Late alveolar bone grafting in complete unilateral cleft lip and palate (UCLP): Biomechanical considerations for the success of orthodontic finishing.

Orthodontic treatment in patients with cleft lip and palate (CLP) is challenging. Alignment of the maxillary segments and orthodontic levelling of the teeth adjacent to the cleft area are important before alveolar bone grafting (ABG), in the permanent dentition. In this clinical report, orthodontic procedures, before and after late ABG, are described as an alternative that can optimise the orthodontic and periodontal results. The gingival margins of the teeth adjacent to the cleft area were levelled. Root divergence was corrected. Interdental papilla and improvement of the periodontal condition were obtained.

A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis.

Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healing.

Raloxifene but not alendronate can compensate the impaired osseointegration in osteoporotic rats.

OBJECTIVES: Alendronate and raloxifene, a bisphosphonate and a selective estrogen modulator, respectively, are established osteoporosis therapies. Current evidence suggests that simultaneous application of osteoporosis therapies modulates osseointegration. However, alendronate shows inconsistent findings and raloxifene has not been studied comprehensively. This study aimed to evaluate the bone dynamics and molecular and microstructural features at the peri-implant bone interface in osteoporotic rats. MATERIALS AND METHODS: Thirty female rats underwent ovariectomy and were fed a diet low in calcium and phosphate and treated with alendronate or raloxifene for 30 days or underwent fictional ovariectomy surgery (SHAM) prior to implant insertion in the tibia; osteoporosis therapies continued thereafter. After 42 days, peri-implant bone was evaluated by histometric and micro-CT analysis. Fluorochrome incorporation and gene expression was determined to evaluate bone turnover. RESULTS: We report here that alendronate had no impact on bone-to-implant contacts and the mineral apposition rate. The RANKL/OPG ratio and local bone volume, however, were increased compared to the untreated osteoporotic rats. Even though signaling to bone resorption activity through RANKL production was observed in the alendronate group, the blockade of bone resorption activity that occurs in decorrence to alendronate activity took place and resulted in an increase in bone volume. Raloxifene significantly increased osseointegration in osteoporotic rats, as indicated by bone-to-implant contacts, mineral apposition, and local bone volume. Raloxifene, however, had no considerable impact on the RANKL/OPG ratio compared to untreated osteoporotic rats. As expected, the SH group showed higher bone-to-implant contacts and mineral apposition rates than the untreated osteoporotic rats. CONCLUSIONS: These findings suggest that raloxifene but not alendronate can compensate for the impaired osseointegration in osteoporotic rats. CLINICAL RELEVANCE: Regarding the superiority of raloxifene observed in the improvement of bone dynamics response, this statement suggests that raloxifene could be a good option for osteoporosis patients in oral rehabilitation procedures.

A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis

Abstract Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healing.

Bone Healing Evaluation in Critical-Size Defects Treated With Xenogenous Bone Plus Porcine Collagen.

PURPOSE: This study aimed to evaluate the osteoconductive features of Bio-Oss Collagen in large critical-size defects (8 mm). MATERIALS AND METHODS: Thirty-six adult Wistar Albinus male adult rats were carried out a critical-size defect with a trephine bur of 8 mm in the calvaria. Groups were divided depending on the filling biomaterial as follows: group BO: Bio-Oss (n = 18); group BOC: Bio-Oss Collagen (n = 18). After 7, 30, and 60 days, 6 rats of each group were euthanized with anesthetic overdose. Specimens were laboratory processed for histomorphometric analysis. Histomorphometric data were statistically analyzed by analysis of variance and post-Tukey test (P < 0.05). RESULTS: Statistical differences were found in new bone formation just in the intragroup comparison among periods after 7 and 60 postoperative days, indicating more new bone formation after 60 days (Tukey test, P = 0.029). CONCLUSION: Under the limitation of this research, it could be concluded that Bio-Oss and Bio-Oss Collagen in this experimental model did not show osteoconductive features.

An Uncommon Occurrence of Three-Fourth Molars Concomitant to Hypodontia in a Nonsyndromic Patient.

