A Novel Parallel-Walled Dental Implant with a Self-Tapping Apex, Conical Connection, and Platform Shifting: Short-Term Results from a Retrospective Multicenter Clinical Study.

This multicenter retrospective study assessed clinical and radiographic outcomes of 686 parallel-walled conical-connection implants consecutively placed in 281 partially and fully edentulous patients. Implants were placed in healed and postextraction sites and subjected to immediate, early, or delayed loading. With a mean follow-up of 10 ± 6.7 months, the implant survival rate was 97.7%, while mean marginal bone loss was 0.7 ± 1.5 mm between implant placement and 1 year (n = 290 implants) and 0.1 ± 0.6 mm between 1 and 2 years (n = 72 implants). Advanced patient age and longer implants were associated with fewer implant failures, while different crestal positions at implant placement were not associated with differences in implant survival or changes in marginal bone level over time.

Randomized, controlled, clinical trial to evaluate a xenogeneic collagen matrix as an alternative to free gingival grafting for oral soft tissue augmentation: A 6- to 8-year follow-up.

BACKGROUND: The purpose of this follow up study was to determine if a xenogeneic collagen matrix (CMX) is as effective as free gingival graft (FGG) in preventing further recession 6+ years following vestibuloplasty. METHODS: This study was a single-blind (examiner), randomized, controlled, split-mouth study of 30 subjects with insufficient zones of KT (< 2 mm), associated with at least two, paired teeth. The study utilized a within subject treatment comparison to examine non-inferiority according to primary and secondary endpoints 6+ years after therapy. The original study primary efficacy endpoint was keratinized tissue width (KTw); however, in this report, prevention of recession (Rec) was also examined, along with traditional, secondary clinical measures, histopathology of mucosal biopsies and exploratory, patient reported outcomes (PROs) for pain and satisfaction. RESULTS: A total of 23 of the 30 original, study patients were available for 6 to 8-year postoperative assessment, and these patients were representative of the original patient population. For preventing further Rec, CMX was not inferior to FGG (ΔRec = -0.07 ± 1.26 mm for CMX and -0.17 ± 0.78 mm for FGG, P = 0.710). There were no adverse results observed, and histological assessment indicated normal, keratinized gingiva for both therapies. Tissue texture and color match to surrounding, native tissues were significantly better for CMX, and patients preferred CMX over FGG therapy. CONCLUSIONS: CMX appears to be a suitable substitute for FGG 6+ years after therapy.

Histologic Evaluation of rhBMP-2 in an Extraction Site Model in the Esthetic Zone: A Series of 16 Cases Preparing for Implant Placement.

Growth factors have been used in numerous oral applications to aid in bone formation after tooth extraction. Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-b superfamily and are involved in the differentiation of pluripotent mesenchymal cells, leading to new bone formation through osteoblastic induction. This study examined histologic wound healing following extraction and ridge preservation using recombinant human BMP-2 (rhBMP-2) and a collagen sponge. Formation of new vital bone was seen, suggesting that this material is a viable option for ridge preservation in preparation for implant placement.

Dorsal Striatal Circuits for Habits, Compulsions and Addictions.

Here, we review the neural circuit bases of habits, compulsions, and addictions, behaviors which are all characterized by relatively automatic action performance. We discuss relevant studies, primarily from the rodent literature, and describe how major headway has been made in identifying the brain regions and neural cell types whose activity is modulated during the acquisition and performance of these automated behaviors. The dorsal striatum and cortical inputs to this structure have emerged as key players in the wider basal ganglia circuitry encoding behavioral automaticity, and changes in the activity of different neuronal cell-types in these brain regions have been shown to co-occur with the formation of automatic behaviors. We highlight how disordered functioning of these neural circuits can result in neuropsychiatric disorders, such as obsessive-compulsive disorder (OCD) and drug addiction. Finally, we discuss how the next phase of research in the field may benefit from integration of approaches for access to cells based on their genetic makeup, activity, connectivity and precise anatomical location.

Accuracy of a Dynamic Dental Implant Navigation System in a Private Practice.

