A great deal of evidence suggests that parental communication and involvement are essential for the development of language in young children. However, hearing parents of deaf children face unique challenges in providing appropriate stimulation and language input to their deaf children. To date, few studies have determined which types of input are best. This study utilized data collected from the largest, youngest, nationally representative sample of deaf children receiving cochlear implants. The purpose of this study was to identify the facilitative language techniques that are most effective in facilitating receptive and expressive language development in young deaf children. Ninety-three deaf children, ages 2 years and under were enrolled at six implant centers. Deaf children were assessed prior to implantation and then followed for three years post-implantation. At each assessment, parent-child interactions were videotaped in an unstructured Free Play and structured Art Gallery task. All parent and child speech, vocalizations, and sign language were transcribed from the 10 minute videotaped parent-child interactions and coded using the Parenting Strategies for Communication coding system. Results revealed that the most frequently used lower-level strategies used by parents were directives, comments, and close-ended questions. The most frequently used higher-level strategies were parallel talk, open-ended questions, and recast. In addition, the Art Gallery task facilitated more parent utterances and longer mean length of utterances compared to Free Play, but the frequency of facilitative language techniques was not different. Using bivariate latent difference score modeling, higher-level strategies predicted growth in expressive language scores across three years post-implantation. Further, higher-level strategies had a delayed effect on receptive language, with techniques used at 24 months post-implantation predicting growth in receptive language at 36 months post-implantation. These results suggested that parent's play an active role in facilitating their child's language development. Interventions for parents should be developed using a coaching model, where parents receive hands-on training and practice using these effective facilitative language techniques. Future studies should evaluate the effectiveness of this intervention, as well as the effectives of these language techniques in children implanted after 2 years of age.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Metallurgy and Material Science, 1974. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. Bibliography: leaves 56-59. / by Thomas Maurice Devine, Jr. / Ph.D.

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The technology and telecommunication industries have made significant progress in the past few decades leading to several inventions and designs that have significantly improved efficiency in all aspects of human life. These innovations in science and technology improve our quality of life. Modern technology enables us to access vast amounts of information and services through a network of interconnected computers and machines. Recently, various technologies have been proposed to incorporate the human body into this incorporated network. One of these proposed technologies are chip implants meant to be inserted into the human body at various suitable body parts, such as the human brain or wrist. As they are a relatively recent technological innovation, chip implants are neither popular nor common yet (Caldera, 2020; Michael et al., 2017). Previous research on chip implants has produced limited information regarding the motivation aspects of using this technology. So, this study uses a self-determination theory to see which motivational factors lead to the use and trust of chip implants. This thesis discusses how implantable technology works, to explore which factors affect an individual's willingness to get a chip implant, personality traits associated with implant adoption, motivational factors affecting adoptions, and other user-centered perspectives of the technology.

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BACKGROUND: Static and dynamic dental implant guidance systems have established themselves as effective choices that result in predictable and relatively accurate dental implant placement. Generally, studies assess this accuracy using a postoperative CBCT, which has disadvantages such as additional radiation exposure for the patient. This pilot study proposed a scanbody-agnostic method of implant position assessment using intraoral scanning technology and applied it as an accuracy test of robotically assisted dental implant placement using the Neocis Yomi. MATERIALS AND METHODS: All of the robotically assisted dental implant surgery was performed in the Postdoctoral Periodontology clinic at Boston University Henry M. Goldman School of Dental Medicine. Completely edentulous patients were excluded. A total of eleven (11) implants were included in the study, eight (8) of which were fully guided. An optical impression of each implant position was obtained using a CEREC Omnicam (SW 5.1) intraoral scanner. Each sample used either a DESS Lab Scan Body or an Elos Accurate Scan Body as a means to indirectly index the position of the implant. A comparison of planned implant position versus executed surgical implant position was performed for each placement using Geomagic Control X software. Global positional and angular deviations were quantified using a proposed scanbody-agnostic method. Intraoral directionality of deviation was visually qualified by the author (D.K). RESULTS: Mean global positional deviations at the midpoints of the top of each scanbody were 1.7417 mm in the partially guided samples and 1.1300 mm in the fully guided samples. Mean global positional deviations at the midpoints of the restorative platforms of each implant were 1.3142 mm in the partially guided sample and 1.27045 mm in the fully guided samples. Mean global positional deviations at the midpoints of the apex of each implant were 1.455 mm in the partially guided samples and 1.574 mm in the fully guided samples. Mean angular deviations were 3.7492 degrees in the partially guided samples and 2.6432 degrees in the fully guided samples. CONCLUSION: Within the sample size limitations, robotically assisted dental implant surgery offers similar implant placement accuracy compared to published static and dynamic implant placement guidance systems. Intraoral optical assessment of dental implant position used in this study allows comparable analysis to other methods without requiring additional exposure to radiation and should be considered the default method of assessing guidance accuracy.

