant-supported rehabilitations. Maxillary reconstruction with bone graft to allow rehabilitation with implants is a treatment with good predictability and high success rate. However, a morbidity is the disease of the donor regions and the greater amount of bone hinders the acceptance of the patients; including, to be contraindicated depending on the systemic condition. Objectives: this article is a review of the literature, such as the indications, complications, predictability of rehabilitations with zygomatic implants, as well as a case report. Case report: the zygomatic implants appeared as an alternative for the rehabilitation of maxilectomized patients, due to the excision of tumors, bone losses due to infections or trauma and cases of severe bone atrophy, as approached in the case in question, in which the patient had total maxillary edentulism and would no longer like to use the conventional prosthesis, opting for the implant prosthesis. Final considerations: rehabilitation with zygomatic implants may present complications, such as poor placement of implants, compromising rehabilitation; however, despite the limitations of the technique, the literature shows that zygomatic implants, when well indicated, represent a good alternative for the rehabilitation of severely atrophied maxilla.(AU)

Prevalence of horizontal alveolar changes in edentulous patients: a retrospective tomographic study

Abstract Horizontal bone loss after tooth extraction is a common finding that demands bone reconstruction in various cases. The aim of this study was to assess the horizontal alveolar status in partially and completely edentulous patients using cone-beam computed tomography (CBCT). In total, 1516 CBCT scans of 1404 adult patients were analyzed. Assessment of the images was performed in accordance with the previously published horizontal alveolar change (HAC) classification, which categorizes horizontal bone defects into four classes: HAC 1, HAC 2, HAC 3 and HAC 4 (from the least severe to the most severe condition). Analysis of 1048 scans from partially edentulous patients presented a distribution of 63.55%, 22.14%, 13.36% and 0.95% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Analysis of 468 scans from completely edentulous patient images presented a distribution of 19.87%, 28.63%, 41.67% and 9.83% in HAC 1, HAC 2, HAC 3 and HAC 4, respectively. Based on these results, as in HAC 4, no cancellous bone was found between the cortical buccal and lingual/palatal bone plates, it seems reasonable to state that the absence of cancellous bone is higher in completely edentulous patients than in partially edentulous patients. Therefore, the absence of cancellous bone seems to be higher in completely edentulous than in partially edentulous patients.

Relação entre reabsorções dentárias e enxerto alveolar em dentes adjacentes à área da fissura / Relationship between root resorption and alveolar graft in teeth adjacent to the cleft lip and palate area

Objetivo: avaliar, radiograficamente, a prevalência, extensão e severidade da reabsorção dentária em dentes adjacentes à área de fissura após enxerto ósseo alveolar. Métodos: radiografias de 200 indivíduos com fissura unilateral e bilateral, alveolar e palatina, foram analisadas para se investigar a presença de reabsorção dentária relacionada com o enxerto ósseo. No total, 1.315 radiografias foram analisadas (periapical, oclusal e radiografias panorâmicas), obtidas a partir de 200 indivíduos com fissura labiopalatina unilateral e bilateral completa ubmetidos a cirurgia de enxerto, disponíveis a partir dos arquivos da Seção de Radiologia do HRAC-USP. Resultados: entre os 200 indivíduos, 33 tinham reabsorções dentárias externas. Dessas, 15 estavam presentes nas radiografias pré-operatórias e 18 só depois do enxerto ósseo. No geral, 30 reabsorções localizaram- se no terço apical da raiz e 3 no terço cervical; o incisivo central esquerdo foi o mais afetado. Não foram observadas reabsorções dentárias no terço médio da raiz e nenhuma reabsorção afetou mais de um terço. Não existiu diferença estatisticamente significativa entre a idade do paciente durante a cirurgia de enxerto ósseo e a presença de reabsorção dentária externa. Conclusões: a prevalência da reabsorção dentária em dentes adjacentes à área da fissura em indivíduos submetidos a enxerto ósseo foi baixa (16,5%). O terço apical da raiz foi o local mais frequente de reabsorção radicular externa, e não houve reabsorções afetando mais de um terço da raiz. (AU)

Comparing osteogenic effects between concentrated growth factors and the acellular dermal matrix

