On-Bone Fixation of Free Gingival Graft Induces an Osteoinductive Effect in Human Alveolar Bone.

We examined alveolar bone samples in the area of on-bone fixation of a free gingival graft performed during surgery in patients aged 37-55 years with a diagnosis of secondary partial adentia of the upper and lower jaws. Six months after fixation of the graft in the alveolar bone, foci of neoosteogenesis were found in the contact zone. They were characterized by the appearance of appositional lines, cords of basophilic osteoblasts, and growing osteons. An immunohistochemical study revealed an increase in the number of CD44+, CD29+, and osteocalcin+ cells in the layer of the outer circumferential lamellae, primary osteons, and the lining of the Haversian canals. TGF-ß1+ cells were located in the intertrabecular reticular tissue and wall of microvessels. The results indicate activation of mesenchymal stem cells in the area of localization of the graft and differentiating osteoblasts. The observed osteoinductive effect of free gingival graft is associated with its participation in reorganization in MSC and induction of morphogenetic molecules.

Estudio de trastornos temporomandibulares en pacientes parcialmente desdentados / A study of temporomandibular disorders in partially edentulous patients

El objetivo de este estudio es determinar la frecuencia y características del edentulismo parcial y patologías de la articulación temporomandibular en pacientes adultos. Se realizó un estudio observacional y descriptivo de pacientes que concurrieron al Módulo de Odontología Rehabilitadora de la Facultad de Odontología, se seleccionaron 60 pacientes que necesitaban rehabilitación protésica parcial. Las variables estudiadas fueron: edad, sexo, clase de Kennedy, dolor articular, ruidos articulares, restricción y desviación mandibulares. Los datos fueron cargados en una base de datos diseñada a tal efecto, para su análisis estadístico. Del análisis del estudio se observó ausencia parcial de piezas dentarias con mayor frecuencia en el sexo femenino (58%), el 52% correspondieron a la clase I de Kennedy: el 64% en el maxilar inferior, el 17% presentó dolor articular, 28% ruidos articulares, 68% presentó desviación mandibular (siendo lo más frecuente hacia la derecha), y el 42% presentó restricción mandibular leve y solo un n=1, grave. Las pérdidas de las piezas dentarias bilaterales posteriores del maxilar inferior son las de mayor frecuencia asociado a patologías frecuentes del ATM. Partiendo desde la prevención, evitando las pérdidas de piezas dentarias y con una correcta rehabilitación se podrá lograr una buena salud bucodental (AU)

The objective of this study is to determine the frequency and characteristics of partial edentulism and pathologies of the temporomandibular joint in adult patients. An observational and descriptive study of patients who attended the Rehabilitation Dentistry Module of the Faculty of Dentistry was carried out; 60 patients who needed partial prosthetic rehabilitation were selected. The variables studied were age, sex, Kennedy class, joint pain, joint noises, mandibular restriction, and mandibular deviation. The data were loaded into a database designed for this purpose, for statistical analysis. From the analysis of the study, partial absence of teeth was observed with greater frequency in females (58%), 52% corresponded to Kennedy Class I: 64% in the lower jaw, 17% presented joint pain, 28 % joint noises, 68% presented mandibular deviation being the most frequent to the right, 42% presented mild mandibular restriction and only one n = 1 severe. Loss of the posterior bilateral teeth of the lower jaw are the most frequent associated with frequent TMJ pathologies. Starting from prevention, avoiding the loss of teeth and with correct rehabilitation, good oral health can be achieved (AU)

Sinus floor elevation using a new bovine bone grafting material: case report and bone grafting materials update / Actualización en materiales de relleno óseo: reporte de un caso clínico de elevamiento del piso del seno maxilar usando un nuevo material de relleno óseo bovino

