Comparação da fragilidade gerada por 3 diferentes osteotomias sagitais de mandíbula: estudo in vitro / Comparison of fragility generated by 3 different sagittal mandible osteotomies: in vitro study / Comparación de la fragilidad generada por 3 osteotomías mandibulares sagitales diferentes: estudio in vitro

A osteotomia sagital bilateral de mandíbula (OSBM) foi publicada por Trauner e Obwegeser em 1957, desde então sofreu várias modificações a fim de diminuir as complicações e tornar o procedimento mais simples e previsível. Sendo assim objetivo do presente trabalho foi avaliar e comparar a fragilidade causada na mandíbula por 3 tipos de OSBM. Para isso, foram realizadas as osteotomias propostas por Trauner e Obwegeser modificada por Hunsuck e Epker (I), a de Sant'Ana (II) e de Wolford (III), em 24 hemimandibulas de poliuretano e foi realizado o ensaio mecânico para gerar a fratura sagital. Os dados foram coletados e tabulados, e obteve como resultado que, a maior quantidade de força máxima aplicada foi observada no grupo III, e a menor quantidade no grupo II; com relação à deflexão, apresentou significância estatística entre o grupo II e grupo III; com relação à rigidez, a maior média, foi encontrada no grupo I. Sendo assim, foi possível concluir que dentro deste modelo de estudo a osteotomia II foi capaz de gerar maior fragilidade à hemimandibula de poliuretano com menor quantidade de força. As OBMD dos grupos I e a III também apresentaram ótimos resultados, entretanto necessitaram mais força para alcançar a fratura... (AU)

The bilateral sagittal split osteotomy of the mandible (BSSO) was published by Trauner and Obwegeser in 1957, since then it has undergone several modifications in order to reduce complications and make the procedure simpler and more predictable. Therefore, the objective of this study was to evaluate and compare the fragility caused in the mandible by 3 types of BSSO. For this, the osteotomies proposed by Trauner and Obwegeser modified by Hunsuck and Epker (I), Sant'Ana (II) and Wolford (III) were performed on 24 polyuretha ne hemimandibles, a mechanical test to generate the sagittal fracture. Data were collected and tabulated, and the result was that, the highest amount of maximum force applied was observed in group III, and the lowest amount in group II; with regard to deflection, it was statistically significant between group II and group III; with regard to stiffness, the highest average was found in group I. Therefore, it was possible to conclude that within this study model, osteotomy II was able to generate greater fragility to the polyurethane hemimandible with less force. The BSSO of the groups I and III also showed excelent results, however they required more force to reach the fracture... (AU)

La osteotomía sagital bilateral de la mandíbula (OSBM) fue publicada por Trauner y Obwegeser en 1957, desde entonces ha sufrido varias modificaciones con el fin de reducir las complicaciones y hacer el procedimiento más simple y predecible. Por lo tanto, el objetivo de este estudio fue evaluar y comparar la fragilidad causada en la mandíbula por 3 tipos de OSBM. Para eso, se realizaron las osteotomías propuestas por Trauner y Obwegeser modificadas por Hunsuck y Epker (I), Sant'Ana (II) y Wolford (III) en 24 hemimandíbulas de poliuretano y se realizó un ensayo mecánico para generar la fractura sagital. Los datos fueron recolectados y tabulados, obteniendo como resultado que, la mayor cantidad de fuerza máxima aplicada se observó en el grupo III, y la menor cantidad en el grupo II; en cuanto a la deflexión, fue estadísticamente significativa entre el grupo II y el grupo III; en cuanto a la rigidez, la media más alta se encontró en el grupo I. Por lo tanto, se pudo concluir que, dentro de este modelo de estudio, la osteotomía II logró generar mayor fragilidad a la hemimandíbula de poliuretano con menor fuerza. El OSBM de los grupos I y III también mostró excelentes resultados, pero requirieron mayor fuerza para llegar a la fractura... (AU)

The Prediction Capacity 3-D Software, on a 2-D Analysis, in Planning the Positioning of the Upper Lip After Maxillary Advancement.