Abstract Concentrated growth factor (CGF) is an autogenuous product that contains highly concentrated number of platelets and can be derived from venous blood by selective centrifugation. It has been speculated that local growth factors in human platelets (insulinlike growth factor, IGF; transforming growth factor, TGF-b; platelet derived growth factor, PDGF) would enhance healing of grafts and also counteract resorption. The osteogensis effect of CGF and acellular dermal matrix (ADM) for alveolar cleft defects was evaluated in this study. Twenty alveolar cleft patients were divided randomly into two groups. One group underwent guided bone regeneration (GBR) using acellular dermal matrix film combined with alveolar bone grafting using iliac crest bone grafts (GBR group), while the other group underwent alveolar bone grafting combined with CGF (CGF group). Cone beam computed tomography (CBCT) images were obtained at 1 week and 6 months following the procedure. Using Mimics 17.0 software, the bone resorption rate and bone density improvement rate were calculated and compared between the two groups. Although not significant between ADM and CGF in bone resorption rate, the bone density improvement in cases with CGF(61.62 ± 4.728%) was much better than in cases with ADM (27.05 ± 5.607%) (p = 0.0002). Thus, CGF could be recommended to patients with alveolar cleft as a better choice.

Maxillary sinus floor pneumatization and alveolar ridge resorption after tooth loss: a cross-sectional study

Abstract This is a cross-sectional study that aimed to estimate maxillary sinus floor (MSF) pneumatization in single missing tooth of posterior maxilla, by using cone-beam computed tomography (CBCT). CBCT images were analyzed bilaterally and divided into 2 groups: edentulous site (EdS) - edentulous single region of upper second premolar, first or second molars; Tooth site (TS) - contralateral region homologous to the EdS region, with tooth present. Variables evaluated were: sinus height (SH), estimated sinus pneumatization (eSP: ∆ EdS - TS), healed ridge height (HR) and presence of localized sinus pneumatization (LSP) in molars teeth at TS. HR were categorized according to therapeutic option for posterior maxilla. 183 CBCT scans were included and it was observed that EdS presented a higher SH than the TS (p < 0.001) showing an eSP of 0.9 ± 2.93 mm. First molars presented the highest SH for both sides, although significant differences were detected when compared to second molars. First molars were mostly affected by LSP at TS (36 out of 43). Individuals with LSP at TS presented lower HR than the ones without LSP (p < 0.05). 54% of the cases presenting LSP obtained HR < 5 mm, which indicates sinus lift surgery. The present study showed that tooth loss in posterior maxilla favors sinus pneumatization and the identification of LSP at molar roots seems to indicate a greater necessity for sinus lift surgeries.

Evaluation of using cone beam computed tomography as a regular test before and after periodontal regenerative surgery / 北京大学学报(医学版)

OBJECTIVE@#To test the accuracy and credibility of cone-beam computed tomography (CBCT) on measuring the height and volume of alveolar bone defects before periodontal regeneration surgery. By comparing the bone density measured by CBCT before and after the operation, the time to evaluate the efficacy of the periodontal regenerative surgery would be determined.@*METHODS@#Periodontal regenerative surgeries were performed on three-wall bone defects of ten teeth in nine patients. The height of bone defects was measured using both periapical film of distant parallel technique and CBCT before periodontal regenerative surgery. Before the surgery, CBCT data were used to measure the volume of the bone defects and the bone density around the defective areas. The height of the bone defects was measured during periodontal regeneration surgery, and the volume of the defective areas was obtained with bone wax in operation. CBCT was taken 6, 12 and 24 weeks after surgery to measure the bone density in the regenerated region.@*RESULTS@#The Wilcoxon test showed that the height of the bone defects measured preoperatively using periapical film was (0.822±0.222) mm deeper than the intraoperative measurement results, and the difference was statistically significant (P<0.05). Whereas CBCT measurement results was (0.150±0.171) mm less than the intraoperative measurement results, without statistical significant (P>0.05). The regression analysis and the Bland-Altman method also showed that the results of CBCT measurement were more accurate. The Wilcoxon test showed that the bone defect volume measured by CBCT preoperatively was accurate, and the difference between the preoperative and the intraoperative measurements was not statistically significant, ranging from 0.38 to 2.83 mm3 (P>0.05). The bone density of the regenerated areas measured by CBCT was (0.49±0.03) times in the sixth week, (0.74±0.09) times in the twelfth week and (1.16±0.11) times in the twentieth week as that of the areas around the bone defects after the surgery.@*CONCLUSION@#The present data suggest that using CBCT before periodontal regenerative surgery could result in accurate measurement of height and volume of alveolar bone defects. For the purpose of evaluating the effectiveness of regenerative surgery, CBCT could be taken 24 weeks after surgery.