PURPOSE: To evaluate the in vivo accuracy of dental implants placed using a dynamic computer-aided dental implant (CAI) navigation system. The impact of various factors on accuracy was also analyzed. MATERIALS AND METHODS: A retrospective, in vivo study was performed during the period of October 2015 to December 2017. Data were obtained on all implants placed during this time frame. A chart review was conducted to identify the type of flap, number of implants placed, number of patients treated, and factors related to the description of edentulism (partial or complete). To evaluate accuracy outcomes, the preoperative cone beam computed tomography (CBCT) plan was volumetrically registered to a postimplant placement CBCT scan. Deviations between the planned and placed implant positions were analyzed. Data were statistically analyzed to factors that may affect the accuracy during usage. RESULTS: Data were obtained on 231 implants placed in healed ridges using a flapless or minimal flap approach under dynamic guidance by a single surgeon. In the 89 arches operated on, 28 (125 implants) were fully edentulous. For all implants, the mean (SD) discrepancies were: 0.71 (0.40) mm for entry point (lateral) and 1.00 (0.49) mm at the apex (3D). The mean angle discrepancy was 2.26 degrees (1.62 degrees) from actual vs planned implant positions. The accuracy measurements for partially edentulous patients using a thermoplastic stent attachment and for fully edentulous patients using a mini-implant-based attachment were nearly identical. No significant accuracy differences were found between implant position within the different sextants. Guided insertion of the implant itself reduced angular and apex location deviations. The accuracy of implant placement improved during the study period, with the mean entry point and apex deviation as well as overall angle discrepancy measured for the last 50 implants being better (0.59 mm, 0.85 mm, and 1.98 degrees, respectively) when compared with the first 50 implants (0.94 mm, 1.19 mm, and 3.48 degrees, respectively). CONCLUSION: Dynamic surgical navigation is an accurate method for executing CBCT-based computer-aided implant surgery. In addition, an increased experience level of the surgeon with dynamic navigation appears to improve accuracy outcomes.

Rapid Assembly of Presynaptic Materials behind the Growth Cone in Dopaminergic Neurons Is Mediated by Precise Regulation of Axonal Transport.

The proper assembly of neural circuits depends on the process of synaptogenesis, or the formation of synapses between partner neurons. Using the dopaminergic PDE neurons in C. elegans, we developed an in vivo system to study the earliest steps of the formation of en passant presynaptic specializations behind an extending growth cone. We find that presynaptic materials coalesce into puncta in as little as a few minutes and that both synaptic vesicle (SV) and active zone (AZ) proteins arrive nearly simultaneously at the nascent sites of synapse formation. We show that precise regulation of UNC-104/Kinesin-3 determines the distribution of SV proteins along the axon. The localization of AZ proteins to en passant puncta, however, is largely independent of the major axonal kinesins: UNC-104/Kinesin-3 and UNC-116/Kinesin-1. Moreover, AZ proteins play a crucial role in recruiting and tethering SV precursors (SVPs).

Autoinhibition of a Neuronal Kinesin UNC-104/KIF1A Regulates the Size and Density of Synapses.

Kinesin motor proteins transport intracellular cargoes throughout cells by hydrolyzing ATP and moving along microtubule tracks. Intramolecular autoinhibitory interactions have been shown for several kinesins in vitro; however, the physiological significance of autoinhibition remains poorly understood. Here, we identified four mutations in the stalk region and motor domain of the synaptic vesicle (SV) kinesin UNC-104/KIF1A that specifically disrupt autoinhibition. These mutations augment both microtubule and cargo vesicle binding in vitro. In vivo, these mutations cause excessive activation of UNC-104, leading to decreased synaptic density, smaller synapses, and ectopic localization of SVs in the dendrite. We also show that the SV-bound small GTPase ARL-8 activates UNC-104 by unlocking the autoinhibition. These results demonstrate that the autoinhibitory mechanism is used to regulate the distribution of transport cargoes and is important for synaptogenesis in vivo.

Regenerative Needs Following Alveolar Ridge Preservation Procedures in Compromised and Noncompromised Extraction Sockets: A Cone Beam Computed Tomography Study.

PURPOSE: The aim of this study was to evaluate the necessity for additional regenerative procedures following healing of compromised and noncompromised extraction sockets with alveolar ridge preservation procedures through the use of virtual implant imaging software. MATERIALS AND METHODS: The cohort was comprised of 87 consecutive patients subjected to a single maxillary tooth extraction with an alveolar ridge preservation procedure for subsequent implant placement. Patients were divided into two main groups based on the integrity of the buccal bone plate following teeth extraction. Patients in the compromised socket (CS) group (n = 52) had partial or complete buccal bone plate loss, and patients in the noncompromised socket (NCS) group (n = 35) exhibited no bone loss of their socket walls following tooth extraction. Following 4 to 6 months of healing, all patients had a cone beam computed tomography (CBCT) study. Root-formed implants were placed virtually in an ideal prosthetic position. The number of implants per group and location (anterior, premolar, molar) exhibiting exposed buccal implant surface was calculated. RESULTS: In the CS group, 5 out of 19 anterior implants (26.3%), 4 out of 14 premolar implants (28.5%), and 7 out of 19 molar implants (36.8%) had exposed buccal surfaces. In the NCS group, 4 out of 9 anterior implants (44.4%), 2 out of 9 premolar implants (22.2%), and 4 out of 17 molar implants (23.5%) had exposed buccal surfaces. There were no statistically significant differences for intragroup and intergroup comparisons (χ² test, P > .05). CONCLUSION: This study failed to find statistically significant differences in the frequency of implants with exposed buccal surfaces placed virtually, following treatment of compromised and noncompromised sockets. A high proportion (22% to 44%) of sites had implants that potentially needed additional regenerative procedures.

