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.

Implant-to-root dimensions projected by panoramic radiographs inthe maxillary canine-premolar region: implications for dental implant treatment.

BACKGOUND: This study aimed to compare panoramic radiography (PAN) and cone beam computed tomography (CBCT) determinations of implant-to-root dimensions (IRD) in anterior and posterior maxillary regions, and to help determine in which instances increased radiation exposure from CBCT scans may be justified. METHODS: IRD measured by PAN (PAN-D) from implant-to-root sites (central incisor, lateral incisor, canine, first premolar, and second premolar) was collected from 418 implant sites in 110 adults. The CBCT technique was used as the reference method for the estimation of IRD. The PAN analysis equations were developed using stepwise multiple regression analysis and the Bland-Altman approach was applied to assess the agreement between PAN and CBCT methods. RESULTS: The odds ratio that an implant at the canine-to-first premolar (9.7:1) (P = 0.000) or at the first premolar-to-second premolar region (4.5:1) (P = 0.000) belongs to the underestimation group was strong and highly significant. The root mean square error (RMSE) and pure error (PE) were highest for the canine-to-first premolar (RMSE = 0.886 mm, PE = 0.45 mm) and the first premolar-to-second premolar region (4.5:1) (RMSE = 0.944 mm, PE = 0.38 mm). CONCLUSIONS: This study provides evidence of site-specific underestimations of available horizontal bone dimensions for implants when assessed by PAN. These data suggest that the canines and first and second premolars may have to be excluded when assessing root angulations via PAN.

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)

Outcomes of maxillary sinus floor augmentation without grafts in atrophic maxilla: A systematic review and meta-analysis based on randomised controlled trials.

BACKGROUND: Maxillary sinus floor augmentation without grafts has been more widely used, but the efficacy is still controversial. PURPOSE: The aim of this review was to systematically evaluate the effectiveness of sinus floor augmentation without grafts in atrophic maxilla. METHODS: The electronic databases included PubMed, EMBASE and the Cochrane Central Register of Controlled Trials. The meta-analysis was conducted by Review Manager 5.1. The quality of evidence was assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE). RESULTS: The electronic database and manual search yield 707 studies. After critical selection, only 6 studies were eligible. Five studies with 336 implants were included in the meta-analysis compared sinus augmentation with grafts to without grafts. No significant differences were found between the two groups in implant survivals (P = 0.94), marginal bone loss (P = 0.73) and new bone density (P = 0.54). There was significantly more endosinus bone gain in the grafting group (P = 0.02). According to the GRADE, the levels of evidence were moderate (implant survival and marginal bone loss), low (endosinus bone gain) and very low (new bone density). CONCLUSION: There were no significant differences between maxillary sinus augmentation with and without grafts in short-term implant survivals.

Marginal bone level and survival of short and standard-length implants after 3 years: An Open Multi-Center Randomized Controlled Clinical Trial.

OBJECTIVES: The present multi-center randomized controlled clinical trial sought to compare the marginal bone level (MBL) changes and survival of 6- and 11-mm implants. MATERIAL AND METHODS: Ninety-five patients receiving a total of 209 dental implants were enrolled. Subjects were randomly allocated to two cohorts: test (4.0 × 6 mm; N = 108) or control (4.0 × 11 mm; N = 101) implant groups. To be randomized, all edentulous sites were anatomically qualified to receive 11 mm implant. Two to three implants were placed in maxillary or mandibular posterior regions and loaded with splinted provisional restoration after 6 weeks and definitive restoration 6 months thereafter. Test and control implants were followed by clinical and radiographic examinations on an annual basis up to 3 years. RESULTS: Radiographic assessment of MBL 3 years after loading revealed the bone to be located at 0.27 mm (±0.40) and 0.44 mm (±0.74) apical to the implant platform in the test and control groups, respectively. During the 3 years of follow-up since loading, 0.04 mm (±0.43) MBL gain and 0.02 mm (±0.76) of MBL loss were observed in the 6-mm (test) and 11-mm (control) groups, respectively. The MBL's for test and control were significantly different (p = 0.000) in favor of short implants. The cumulative survival rates from placement after 3 years were 96% and 99% for the 6- and 11-mm implants, respectively, with no statistical significance. CONCLUSIONS: Reconstruction of partially edentulous posterior maxilla or mandible with 6- or 11-mm implants led to stable marginal bone level and high implant survival rate after 3 years.

Mesiodistal dental movement toward remodeled edentulous alveolar ridge: Digital model assessment.