Accuracy analysis of alveolar dehiscence and fenestration of maxillary anterior teeth of Angle class III by cone-beam CT / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the accuracy and reliability of detecting alveolar bone dehiscence and fenestration of maxillary anterior teeth of Angle class III by cone-beam computed tomography (CBCT).@*METHODS@#Eighteen Angle class III patients with 108 maxillary anterior teeth were included (3 males and 15 females) who accepted modified corticotomy in orthodontic therapy. The mean age was 23.6 years (18-30 years). The clinical detection of dehiscence and fenestration was done when modified corticotomy was performed by the same periodontist. The CBCT examination was conducted pre-operation and the detection of dehiscence and fenestration by CBCT was done by two periodontists. The data in modified corticotomy were used as the golden standard to calculate the parameters, such as sensitivity, specificity, positive and negative predictive values, Youden index (YI), positive and negative likelihood ratio. Kappa statistic was used to analyze the agreement between the clinical detection and the CBCT detection.@*RESULTS@#The incidence of dehiscence and fenestration was about 10.19% and 13.89% respectively, which mainly occurred on lateral incisors and canines. The median values of length and width of dehiscence were about 5 mm and 4 mm, and the median values of length and width of fenestration were 3 mm and 2 mm, respectively. Most fenestrations were detected on the middle third to the apical third of the root. For dehiscence, the agreement between clinical detection and CBCT detection was statistically significant (P<0.05). For fenestration, the agreement between clinical detection and CBCT detection was statistically significant (P<0.05). The values of sensitivity and specificity for detecting dehiscence were more than 0.7. The values of positive and negative predictive values for detecting dehiscence were 0.44 and 0.97. The values of sensitivity and specificity for detecting fenestration were 0.93 and 0.52. The values of positive and negative predictive values for detecting fenestration were 0.24 and 0.98.@*CONCLUSION@#For dehiscence, the agreement between clinical detection and CBCT detection was good. For fenestration, the agreement between clinical detection and CBCT detection was general. Detection of dehiscence and fenestration of maxillary anterior teeth of Angle class III by CBCT had limited diagnostic value in clinical practice with overestimation of dehiscence and fenestration incidence.

Treatment of endo-periodontal lesion using leukocyte-platelet-rich fibrin. A case report / Tratamiento de una lesión endoperiodontal utilizando fibrina rica en plaquetas y leucocitos. Un reporte de caso

Abstract Case Description: The main objective of this paper was to report the clinical effectiveness of leukocyte- platelet- rich fibrin (L-PRF) in the treatment of a combined endo-periodontal lesion of an upper first premolar. Clinical Findings: The tooth had a profound abfraction on the vestibular aspect and presented no mobility but revealed a deep pocket measuring of 11 mm on the mesial vestibular aspect and 14 mm on the mesial palatine aspect. The three dimensional image analysis showed total bone loss in the mesial aspect and an extensively bone loss of the vestibular aspect of the vestibular root. Treatment and Outcome: Endodontic treatment was performed and periodontal access surgery (surgical periodontal therapy) was done with the application of autologous L-PRF. Three month and 6 months after surgery, the cone beam computed tomography (CBCT) exams showed no bone regeneration in any aspect of the tooth. However, periodontal examination showed a significative improvement in the deepness of surcus. The mesial vestibular aspect had a deep pocket of 3 mm and 5 mm on the mesial palatine aspect showing a reduction in deepness of 8 mm and 9 mm, respectively. Clinical Relevance: The actual treatment for teeth with bad prognosis is the extraction and replacement with implants. Even though implants are capable of restore function and aesthetic, the abuse of this approach have led to the loss of teeth that could be successfully treated with a less invasive technique. The prognosis of teeth with endoperiodontal lesion is poor but could be enhanced with regenerative therapies. Until now there are no clinical trials and just four case report about the treatment of these teeth with platelet rich fibrin.