The Effect of Interimplant Distance on Peri-implant Bone and Soft Tissue Dimensional Changes: A Nonrandomized, Prospective, 2-Year Follow-up Study.

PURPOSE: To prospectively evaluate peri-implant bone and soft tissue dimension changes around adjacent implants placed at different horizontal interimplant distances. MATERIALS AND METHODS: Thirty partially edentulous patients, who underwent rehabilitation with two adjacent implant-supported crowns as part of their treatment plan, were assigned to three groups based on their prosthetic needs. Patients in group A (10 patients, 20 implants) were to have two implants placed at a 2-mm interimplant distance, patients in group B (10 patients, 20 implants) were to have two implants placed at a 3-mm interimplant distance, and patients in group C (10 patients, 20 implants) were to have two implants placed at an interimplant distance of > 4 mm according to their prosthetic needs. All patients received single-crown restorations after 3 months. Clinical examinations were performed at the time of crown placement (T3), and 6 months (T6), 12 months (T12), and 24 months (T24) after implant placement. Peri-implant bone levels were assessed radiographically at the time of implant placement (T0), and at T3, T12, and T24. RESULTS: One patient from group C did not return for follow-up examinations after implant placement. The mean (± standard deviation) horizontal interimplant distance was 1.97 ± 0.44 mm for implants in group A, 3.12 ± 0.15 mm for implants in group B, and 5.3 ± 0.64 mm for implants in group C. For group A, the mean marginal bone loss was 0.29 ± 0.51 mm at the T0-T3 interval, 0.31 ± 0.36 mm at the T0-T12 interval, and 0.27 ± 0.33 mm at the T0-T24 interval. For group B, the mean marginal bone loss was 0.16 ± 0.29 mm at the T0-T3 interval, 0.20 ± 0.28 mm at the T0-T12 interval, and 0.23 ± 0.28 mm at the T0-T24 interval. For group C, the mean marginal bone loss was 0.51 ± 0.84 mm at the T0-T3 interval, 0.45 ± 0.72 mm at the T0-T12 interval, and 0.44 ± 0.74 mm at the T0-T24 interval. For group A, the mean midproximal bone loss was 0.33 ± 0.50 mm at the T0-T3 interval, 0.45 ± 0.35 mm at the T0-T12 interval, and 0.40 ± 0.32 mm at the T0-T24 interval. For group B, the mean midproximal loss was 0.31 ± 0.37 mm at the T0-T3 interval, 0.32 ± 0.39 mm at the T0-T12 interval, and 0.33 ± 0.42 mm at the T0-T24 interval. For group C, the mean midproximal bone loss was 0.40 ± 0.44 mm at the T0-T3 interval and 0.41 ± 0.50 mm at both the T0-T12 and T0-T24 intervals. There were no statistically significant differences in marginal and midproximal bone crest loss between the different groups at any time point. CONCLUSION: The study failed to support the hypothesis that horizontal interimplant distance has an effect on peri-implant bone and soft tissue dimension changes for implants with internal conical implant-abutment interface connection and platform-switching characteristics.

Descriptive review of asbestosis and silicosis hospitalization trends in North Carolina, 2002-2011.