PURPOSE: The maxillary advancement using Le Fort I osteotomy directly affects in the positioning of the upper lip (UL) and the nasolabial angle (NLA), which plays an important role in facial expression and aesthetics, because of this, the aim of this study was to evaluate the ability of Dolphin Imaging 11.8 software in predicting changes to the UL position and NLA in patients undergoing maxillary advancement. MATERIALS AND METHODS: It was a retrospective cohort study. Predictive and final tracings using pre- and postoperative Cone beam computed tomography (CBCT) of 24 patients undergoing maxillary advancement, regardless of mandibular movement, were compared. Whether the amount of advancement changes this predictability was also analyzed. The predictive and the 12-month postoperative data were evaluated using Dolphin Imaging 11.8 software and compared. Student t test was used to get the results. RESULTS: The vertical analysis of the incisal tip and cementoenamel junction of the upper central incisor (UCI) and of the UL were statistically significant (P = .001 for all). The horizontal measurements of the same variables (P = .238, P = .516, P = .930, respectively) and the NLA (P = .060) showed no statistical significance. The amount of advancement did not interfere with the variables analyzed, except for the exposure (P = .009) and inclination of the UCI (P = .010). CONCLUSION: It was concluded that the amount of maxillary advancement does not interfere with the UL prediction; the prediction capacity of the software was good for the horizontal measurements, but had a significant error index for vertical measurements.

Influence of collagen membrane on bone quality in titanium mesh reconstructions-Study in rats.

BACKGROUND: New bone formation and tissue remodeling are the major challenges in implantology today. Titanium meshes have demonstrated reconstructive potential for vertical bone gain. However, the soft tissue healing is technically sensitive to the surgical procedure. The combined usage of collagen membrane and specification of the meshes may ensure greater predictability. Therefore, this study aims to evaluate the influence of collagen membrane on the quality of the new bone formation in guided bone regeneration (GBR) procedures with different titanium meshes. METHODS: Twenty-eight Wistar rats were randomly allocated into four main experimental groups, according to mesh pore size in µm: Group P300 (titanium meshes, with 0.3-mm thickness and 3-mm pore size; n = 7); Group P175 (titanium meshes, with 0.3-mm thickness and 1.75-mm pore size; n = 7); Group P85: (titanium meshes, with 0.04-mm thickness and 0.85-mm pore size; n = 7); Group P15: (titanium meshes. with 0.04-mm thickness and 0.15-mm pore size; n = 7). The femurs of each animal were subdivided into test and control groups: Test: bovine bone graft associated with porcine collagen and collagen membrane was used; control: bovine bone graft associated with porcine collagen was used without association with collagen membrane. Bone quality evaluation by in vivo microtomography and histologic analysis were performed. RESULTS: Bone volume formation was similar between groups (P >0.05). However, the titanium meshes with pore size >1 mm demonstrated higher mineral bone density in comparison with meshes with pore size <1 mm (P <0.05), regardless of the combined usage of collagen membrane. All groups showed a spongy bone formation after 30 days. CONCLUSIONS: Combined usage of collagen membrane in GBR procedures with titanium mesh did not show improvements in new bone quality in rat femur model. However, titanium mesh pore size specifications may influence bone quality.

Computed tomography visualizing alterations in the upper airway after orthognathic surgery.

Three-dimensional (3D) software has revolutionized planning in orthognathic surgery. This technology allows the simulation of surgical movements and evaluation of the volume and area of the pharyngeal airway space (PAS), which are not possible with two-dimensional (2D) software. Many patients undergo orthognathic surgery to improve occlusion and facial profile. The PAS may increase or decrease depending on the surgical movements. This study aimed to evaluate the changes in the area and volume of the PAS in patients having bimaxillary movement in orthognathic surgery. The minimum axial area and volume of the PAS (preoperative (T0) and postoperative (T1) air volumes) of 68 patients (26 male and 42 female, mean age 36.6 ± 12.1 years) were analyzed. Evaluations were conducted using cone-beam computed tomography in the Nemoceph 3D-OS program. A paired t-test was used to compare pre- and postoperative volume data, and the Wilcoxon test was used to compare pre- and postoperative data of the minimal axial area. All the tests were performed with Statistica software (StatSoft Inc., Tulsa, OK, USA), and a significance level of 5% was adopted. In the study of the method error, no casual or systematic error was found between the first and second measurements of the variables (p > 0.05 in all measurements). Bimaxillary surgery presented a mean of 70.46% in volume and a median increase of 61.27% in the minimum axial area, which varied from -22.50% to 659.06%. The results demonstrated that bimaxillary advancement significantly increased the volume and minimum axial area of the upper airway; however, the increase was not homogeneous in all the patients.