Jusqu'à il y a quelques années, chaque année, aux États-Unis, plus de 500 000 personnes devaient réparer leurs défauts osseux. Il a été prédit que le besoin de telles réparations doublerait aux États-Unis et dans le monde d'ici 2020. Les techniques de greffe osseuse sont couramment utilisées pour guérir de gros défauts osseux. Cependant, la greffe osseuse présente certains inconvénients tels que l'infection, la douleur, la morbidité et le manque de site donneur. L'échafaudage osseux est considéré comme une approche alternative pour guérir les défauts osseux sans complications liées à la greffe. Les échafaudages osseux sont considérés comme des implants temporaires, car après la formation de nouveaux tissus, leur présence n'est plus nécessaire. Des métaux poreux biodégradables (résorbables) ont été développés et étudiés en tant qu'échafaudages osseux temporaires. Ces structures poreuses fournissent un support mécanique et un espace biologique pour la régénération tissulaire. Ces implants se corrodent pendant le processus de régénération tissulaire et, idéalement, ils devraient disparaître une fois le processus de guérison terminé. Ainsi, aucune chirurgie secondaire pour les retirer ne serait nécessaire. Une tâche cruciale des échafaudages osseux résorbables est de fournir un support mécanique pour la formation de nouveaux tissus. Les échafaudages doivent conserver leur intégrité mécanique sans défaillance en raison des charges mécaniques appliquées à partir du milieu environnant. En revanche, en tant qu'implants orthopédiques, leur rigidité ne doit pas être supérieure à celle du tissu osseux environnant en raison du risque de stress shielding. Ainsi, la compréhension des facteurs influençant la réponse mécanique de l'échafaudage osseux lors de la dégradation et la prédiction de leurs propriétés mécaniques sont cruciales. La conception et la fabrication d'échafaudages résorbables sont un sujet d'intérêt pour les chercheurs. Des analyses détaillées qui expliquent les propriétés mécaniques post-corrosion des échafaudages métalliques résorbables en fonction de leurs caractéristiques architecturales post-corrosion font défaut dans la littérature. Ce projet de doctorat porte sur le comportement mécanique de la mousse de fer galvanisée à cellules ouvertes avec des entretoises creuses pour les applications d'échafaudage osseux. En particulier, les relations entre les propriétés structurales et mécaniques, les propriétés mécaniques après corrosion et les paramètres micro-architecturaux induits par la corrosion des mousses de fer ont été explorées. En outre, des modèles d'éléments finis idéalisés (mousse Kelvin) d'un témoin ainsi qu'un échantillon de mousse de fer corrodé ont été développés sur la base de mesures de tomographie micro-calculée et de modes de corrosion pour prédire la réponse mécanique post-corrosion de la mousse de fer (test in silico). La thèse comprend une introduction, trois chapitres contenant une revue approfondie de la littérature et les études menées pour le projet de doctorat, et une section Conclusion. Des données supplémentaires sur les études réalisées se trouvent en annexe. Dans l'introduction, un bref historique sur les échafaudages osseux, l'application de métaux poreux biodégradables (résorbables) dans les échafaudages, l'énoncé du problème, les objectifs de recherche, la stratégie de recherche et la nouveauté de cette recherche sont présentés. Le chapitre 1 contient une revue approfondie de la littérature sur les sujets pertinents au sujet de la thèse tels que l'application de métaux biodégradables comme implants temporaires, la fabrication et l'application de mousses métalliques résorbables comme échafaudages osseux ainsi que leurs propriétés mécaniques et de corrosion, temps de corrosion propriétés mécaniques dépendantes des échafaudages métalliques résorbables, approches de modélisation analytique et informatique pour prédire le comportement mécanique des mousses métalliques et modélisation informatique de la dégradation dans les métaux résorbables. Le chapitre 2 traite de la première étape du projet de doctorat qui était une étude sur les propriétés mécaniques des mousses de fer électrolytiques à cellules ouvertes avec entretoises creuses. Dans cette étude, des échantillons de mousses de fer aux propriétés architecturales différentes, c'est-à-dire la taille des alvéoles, l'épaisseur des branches et la taille des pores, ont subi des essais de compression mécanique et le rôle de leurs paramètres architecturaux ainsi que leur densité relative dans leurs différentes réponses à la compression (quasi-gradient élastique, élasticité et résistance à la compression) a été discuté. De plus, une modélisation par éléments finis des mousses Kelvin a été développée pour fournir une meilleure compréhension des effets de creux des entretoises sur les propriétés mécaniques de la mousse. Le chapitre couvre une introduction, la méthodologie, les résultats, la discussion et une section de conclusion. Le chapitre 3 traite des propriétés mécaniques post-corrosion et des configurations architecturales des mousses de fer à entretoises creuses. Les échantillons de mousse de fer ont subi des tests d'immersion dans une solution de Hanks jusqu'à 14 jours, suivis de tests de nettoyage et de compression mécanique. Les facteurs influençant les propriétés mécaniques de la mousse corrodée ont été explorés, c'est-à-dire la dégradation structurelle, les produits de corrosion adhérents et les changements micro-architecturaux au niveau des entretoises. une tomographie micro-calculée a été utilisée pour mesurer les paramètres architecturaux du contrôle et des mousses corrodées pendant 14 jours. Sur la base des mesures architecturales, des modèles d'éléments finis de mousse Kelvin ont été développés pour prédire la réponse mécanique des mousses corrodées. De plus, un nouveau modèle de mousse Kelvin a été développé pour prédire la réponse mécanique des mousses de fer corrodées sous corrosion homogène, le mécanisme