INTRODUCTION: The aims of this study were to compare the changes in posterior dental inclination and angulation, and the posterior tooth crown sizes and alveolar ridge thicknesses consequent to the orthodontic procedures of closing and opening of mandibular first molar edentulous spaces. METHODS: The sample comprised 16 patients (4 men, 12 women) with an initial mean age of 34.17 years and unilateral or bilateral absence of mandibular permanent first molars. The space closure group (SCG) comprised 12 hemiarches with a mandibular first molar edentulous space varying from 2 to 7 mm, orthodontically treated with space closure. The space opening group (SOG) comprised 14 quadrants with a mandibular first molar edentulous space varying from 7.1 to 12 mm, orthodontically treated with space reopening for prosthetic replacement. Digital dental models were obtained before treatment and after space closure or opening, and posterior tooth angulation and inclination, cervico-occlusal crown height, and alveolar ridge thickness were evaluated. Interphase and intergroup comparisons were performed with dependent t tests and t tests, respectively (P <0.05). RESULTS: Mandibular second molar uprighting and changes in buccolingual inclination of the posterior teeth were similar in the groups. The second molar cervico-occlusal crown height increased in the SCG and decreased in the SOG. The alveolar ridge thickness increased in the SCG and remained stable in the SOG. CONCLUSIONS: The only significant intergroup differences were that the second molar cervico-occlusal crown height and the alveolar ridge thickness increased in the SCG, and decreased and remained stable in the SOG.

Precision of Dental Implant Digitization Using Intraoral Scanners.

PURPOSE: The digitization of scanbodies on dental implants is required to use computer-aided design/computer-assisted manufacture processes for implant prosthetics. Little is known about the accuracy of scanbody digitization with intraoral scanners and dental lab scanners. This study aimed to examine the precision of different intraoral digital impression systems as well as a dental lab scanner using commercially available implant scanbodies. MATERIALS AND METHODS: Two study models with a different number and distribution of dental implant scanbodies were produced from conventional implant impressions. The study models were scanned using three different intraoral scanners (iTero, Cadent; Trios, 3Shape; and True Definition, 3M ESPE) and a dental lab scanner (D250, 3Shape). For each study model, 10 scans were performed per scanner to produce repeated measurements for the calculation of precision. The distance and angulation between the respective scanbodies were measured. The results of each scanning system were compared using analysis of variance, and post hoc Tukey test was conducted for a pairwise comparison of scanning devices. RESULTS: The precision values of the scanbodies varied according to the distance between the scanbodies and the scanning device. A distance of a single tooth space and a jaw-traversing distance between scanbodies produced significantly different results for distance and angle measurements between the scanning systems (P < .05). CONCLUSION: The precision of intraoral scanners and the dental lab scanner was significantly different. The precision of intraoral scanners decreased with an increasing distance between the scanbodies, whereas the precision of the dental lab scanner was independent of the distance between the scanbodies.

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.

Effect of prosthetic restoration on oral health-related quality of life in patients with shortened dental arches: a multicentre study.

The aim of this multicentre prospective study was to investigate the effect of prosthetic restoration for missing posterior teeth in patients with shortened dental arches (SDAs). SDA patients with 2-12 missing occlusal units (a pair of occluding premolars corresponds to one unit, and a pair of occluding molars corresponds to two units) were consecutively recruited from seven university-based dental hospitals in Japan. Patients chose no replacement of missing teeth or prosthetic treatment with removable partial dentures (RPDs) or implant-supported fixed partial dentures (IFPDs). Oral health-related quality of life (OHRQoL) was measured using the oral health impact profile (Japanese version - OHIP-J) at baseline and follow-up/post-treatment evaluation. Of the 169 subjects who completed baseline evaluation, 125 subjects (mean age; 63.0 years) received follow-up/post-treatment evaluation. No-treatment was chosen by 42% (53/125) of the subjects, and 58% (72/125) chose treatment with a RPD (n = 53) or an IFPD (n = 19). In the no-treatment (NT) group, the mean OHIP summary score at baseline was similar to that at follow-up evaluation (P = 0.69). In the treatment (TRT) group, the mean OHIP summary score decreased significantly after the RPD treatment (P = 0.002), and it tended to decrease, though not statistically significant (P = 0.18), after the IFPD treatment. The restoration of one occlusal unit was associated with a 1.2-point decrease in OHIP summary score (P = 0.034). These results suggest that the replacement of missing posterior teeth with RPDs or IFPDs improved OHRQoL. Prosthetic restoration for SDAs may benefit OHRQoL in patients needing replacement of missing posterior teeth.

Accuracy of surgical guides made from conventional and a combination of digital scanning and rapid prototyping techniques.