Lingual Short Split: A Bilateral Sagittal Split Osteotomy Technique Modification.

The technique of sagittal split osteotomy of the mandibular ramus is an established technique that has been evolving over the years, with significant improvements regarding stability, better bone contact between the segments, and possibilities of osteosynthesis. However, paresthesia is common in the postoperatory, sometimes permanent, and undesirable fractures in the subcondylar region can occur leading to longer operative time and extraoral scars. The short lingual split technique is an easy technique that simplifies the horizontal osteotomy of the ramus and decreases the risk of undesirable fractures with a neurosensitive recovery of patients in a much shorter time because of minor trauma and nerve manipulation during the execution.

Outcomes in Surgical Treatment of Mucocele in Frontal Sinus.

The aim of the study was to correlate several studies dating from 1997 to 2015 to identify the most effective treatments for mucocele in the frontal sinus (with/without other paranasal sinuses), considering successful outcomes and recurrence. We aimed to conduct a literature review for articles published between 1997 and 2015. For this, we accessed articles in the SciELO database, as well as LILACS, PubMed, and Google Scholar databases. Were identified 32 work-related injuries in the paranasal sinuses; 2 of these were not related to mucoceles or mucopyocele, 4 had no relation to the frontal sinus, 9 were related to the frontal sinus and other paranasal sinuses, 4 were related to mucocele associated with other sinuses, and 13 involved only the frontal sinus. Endoscopic techniques decrease intra- and postoperative morbidity, reducing the operative time, allow a larger view of the lesion and surrounding anatomical structures, and decrease chances of recurrence. Thus, the successful outcomes have been beneficial to both the surgeon and the patient.

Surgical Reconstruction of Lower Face Degloving.

One of the most impressive soft tissue injuries is the facial degloving, normally associated with industrial machines and traffic accidents. This injury is characterized by the separation of the skin and cartilage from the bones, compromising the soft tissues correlated in the trauma area, nerves, and blood vessels. A 28-year-old patient, male, was referred to Araçatuba's Santa Casa Hospital, after a motorcycle accident, hitting his face on the sidewalk. The patient was conscious, oriented, denying fainting and unconsciousness during the accident, and complaining of pain in the nasal region of the face. The suture of wounds was performed using 5-0 absorbable sutures for muscle planes, and reconstruction of the septum and nasal cartilages. The skin was sutured with interrupted stitches using 6-0 nylon. After reducing the edema, a slight increase in alar base was observed. Subsequently, the alar base cinch suture was performed aiming to bring the alar bases to a measure of 34.0 mm in diameter. As a conclusion, the knowledge of the anatomy of the region involved, the healing of tissues, and suture techniques for the facial region process were critical to the successful treatment. The evaluation of the alar base in degloving cases can involve aesthetic features.

Immediate loading of implants in the edentulous mandible: a multicentre study.

PURPOSE: The aim of this prospective study was to investigate the two-year outcomes following immediate loading of mono-cortically engaged implants. MATERIALS AND METHODS: Thirty healthy mandible edentulous patients with an average age of 67.3 years and presenting with sufficient bony ridge at the mandible symphysis were included in the study. Four Astra Tech, Ti-Oblast® implants were installed between the mental foramina using the mono-cortical anchorage technique. The primary stability of the implants was assessed by resonance frequency analysis (RFA). After uni-abutments were placed, a temporary bridge was constructed and fixed the same day. The definitive bridges were installed 6 weeks after implant surgery. Five of 120 placed implants were lost in four patients during the first 6 weeks and these patients were excluded from the follow-up. The changes in marginal bone level (n = 20) were evaluated in Brazilian and Swedish groups at baseline, 6 weeks, 6 months, 12 months and 24 months. The RFA (n = 30) was evaluated at baseline, 6 weeks, 6 months, 12 months and 24 months postoperatively. RESULTS: Compared with baseline measurements, the postoperative values for marginal bone level (6 weeks, 6 months, 12 months and 24 months) were significantly reduced (p < 0.05), while no differences were observed in the RFA analysis (12 months and 24 months). CONCLUSIONS: The immediate loading of mono-cortically engaged implants in the edentulous mandible is safe and predictable and implant stability remains excellent after 2-year follow-up.

