Analysis of Satisfaction Levels in Completely Edentulous Patients Treated with Different Configurations of Implant Supported Rosthesis.

PURPOSE: The aim of this study is to evaluate and compare patient satisfaction levels in edentulous patients treated with different configurations of implant supported prosthesis. Also, the effect of previous prosthesis experience before implant treatment on patient satisfaction was investigated. MATERIALS AND METHODS: A study population of 142 patients was identified. Patients seperated into four treatment types. Group 1 comprised 43 patients treated with implant supported overdenture for mandible and conventional complete denture for maxilla while group 2 comprised 32 patients treated with implant supported overdentures for maxilla and mandible. Group 3 comprised 26 patients treated implant supported overdenture for mandible and fixed prosthesis for maxilla. Group 4 comprised 41 patients treated with implant supported maxillomandibular fixed restorations. A questionnaire consisting of specific issues about masticatory performance, pronunciation, comfort, social ability were used to evaluate treatment outcomes. RESULTS: The patients in group 4 were significantly more satisfied regarding masticatory performance than other treatment modalities. VAS scores of Group 3 and group 4 regarding comfort and social ability were similar while scores of these two groups were significantly higher than that of group 1 and 2. The patients who used conventional removable prosthesis before implant treatment were more satisfied with their implant supported prosthesis regarding social ability.(p=.03) Conclusion: It was found that treatment design of that implant supported fixed prosthesis on maxilla and implant overdenture on mandible provided comparable level of satisfaction with maxillomandibular fixed prosthesis for edentulous patients. Implant supported fixed prosthesis for maxilla and implant supported overdenture for mandible served as a practical alternative to satisfy patients especially in patients with mandibular atrophy who would demand extensive surgeries for maxillomandibular fixed prosthesis. Satisfaction level of implant supported overdenture was not superior to conventional prosthesis for maxilla. Previous removable prosthesis experience may influence social comfort of patients.

Finite element analysis of biplanar customized reconstruction plates for lateral and central segmental defects of mandible.

The purpose of this study is to compare biplanar custom mandibular reconstruction plates with locking reconstruction plates in bridging central and lateral mandibular segmental defects by using the finite element method. Central and two different types of lateral segmental defects were created on mandibular model that was generated from computed tomography of a male patient. Segmental defects were fixed with conventional locking reconstruction plates and two different custom designed plates with caudobuccal and dorsobuccal cover. Stress formation on hardware and screws, strain on bone under masticatory simulation were evaluated with a finite element model. The stress values on plate and screws were higher in conventional reconstruction plate than custom plates. Simulations of central segmental defect revealed maximum von Mises stresses of 643.62 MPa and 101.83 MPa in conventional reconstruction plate and biplanar plate, respectively. Biplanar plates revealed slightly higher von Mises stresses than extended surfaced biplanar plates. The screws close to resection area were exposed to higher stress than farther screws for whole groups. In conventional reconstruction plate, the maximum von Mises stress values of fixation screws were 268.66 MPa and 95 MPa for central segmental defect and lateral segmental defect, respectively. The study reveals that the biplanar custom reconstruction plates had a favourable effect on stress distribution and can enhance function and aesthetics as supporting mandible and flaps from two different planes.

Is Incisive Papilla a Good Landmark to Predict Clinical Outcomes and the Esthetic Perceptions of Edentulous Patients Treated with Implant-Supported Fixed Prostheses on Maxillae?

Purpose: To investigate the effect of incisive papilla on esthetic ratings and lip support for patients who are treated with implant-supported fixed prostheses on edentulous maxillae. Materials and Methods: A study population of 118 patients with maxillomandibular edentulism was identified. A self-administered questionnaire was used to evaluate treatment outcomes through a patient perspective. Also, clinical factors such as smile line, maxillary resorption, incisive papilla position, and lip support were evaluated. Results: Lip support has a significant effect on the facial esthetic scores of patients, while smile line and incisive papilla localization have not had a proven statistically significant effect on esthetic and facial esthestic scores of patients treated with implant-supported fixed prostheses on maxillae. Conclusion: Although the patients were diagnosed with disadvantageous clinical factors such as crestally localized incisive papilla, they still noted higher esthetic scores with their fixed prostheses. Factors that affect the esthetic perception of patients or their priorities should be investigated more to understand the reasons for patient satisfaction with prostheses.

Conservative treatment of a unicystic ameloblastoma by marsupialization with a favorable response: A case report and review of the literature.

Ameloblastoma is a benign tumor of odontogenic epithelium which is slow growing, locally invasive, expansive that may result with asymmetries of the face. Conservative treatment of odontogenic tumors with marsupialization is not common but can be done successfully in those with cystic pattern. The aim of this case and literature review is to propose marsupialization as an initial procedure for its treatment. We have presented a case of an ameloblastoma involving 56-year-old male patient. Orthopantomography and computed tomography showed the lesion extended between the right molar region and left molar region of mandible with both buccal and lingual expansion and root resorptions. On clinical examination, expansions of mandible and slight tooth mobilities were seen. An incisional biopsy was carried out and histopathologic examination revealed ameloblastoma although clinical features of lesion were more suggestive of cyst. Our case was treated by obturator marsupialization with a good healing. This case and review of the literature discusses the available treatment option according to macroscopic features of jaw lesions and emphasizes on the importance of the most conservative treatment option. Conservative treatment preserves integrity of bones while radical treatment can leave major cosmetic and functional sequelae such as pathologic fractures, complication with reconstruction plates.

Dynamic evolution of hyperuniformity in a driven dissipative colloidal system.