STATEMENT OF PROBLEM: Surgical guides aid in accurately placing dental implants to achieve a predictable restorative outcome. Which surgical guide fabrication technique results in the most accurately fitting surgical guide is unknown. PURPOSE: The purpose of this investigation was to determine the internal fit of dental implant surgical guides on dentate and edentulous ridges by using implant surgical guides fabricated from conventional and computer-aided design/computer-aided manufacturing (CAD/CAM) techniques. MATERIAL AND METHODS: Eighty surgical guides were fabricated from conventional and CAD/CAM techniques; half were designed from Kennedy Class 2 (K2) casts, and half were designed from Kennedy Class 3 (K3) casts. Conventional surgical guides were fabricated from acrylic resin. The CAD/CAM surgical guides were scanned by using cone beam computed tomography (CBCT) or an optical scan (OS). The guides were printed with stereolithography (SL) or 3-dimensional digital printing (3DP). All surgical guides were cemented to their respective design casts, sectioned, and measured at standardized locations. A 2-way ANOVA and the post hoc Fisher least square difference t test was performed (α=.05). RESULTS: The 2-way ANOVA indicated that the difference between surgical guide groups and Kennedy class was statistically significant (P<.05) and the interaction between groups and Kennedy class was statistically significant (P<.05). The OS/3DP CAD/CAM guide was the best-fitting cast for the K2 cast group, and the conventional guide was the best-fitting guide for the K3 group. CONCLUSIONS: Conventionally fabricated and OS surgical guides have greater accuracy of fit than CBCT scanned surgical guides.

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.

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.

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.

Guided "sandwich" technique: a novel surgical approach for safe osteotomies in the treatment of vertical bone defects in the posterior atrophic mandible: a case report.

PURPOSE: A novel technique to perform safe osteotomies during inlay block regenerative procedures in the posterior atrophic mandible is described. MATERIAL AND METHODS: A 52-year-old male patient with vertical atrophy of the left posterior mandible was treated adopting an inlay block "sandwich" technique using an allogenic cancelous block and a mixture of mineralized and demineralized human bone allograft in putty form as graft. The horizontal osteotomy for the lifting of the osteotomized bone segment was performed using a template prepared from a virtual anatomical replica of the patient's mandible obtained from cone beam computed tomography data. In the second surgical phase, 3 months after the augmentation, 2 implants were easily placed. RESULTS: The horizontal osteotomy was carried out, with no risk, very close to the nerve structures after the precise osteotomy line established preoperatively on the three-dimensional computed tomography (3D-CT) virtual reconstruction. No neurological complications were observed in the first days after the procedure, and no subsequent problems were recorded during the 3-month healing period. CONCLUSION: Radiographic evaluations and complication-free clinical healing demonstrate the effectiveness of this technique to obtain safe and precise osteotomies.

Vertical ridge augmentation of the atrophic posterior mandible with sandwich technique: bone block from the chin area versus corticocancellous bone block allograft--clinical and histological prospective randomized controlled study.

UNLABELLED: The aim of the present study is to compare the histological aspects of bone formation in atrophic posterior mandibles augmented by autologous bone block from chin area with corticocancellous bone block allograft used as inlays with the sandwich technique. MATERIALS AND METHODS: Sixteen patients with bilateral partial edentulism in the posterior mandible were selected. The residual bone height, preliminarily measured by computed tomography scans, ranged between 5 and 7 mm from the inferior alveolar nerve. All patients required regeneration procedure with autologous bone block from chin area (control group) versus bone block allograft Puros (Zimmer Dental, 1900 Aston Avenue, Carlsbad, CA, USA) (test group). Histological and histomorphometric samples were collected at the time of implant positioning in order to analyze the percentage of newly formed bone, the residual graft material, and marrow spaces/soft tissue. RESULTS: No statistically significant differences between the two groups were found regarding the percentage of newly formed bone. The percentage of residual grafted material was significantly higher in the test group, whilst the percentage of marrow spaces was higher in control group. CONCLUSIONS: In conclusion, both procedures supported good results, although the use of bone blocks allograft was less invasive and preferable than harvesting bone from the mental symphysis.

Implant site development in the distal region of the mandible: bone formation and its stability over time.

INTRODUCTION: The purpose of this study was to determine the dimensional changes that occur in the alveolar ridge of patients upon distalization of the mandibular first premolars into the place of congenitally missing mandibular second premolars. The amount of bone formation that accompanied orthodontic treatment and the long-term stability of the new bone were assessed. METHODS: Fifty-five patients were included in the study, representing 71 congenitally missing mandibular second premolars. The dimensional changes were evaluated by comparing the dental stone casts and panoramic radiographs taken at treatment initiation (T1) and end (T2) and at follow-ups of 2 years (T3A) and 5 years (T3B). RESULTS: During the treatment period (T1-T2), the alveolar ridge width increased by an average of 28.5%, and the height increased by an average of 1.1 mm. During the retention periods (T2-T3A, T2-T3B), the alveolar ridge decreased by an average of 4.2%, but the height decreased only slightly (by an average of 0.07 mm). CONCLUSIONS: Orthodontic tooth movement created a significant amount of new bone that was stable in both the horizontal and vertical directions.

The randomized shortened dental arch study: temporomandibular disorder pain.