Atypical Case of Three Dental Implants Displaced into the Maxillary Sinus.

Oral rehabilitation with dental implants has become a routine treatment in contemporary dentistry. The displacement of dental implants into the sinus membrane, a complication related to the maxillary sinus, is one of the most common accidents reported in the literature. The treatment for this complication is the surgical removal of the implant. A 60-year-old woman with three dental implants displaced into the maxillary sinus (one implant displaced into the left maxillary sinus and two implants displaced into the right maxillary sinus) underwent surgery for removal of the implants. The surgery to remove the implants was performed under local anesthesia through the Caldwell-Luc technique. The patient was subsequently administered antibiotic, anti-inflammatory, and analgesic drugs. The patient returned 7 days after the surgery for suture removal and is being regularly monitored to determine whether future rehabilitation of the edentulous area is necessary. In conclusion, surgical removal of the dental implant displaced into the maxillary sinus is the treatment of choice. This technique is appropriate because it allows the use of local anesthesia and provides direct visualization for the removal of the implants.

Effects of Photodynamic Process (PDP) in Implant Osseointegration: A Histologic and Histometric Study in Dogs.

BACKGROUND: The combination between photosensitivity substances with laser or light-emitting diode (LED) form the photodynamic therapy basis that consists of photosensitivity drug activated by low-frequency light. This mechanism is used in soft tissue healing process to improve the oxygen tension leading to a fast revascularization. PURPOSE: The objective of this study was to evaluate the effects of photosensitivity drugs activated through LED on osseointegration process. MATERIALS AND METHODS: Eight mongrel dogs underwent implant therapy in four mandibular bone defects using 5.0 mm trephine drill on each side of the mandible. The defects were randomly filled up with (1) Nano emulsion, (2) liposome, (3) blood clot, and (4) autogenous bone. LED with visible and infrared light were applied after 48/72 postoperative hours on four dogs and after 96/120 postoperative hours in the other four dogs. All the animals were euthanized at 15 days after surgery. Ground sections slides were prepared from the experimental site for histomorphometry and histological analysis. RESULTS: No difference was detected in the following parameters: bone-implant contact, bone inside the defect and crest level on LED 48/72. Significant difference was detected inside the defect when filled with autogenous bone (p = .0238) on LED 96/120. When LED 48/72 and LED 96/120 were compared, significant higher bone formation was detected when autogenous bone on bone-implant contact (p = .0043) and bone inside the defect (p = .0008) was used. CONCLUSION: The use of photosensitivity drugs activated by LED demonstrated a tendency to stimulate bone formation, similar to autogenous bone graft on later time point.

Levantamento do assoalho do seio maxilar – aspectos clínicos e de imagem / Maxillary sinus floor lifting – clinical and imaging aspects

Este artigo demonstra os recursos de imagens que contribuem para um diagnóstico e planejamento eficazes na execução previsível do procedimento cirúrgico de levantamento de assoalho de seio maxilar (ESM), um problema comumente encontrado na reabilitação posterior de maxila, limitando a instalação de implantes de comprimento médio (10 mm). Os procedimentos de elevação do assoalho do seio maxilar (ESM) são uma opção para a resolução desse problema. Atualmente, duas principais técnicas são utilizadas para ESM: a técnica atraumática, com a utilização de osteótomos e instalação simultânea de implantes; e a técnica de janela lateral, com ou sem instalação simultânea de implantes. A decisão da técnica a ser realizada é baseada na avaliação da quantidade óssea e na possibilidade de estabilidade primária dos implantes. Esse passo é realizado com o auxílio de exames de imagens bi e tridimensionais. Nos casos em que é necessária a utilização de enxertos, o osso autógeno é considerado o padrão-ouro. No entanto, a literatura também apresenta casos de sucesso utilizando substitutos ósseos e combinações com osso autógeno. Apesar da técnica já estar bem desenvolvida, algumas complicações podem ocorrer em procedimentos de ESM, como a perfuração da membrana sinusal, hemorragias, estabilidade primária do implante insuficiente, deslocamento do enxerto dentro do seio maxilar e exposição ou lesões de nervos...