Bilaterally mandibular and maxillary fourth molars, concomitant to hypodontia, are uncommon. These dental anomalies, called hypohyperdontia, are rare and etiology is not well defined. Several complications may occur as a consequence of supernumerary teeth, such as teeth impaction, resorption of adjacent teeth, and development of cysts and tumors. The authors present an uncommon occurrence of three-fourth molars concomitant to hypodontia and dentigerous cyst associated with impacted mandibular second and third molars in a nonsyndromic patient. The authors attempt to discuss the occurrence of bilaterally fourth molars and reinforce the importance of clinical approach, considering risks and benefits for the patient.

Effect of antiresorptive drugs in the alveolar bone healing. A histometric and immunohistochemical study in ovariectomized rats.

OBJECTIVES: The aim of this study is to evaluate the alendronate and raloxifene influence in the alveolar healing process of osteoporotic rats. MATERIALS AND METHODS: Sixty-four female rats were divided in four groups: sham rats (SHAM), ovariectomized rats and no medical treatment (OVX NT), ovariectomized rats and submitted to alendronate treatment (OVX ALE), and ovariectomized and submitted to raloxifene treatment (OVX RAL). The histomorphometrical and immunohistochemical analysis was performed. The quantitative data were analyzed through Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: In the longest period, SHAM and OVX RAL groups showed the better bone formation responses (P < 0.05). The worst bone formation response was observed in the group OVX NT. OVX RAL group showed the better response at 42 days. OVX ALE group showed a favorable response at 14 days, in comparison with OVX RAL group, but a reduced response at 42 days. It was possible to observe a mature bone in SHAM group at 14 days and an immature bone in the OVX NT group. An intermediate quality bone was observed in the groups OVX ALE and OVX RAL. CONCLUSION: Alendronate and raloxifene treatment improved the alveolar healing process in osteoporotic rats, but not enough to achieve the histometrical and protein expression values that were observed in the SHAM group. CLINICAL RELEVANCE: Alendronate is largely used as a potent antiresorptive agent. Otherwise, considering the undesirable effects in relation to the alveolar healing, other antiosteoporosis medications should be studied. Raloxifene seems to be a good candidate once its action mechanism involves the activation of osteoblasts.

Misdiagnosis of Extensive Maxillofacial Infection and Its Relationship with Periodontal Problems and Hyperglycemia.

Background. Complex dental infections can reach distant areas of the alveolar process, invading the secondary fascial spaces. Objectives. This case report aims to show a misdiagnosis of odontogenic infection and a great need for dentist in the hospital environment. Case Report. A male patient presented facial asymmetry and trismus, while the facial CT examination showed a hyperdense mass involving the left masseteric, pterygomandibular, and superficial temporal regions. The patient was then referred to oral oncology center by emergency physician with cancer suspicion. After 15 days, the patient returned to the same emergency room and was attended by the surgical and maxillofacial trauma team, presenting tachycardia, tachypnea, dysphagia, and trismus. During anamnesis, the patient reported being an uncontrolled diabetic. In intraoral exam, a poor oral condition and generalized periodontitis were observed. Results. Correct diagnosis of odontogenic infection was established and adequately treated. Conclusions. Symptomatology bland may mask the severity of an infection; every increase in volume associated with trismus, poor oral hygiene with or without hyperglycemia should be heavily investigated for the presence of an infectious process. It emphasizes the importance of a dentist working with the physician in emergency room.

Alveolar bone dynamics in osteoporotic rats treated with raloxifene or alendronate: confocal microscopy analysis.

In this study, the characteristics of the alveolar bone of rats with induced osteoporosis were examined. Thirty-two rats were divided into four groups according to the induction of osteoporosis and drugs administered: OG, osteoporotic rats without treatment (negative control); SG, rats which underwent sham surgery ovariectomy (SHAM); alendronate (AG), osteoporotic rats treated with alendronate; and RG, osteoporotic rats treated with raloxifene (RG). On the 8th day after ovariectomy and SHAM surgeries, drug therapy was started with AG or RG. On the 52nd day, 20 mg/kg calcein was administered to all of the rats, and on the 80th day, 20 mg/kg alizarin red was administered. Euthanasia was performed on the 98th day. The bone area marked by fluorochromes was calculated and data were subjected to two-way ANOVA test and Tukey's post-hoc test (p < 0.05). The comparison of the induced osteoporosis groups showed no statistically significant differences in bone turnover only between RG and SG (p = 0.074) and AG and OG (p = 0.138). All other comparisons showed significant differences (p < 0.001). The largest bone turnover was observed in RG and SG groups. RG was the medication that improved the dynamics of the alveolar bone of rats with induced osteoporosis, resembling that of healthy rats.