BACKGROUND: Asbestosis and silicosis are debilitating pulmonary conditions resulting from inhalation of asbestos fibers or silica dust. PURPOSE: We provide a descriptive analysis of asbestosis and silicosis hospitalizations in North Carolina to assess trends over a 10-year period. METHODS: Events were defined as inpatient hospital discharges during the period 2002-2011 with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis code of 501 or 502. Using statewide discharge data for 2002-2011, we calculated asbestosis and silicosis hospitalization rates in North Carolina (by demographics, hospital length of stay, cost, and payment type) and compared them with national rates. RESULTS: In North Carolina, average annual age-standardized hospitalization rates for asbestosis and silicosis were 71.2 hospitalizations per 1 million residents and 6.2 hospitalizations per 1 million residents, respectively. Rates for asbestosis and silicosis decreased significantly (less than .01 for both conditions) between 2002 and 2011, by 46% and 67%, respectively. Men had significantly higher rates than women (less than .01), more than half of hospitalizations were among persons aged 65-84 years, and Medicare was the predominant payment source. The highest silicosis rates by county were clustered in Western North Carolina; no geographic patterns were observed for asbestosis. The estimated average annual cost statewide for these hospitalizations was $10,170,417 for asbestosis and $886,143 for silicosis. LIMITATIONS: ICD-9-CM misclassification and duplicate hospitalization records may have biased the observed rates of asbestosis and silicosis. CONCLUSIONS: Decreases in hospitalization rates in North Carolina may be due to misdiagnosis, underreporting, or the declining use of asbestos in industries. Obtaining complete exposure histories at diagnosis is useful for continued public health surveillance.

EphB-mediated degradation of the RhoA GEF Ephexin5 relieves a developmental brake on excitatory synapse formation.

The mechanisms that promote excitatory synapse formation and maturation have been extensively studied. However, the molecular events that limit excitatory synapse development so that synapses form at the right time and place and in the correct numbers are less well understood. We have identified a RhoA guanine nucleotide exchange factor, Ephexin5, which negatively regulates excitatory synapse development until EphrinB binding to the EphB receptor tyrosine kinase triggers Ephexin5 phosphorylation, ubiquitination, and degradation. The degradation of Ephexin5 promotes EphB-dependent excitatory synapse development and is mediated by Ube3A, a ubiquitin ligase that is mutated in the human cognitive disorder Angelman syndrome and duplicated in some forms of Autism Spectrum Disorders (ASDs). These findings suggest that aberrant EphB/Ephexin5 signaling during the development of synapses may contribute to the abnormal cognitive function that occurs in Angelman syndrome and, possibly, ASDs.

The Angelman Syndrome protein Ube3A regulates synapse development by ubiquitinating arc.

Angelman Syndrome is a debilitating neurological disorder caused by mutation of the E3 ubiquitin ligase Ube3A, a gene whose mutation has also recently been associated with autism spectrum disorders (ASDs). The function of Ube3A during nervous system development and how Ube3A mutations give rise to cognitive impairment in individuals with Angleman Syndrome and ASDs are not clear. We report here that experience-driven neuronal activity induces Ube3A transcription and that Ube3A then regulates excitatory synapse development by controlling the degradation of Arc, a synaptic protein that promotes the internalization of the AMPA subtype of glutamate receptors. We find that disruption of Ube3A function in neurons leads to an increase in Arc expression and a concomitant decrease in the number of AMPA receptors at excitatory synapses. We propose that this deregulation of AMPA receptor expression at synapses may contribute to the cognitive dysfunction that occurs in Angelman Syndrome and possibly other ASDs.

Mites associated with the small ground finch, Geospiza fuliginosa (Passeriformes: Emberizidae), from the Galápagos Islands.

In collections of ectoparasites from 368 small ground finches, Geospiza fuliginosa, in populations from the islands of Isabela, Santa Cruz, San Cristóbal, and Santa Fé, in the Galápagos Archipelago, Ecuador, we found 8 species of mites. Four mite species were common on all islands sampled, i.e., Mesalgoides geospizae Mironov and Pérez (Psoroptoididae), Xolalges palmai Mironov and Pérez (Xolalgidae), and 2 new species, Trouessartia geospiza n. sp. (Trouessartiidae) and Proctophyllodes darwini n. sp. (Proctophyllodidae). Four other species were represented by single collections from G. fuliginosa, i.e., Pterodectes atyeoi n. sp. (Proctophyllodidae), Strelkoviacarus sp. (Analgidae), Dermoglyphus sp. (Dermoglyphidae), and Dermanyssus sp. (Dermanyssidae). Authorship of new species names is attributed to the 3 authors who prepared the descriptions (B.M.O.C., J.F., D.L.). Trouessartia geospiza and P. atyeoi were also found on previously collected specimens of other Geospiza species in museum collections. For the 4 common species, we found no differences in prevalence among the 4 island populations, but infection prevalence differed among the 4 species. The mean infection prevalence was high for T. geospizae (89%), moderate for M. geospizae (58%) and X. palmai (44%), and low for P. darwini (26%) in all populations. The feather mite fauna of G. fuliginosa was similar to that of other Geospiza species, and generally related to communities found on other emberizid finches.