This article highlights the imaging resources contributing to effective diagnosis and planning for elevation of the maxillary sinus floor (ESM), a common issue at the posterior region which prevents implant placement of 10 mm in length. ESM procedures can overcome this situation. Nowadays, two main techniques are available for ESM: the atraumatic technique, with the use of osteotomes and immediate implant placement, and the lateral window technique, with/without implant placement. Decisions are based on available bone quantity and primary implant stability. Also, bi- and three-dimensional imaging techniques are valuable tool in this process. When necessary, the autogenous bone is still the gold standard. However, there are reports of success with bone substitutes and combinations with autogenous material. Although well-developed, some complications occur with ESM procedures, as well as membrane perforation, hemorrhage, lack of primary implant stability, and graft displacement inside the maxillary sinus, exposure, and nerve damage...

Considerações clínicas no planejamento e instalação de implantes imediatos / Clinical considerations for immediate implant placement and treatment planning

As reabilitações implantossuportadas permitem o restabelecimento da função e da estética após perdas dentárias totais e parciais com previsibilidade e altas taxas de sucesso. A instalação de implantes imediatos com carga imediata, a fim de evitar as alterações dimensionais sofridas pelo osso alveolar e tecidos moles, após a extração dentária, apresenta algumas vantagens em relação à técnica convencional, como redução do número de procedimentos cirúrgicos, possível preservação do osso alveolar, redução de custos e do período de ausência dentária, além de maior aceitação por parte do paciente. Vários estudos têm demonstrado que implantes instalados em alvéolos frescos e com carga imediata apresentam uma taxa de sobrevivência entre 94,5% a 100%. No entanto, para que um resultado funcional e estético adequado seja obtido, é fundamental que seja realizado um planejamento preciso, lançando mão dos recursos de diagnóstico bi e tridimensionais disponíveis, para que fatores relacionados à qualidade e à quantidade óssea sejam avaliados...

Dental implant-supported restorations present predictability and high success rates in restoring function and esthetics. The immediate placement/loading of dental implants is considered an option to reduce the risk of dimensional changes due to alveolar bone resorption and soft tissue collapse following tooth extraction. Other advantages over the conventional technique are the reduced number of surgical procedures, possible alveolar bone preservation, reduced costs, shorter period for temporary crowns or bridges, and greater acceptance by the patient. Several studies have shown that implants placed in fresh sockets with immediate loading have a high survival rate between 94.5 to 100%. However, for achieving a functional and aesthetic result, adequate treatment planning is fundamental including clinical and two- and three-dimensional diagnostic approaches...

Avaliação histológica e histomorfométrica do efeito de fármacos fotossensíveis ativados por LED no reparo ósseo: estudo em coelhos / Photodynamic therapy on bone healing in rabbits