Unerupted lower third molar extractions and their risks for mandibular fracture.

As every surgical procedure extraction of third molars can result in several complications, among them the mandibular angle fracture. Predisposing factors for fracture should be analyzed during and after the surgery. This paper aims to discuss the predisposing factors to the occurrence of mandibular angle fractures during and after the procedure for third molars extraction, as well as surgical principles to avoid this complication.

Surgical techniques for maxillary bone grafting - literature review.

For oral rehabilitation with implant-supported prostheses, there are required procedures to create the bone volume needed for installation of the implants. Thus, bone grafts from intraoral or extraoral donor sites represent a very favorable opportunity. This study aimed to review the literature on the subject, seeking to discuss parameters for the indications, advantages and complications of techniques for autogenous bone grafts.

The influence of bone quality on the biomechanical behavior of full-arch implant-supported fixed prostheses.

We evaluated the influence of bone tissue type on stress distribution in full-arch implant-supported fixed prostheses using a three-dimensional finite element analysis. Stresses in cortical and trabecular bones were also investigated. Edentulous mandible models with four implants inserted into the interforaminal region were constructed from different bone types: type 1 - compact bone; type 2 - compact bone surrounding dense trabecular bone; type 3 - a thin layer of compact bone surrounding trabecular bone; and type 4 - low-quality trabecular bone. The mandible was restored with a full-arch implant-supported fixed prosthesis. A 100-N oblique load was applied to the left lower first molar of the prosthesis. The maximum (σmax) and minimum (σmin) principal stress values were determined. The σmax in the type 4 cortical bone was 22.56% higher than that in the type 1 bone. The σmin values in the cortical bone were similar among all the bone types. For the superstructure, increases of 9.04% in the σmax and 11.74% in the σmin in G4 (type 4 bone) compared with G1 (type 1 bone) were observed. For the implants, the highest stress values were located in G4, and the lowest values were observed in G1. In the trabecular bone, the highest stress was generated in G1 and G2. In conclusion, the more compact bones (types 1 and 2) are the most suitable for supporting full-arch implant-supported fixed prostheses, and poor bone quality may increase the risk of biological and mechanical failure.

Surgical techniques for maxillary bone grafting - literature review / Técnicas cirúrgicas para a enxertia óssea dos maxilares - revisão da literatura

For oral rehabilitation with implant-supported prostheses, there are required procedures to create the bone volume needed for installation of the implants. Thus, bone grafts from intraoral or extraoral donor sites represent a very favorable opportunity. This study aimed to review the literature on the subject, seeking to discuss parameters for the indications, advantages and complications of techniques for autogenous bone grafts.

Para a reabilitação bucal com as próteses implantossuportadas é necessário a realização de procedimentos para criar o volume ósseo necessário para a instalação dos implantes. Com isso, os enxertos ósseos provenientes de áreas doadoras intrabucais ou extrabucais, representam uma possibilidade bastante favorável. O presente trabalho objetivou realizar uma revisão da literatura em que procurou discutir parâmetros para as indicações, as vantagens e complicações para as técnicas dos enxertos ósseos autógenos.

Intraoperative blood loss and blood transfusion requirements in patients undergoing orthognathic surgery.

Procedures for the surgical correction of dentofacial deformities may produce important complications, whether due to the potential for vascular injury or to prolonged surgery, both of which may lead to severe blood loss. Fluid replacement with crystalloid, colloid, or even blood products may be required. The aim of this study was to assess blood loss and transfusion requirements in 45 patients (18 males and 27 females; mean age 29.29 years, range 16-52 years) undergoing orthognathic surgery, assigned to one of two groups according to procedure type-rapid maxillary expansion or double-jaw orthognathic surgery. Preoperative hemoglobin and hematocrit levels and intraoperative blood loss were measured. There was a substantial individual variation in pre- and postoperative hemoglobin values (10.3-17 and 8.8-15.4 g/dL, respectively; p < 0.05). Mean hematocrit values were 41.53 % preoperatively (range 31.3-50.0 %) and 36.56 % postoperatively (range 25-43.8 %) (p < 0.05). Mean blood loss was 274.60 mL (range 45-855 mL). Only two patients required blood transfusion. Although blood loss and transfusion requirements were minimal in the present study, surgical teams should monitor the duration of surgery and follow meticulous protocols to minimize the risks.