Bone grafting is important to preserve the alveolar bone ridge height and volume for dental implant placement. Even though implant-supported overdentures present highly successful outcomes, it seems that a great number of edentulous individuals have not pursued implant-based rehabilitation. The cost of the treatment is one of the reasons of discrepancy between highly successful therapy and its acceptance. Therefore, the development of biomaterials for bone grafting with comparable characteristics and biological effects than those renowned internationally, is necessary. In addition, domestic manufacture would reduce the high costs in public health arising from the application of these biomaterials in the dental feld. The purpose of this clinical case report is to provide preliminary clinical evidence of the efficacy of a new bovine bone graft in the bone healing process when used for sinus floor elevation. (AU)

El uso de injertos óseos es importante para preservar la altura y el volumen de la cresta alveolar para la colocación de implantes dentales. Si bien las sobredentaduras implanto-soportadas presentan resultados altamente exitosos, la mayoría de las personas desdentadas no han sido rehabilitadas mediante implantes dentales. Uno de los principales motivos por los cuales los pacientes no aceptan este tipo de tratamiento, altamente exitoso, es el elevado costo del mismo. Por ello, es necesario el desarrollo de biomateriales de injerto óseo con características y efectos biológicos comparables a los reconocidos internacionalmente. Asimismo, la fabricación nacional reduciría los altos costos en Salud Pública derivados de la aplicación de estos biomateriales en el campo dental. El objetivo de esta comunicación es presentar un caso clínico a fin de proporcionar evidencia preliminar acerca de la eficacia de un nuevo injerto de hueso bovino en el proceso de cicatrización ósea en el levantamiento del piso del seno maxilar. (AU)

First-in-human study and clinical case reports of the alveolar bone regeneration with the secretome from human mesenchymal stem cells.

BACKGROUND: Secreted growth factors and cytokines in the conditioned medium from bone marrow-derived mesenchymal stem cells (MSC-CM) have several effects on cell behavior. Our previous studies revealed that MSC-CM enhances bone regeneration by increasing cell mobilization, angiogenesis, and osteogenesis in vitro and in vivo. This clinical study was undertaken to evaluate the safety and use of MSC-CM for alveolar bone regeneration in eight patients who were diagnosed as needing bone augmentation prior to dental implant placement. METHODS: The protocol of this clinical study was approved by the ethics committee of Nagoya University Hospital. MSC-CM was prepared from conditioned medium from commercially available human bone marrow-derived MSCs. Patients were treated with beta-tricalcium phosphate (ß-TCP) or an atelocollagen sponge soaked with MSC-CM. Clinical and radiographic assessments were performed during the follow-up period. Histological assessments were also performed in some cases. Clinical and histological data from patients who underwent the SFE procedure without MSC-CM were also used retrospectively as reference controls. RESULTS: MSC-CM contained several cytokines such as insulin-like growth factor-1, vascular endothelial growth factor, transforming growth factor-ß1, and hepatocyte growth factor in relatively low amounts. No systemic or local complications were reported throughout the study. Radiographic evaluation revealed early bone formation in all cases. Histological evaluation also supported the radiographic findings. Furthermore, infiltration of inflammatory cells was scarce throughout the specimens. CONCLUSIONS: MSC-CM was used safely and with less inflammatory signs and appears to have great osteogenic potential for regenerative medicine of bone. This is the first in-human clinical study of alveolar bone regeneration using MSC-CM.

Multivariate assessment of site of lingual nerve.

Injury to the lingual nerve can cause debilitating symptoms. The nerve lies in the retromolar region and its anatomical site can vary within patients and according to sex, age, and dentate status. To our knowledge, no previous studies have recorded its course from multiple bony landmarks and examined the association between age, dentate status, and sex, in the same sample. We dissected 30 white cadavers and took primary and secondary reference points from the internal oblique ridge. We measured the distance to the lingual nerve in sagittal, vertical, and horizontal planes, and recorded the position where the nerve was closest to the lingual plate. We dissected 46 hemimandibles (23 male, mean age 79 years, range 52-100) of which 26 were from the left side. Mean (SD) sagittal, vertical, and horizontal distances from the primary reference point were 9.29 (3.41)mm, 9.15 (3.87)mm, and 0.57 (0.56)mm, respectively. Mean (SD) vertical and horizontal distances from the secondary point were 7.79 (5.45) mm and 0.59 (0.64)mm, respectively. The proximity of the nerve to the lingual plate varied widely (range -13.00 to 15.17mm from the primary reference point). Dentate status was significant for the sagittal measurement from the primary point, and the vertical measurement from the secondary point. Differences in age, sex, or site of the contralateral nerve were not significant (n=16 pairs). Our findings suggest that the site of the nerve is consistent between and within subjects for sex and age, but not for dentate status. The association between the nerve and the lingual plate varied, which suggests that care must be taken when operating in the area.