Hyperuniformity is evolving to become a unifying concept that can help classify and characterize equilibrium and nonequilibrium states of matter. Therefore, understanding the extent of hyperuniformity in dissipative systems is critical. Here, we study the dynamic evolution of hyperuniformity in a driven dissipative colloidal system. We experimentally show and numerically verify that the hyperuniformity of a colloidal crystal is robust against various lattice imperfections and environmental perturbations. This robustness even manifests during crystal disassembly as the system switches between strong (class I), logarithmic (class II), weak (class III), and non-hyperuniform states. To aid analyses, we developed a comprehensive computational toolbox, enabling real-time characterization of hyperuniformity in real- and reciprocal-spaces together with the evolution of several order metric features, and measurements showing the effect of external perturbations on the spatiotemporal distribution of the particles. Our findings provide a new framework to understand the basic principles that drive a dissipative system to a hyperuniform state.

Dynamics of pattern formation and emergence of swarming in Caenorhabditis elegans.

Many animals collectively form complex patterns to tackle environmental difficulties. Several biological and physical factors, such as animal motility, population densities, and chemical cues, play significant roles in this process. However, very little is known about how sensory information interplays with these factors and controls the dynamics of pattern formation. Here, we study the direct relation between oxygen sensing, pattern formation, and emergence of swarming in active Caenorhabditis elegans aggregates. We find that when thousands of animals gather on food, bacteria-mediated decrease in oxygen level slows down the animals and triggers motility-induced phase separation. Three coupled factors-bacterial accumulation, aerotaxis, and population density-act together and control the entire dynamics. Furthermore, we find that biofilm-forming bacterial lawns including Bacillus subtilis and Pseudomonas aeruginosa strongly alter the collective dynamics due to the limited diffusibility of bacteria. Additionally, our theoretical model captures behavioral differences resulting from genetic variations and oxygen sensitivity.

Clinical evaluation of efficacy of transcortical anesthesia for the extraction of impacted mandibular third molars: a randomized controlled trial.

BACKGROUND: This study aimed to compare the pain levels during anesthesia and the efficacy of the QuickSleeper intraosseous (IO) injection system and conventional inferior alveolar nerve block (IANB) in impacted mandibular third molar surgery. METHODS: This prospective randomized clinical trial included 30 patients (16 women, 14 men) with bilateral symmetrical impacted mandibular third molars. Thirty subjects randomly received either the IO injection or conventional IANB at two successive appointments. A split-mouth design was used in which each patient underwent treatment of a tooth with one of the techniques and treatment of the homologous contralateral tooth with the other technique. The subjects received 1.8 mL of 2% articaine. Subjects' demographic data, pain levels during anesthesia induction, tooth extractions, and mouth opening on postoperative first, third, and seventh days were recorded. Pain assessment ratings were recorded using the 100-mm visual analog scale. The latency and duration of the anesthetic effect, complications, and operation duration were also analyzed in this study. The duration of anesthetic effect was considered using an electric pulp test and by probing the soft tissue with an explorer. RESULTS: Thirty patients aged between 18 and 47 years (mean age, 25 years) were included in this study. The IO injection was significantly less painful with lesser soft tissue numbness and quicker onset of anesthesia and lingual mucosa anesthesia with single needle penetration than conventional IANB. Moreover, 19 out of 30 patients (63%) preferred transcortical anesthesia. Mouth opening on postoperative first day was significantly better with intraosseous injection than with conventional IANB (P = 0.013). CONCLUSION: The IO anesthetic system is a good alternative to IANB for extraction of the third molar with less pain during anesthesia induction and sufficient depth of anesthesia for the surgical procedure.

Emergence of active nematics in chaining bacterial biofilms.

Growing tissue and bacterial colonies are active matter systems where cell divisions and cellular motion generate active stress. Although they operate in the non-equilibrium regime, these biological systems can form large-scale ordered structures. How mechanical instabilities drive the dynamics of active matter systems and form ordered structures are not well understood. Here, we use chaining Bacillus subtilis, also known as a biofilm, to study the relation between mechanical instabilities and nematic ordering. We find that bacterial biofilms have intrinsic length scales above which a series of mechanical instabilities occur. Localized stress and friction drive buckling and edge instabilities which further create nematically aligned structures and topological defects. We also observe that topological defects control stress distribution and initiate the formation of sporulation sites by creating three-dimensional structures. In this study we propose an alternative active matter platform to study the essential roles of mechanics in growing biological tissue.

Supercooling as a viable non-freezing cell preservation method of rat hepatocytes.

Supercooling preservation holds the potential to drastically extend the preservation time of organs, tissues and engineered tissue products, and fragile cell types that do not lend themselves well to cryopreservation or vitrification. Here, we investigate the effects of supercooling preservation (SCP at -4(o)C) on primary rat hepatocytes stored in cryovials and compare its success (high viability and good functional characteristics) to that of static cold storage (CS at +4(o)C) and cryopreservation. We consider two prominent preservation solutions a) Hypothermosol (HTS-FRS) and b) University of Wisconsin solution (UW) and a range of preservation temperatures (-4 to -10 (o)C). We find that there exists an optimum temperature (-4(o)C) for SCP of rat hepatocytes which yields the highest viability; at this temperature HTS-FRS significantly outperforms UW solution in terms of viability and functional characteristics (secretions and enzymatic activity in suspension and plate culture). With the HTS-FRS solution we show that the cells can be stored for up to a week with high viability (~56%); moreover we also show that the preservation can be performed in large batches (50 million cells) with equal or better viability and no loss of functionality as compared to smaller batches (1.5 million cells) performed in cryovials.