A combinação de um fármaco fotossensível (FS) ativado por luz (vermelha, infravermelho ou ambas) forma uma das vertentes de aplicação da Terapia Fotodinâmica (TFD), que consiste na administração de um FS que posteriormente é ativado pela irradiação do LED ou Laser junto ao tecido, sendo que o FS ou a luz sozinhas, não apresentam citotoxicidade. O presente estudo teve por objetivos estabelecer o potencial regenerador do tecido ósseo para o reparo em calvária de coelho, utilizando três sistemas de liberação de drogas (DDS) de FS, estimulado pela combinação da fotobiomodulação de sistemas LED operando na faixa do visível e infravermelho. Foram utilizados 48 coelhos New Zealand White divididos em 3 grupos: Grupo LED 24/48 (dezoito coelhos) com aplicações de LED 24/48 horas após a cirurgia, Grupo LED 72/96 (dezoito coelhos) com aplicações de LED 72/96 horas após a cirurgia e Controle (doze coelhos) onde não houve aplicação de LED. Nos grupos experimentais foram realizadas 4 perfurações nas calvárias com preenchimento aleatoriamente de 1) Base em gel, 2) nanoemulsão carregada com FS, 3) lipossoma em gel com FS e 4) nanopartículas de albumina (BSA) carregada com FS. No grupo controle foram feitas duas perfurações, uma preenchida por osso autógeno e outra com coágulo. Dezesseis animais foram submetidos à eutanásia em cada tempo experimental: 5 dias, 10 dias e 20 dias. Lâminas histológicas foram feitas a partir dos defeitos e o osso neoformado foi mensurado. O uso de FS nos DDS não foi efetivo para abreviar o tempo de reparo ósseo em calvária de coelhos nos intervalos de tempo deste estudo

The combination between photosensitizer substances with laser or LED (light emitting diode) form the photodynamic therapy (PDT) basis that consists of photosensitivity drug activated by low frequency light. This mechanism is used in soft tissue healing process to improve the oxygen tension leading to a fast revascularization. The objective of this study was to evaluate the effects of photosensitivity drugs activated through LED on bone healing process. Fourty eight New Zealand White rabbits were underwent to four bicortical calvaria defects made by 6.0 mm trephine drill. The defects were randomly filled up with (1) Gel, (2) Nanoemulsion + photosensitizer drug, (3) Liposome + photosensitizer drug, (4) NPS (nanostructure polymeric system) + photosensitizer drug. After 24/48 hours or 72/96 hours a LED were applied on all the rabbits. Sixteen animals were sacrificed, respectively, at 5, 10 and 20 days after surgery. Histological slides were prepared from each experimental site for histomorphometry and histological analysis. Bone graft was significant higher bone level in all experimental time points.. At 10 days liposome showed higher bone level than Gel (p=0,0161). However on 20 days, no difference was detected between the materials. The use of photosensitizer drugs activated by LED demonstrated do not achieve the stimulate bone formation on later time points on thsi presente study

Avaliação histológica e histomorfométrica do efeito de fármacos fotossensíveis ativados por LED no reparo ósseo: estudo em coelhos / Photodynamic therapy on bone healing in rabbits

A combinação de um fármaco fotossensível (FS) ativado por luz (vermelha, infravermelho ou ambas) forma uma das vertentes de aplicação da Terapia Fotodinâmica (TFD), que consiste na administração de um FS que posteriormente é ativado pela irradiação do LED ou Laser junto ao tecido, sendo que o FS ou a luz sozinhas, não apresentam citotoxicidade. O presente estudo teve por objetivos estabelecer o potencial regenerador do tecido ósseo para o reparo em calvária de coelho, utilizando três sistemas de liberação de drogas (DDS) de FS, estimulado pela combinação da fotobiomodulação de sistemas LED operando na faixa do visível e infravermelho. Foram utilizados 48 coelhos New Zealand White divididos em 3 grupos: Grupo LED 24/48 (dezoito coelhos) com aplicações de LED 24/48 horas após a cirurgia, Grupo LED 72/96 (dezoito coelhos) com aplicações de LED 72/96 horas após a cirurgia e Controle (doze coelhos) onde não houve aplicação de LED. Nos grupos experimentais foram realizadas 4 perfurações nas calvárias com preenchimento aleatoriamente de 1) Base em gel, 2) nanoemulsão carregada com FS, 3) lipossoma em gel com FS e 4) nanopartículas de albumina (BSA) carregada com FS. No grupo controle foram feitas duas perfurações, uma preenchida por osso autógeno e outra com coágulo. Dezesseis animais foram submetidos à eutanásia em cada tempo experimental: 5 dias, 10 dias e 20 dias. Lâminas histológicas foram feitas a partir dos defeitos e o osso neoformado foi mensurado. O uso de FS nos DDS não foi efetivo para abreviar o tempo de reparo ósseo em calvária de coelhos nos intervalos de tempo deste estudo.