de corrosion qui n'avait pas été observé dans les expériences. Enfin, les faits saillants les plus importants des études sont présentés dans la section Conclusion. Aussi, les limites et les bénéfices potentiels des résultats de ce projet pour les futurs travaux de recherche sont expliqués, et de nouvelles idées pour les futurs projets concernant le comportement mécanique des mousses métalliques résorbables sont proposées. / Up to a few years ago, every year, in the Unites States, more than 500,000 people needed to repair their bone defects. It was predicted that the need for such repairs would double in US and worldwide by 2020. Bone grafting techniques are commonly used to heal large bone defects. However, there are certain drawbacks with bone grafting such as infection, pain, morbidity and shortage of donor site. Bone scaffolding is considered as an alternative approach to heal bone defects without complications raised from grafting. Bone scaffolds are considered as temporary implants, since after the formation of new tissue, their presence is not needed anymore. Porous biodegradable (absorbable) metals have been developed and studied as temporary bone scaffolds. These porous structures provide mechanical support and biological space for tissue regeneration. These implants corrode during tissue regeneration process, and, ideally, they should disappear once the healing process ends. Thus, no secondary surgery to remove them would be needed. One crucial task for absorbable bone scaffolds is to provide mechanical support for new tissue formation. The scaffolds must keep their mechanical integrity without failing due to mechanical loads applied from the surrounding environment. On the other hand, as orthopedic implants, their stiffness should not be higher than the surrounding bone tissue due to the risk of stress shielding. Thus, understanding the influencing factors on the mechanical response of the bone scaffold during degradation and predicting their mechanical properties are crucial. Design and fabrication of absorbable scaffolds is a topic of interest for researchers. Detailed analyses that explain the post-corrosion mechanical properties of absorbable metal scaffolds based on their post-corrosion architectural features are lacking in the literature. This PhD project addresses the mechanical behavior of electroplated open cell iron foam with hollow struts for bone scaffolding applications. In particular, the structural-mechanical properties relationships, post-corrosion mechanical properties and the corrosion-induced micro-architectural parameters of the iron foams have been explored. In addition, idealized finite element models (Kelvin foam) of a control as well as a corroded iron foam specimen were developed based on micro-computed tomography measurements and corrosion modes to predict the post-corrosion mechanical response of the iron foam (in silico test). The thesis comprises an Introduction, three chapters containing a thorough literature review and the studies conducted for the PhD project, and a Conclusion section. Additional data about the performed studies are found in the Appendix. In the Introduction, a brief background on bone scaffolds, the application of porous biodegradable (absorbable) metals in scaffolding, problem statement, research objectives, research strategy, and the novelty of the research are presented. Chapter 1 contains a thorough literature review on the subjects relevant to the topic of the thesis such as the application of biodegradable metals as temporary implants, fabrication and application of absorbable metal foams as bone scaffolds as well as their mechanical and corrosion properties, corrosion-time dependent mechanical properties of absorbable metallic scaffolds, analytical and computational modelling approaches to predict the mechanical behavior of metal foams and computational modeling of degradation in absorbable metals. Chapter 2 discusses the first step of the PhD project which was a study on the mechanical properties of the electroplated open-cell iron foams with hollow struts. In this study, samples of iron foams with different architectural properties, i.e. cell size, branch-strut thickness and pore size, underwent mechanical compression tests and the role of their architectural parameters as well as their relative density in their different compressive response (quasi-elastic gradient, yield and compressive strength) was discussed. In addition, finite element modeling of Kelvin foams was developed to provide a better understanding of the strut hollowness effects on the foam mechanical properties. The chapter covers an introduction, the methodology, results, discussion, and a concluding section. Chapter 3 discusses the post-corrosion mechanical properties and architectural configurations of the iron foams with hollow struts. The iron foam samples underwent immersion tests in a Hanks' solution up to 14 days which were followed by cleaning and mechanical compression tests. The factors influencing the corroded foam mechanical properties were explored, i.e. structural degradation, adherent corrosion products and micro-architectural changes on the strut level. micro-computed tomography was employed to measure architectural parameters of the control and the 14-day corroded foams. Based on the architectural measurements, Kelvin foam finite element models were developed to predict the mechanical response of the corroded foams. Also, a new Kelvin foam model was developed to predict the mechanical response of the corroded iron foams under homogeneous corrosion, the corrosion mechanism which had not been observed in the experiments. Finally, the most important highlights of the studies are presented in the Conclusion section. Also, the limitations and the potential benefits of the results of this project for the future research works is explained, and new ideas for the future projects concerning the mechanical behavior of absorbable metal foams is proposed.