Resumen Descripción del caso: El objetivo de este artículo fue reportar la efectividad clínica del uso de fibrina rica en plaquetas y leucocitos (L-PRF) en el tratamiento de una lesión endoperiodontal en un primer premolar superior. Hallazgos clínicos: El diente presentaba una abfracción profunda en la superficie vestibular, sin movilidad, pero reveló una bolsa profunda de 11 mm en la superficie mesio-vestibular y de 14 mm en la superficie palato-mesial. El análisis tridimensional de la imagen mostró una pérdida ósea total en la superficie mesial y una pérdida ósea extensa de la cara vestibular de la raíz. Tratamiento y resultado: Se realizó el tratamiento endodóntico y posteriormente cirugía de acceso periodontal (terapia periodontal quirúrgica) con la aplicación de L-PRF autóloga. Tres meses y 6 meses después de la cirugía, los examenes de Tomografía Computarizada Cone Beam (CBCT) no evidenciaron regeneración ósea en ningún sector del diente. Sin embargo, el examen clínico periodontal mostró una mejora significativa en la profundidad de la bolsa. La superficie mesio-vestibular registró una profundidad de bolsa de 3 mm y 5 mm en la superficie mesio-palatino, mostrando una reducción en la profundidad de 8 mm y 9 mm, respectivamente. Relevancia clínica: El tratamiento actual para los dientes con mal pronóstico es la extracción y el reemplazo con implantes. A pesar de que los implantes son capaces de restaurar función y estética, el abuso de este enfoque ha llevado a la pérdida de dientes que podrían tratarse con éxito con una terapia más conservadora. El pronóstico de los dientes con lesión endoperiodontal es pobre, pero podría mejorarse con el uso de terapias regenerativas. Hasta ahora no hay ensayos clínicos y solo cuatro reportes de casos acerca del tratamiento de estos dientes con fibrina rica en plaquetas y leucocitos.

Peri-implant assessment via cone beam computed tomography and digital periapical radiography: an ex vivo study

OBJECTIVES: This research evaluated detail registration in peri-implant bone using two different cone beam computer tomography systems and a digital periapical radiograph. METHODS: Three different image acquisition protocols were established for each cone beam computer tomography apparatus, and three clinical situations were simulated in an ex vivo fresh pig mandible: buccal bone defect, peri-implant bone defect, and bone contact. Data were subjected to two analyses: quantitative and qualitative. The quantitative analyses involved a comparison of real specimen measures using a digital caliper in three regions of the preserved buccal bone - A, B and E (control group) - to cone beam computer tomography images obtained with different protocols (kp1, kp2, kp3, ip1, ip2, and ip3). In the qualitative analyses, the ability to register peri-implant details via tomography and digital periapical radiography was verified, as indicated by twelve evaluators. Data were analyzed with ANOVA and Tukey's test (α=0.05). RESULTS: The quantitative assessment showed means statistically equal to those of the control group under the following conditions: buccal bone defect B and E with kp1 and ip1, peri-implant bone defect E with kp2 and kp3, and bone contact A with kp1, kp2, kp3, and ip2. Qualitatively, only bone contacts were significantly different among the assessments, and the p3 results differed from the p1 and p2 results. The other results were statistically equivalent. CONCLUSIONS: The registration of peri-implant details was influenced by the image acquisition protocol, although metal artifacts were produced in all situations. The evaluators preferred the Kodak 9000 3D cone beam computer tomography in most cases. The evaluators identified buccal bone defects better with cone beam computer tomography and identified peri-implant bone defects better with digital periapical radiography.

Dehiscences and fenestrations: methodological care necessary to avoid errors in diagnosis and measurement

ABSTRACT The low prevalence of gingival recessions observed in orthodontic clinical practice may be assigned to the fact that in studies in which dehiscences and bone fenestrations are described as frequent, they were diagnosed based on: 1) dry skull studies; 2) areas with periosteal reflection together with flap; and 3) imaging techniques with low sensitivity to detect these defects, which have a delicate structure and function. In areas of pseudo-dehiscences and fenestrations, the periosteum and the alveolar cortical bone are very thin; also, they either have been removed during preparation of the dry specimens in the areas for analysis, or, alternatively, have not been investigated using an ideal imaging method.