The combination between photosensitizer substances with laser or LED (light emitting diode) form the photodynamic therapy (PDT) basis that consists of photosensitivity drug activated by low frequency light. This mechanism is used in soft tissue healing process to improve the oxygen tension leading to a fast revascularization. The objective of this study was to evaluate the effects of photosensitivity drugs activated through LED on bone healing process. Fourty eight New Zealand White rabbits were underwent to four bicortical calvaria defects made by 6.0 mm trephine drill. The defects were randomly filled up with (1) Gel, (2) Nanoemulsion + photosensitizer drug, (3) Liposome + photosensitizer drug, (4) NPS (nanostructure polymeric system) + photosensitizer drug. After 24/48 hours or 72/96 hours a LED were applied on all the rabbits. Sixteen animals were sacrificed, respectively, at 5, 10 and 20 days after surgery. Histological slides were prepared from each experimental site for histomorphometry and histological analysis. Bone graft was significant higher bone level in all experimental time points.. At 10 days liposome showed higher bone level than Gel (p=0,0161). However on 20 days, no difference was detected between the materials. The use of photosensitizer drugs activated by LED demonstrated do not achieve the stimulate bone formation on later time points on thsi presente study.

Use of titanium mesh for reconstruction of extensive defects in fronto-orbito-ethmoidal fracture.

Traumatic injuries treatment of the fronto-naso-orbito-ethmoidal region has been one of the most challenging treatments within maxillofacial surgery, particularly of extensive orbital defects, very common in this type of pathologic condition. A 48-year-old man involved in a car collision presented an extensive bilateral fracture of the orbit medial wall, nasal bones, the nasal septum, and the frontal anterior table. The clinical and tomographic findings concluded the diagnosis of a maxilla and fronto-naso-orbito-ethmoidal fracture. Among the variety of biomaterials, the titanium mesh was elected because of the extension and magnitude of the bone defect, obtaining this way esthetic and functional results with better prognosis.

Bone formation following implantation of titanium sponge rods into humeral osteotomies in dogs: a histological and histometrical study.

BACKGROUND: Titanium (Ti) is widely proven to enhance bone contact and growth on its surface. It is expected that bone defects could benefit from Ti to promote healing and to increase strength of the implanted area. PURPOSE: The present study aimed at comparing the potential of porous Ti sponge rods with synthetic hydroxyapatite (HA) for the healing of bone defects in a canine model. MATERIAL AND METHODS: Six mongrel dogs were submitted to three trephined osteotomies of 6.0 x 4.0 mm in one humerus and after 2 months another three osteotomies were performed in the contralateral humerus. A total of 36 defects were randomly filled either with Ti foam, particulate HA, or coagulum (control). The six animals were killed 4 months after the first surgery for histological and histometrical analysis. RESULTS: The Ti-foam surface was frequently found in intimate contact with new bone especially at the defect walls. Control sites showed higher amounts of newly formed bone at 2 months - Ti (p = 0.000) and HA (p = 0.009) - and 4 months when compared with Ti (p = 0.001). Differently from HA, the Ti foam was densely distributed across the defect area which rendered less space for bone growth in the latter's sites. The use of Ti foams or HA resulted in similar amounts of bone formation in both time intervals. Nevertheless, the presence of a Ti-foam rod preserved defect's marginal bone height as compared with control groups. Also, the Ti-foam group showed a more mature bone pattern at 4 months than HA sites. CONCLUSION: The Ti foam exhibited good biocompatibility, and its application resulted in improved maintenance of bone height compared with control sites. The Ti foam in a rod design exhibited bone ingrowth properties suitable for further exploration in other experimental situations.

Immunohistochemical, tomographic and histological study on onlay bone graft remodeling. Part II: calvarial bone.