Correlation of fractal dimension with histomorphometry in maxillary sinus lifting using autogenous bone graft.

The aim of this study was to determine the pattern of bone remodeling after maxillary sinus lifting in humans by means of fractal dimension (FD) and histomorphometric analysis. Therefore, the correlation between FD and the histomorphometric findings was evaluated. Sixteen patients with posterior edentulous maxilla were enrolled in this study. Maxillary sinus lifting was performed using autogenous bone grafted from the mandibular retromolar area. Three direct digital panoramic radiographs were obtained: before surgery (Group 1), immediately postoperatively (Group 2) and after 6 months of healing (Group 3) for FD analysis. Biopsies were taken after 6 months, processed and submitted to histological and histomorphometric analysis. Data were analyzed by Shapiro-Wilk test and ANOVA test followed by a Tukey test (a = 0.05). The bone volume fraction of newly trabecular bone (TB) and medullary area (MA) was measured as 62.75% ± 17.16% and 37.25 ± 17.16%, respectively. Significant difference in FD analysis was measured between Group 1 and Group 3. No significant difference was found in the correlation between FD and histomorphometric analysis for TB and MA (p = 0.84). In conclusion, all performed analyses were effective in assessing the bone-remodeling pattern in the maxillary sinus, offering complementary information about healing and predictable outcomes. There were no correlations between FD and histomorphometric analysis.

Correlation of Fractal Dimension with Histomorphometry in Maxillary Sinus Lifting Using Autogenous Bone Graft

The aim of this study was to determine the pattern of bone remodeling after maxillary sinus lifting in humans by means of fractal dimension (FD) and histomorphometric analysis. Therefore, the correlation between FD and the histomorphometric findings was evaluated. Sixteen patients with posterior edentulous maxilla were enrolled in this study. Maxillary sinus lifting was performed using autogenous bone grafted from the mandibular retromolar area. Three direct digital panoramic radiographs were obtained: before surgery (Group 1), immediately postoperatively (Group 2) and after 6 months of healing (Group 3) for FD analysis. Biopsies were taken after 6 months, processed and submitted to histological and histomorphometric analysis. Data were analyzed by Shapiro-Wilk test and ANOVA test followed by a Tukey test (a=0.05). The bone volume fraction of newly trabecular bone (TB) and medullary area (MA) was measured as 62.75%±17.16% and 37.25±17.16%, respectively. Significant difference in FD analysis was measured between Group 1 and Group 3. No significant difference was found in the correlation between FD and histomorphometric analysis for TB and MA (p=0.84). In conclusion, all performed analyses were effective in assessing the bone-remodeling pattern in the maxillary sinus, offering complementary information about healing and predictable outcomes. There were no correlations between FD and histomorphometric analysis.