RESUMO A ausência de prevalência elevada das recessões gengivais relacionadas à prática clínica ortodôntica se explica, provavelmente, porque, nos trabalhos em que as deiscências e fenestrações ósseas são descritas como frequentes, essas foram diagnosticadas a partir de: 1) estudos em crânios secos; 2) áreas com rebatimento periosteal junto com o retalho; e 3) uso de métodos imagiológicos que falham em sensibilidade para captá-las, pela sua delicadeza estrutural e funcional. Nessas áreas de pseudodeiscências e fenestrações, existe periósteo e cortical óssea alveolar muito fina, que foram eliminados nos procedimentos de preparação dos espécimes secos, nas áreas para a análise ou, então, não se aplicou um método imagiológico ideal.

Agreement, correlation, and kinetics of the alveolar bone-loss measurement methodologies in a ligature-induced periodontitis animal model

Abstract Periodontal research involves the use of animal models to better understand the biological processes of periodontal diseases and the potential of new or existing therapies. Currently, ligature-induced periodontitis in rats is the main model used in periodontal research, in this model, alveolar bone loss (ABL) is the main parameter evaluated by radiographic, morphometric, and histological techniques. Interestingly, although these methodologies are widely used, it is not totally clarified neither the kinetics of ABL over the induction time nor the agreement degree (repeatability and reproducibility) of these techniques. Objective: To characterize ABL kinetics at 0, 3, 7, 15, 30, and 60 days after ABL induction by ligature and to evaluate the intra- (repeatability) and inter-examiner (reproducibility) agreement and the correlation among the radiographic, morphometric, and histological methodologies. Material and Methods: 60 male Wistar rats with induced ABL were randomly divided into 6 experimental groups (n = 10 animals/group). After 0, 3, 7, 15, 30, and 60 days, the animals were euthanized and their hemimandibles were removed for ABL determination using radiographic, morphometric and histological techniques. Results: Radiographic and morphometric/linear techniques allowed the detection of statistically significant ABL on the third day, while histological and morphometric/area techniques could only detect ABL after the seventh day (ANOVA/Tukey, p<0.05). After the fifteenth day, except for histological analysis, the ABL was stabilized. Concerning the agreement of the methodologies, Bland Altman's test (intra and inter-examiner evaluations) showed no difference among the measurements (p>0.05). In addition, high correlations (Pearson's test, r2>0.9, p<0.05) were observed. Conclusion: The results indicated that the minimum time for ABL induction could vary from 3 to 7 days, according to the chosen analysis methodology. Agreement and correlation data support the comparison of results between studies with same induction time.

Effects of platelet-rich fibrin on healing of intra-bony defects treated with anorganic bovine bone mineral

Abstract Anorganic bovine bone mineral (ABBM) is extensively used in the treatment of intra-bony defects. Platelet-rich fibrin (PRF) is a new-generation platelet concentrate with a simplified technique. Although certain studies have reported the use of PRF in the treatment of intra-bony defects, to date, none of them have evaluated its additive effects with ABBM. Therefore, a randomised, split-mouth clinical trial was conducted to compare healing of intra-bony defects treated with an ABBM-PRF combination with healing of those treated with ABBM alone. By using a split-mouth design, 15 paired intra-bony defects were randomly treated with either ABBM alone (control group) or ABBM-PRF combination (test group). Following clinical parameters and radiographical measurements were recorded at baseline and 6 months after treatment: plaque index (PI), gingival index (GI), probing depth (PD), gingival recession (GR), clinical attachment level (CAL), vertical bone loss, depth of defect and defect angle. Preoperative clinical and radiographical measurements were similar for the test and control groups. Statistically significant reductions in GI, PD, CAL, vertical bone loss, depth of intra-bony defect and widening of defect angle were detected after treatment in both groups. With respect to inter-group analysis, gain in CAL was significantly greater in the test group than in the control group, whereas no inter-group differences were observed in any other parameter. The results of this study indicate that both therapies are effective in the treatment of intra-bony defects.