OBJECTIVES: The aim of this multi-center, randomized controlled trial was to assess the impact of missing posterior support on the risk for temporomandibular disorder (TMD) pain by comparing patients with either shortened dental arches (SDA) or molar replacement by removable dental prostheses (RDP). METHODS: A sample of 215 patients with bilateral molar loss in at least one jaw was consecutively recruited in 14 prosthodontic departments of dental schools in Germany. Of the initial sample, 152 patients (mean age: 59.7 years; 53.9 % female) received randomly allocated interventions (SDA: n = 71; RDP: n = 81). Presence of TMD pain was assessed using patients' self-reports and was verified by physical examination and by pain intensity, as the mean of current pain, worst pain, and average pain in the last 6 months, with 10-point ordinal rating scales. Assessments were performed before treatment and at follow-ups until 60 months after treatment. Impact of interventions on TMD risk and pain intensity was computed by applying logistic and linear random-intercept models. RESULTS: Tooth replacement (RDP) did not significantly change the risk for self-reported (odds ratio [OR]: 1.1; confidence interval [CI]: 0.4 to 3.4) or clinically verified (OR: 0.7; CI: 0.1 to 4.3) TMD pain compared to no tooth replacement (SDA). Mean characteristic pain intensity was virtually identical in both groups (Coeff: 0.01; CI: -0.30 to 0.32). CONCLUSION: Retaining or preservation of an SDA is not a major risk factor for TMD pain over the course of 5 years when compared to molar replacement with RPDs. CLINICAL RELEVANCE: Seemingly, missing molars do not have to be replaced in order to prevent TMD pain.

Clinical performance of cantilevered fixed dental prostheses abutments in the shortened dental arch.

OBJECTIVES: This article is part of a randomized clinical trial on different treatments in the shortened dental arch (SDA). It focused on the abutment tooth prognosis with cantilevered fixed dental prostheses (CFDPs). METHODS: Sixty-two patients with a bilaterally SDA up to the first or second premolar in the mandible or maxilla were evaluated. In 57 of 124 quadrants, second premolars were replaced by a CFDP (cantilever group). In the remaining 67 quadrants, a natural second premolar was present and thus no need for a CFDP was given (non-cantilever group). Patients were recalled annually up to 5 years. RESULTS: The mean observation period was 56.3 months (min. 3.0, max. 76.2, SD 16.1). Kaplan-Meier survival rates concerning tooth loss and tooth fracture were 93.9%/94.0% in the cantilever group and 91.9%/92.8% in the non-cantilever group. Differences between both groups were not significant. The survival rate concerning loss of retention of CFDP retainers was 92.1% in the cantilever group. CONCLUSION: After 5 years of clinical service, CFDPs for the replacement of the second premolar showed no negative impact on the abutment tooth prognosis. CLINICAL SIGNIFICANCE: Cantilevered fixed dental prostheses present a viable treatment option in the shortened dental arch without compromising the medium-term abutment tooth prognosis.

Maxillary sinus lateral wall thickness and morphologic patterns in the atrophic posterior maxilla.

BACKGROUND: The aim of the present study is to examine the sinus lateral wall thickness (LWT) of atrophic posterior maxilla (<10 mm) of patients with complete and partial edentulism and determine the influence of residual ridge height (RH), sex, and age on maxillary LWT. METHODS: Four hundred fourteen measures were taken from 140 consecutive patients that met the inclusion criteria. On the selected sagittal section, a built-in digital caliper recorded in millimeters the RH and LWT (a perpendicular line at 3, 5, 7, 10, 13, and 15 mm from the lowest point of the sinus floor). Edentulous spans were further classified as complete edentulous atrophic maxilla (CEM) and partial edentulous atrophic maxilla (PEM). The mixed linear model was used to test the effects of sex, type of edentulism, edentulous span, and RH on the measurement of the LWT of the sinus. RESULTS: Mean LWT for PEM was 1.71 ± 0.12 mm, and for CEM, 1.57 ± 0.07 mm (P = 0.01). The mixed model yielded significant effect of edentulous span (P = 0.048) and interactions among type of edentulism and edentulous span (P <0.001) and edentulous span by RH (P <0.01). Age and RH were positively associated with LWT; however, they did not interact with RH, sex, or type of edentulism. RH has been shown to correlate with edentulous span (P <0.001) and type of edentulism (P = 0.01). The longer the edentulous span, the thinner the LWT. Similarly, RH was larger for PEM (6.85 ± 0.34 mm) than CEM (5.69 ± 0.26 mm). CONCLUSIONS: The maxillary sinus lateral wall tends to increase in thickness from the second premolar to the second molar and from 5 mm up to 15 mm. In addition, RH, presence of teeth adjacent to the edentulous atrophic ridge, and age were shown to influence maxillary sinus LWT.