O objetivo deste estudo foi determinar o padrão de remodelação óssea após levantamento de seio maxilar in humanos por meio de analise de dimensão fractal (FD) e histomorfometria. Além disso, a correlação entre FD e histomorfometria foi avaliada. Dezesseis pacientes com edentulismo na região posterior da maxila foram relacionados para este estudo. Levantamento de seio maxilar foi realizado utilizando-se enxerto de osso autógeno coletado da região retro molar da mandíbula. Três radiografias panorâmicas digitais foram obtidas: antes da cirurgia (Grupo 1), imediatamente após o levantamento de seio (Grupo 2) e após 6 meses de cicatrização (Grupo 3) para analise de FD. Biopsias foram coletadas após 6 meses, processadas e submetidas para analise histológica e histomorfométrica. Os dados foram analisados utilizando-se o teste Shapiro-Wilk e ANOVA seguido pelo pós teste de Tukey (a=0.05). A fração de volume de ósseo neoformado para o osso trabecular (TB) e para a área medular (MA) foi mensurado como 65,75%±17,16% and 37,25±17,16%, respectivamente. Diferença significante na analise FD foi observada entre os grupos 1 e 3. Nenhuma diferença estatística foi encontrada para correlação entre FD e histomorfometria para TB e MA (p=0,84). Em conclusão, todas as análises realizadas foram efetivas em acessar o padrão de remodelação ósseo no seio maxilar, oferecendo informações complementares sobre cicatrização e previsibilidade de resultados. Não houve correlação entre FD e histomorfometria.

Volumetric changes after sinus augmentation using blocks of autogenous iliac bone or freeze-dried allogeneic bone. A non-randomized study.

OBJECTIVES: To compare volumetric bone changes after sinus augmentation for implant positioning using blocks of autogenous iliac bone or freeze-dried allogeneic bone (FDBA) from the hip. Variables were compared between the two sources and for each surgical procedure at set times (pre- and post-augmentation procedure). PATIENTS AND METHODS: A non-randomized retrospective chart review of 7 patients who had autogenous and 7 allogeneic block grafts was carried out (1 procedure per patient). Analysis of Computer Tomographic (CT) data of maxillary sinuses, acquired with high-speed, double-detector CT scanner, was performed using dentascan software. The change between the preoperative (T0) and postoperative volume was measured at 4-6 months (T2) and 1.5 year after transplantation (T3). Annual- and overall-rates of bone change were calculated for the two sources. RESULTS: All patients were partially edentulous with a residual maxillary floor thickness in the planned implant insertion sites of 2.7 (0.5) mm and 2.8 (0.5) mm for allogeneic and autogenous procedures respectively. From identical intraoperative volume of grafts (2.25 cc at T1), volumetric changes were recorded at T2 and T3. The final volume of the grafts was 1.44 cc for allogeneic group and 1.78 cc for the autogenous group. Significant volumetric changes over time of transplanted grafts for both sources (23% for autograft and 18% for allograft) were found at T2. At 1.5-years post-operatively comparisons of volumes and rates of bone loss between sources were not statistically significant. No failure was recorded for either bone grafts or dental implants. CONCLUSIONS: Short-term sinus grafting procedure for dental implant placement performed with FDBA showed an outcome close to that reported for autogenous bone. Volumetric changes were comparable between the sources. These data suggest that performing maxillary sinus augmentation with dry-preserved bone allogeneic materials in block form could be considered even when the residual floor thickness is less than 3 mm.

Visualización del plano oclusal y guía anterior en desdentados parciales en la telerradiografía lateral: descripción de la técnica a través de casos clínicos / Occlusal plane and anterior guidance visualization in lateral cephalometric radiographs in partially edentulous patients: technique description through case reports

El uso de la telerradiografía lateral ha tomado gran importancia en Rehabilitación Oral ayudando al clínico en el diagnóstico y planificación del tratamiento a través de la identificación del biotipo facial del paciente, la inclinación del plano oclusal, la relación anteroposterior entre maxilar y mandíbula, inclinación de los ejes dentarios y como ayuda complementaria en casos de alteraciones de la Dimensión Vertical. El problema surge cuando estamos frente a pacientes desdentados que han perdido puntos de referencia cefalométricos necesarios para el análisis. El presente trabajo muestra una técnica para poder visualizar radiográficamente el plano oclusal y la guía anterior utilizando láminas de plomo.