BACKGROUND: Implants have been widely used in the medical field. It was adopted in dentistry, offering patients replacement of missing teeth. Researchers have been investigating techniques to improve implants’ survival. Among these techniques is plasma glow discharge. Radio-frequency Glow discharge (RGD) is a surface treatment and sterilization technique with the aim to improve the titanium oxide layer for better osseointegration. Previous studies have evaluated its effect on non-human cell lines with promising results. Up to date, there is no report on how RGD surface treatment of titanium affects normal human osteoblasts. MATERIAL AND METHODS: Human bone fragments were obtained from dental extraction sites and were processed to culture normal human osteoblasts. Cells were seeded on three different surfaces at a concentration of 1x105 cells per plate; Titanium discs with and without Argon RGD (ARGD), and tissue culture plates (TCP). Dishes were allocated to 3 timelines: 16 hours, 7 days and 14 days. The outcome measures were cell attachment, cell number, alkaline phosphatase and osteocalcin levels. RESULTS: Data was analyzed using a one-way ANOVA test. Mean cell proliferation percentage for the ARGD group at 7 days was the highest (167.966%). The difference in means among the three groups at 7 days was statistically significant (p=0.0022). At 14 days, the highest mean of cell proliferation percentage was highest for the ARGD group. When testing all pairs, at 7 days the differences in means were statistically significant between (ARGD vs. no ARGD, and ARGD vs. TCP) (p=0.0018, and p=0.0286), respectively. At 14 days, the differences in means were statistically significant between (ARGD vs. TCP, p= 0.0003) and (no ARGD vs. TCP, p=0.0007). There was a significant difference in means for alkaline phosphatase and osteocalcin at 7 and 14 days between TCP and ARGD, and TCP and no ARGD groups (p < 0.05). CONCLUSIONS: The results of this study on normal human osteoblasts indicated that ARGD significantly enhanced cell proliferation. There was no significant difference in osteogenic behavior between with and without ARGD treatment on titanium surfaces within the time studied. A prolonged phase of cell proliferation was observed in ARGD treated groups.

Indiana University-Purdue University Indianapolis (IUPUI) / Anchorage control is fundamental to successful orthodontic treatment. Dental implants can serve as ideal anchorage units because of their stability in bone. Previous studies limit the use of existing implants for anchorage because of their large size. Minimizing the size of the implant would reduce the extent of the surgery and may result in a decreased and less traumatic healing period. The objective of this study was to histomorphometrically analyze the use of miniature implants. A total of 96 miniature implants (1.0 x 5.0 mm; 48 loaded and 48 healing control) were placed in the mandible and maxilla of 8 male dogs. The implants were allowed to heal for three different periods (3, 6, and 12 weeks) followed by 12 weeks of 200 to 300 g of orthodontic force application. Bone specimens containing implants were collected for histomorphometric analysis. The results indicate that clinical rigidity (osseointegration) was achieved by 96.9 percent of the miniature implants. Histomorphometric analysis revealed that the amount of bone contact at the implant-bone interface ranged from 11.3 to 68 percent (mean ± SEM=34.4 ± 4.6 percent) in the healing control groups and from 18.8 to 63 percent (mean=43.l ± 4.0 percent) in the force applied groups in the maxilla. On the other hand, in the mandible, bone-implant contact ranged from 7 to 82 percent (mean=44.1 ± 6.8 percent) in the healing control groups and from 12 to 72 percent (mean=50.7 ± 5.3 percent) in the force applied groups. Results from bone formation rate, mineralizing surface/bone surface and mineral appositional rate showed a significant difference in the 3-week healing control group compared to those in other groups. From these results, we concluded that miniature implants are able to function as rigid osseous anchorage for orthodontics with minimal (less than 3 weeks) healing period. This study was supported by Matsumoto Research fund.

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