Medication-related osteonecrosis of the jaw. Introduction of a new modified experimental model

ABSTRACT PURPOSE : To evaluate a modified experimental model for medication-related osteonecrosis of the jaw (MRONJ) through the upper right central incisor extraction followed by intravenous bisphosphonate administration. METHODS: Forty five rats underwent the upper right central incisor tooth extraction were divided in 2 groups: Group I - experimental group, 30 rats received an intravenous administration protocol of zoledronic acid 35μg/kg into the tail vein every two weeks, totalizing four administrations, during eight weeks of administration, previously the extraction, and Group II - control group, 15 rats didn't received any medication before extraction. The groups were subdivided in postoperative periods: 14/28/42 days. Clinical analysis and microtomography were performed to verify the presence of osteonecrosis. In addition, descritive histological analysis of hematoxylin-eosin stained sections was performed to evaluate the presence of osteonecrosis or necrotic foci. RESULTS: Twelve (40%) rats, from experimental group, showed clinical signs of MRONJ (p=0.005), however, all samples showed imaginologic findings like osteolysis and loss of integrity of the cellular walls (p≤0.001). Microscopic evaluation revealed osteonecrosis areas with microbial colonies and inflammatory infiltrate (p≤0.001). In the control group, all animals presented the chronology of a normal wound healing. CONCLUSIONS: The presence of medication-related osteonecrosis of the jaw after maxillary central incisor extraction in rats. This new experimental model may be considered an option for the study of MRONJ.

Changes in alveolar bone support induced by the Herbst appliance: a tomographic evaluation

ABSTRACT Objective: This study evaluated alveolar bone loss around mandibular incisors, induced by the Herbst appliance. Methods: The sample consisted of 23 patients (11 men, 12 women; mean age of 15.76 ± 1.75 years), Class II, Division 1 malocclusion, treated with the Herbst appliance. CBCT scans were obtained before treatment (T0) and after Herbst treatment (T1). Vertical alveolar bone level and alveolar bone thickness of mandibular incisors were assessed. Buccal (B), lingual (L) and total (T) bone thicknesses were assessed at crestal (1), midroot (2) and apical (3) levels of mandibular incisors. Student's t-test and Wilcoxon t-test were used to compare dependent samples in parametric and nonparametric cases, respectively. Pearson's and Spearman's rank correlation analyses were performed to determine the relationship of changes in alveolar bone thickness. Results were considered at a significance level of 5%. Results: Mandibular incisors showed no statistical significance for vertical alveolar bone level. Alveolar bone thickness of mandibular incisors significantly reduced after treatment at B1, B2, B3, T1 and significantly increased at L2. The magnitude of the statistically significant changes was less than 0.2 mm. The changes in alveolar bone thickness showed no statistical significance with incisor inclination degree. Conclusions: CBCT scans showed an association between the Herbst appliance and alveolar bone loss on the buccal surface of mandibular incisors; however, without clinical significance.

RESUMO Introdução: este estudo avaliou a perda óssea alveolar ao redor dos incisivos inferiores induzida pelo aparelho de Herbst. Métodos: a amostra foi composta por 23 pacientes (11 homens e 12 mulheres; média de idade 15,76 ± 1,75 anos), má oclusão de Classe II, divisão 1, tratados com aparelho de Herbst. TCFCs foram realizadas antes do tratamento (T0) e após o tratamento (T1) com o Herbst. A altura e a espessura óssea alveolar dos incisivos inferiores foram avaliadas. As espessuras ósseas vestibular (V), lingual (L) e total (T) foram mensuradas nos terços cervical (1), médio (2) e apical (3) dos incisivos inferiores. O teste t de Student e o teste t de Wilcoxon compararam as amostras dependentes nos casos paramétricos e não paramétricos, respectivamente. As análises de Pearson e Spearman determinaram a correlação entre as alterações na espessura do osso alveolar. Os resultados foram considerados para um nível de significância de 5%. Resultados: os incisivos inferiores não apresentaram significância estatística para a altura óssea alveolar. Após o tratamento, a espessura óssea alveolar dos incisivos inferiores reduziu-se significativamente em V1, V2, V3 e T1 e aumentou significativamente em L2. A quantidade da alteração óssea significativa foi menor que 0,2mm. As alterações na espessura óssea alveolar não apresentam correlação estatisticamente significativa com o grau de inclinação do incisivo. Conclusões: as imagens de TCFC demonstram associação entre o uso do aparelho de Herbst e a perda óssea alveolar no lado vestibular dos incisivos inferiores; entretanto, sem significância clínica.

Use of a Titanium Mesh "Shelter" Combined with the Soft Tissue Matrix Expansion (Tent Pole) Grafting in the Reconstruction of a Severely Resorbed Edentulous Mandible. Technical Note.

