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Purpose: To analyze and compare the frequency, type, and location of maxillary sinus septa in patients with a dentate and an edentulous posterior maxilla using cone beam computed tomography (CBCT) imaging., Materials and Methods: The study consisted of 100 maxillary sinuses: 50 from patients with a dentate and 50 from patients with an edentulous posterior maxilla. The aim was to assess the frequency, morphology, and location of maxillary sinus septa in axial, sagittal, and coronal CBCT images. Images were only included in this study provided that patients were older than 30 years of age, at least one maxillary sinus was completely visible in the field of view (FOV), and the sinus membrane exhibited a mucosal thickening of a maximum 4 mm. Differences regarding age, sex, side, septa location, and type of dentition (dentate/edentulous posterior maxilla) were analyzed., Results: The mean age of the 100 patients (66 women, 34 men) was 58.3 years. A total of 60 sinus septa were found in exactly half of the evaluated sinuses. The major part of the septa was found on the floor of the maxillary sinus (n = 34/56.7%). Of these, the majority was located in the posterior maxilla in the region of the second molars (n = 27/79.4%). The most common orientation of the septa was coronal (63.3%), followed by septa in relation to the infraorbital canal (23.3%). Regarding the status of the dentition in the posterior maxilla in relation to the distribution of sinus septa, septa were present in 26 (52%) dentate and in 24 (48%) edentulous regions. Thus, for a potential influence of the status of the dentition in the posterior maxilla on the frequency of sinus septa, no significant impact was found (P = .69)., Conclusion: Sinus septa are frequent anatomical structures, and are found equally often in patients with a dentate and an edentulous posterior maxilla. This is of clinical relevance, as patients with missing teeth in the posterior area of the maxilla are often in need of a sinus floor elevation (SFE) procedure when dental implant placement is intended. As sinus septa are reported to be an important reason for surgical complications during SFE, a three-dimensional radiographic examination using CBCT prior to surgery might be helpful for diagnostic evaluation and treatment planning.

Purpose: To evaluate the frequency, morphology, and locations of maxillary sinus septa using cone beam computed tomographic (CBCT) imaging of the entire maxillary sinus and to analyze factors influencing the presence or absence of septa., Materials and Methods: CBCT images of the maxilla taken during a 1-year study period (October 1, 2012, to September 30, 2013) were evaluated for the presence and type of septa as well as the health or pathology of the maxillary sinus. Differences in age, gender, type of dentition, septa location, and sinus pathology with regard to the incidence of sinus septa were analyzed statistically., Results: The study included 294 maxillary sinuses in 212 patients (126 women and 86 men) with a mean age of 53.8 years. Sinus septa were present in 141 patients (66.5%) and in 166 of 294 sinuses (56.5%). The most common orientation of the septa was coronal (61.8%), 7.6% were oriented axially, and 3.6% were aligned sagittally. Most septa were located on the floor of the maxillary sinus (58.6%), commonly (60.7%) in the region of the first and second molars. The maxillary sinuses were diagnosed in 36.4% of cases as healthy and without thickening of the sinus membrane. Sex was a significant variable in the health of the maxillary sinus; 57.7% of the sinuses in women and 72.3% in men were diagnosed as pathologic., Conclusion: Septa are common anatomical structures and are most often found in the first or second molar region on the floor of the maxillary sinus. To prevent possible complications during sinus floor elevation procedures, a thorough three-dimensional radiographic examination of the sinus prior to surgery is recommended.

Purpose: To analyze the frequency of perforation of the sinus membrane during maxillary sinus floor elevation (SFE) and to assess possible risk factors., Materials and Methods: Seventy-seven cases of SFE performed with a lateral window approach were evaluated retrospectively. Clinical and radiographic variables potentially influencing the risk of sinus membrane perforation were evaluated and divided into patient-related factors (age, sex, smoking habit); surgery-related factors (type of surgical approach, side, units, sites, and technique of osteotomy); and maxillary sinus-related factors (presence and height of septum, height of residual ridge, thickness of lateral sinus wall, width of antrum, and thickness and status of sinus membrane)., Results: The following factors presented with at least a 10% difference in rates of perforations: smokers (46.2%) versus nonsmokers (23.4%), simultaneous (32%) versus staged (18.5%) approach, mixed premolar-molar sites (41.2%) versus premolar-only sites (16.7%) versus molar-only sites (26.2%), presence of septa (42.9%) versus no septa (23.8%), and minimum height of residual ridge ≤4 mm (34.2%) versus > 4 mm (20.5%). These same parameters, except minimum height of residual ridge, also showed an odds ratio above 2. However, none of the comparisons reached statistical significance., Conclusion: The present study failed to demonstrate any factor that statistically significantly increased the risk of sinus membrane perforation during SFE using the lateral window approach.

Purpose: To systematically review clinical studies examining the survival and success rates of implants in horizontal ridge augmentation, either prior to or in conjunction with implant placement in the anterior maxilla., Materials and Methods: A literature search was undertaken up to September 2012 including clinical studies in English with ≥ 10 consecutively treated patients and a mean follow-up of at least 12 months. Two reviewers screened the pertinent articles and extracted the data. Key words focused on the outcome parameters (implant success, implant survival, horizontal bone gain, and intra- and postoperative complications) in studies utilizing either a simultaneous approach (ridge augmentation performed at the time of implant placement) or a staged approach (ridge augmentation performed prior to implant placement) were analyzed., Results: A total of 13 studies met the inclusion criteria, with 2 studies in the simultaneous group and 11 studies in the staged group. In the simultaneous group, survival rates of implants were 100% in both studies, with one study also reporting a 100% implant success rate. No data on horizontal bone gain were available. In the staged group, success rates of implants placed in horizontally augmented ridges ranged from 96.8% to 100% (two studies), and survival rates ranged from 93.5% to 100% (five studies). However, follow-up periods differed widely (up to 4.1 years). Mean horizontal bone gain determined at reentry (implant placement) ranged from 3.4 to 5.0 mm with large overall variations (0 to 9.8 mm, five studies). Intraoperative complications were not reported. Postsurgical complications included mainly mucosal dehiscences (five studies), and, occasionally, complete failures of block grafts were described in one study., Conclusions: Staged and simultaneous augmentation procedures in the anterior maxilla are both associated with high implant success and survival rates. The level of evidence, however, is better for the staged approach than for the simultaneous one.