The use of lateral cephalometric radiographs has become very important in Oral Rehabilitation, helping the clinician in the diagnosis and treatment planning through the identification of facial biotype, occlusal plane inclination, sagittal relationship between maxilla and mandible, inclination of the dental axes, and a valuable help in assessing alterations of the vertical dimension of occlusion. The problem arises when treating partially edentulous patients who have lost their cephalometric reference points necessary for the analysis. This paper shows a technique to visualize the occlusal plane and anterior guidance in partially edentulous patients who have lost these anatomical landmarks in a lateral cephalometric radiograph, using lead sheets.

Differences in peri-implant conditions between fully and partially edentulous subjects: a systematic review.

AIM: The aim of this study was to compare peri-implant conditions between fully edentulous (FES) and partially edentulous subjects (PES). MATERIAL AND METHODS: A systematic review was conducted. The MEDLINE, EMBASE and COCHRANE databases were searched for publications up to January 1st 2012. Studies reporting on the bleeding tendency of the peri-implant mucosa and/or studies reporting on the prevalence of peri-implant mucositis and/or peri-implantitis were considered. RESULTS: Fifty-five publications describing 46 studies were selected. One study described both FES and PES, and all other studies described either FES or PES. Subgroup analyses were performed according to dental status (fully/partially edentulous), follow-up time (≥5 years and ≥ 10 years) and study design (prospective/cross-sectional). FES harboured more plaque at their implants than PES. Modified bleeding index scores were significantly higher in FES, but no differences in bleeding on probing, implant loss and probing pocket depth were observed between FES and PES. No meta-analysis could be performed on prevalence of peri-implant mucositis and peri-implantitis. Overall prevalence of peri-implantitis was 0-3.4% after 5 years and 5.8-16.9% after 10 years of implant evaluation. CONCLUSION: FES and PES show comparable implant survival rates. However, no conclusion can be drawn regarding differences in prevalence of peri-implant mucositis and peri-implantitis between FES and PES.

Minimally invasive sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure: a multicenter retrospective study.

PURPOSE: The purpose of this study was to evaluate the success rate of implants and vertical bone gain of edentulous posterior maxilla using ultrasonic piezoelectric vibration and hydraulic pressure, namely the hydrodynamic piezoelectric internal sinus elevation (HPISE) technique through a crestal approach. MATERIALS AND METHODS: A total of 250 maxillary sinuses were augmented using HPISE and 353 implants (averaging 11.8 mm in length and 4.5 mm in diameter), with 12 different systems, were placed simultaneously with or without additional bone grafting. Plain radiograms and cone beam computed tomograms were taken in all patients to evaluate sinus augmentation. RESULTS: Membrane perforation was recorded at 10 of the 353 implant sites. The perforation rate was 2.83%. The total success rate of implantation was 97.2% after an average of 69.3 weeks of loading. CONCLUSION: The crestally approached sinus augmentation using ultrasonic piezoelectric vibration and hydraulic pressure is an additional method of maxillary sinus augmentation.

A laboratory study comparing the effect of ridge exposure using tissue punch versus mucoperiosteal flap on the formation of the implant-epithelial junction.

OBJECTIVE: The objective of the present study was to clarify the influence of the incision design at the time of implant placement on the consolidation of the implanto-epithelial junction. STUDY DESIGN: Twelve minipigs were chosen for the study. Four weeks after premolar extraction in the maxilla, 4 BEGO Semados RI implants were inserted in each quadrant. Using a split-mouth design, the alveolar crest was exposed by a punch ("flapless surgery") on one side and by a crestal incision ("flap surgery") on the other side. Biopsies were obtained from the peri-implant soft tissue at weeks 1, 2, 4, and 12 postinsertion, respectively, and analyzed for the expression of integrin α(6)ß(4) chain ß(4) (ITGB4) and laminin 5 γ(2) chain (lamc2), 2 important marker molecules for the formation of the implanto-epithelial junction. RESULTS: Following exposure of the alveolar crest by the punch technique, a significantly higher expression of ITGB4 was found at the 2- (P = .009), 4- (P = .001), and 12-week (P = .005) follow-up. Furthermore, the expression of lamc2 was significantly higher following punch exposure after 1 (P = .033), 2 (P = .041), 3 (P = .004), and 12 weeks (P = .002) of transmucosal implant healing. CONCLUSIONS: The data of the present study indicate that flapless placement improved the formation of a sufficient implanto-epithelial junction.