Effect of bleaching agents and soft drink on titanium surface topography.

The effects of carbamide peroxide, hydrogen peroxide and cola soft drink on the topographic modifications of commercially-pure titanium (CP-Ti) and Ti-6Al-4V were investigated. Ti discs were divided into 18 groups (n = 4) based on the solution treatment and Ti type. Specimens were immersed in 3 mL of each solution for 4 h per day (for the remaining 20 h, discs were left dry or immersed in artificial saliva) for 15 days. For control, specimens were immersed in only artificial saliva. Ti surfaces were examined using scanning electron (SEM) and atomic force (AFM) microscopes and their surface roughness (in µm) and surface chemical modifications were investigated. Data were analyzed by ANOVA and Tukey's test (α = 0.05). Groups immersed in 35% hydrogen peroxide showed the highest roughness (Ra) (171.65 ± 4.04 for CP-Ti and 145.91 ± 14.71 for Ti-6Al-4V) (p < 0.05), followed by groups treated with carbamide peroxide 16% (110.91 ± 0.8 for CP-Ti and 49.28 ± 0.36 for Ti-6Al-4V) and 35% (65.67 ± 1.6 for CP-Ti and 53.87 ± 1.98 for Ti-6Al-4V); treatment with artificial saliva did not affect the results. These values were statistically superior to those observed prior to the treatment and to those of the control group (31.0 ± 0.99 for CP-Ti and 29.95 ± 0.58 for Ti-6Al-4V). Cola soft drink did not alter the surface roughness of either Ti type (p > 0.05). SEM and AFM revealed dramatic changes in the specimens surfaces immersed in the 35% hydrogen peroxide, mainly for CP-Ti. No detectable chemical modifications on the Ti surface were observed. Bleaching agents promoted significant changes in Ti topography, which could affect the longevity of implants treatments.

The Fresh Frozen Bone Allograft (FFBA) to Reconstruct the Atrophic Maxilla: Evaluation of the Clinical and Histological Viability at Six and Nine Months in the Maxillary Sinus / Aloinjerto Óseo Fresco Congelado (FFBA) en la Reconstrucción del Maxilar Atrófico: Evaluación de la Viabilidad Clínica e Histológica a los Seis y Nueve Meses en el Seno Maxilar

This work aimed to analyze clinically and histologically the allogen bone graft behavior at 6 and 9 months. A leukoderm, female, 55 years old patient sought dental care for oral rehabilitation with dental implants and implant supported fixed prosthesis in the maxilla. Bilateral sinus lifting procedure were performed in a same patient, the analysis were made after 6 and 9 months, respectively. At 6 months, there was lack of a better bone remodeling in the region, associated to the presence of fibrous connective tissue within the collected tissue, showing us that this is not the best stage of tissue maturation to place dental implants. The 9 months period showed an improvement, with a more organized bone tissue surrounding particles of homogenous bone, what possibly had increased implant stability at the time of surgery. There is no doubt about the increase of clinical applications of FFBA, but there are no studies available regarding the standardization of time to load implants inserted in allografts. So papers with long-term monitoring are necessary to eliminate questions that still remain to be answered.

El objetivo fue analizar clínica e histológicamente el injerto óseo alógeno a los 6 y 9 meses. Una paciente sexo femenino, leucoderma de 55 años de edad consultó por atención odontológica para la rehabilitación oral con implantes y prótesis fija implanto soportada en el maxilar. Procedimientos de elevación del seno maxilar bilateralmente fueron realizados en la misma paciente, y se hicieron los análisis después del sexto y noveno mes, respectivamente. Al sexto mes, se observó una remodelación ósea deficiente de la región asociada a la presencia de tejido conectivo fibroso en el tejido analizado, demostrando que no era la mejor etapa de maduración óseo para instalar los implantes. Al noveno mes se observo una mejora, con un tejido óseo mas organizado rodeando partículas de hueso homogéneo, el cual posiblemente incrementaría la estabilidad del implante en el momento de la cirugía. No hay dudas respecto del incremento de aplicaciones clínicas del FFBA, pero no hay estudios capaces de estandarizar el tiempo de carga de los implantes instalados sobre aloinjertos. Investigaciones con seguimientos a largo plazo son necesarios para eliminar las preguntas que aun se mantienen sin respuesta.