Purpose: To evaluate the pulp sensitivity and vitality of mandibular incisors and canines before and after bone harvesting in the symphysis., Materials and Methods: In 20 patients requiring bone grafts from the symphysis, pulp sensitivity (carbon dioxide [CO2]) and pulpal blood flow (laser Doppler flowmetry [LDF]) of mandibular incisors and canines were evaluated preoperatively, postoperatively, and 6 months after surgery. Teeth were allocated to 1 of 3 groups according to their initial and final reaction to CO2 (group A = teeth with a positive reaction throughout the study, group B = teeth that exhibited a sensitivity change from positive to negative, and group C = teeth with a negative reaction throughout the study)., Results: Preoperative flux measurements (LDF) did not differ between groups A, B, and C. Teeth with sensitivity changes (group B) showed the greatest decrease (a statistically significant decrease) of pulpal blood flow over time, whereas teeth in groups A and C demonstrated an insignificant reduction of flux over time., Discussion and Conclusions: LDF was purely used as an experimental tool in the present study. Pulpal blood flow measurements using LDF demonstrated a decrease of flux over time in anterior mandibular teeth following bone harvesting in the symphysis. A significant change of flux, however, was only observed for teeth that also demonstrated a loss of pulp sensitivity during the same study period. Loss of pulp sensitivity appeared to be correlated to a significant decrease of blood flow assessed by LDF.

Purpose: The objective of the present study was to histologically evaluate barrier durability and host tissue response of new prototype collagen membranes in comparison to clinically available collagen and synthetic polymer membranes., Materials and Methods: The experimental study was conducted in 20 rabbits with 4 different healing periods of 2, 6, 12, and 28 weeks. Following surgical exposure of the calvarium, 6 circular bone defects (diameter 4 mm, depth 1.5 mm) were drilled into the outer cortex. After the bone had been removed, each defect was covered with 1 of 6 different membranes: 3 collagen prototype membranes, a Bio-Gide collagen membrane (BG), a glycolide-lactide-trimethylene carbonate Osseoquest membrane (OQ), and a polylactide Atrisorb membrane (AS). Histological analysis was performed following staining with toluidine blue and transversal sectioning of the calvarial bone., Results: All collagen membranes showed similar tissue integration characterized by fibrous encapsulation with differentiation of a periosteumlike tissue upon the external bony surface. One prototype collagen membrane displayed clearly longer membrane integrity. The evaluated synthetic membranes demonstrated extended barrier durability but also exhibited inflammatory foreign-body reactions., Discussion: Recent experimental investigations have shown that degradation of collagen membranes may begin within days to weeks of membrane placement. This was confirmed in the present study. However, 1 of the chemically modified collagen prototype membranes exhibited prolonged membrane integrity in the absence of an inflammatory tissue response., Conclusion: Further investigation of the prototype membrane that showed prolonged membrane integrity to evaluate its potential in GBR procedures is needed.

The present study investigated the osseointegration of dental implants with a titanium plasma-sprayed surface (TPS) in regenerated and native bone in an experimental dog study. Initially, lateral bone defects were created in the alveolar ridge on both sides of the mandible. Two months later, lateral ridge augmentation was performed with (1) autogenous corticocancellous block grafts, (2) autogenous corticocancellous block grafts and e-PTFE membrane, (3) tricalcium phosphate particles and e-PTFE membrane, or (4) canine-derived demineralized freeze-dried bone allograft particles and e-PTFE membrane. After 4 months, membranes were removed, and non-submerged titanium implants were placed in regenerated bone (test implants) and in native bone (control implants). Two months later, the animals were sacrificed and non-decalcified orofacial sections were evaluated histometrically. All implants demonstrated high percentages (59% to 75%) of bone-to-implant contact, with no significant differences across the various treatment groups. The different grafting techniques did not significantly influence the location of first bone-to-implant contact and the horizontal bone width at the most coronal bone level.

Sufficient bone volume is still considered the most important prerequisite for the osseointegration of dental implants. The TIME technique (autogenous bone grafting combined with stabilization using a titanium mesh) for localized alveolar ridge augmentation was evaluated in 20 patients who had insufficient bone volumes for the primary placement of dental implants. Different clinical recordings were evaluated at TIME stage 1 (augmentation surgery) and at TIME stage 2 (reentry surgery with mesh removal and simultaneous dental implant placement). In most patients, single- or extended-tooth gaps (up to four units) were augmented with autogenous bone harvested from the chin or retromolar area. With the exception of temporary disturbances of tooth sensibility, no morbidity at the donor sites was observed. In one patient, the stabilizing titanium micromesh had to be removed prematurely because of graft infection. At the reentry surgery, the bone grafts were found to be completely incorporated in 75% of the patients. In 15% of the patients, only minimal graft resorption was observed (less than 10% of the graft volume). Subsequently, 28 implants could be placed in 19 patients. The stabilizing titanium mesh was best suited for vertical ridge augmentations. Another feature of the mesh was the excellent tissue compatibility, with little clinical or histologic inflammation, even when the mesh had become exposed.