A relaxed implant bed: implants placed after two weeks of osteotomy with immediate loading: a one year clinical trial.

A waiting period of 2 weeks after osteotomy increases the surrounding tissue activity to its maximum level as collagen formation and neoangiogenesis represent a relaxed and acceptable implant bed configuration. The aim of the present study was a clinical and radiologic evaluation of early osteotomy with implant placement delayed for 2 weeks with immediate loading in the anterior and premolar region with minimally invasive approach. Seven GS II implants (Osstem) were placed in 6 patients. Osteotomy was done followed by flap closure without placement of the implant. After waiting for approximately 2 weeks, implant placement was done, which was loaded immediately with provisional crown in implant protected occlusion. It was replaced by definitive restoration after 6-8 weeks, which was considered baseline. Implant stability and marginal bone levels were assessed with clinical and radiologic parameters at baseline, 6- and 12-month intervals. None of the implants were found mobile during the 1-year period. The average mean marginal bone loss was 0.4 mm over the 1-year follow-up period. In the present study, early osteotomy with delayed implant placement showed negligible crestal bone loss with no mobility.

Morphology of the nasopalatine canal and dental implant surgery: a radiographic analysis of 100 consecutive patients using limited cone-beam computed tomography.

OBJECTIVES: To analyze the dimensions and anatomic characteristics of the nasopalatine canal and the corresponding buccal bone plate of the alveolar process, using limited cone-beam computed tomography (CBCT) imaging. MATERIAL AND METHODS: Partially edentulous patients scheduled for CBCT imaging for further radiographic evaluation of a prospective implant recipient site in the anterior maxilla were consecutively enrolled in this study. For all CBCT images, a limited field of view (FOV) of 4 × 4 cm, 6 × 6 cm or 8 × 8 cm was selected. Reformatted sagittal and coronal slices were analyzed with regard to dimensions and anatomic characteristics of the nasopalatine canal as well as the dimensions of the buccal bone wall. Factors influencing these parameters were evaluated using univariate and multivariate linear regression models. RESULTS: The study population comprised 44 men and 56 women with a mean age of 43.09 years. Gender of the included patients had a statistically significant influence on the dimensions of the buccal bone plate, the mean values being generally higher for male subjects. In the multivariate linear regression model, the status of the central maxillary incisors (both present, one missing, and both missing) and the time elapsed since loss of the central incisors (<1 year vs. >1 year) were independently associated with buccal bone wall measurements, adjusted for age and sex. CONCLUSION: The present study demonstrates decreasing values for the coronal width of the buccal bone wall in patients with missing central incisors and a time span since tooth loss of over 1 year. The age of the patients had a significant influence only on the length of the nasopalatine canal, with the mean values generally decreasing with an increasing age. The limited CBCT scans with FOVs varying between 4 × 4 and 8 × 8 cm are a valid diagnostic alternative to cross-sectional imaging in the anterior maxilla for dental implant treatment planning.

Bone density at implant sites and its relationship to assessment of bone quality and treatment outcome.