Patients wearing complete dentures for a long time usually exhibit lack of bone and keratinized mucosa in the bearing area due to bone resorption. The patients suffering from this phenomenon usually have unstable and non-retentive complete denture, which result in constant trauma to the mucosa, pain, functional limitations and worsening of facial esthetics. An innovative technique has been described in which a novel surgical approach using osseointegrated dental implants as "tent poles" was applied concomitant with particulate autogenous bone graft. The authors claim that the control and maintenance of the surgically expanded soft tissue volume should prevent graft resorption in the long term. Nevertheless, resorption of the bone graft is usually more significant where the bone mass is poorer, in the mandibular body. This paper describes a case of severely resorbed edentulous mandible in which the "tent pole" technique was applied with some modifications. Use of the titanium mesh "shelters" and two additional implants was effective in "protecting" the bone graft in the posterior portion of the mandibular body increasing bone mass volume in this area. Furthermore, we believe that this kind of graft "protection" on the whole residual alveolar ridge can increase the width of bone mass gain optimizing the "tent pole" technique.

Pacientes portadores de próteses totais por um longo período geralmente apresentam perda significativa de osso do processo alveolar e de mucosa ceratinizada na área chapeável devido ao processo de reabsorção óssea associada com a perda de função. Estes pacientes geralmente possuem próteses totais sem retenção e estabilidade, o que resulta em trauma crônico à mucosa, limitações funcionais e piora da estética facial. Uma técnica cirúrgica inovadora foi descrita na qual implantes osseointegráveis são posicionados em forma de "pilares" conjuntamente com enxerto ósseo autógeno particulado. Os autores afirmam que o controle e manutenção do volume tecidual obtido cirurgicamente diminui a perda em volume do enxerto ósseo utilizado. Entretanto esta reabsorção geralmente ocorre com maior intensidade onde a massa óssea é mais pobre, ou seja, em corpo mandibular. Este artigo descreve um caso onde uma mandíbula severamente reabsorvida foi reconstruída utilizando-se a técnica de "tent pole" com algumas modificações propostas pelos autores. O uso da malha de titânio em forma de "cabana" e dois implantes dentários osseointegráveis adicionais contribuíram para "proteger" o enxerto ósseo autógeno na região posterior do corpo mandibular aumentando o volume ósseo na região. Adicionalmente, nós acreditamos que o uso deste tipo de proteção em todo rebordo alveolar residual pode melhorar o ganho de massa óssea otimizando, portanto, a técnica original de "tent pole".

Evaluation and new classification of alveolar bone dehiscences using cone-beam computed tomography in vivo / Evaluación y nueva clasificación de las dehicencias del hueso alveolar mediante tomografía computadorizada de haz cónico in vivo

Alveolar bone dehiscences, which were "V" shaped defects related the margin of the alveolar bone, were common findings in different populations and decreased bony support of teeth. It was difficult to detect dehiscence during direct clinical examination. All of the previous studies on the prevalence of dehiscences were based on dry human skulls. In the current article, we evaluated the prevalence of dehiscences occurring naturally in a Chinese subpopulation, and prepared a classification of dehiscences using cone-beam computed tomography (CBCT). The high prevalence rate of dehiscences and different characteristics of each category suggest that it would be helpful for clinicians who perform periodontal surgery, endodontic surgery, implant surgery or orthodontic treatment to understand which teeth are most often associated with such bony defects, and to consider the effect of severe dehiscences on their diagnosis and treatment plan.

Las dehiscencias óseas alveolares, con forma de "V" en el margen del hueso alveolar, son hallazgos comunes en diferentes poblaciones y provocan una disminución del soporte óseo de los dientes. La dehiscencia fue difícil de identificar durante la exploración clínica directa. Todos los estudios anteriores sobre la prevalencia de dehiscencia se basaron en cráneos humanos secos. En el presente artículo, se evaluó la prevalencia de dehiscencia natural ocurrido en una subpoblación de China. Realizamos una clasificación de las dehiscencias mediante tomografía computarizada cone-beam (TCCB). La alta prevalencia de dehiscencias y las diferentes características de cada categoría sugieren que esta clasificación sería de gran ayuda para los médicos que realizan cirugía periodontal, endodóntica, cirugía de implantes o tratamiento de ortodoncia, permitiendo informar sobre que dientes están más frecuentemente asociados con tales defectos óseos, y poder considerar los efectos severos de las dehiscencias severas en el diagnóstico y el plan de tratamiento.