OBJECTIVES: Little information is available on the molecular events that occur during graft incorporation over time. The calvarial bone (Cb) grafts have been reported to produce greater responses compared with other donor regions in maxillofacial reconstructions, but the scientific evidences for this are still lacking. The objectives of this study are (1) to study the morphological pattern of Cb onlay bone grafts and compare them with the biological events through immunohistochemical responses and (2) to establish the effects of perforations in maintaining the volume and bone density of the receptor bed. MATERIAL AND METHODS: Sixty New Zealand White rabbits were submitted to Cb onlay bone grafts on the mandible. In 30 rabbits, the receptor bed was perforated (perforated group), while for the remaining animals the bed was kept intact (non-perforated group). Six animals from each group were sacrificed at 5, 7, 10, 20 and 60 days after surgery. Histological sections from the grafted area were prepared for immunohistochemical and histological analyses. Immuno-labeling was found for proteins Osteoprotegerin (OPG), receptor activator of nuclear factor-kappabeta ligand (RANKL), alkaline phosphatase (ALP), osteopontin (OPN), vascular endothelial growth factor (VEGF), tartrate-resistant acid phosphatase (TRAP), Type I collagen (COL I) and osteocalcin (OC). The tomography examination [computerized tomography (CT) scan] was conducted just after surgery and at the sacrifice. RESULTS: The histological findings revealed that the perforations contributed to higher bone deposition during the initial stages at the graft-receptor bed interface, accelerating the graft incorporation process. The results of the CT scan showed lower resorption for the perforated group (P

Estudo histomorfométrico da influência do diâmetro do orifício piloto na interface entre o implante e o osso vertebral / Histomorphometric study of the influence of the pilot hole diameter on the interface between implant and vertebral bone

OBJETIVO: Estudar as alterações agudas da interface entre os parafusos e o tecido ósseo vertebral, considerando o diâmetro do orifício-piloto em relação ao diâmetro interno do parafuso. MÉTODOS: O estudo foi realizado em carneiros e a segunda vértebra cervical selecionada para o estudo. Foram utilizados parafusos corticais de 3,5mm de diâmetro externo (2,4mm de diâmetro interno) e 14mm de comprimento. Foram formados quatro grupos experimentais: 1) orifício-piloto de 2,0mm e colocação do parafuso de 3,5mm; 2) orifício-piloto de 2,5mm e colocação do parafuso de 2,5mm; 3) orifício-piloto de 2mm sem colocação do parafuso; e 4) orifício-piloto de 2,5mm sem colocação do parafuso. RESULTADOS: O grupo 1 (orifício-piloto menor do que o diâmetro interno do parafuso) apresentou maior densidade óssea no interior da rosca do implante e maior densidade óssea na área em espelho do que o grupo 2 (orifício-piloto maior que o diâmetro interno do parafuso). A superfície de contato entre o tecido ósseo e o implante foi maior no grupo 2 em relação ao grupo 1. A comparação da densidade óssea na área em espelho entre os grupos com e sem implante (1 e 3) e (2 e 4) mostrou que a densidade óssea era maior nos grupos com o implante. Não foi observada diferença estatística entre as comparações dos grupos experimentais. CONCLUSÃO: A utilização de orifício-piloto de menor diâmetro em relação ao diâmetro interno do parafuso apresentou tendência a provocar maior compactação do osso ao redor do implante.

OBJECTIVE: To study acute changes in the interface between screws and vertebral bone tissue, considering the pilot hole diameter in relation to the inner diameter of the screw. METHODS: The study was carried out in sheep, and the second cervical vertebra was selected for the study. Cortical screws were used, with 3.5 mm of external diameter (2.4 mm of inner diameter) and 14 mm in length. Four experimental groups were formed: 1 2.0 mm pilot hole and placement of 3.5 mm screw; 2 - 2.5 mm pilot whole and placement of 2.5 mm screw; 3 - 2 mm pilot hole with no screw placement; and 4 2.5 mm pilot whole with no screw placement. RESULTS: Group 1 (pilot hole smaller than the inner diameter of the screw) presented more bone density inside the implant thread and more bone density in the mirror area than group 2 (pilot hole larger than the inner diameter of the screw). The contact surface between bone tissue and the implant was larger in group 2 when compared to group 1. The comparison of bone density in the mirror area among the groups with and without screw placement (1 and 3) and (2 and 4) showed that bone density was greater in the groups with screw placement. No statistical differences were seen among the comparisons of the experimental groups. CONCLUSION: The use of a pilot hole with a smaller diameter than the inner diameter of the screw tended to cause more bone compaction around the screw.