PURPOSE: To investigate the relationship between bone mineral density (BMD) before implant placement, implant stability measures at implant placement, and marginal bone loss of immediately loaded implants after 1 year in situ. MATERIALS AND METHODS: Consecutively recruited patients received Straumann SLActive implants loaded with fixed provisional prostheses within 24 hours. BMD was measured from computed tomographic images before implant placement. Alveolar bone quality was assessed during surgery. Implant stability-both rotational and as measured with resonance frequency analysis-and marginal bone height were assessed at implant placement and after 1 year. The Pearson correlation coefficient was used to calculate correlations, and significance was considered when P < .05. RESULTS: Twenty-one patients received 137 implants (87 in maxillae and 50 in mandibles). BMD was significantly correlated with bone quality classification in both arches (P < .001). Mean BMD was also significantly correlated with stability values (P < .001). Mean marginal bone loss at implant surfaces differed, but not significantly, at the 1-year follow-up, regardless of BMD values (P = .086) and measured stability (rotational stability P = .34, resonance frequency analysis P = .43) at implant placement. CONCLUSION: Within the limits of this study, it can be concluded that computed tomographic examination can be used as a preoperative method to assess jawbone density before implant placement, since density values correlate with prevailing methods of measuring implant stability. However, in the short time perspective of 1 year, there were no differences in survival rates or changes in marginal bone level between implants placed in bone tissue of different density.

Clinical evaluation of marginal bone level change of multiple adjacent implants restored with splinted and nonsplinted restorations: a 5-year prospective study.

PURPOSE: The success of single-tooth implant restorations has resulted in an increased use of nonsplinted implants to replace adjacent missing teeth; however, this may result in excessive force transmission to the implant and bone, causing bone loss. The purpose of this prospective study was to compare the marginal bone level change of adjacent splinted implants and of nonsplinted implants functionally loaded with cemented restorations up to 5 years in maxillae. MATERIAL AND METHODS: Between 2002 and 2004, all patients who received three consecutive adjacent implants in a private office and a university implant dentistry department were included in this study. All implants were placed in posterior maxillae. Maxillary left implants were restored with splinted cemented restorations, and maxillary right implants were restored with nonsplinted cemented restorations. Marginal bone resorption was measured with intraoral radiographs annually for 5 years. The data were analyzed statistically with the Mann-Whitney U test and the two-sample Kolmogorov-Smirnov test to identify differences between splinted and nonsplinted implant restorations. RESULTS: One hundred thirty-two implants were placed in 44 patients. Two subjects (6 implants in total) did not complete the study. Three implants failed at stage-two surgery. Of the remaining 123 implants, 63 were restored with splinted cemented restorations and 60 were restored with nonsplinted cemented restorations. The mean marginal bone level changes at the 5-year recall were -0.7 ± 0.2 mm for splinted restorations and -0.8 ± 0.2 mm) for nonsplinted restorations. CONCLUSIONS: Peri-implant marginal bone loss around nonsplinted implants in the present study was statistically equivalent to that observed in splinted implants. Multiple nonsplinted implants can be successfully included in many clinical situations in an effort to optimize esthetics and circumvent the problem of nonpassively fitting frameworks.

Adjacent dentigerous cysts with the ectopic displacement of a third mandibular molar and supernumerary (forth) molar: a rare occurrence.

Dentigerous cysts are the most common odontological cysts of the jaws, being associated with the crowns of permanent teeth, especially unerupted mandibular third molars. Multiple dentigerous cysts are rare and most often occur in association with a developmental syndrome. This article presents an unusual case of nonsyndromic adjacent dentigerous cysts associated with a mandibular third molar and a supernumerary molar. This occurrence has not been previously reported.

Measurement of anterior loop length for the mandibular canal and diameter of the mandibular incisive canal to avoid nerve damage when installing endosseous implants in the interforaminal region: a second attempt introducing cone beam computed tomography.

PURPOSE: To measure and compare the anterior loop length (ALL) for the mandibular canal and the mandibular incisive canal diameter (ICD) at its origin in cadavers using anatomy and cone beam computed tomography (CBCT) to safely install endosseous implants in the most distal area of the interforaminal region. MATERIALS AND METHODS: The ALL and ICD were measured using CBCT in 4 cadavers, and using anatomy in 71 cadavers. RESULTS: The ranges and mean +/- SD for the anatomic measurements were: ALL, 0.0 to 9.0 mm and 1.9 +/- 1.7 mm; ICD, 1.0 to 6.6 mm and 2.8 +/- 1.0 mm. The average discrepancies between CBCT and anatomic measurements were 0.06 mm or less for both the ALL and the ICD, which were less than the resolution of CBCT. CONCLUSIONS: Because large variations in measurements were observed, both for ALL and ICD, no fixed distance mesially from the mental foramen should be considered safe. The ALL and the ICD can be estimated from the CBCT measurement. The preoperative CBCT measurement yields important information for each case.

Methods to treat the edentulous posterior maxilla: implants with sinus grafting.

Prosthetic rehabilitation of the edentulous posterior maxilla with implant-supported prostheses frequently presents a challenge for the oral surgeon because of the lack of bone due to alveolar ridge resorption or maxillary sinus pneumatization. To overcome these problems, different solutions were proposed over the years, such as the use of short implants or tilted implants (including zygoma implants), with the aim of avoiding maxillary sinus floor elevation. Both of these techniques have advantages and disadvantages that should be evaluated carefully to choose the most appropriate treatment. Zygoma implants or short/tilted implants are not a panacea for the treatment of patients with inadequate posterior maxillary bone stock. Instead, treatment should be based on the characterization of resorption patterns of the posterior maxilla, and may include the need for sinus grafting or other grafting procedures to reestablish not only adequate bone volume for implant placement, but also a favorable intermaxillary relationship, to optimize the functional and esthetic outcome of the final prosthetic rehabilitation. The authors discuss the indications, advantages, and disadvantages of sinus-grafting procedures in association with or without other reconstructive procedures.

A new technique for reconstruction of the atrophied narrow alveolar crest in the maxilla using morselized impacted bone allograft and later placement of dental implants.

BACKGROUND: In cases when the alveolar crest is too narrow to host an implant, lateral augmentation is required. The use of autogenous bone blocks harvested from the iliac crest is often demanded. One disadvantage is the associated patient morbidity. PURPOSE: The purpose of this study was to clinically and histologically evaluate the use of morselized impacted bone allograft, a novel technique for reconstruction of the narrow alveolar crest. MATERIALS AND METHODS: Two patients with completely edentulous maxillae and one partially edentulous, with a mean age of 77 years (range 76-79 years) were included in the study. The alveolar crest width was <3 mm without possibility to place any implant. Bone grafts were taken from a bone bank in Gävle Hospital. Bone from the neck of femur heads was milled to produce bone chips. The milled bone was partially defatted by rinsing in 37 degrees C saline solution. After compression of the graft pieces with a size of 15 mm (height), 30 mm (length), and 6 mm (width), they were then fit to adapt to the buccal surface of the atrophied alveolar crest. One piece was placed to the right and one to the left side of the midline. On both sides fibrin glue was used (Tisseel, Baxter AG, Vienna, Austria) to stabilize the graft. After 6 months of graft healing, dental implants were placed, simultaneously biopsies were harvested and in one patient two oxidized microimplants were placed. At the time of abutment connection, microimplants were retrieved with surrounding bone for histology. Fixed screw-retained bridges were fabricated in mean of 7 months after implant surgery. Radiographs were taken before and after implant surgery and after 1 year of loading. RESULTS: Sixteen implants with an oxidized surface were placed (TiUnite, Nobel Biocare AB, Göteborg, Sweden). After 1 year of functional loading, all implants were clinically stable. The marginal bone loss was 1.4 mm (SD 0.3) after 1 year of loading. The histological examination showed resorption and subsequent bone formation on the allograft particles. There were no signs of inflammatory cell infiltration in conjunction with the allograft. The two microimplants showed bone formation directly on the implant surface. CONCLUSIONS: This study shows that morselized impacted bone allograft can be used to increase the width of the atrophied narrow alveolar crest as a good alternative to autogenous bone grafts in elderly patients. The histological examination of biopsies revealed a normal incorporation process and no signs of an immunological reaction. Further studies with larger samples are of important to be able to conclude if equal results can be obtained using morselized impacted bone allograft as for autogenous bone graft.