Immunization Coverage of Children in Care of the Child Welfare System in High-Income Countries: A Systematic Review

CONTEXT

Children in care of the child welfare system tend to underutilize preventive health services compared with other children. The purpose of this systematic review was to assess current knowledge regarding immunization coverage levels for children in the child welfare system and to determine barriers and supports to them utilizing immunization services.

EVIDENCE ACQUISITION

Articles published in Medline, Embase, Cochrane Library, CINAHL, SocINDEX, and ERIC from January 1, 2000 to October 13, 2017 were searched. Thesis and conference databases and relevant websites were also examined. Studies were included if written in English, from high-income countries, and addressed immunizations for children in the child welfare system. Independent dual screening, extraction, and quality appraisal were conducted between October 2016 and December 2017, followed by narrative synthesis.

EVIDENCE SYNTHESIS

Of 2,906 records identified, 33 met inclusion criteria: 21 studied coverage, two studied barriers/supports, and ten studied both. Nineteen studies were moderate or high quality and thus included in the narrative synthesis; 15 studied coverage, one studied barriers/supports, and three studied both. Most studies found lower coverage among children in child welfare. The few studies that explicitly studied barriers/supports to immunization identified that a collaborative and coordinated approach between health and social services was key to service delivery to this population.

CONCLUSIONS

This review highlights that children in care of the child welfare system are at risk of poor immunization coverage. There is a need for high-quality studies on this issue, with a focus on assessing supports/barriers to immunization in this population.

Vaccine coverage of children in care of the child welfare system

OBJECTIVE

To assess vaccine coverage for a cohort of children who have been in the care of the child welfare system compared to children in the general population.

METHODS

This retrospective cohort study used population-based administrative health data for a 2008 birth cohort of children from Alberta, Canada. We assessed coverage at ages 2 (n = 44,206) and 7 (n = 42,241) for three vaccines with different administration schedules for children in care (at any period before the age of assessment) and those who had never been in care, comparing them using risk differences and relative risks (RRs). We similarly assessed coverage for children not in care who shared characteristics of children in care.

RESULTS

At age two, vaccination coverage for children in care ranged from 54.3% to 81.4%, depending on vaccine. In comparison, coverage for those not in care ranged from 74.2% to 87.4%. At age seven, coverage for children in care ranged from 53.1% to 65.3%, compared to 76.6% to 83.4% for those not in care. For all vaccines at both ages, the risk for being under-vaccinated was higher for children in care (e.g., diphtheria, pertussis, tetanus, polio, Haemophilus influenzae type b at age 7: RR 2.01, 95% confidence interval [CI] (1.74-2.32). Even for children not in care who had characteristics similar to children in care, we found children in care had lower coverage.

CONCLUSION

Children in care have consistently lower vaccine coverage than children not in care. Policies and practices should promote optimal access to vaccination for these children.

Immunisation coverage of children in the child welfare system: a systematic review protocol

INTRODUCTION

Children may be placed in the care of the child welfare system when they require additional supports or intervention to ensure their safety and security. Transitions in living arrangements (eg, home to foster care and return to home) and other difficult circumstances for these children may result in interruptions in routine preventive healthcare, such as childhood immunisations. The purpose of this systematic literature review is to determine whether immunisation coverage is a problem among children in the child welfare system and identify any known supports and/or barriers to vaccine uptake in this population.

METHODS AND ANALYSIS

This systematic review will encompass published and unpublished primary research studies that assess (A) immunisation coverage of children in the child welfare system, (B) how this coverage compares to the general population and/or children not in the child welfare system, and (C) supports and barriers affecting immunisation status of these children. Vaccines in the recommended childhood immunisation schedule for each study setting will be considered. Medline, Embase, Cochrane Library, CINAHL, SocINDEX and ERIC will be comprehensively searched. We will also search ProQuest dissertations and theses, the Conference Proceedings Citation Index for Science and Social Science & Humanities, and a sample of relevant provincial, national and international websites. References of included studies will be manually searched for relevant studies. English language primary studies from 2000 to current focused on immunisations of children (age 0-17 years) in the child welfare system, in a high-income country, will be included. A narrative analysis of key findings from included studies will be performed and presented.

ETHICS AND DISSEMINATION

This protocol does not require ethics approval. Planned dissemination includes peer-reviewed publication, conference presentations and briefs for policy makers.

TRIAL REGISTRATION NUMBER

This protocol is registered in the PROSPERO International Prospective Register of Systematic Reviews, registration number CRD42016047319.

Peri-implant Inflammation Defined by the Implant-Abutment Interface

An implant-abutment interface at the alveolar bone crest is associated with sustained peri-implant inflammation; however, whether magnitude of inflammation is proportionally dependent upon interface position remains unknown. This study compared the distribution and density of inflammatory cells surrounding implants with a supracrestal, crestal, or subcrestal implant-abutment interface. All implants developed a similar pattern of peri-implant inflammation: neutrophilic polymorphonuclear leukocytes (neutrophils) maximally accumulated at or immediately coronal to the interface. However, peri-implant neutrophil accrual increased progressively as the implant-abutment interface depth increased, i.e., subcrestal interfaces promoted a significantly greater maximum density of neutrophils than did supracrestal interfaces (10,512 ± 691 vs. 2398 ± 1077 neutrophils/mm2). Moreover, inflammatory cell accumulation below the original bone crest was significantly correlated with bone loss. Thus, the implant-abutment interface dictates the intensity and location of peri-implant inflammatory cell accumulation, a potential contributing component in the extent of implant-associated alveolar bone loss.

PKA-type I selective constrained peptide disruptors of AKAP complexes

A-Kinase Anchoring Proteins (AKAPs) coordinate complex signaling events by serving as spatiotemporal modulators of cAMP-dependent protein kinase activity in cells. Although AKAPs organize a plethora of diverse pathways, their cellular roles are often elusive due to the dynamic nature of these signaling complexes. AKAPs can interact with the type I or type II PKA holoenzymes by virtue of high-affinity interactions with the R-subunits. As a means to delineate AKAP-mediated PKA signaling in cells, we sought to develop isoform-selective disruptors of AKAP signaling. Here, we report the development of conformationally constrained peptides named RI-STapled Anchoring Disruptors (RI-STADs) that target the docking/dimerization domain of the type 1 regulatory subunit of PKA. These high-affinity peptides are isoform-selective for the RI isoforms, can outcompete binding by the classical AKAP disruptor Ht31, and can selectively displace RIα, but not RIIα, from binding the dual-specific AKAP149 complex. Importantly, these peptides are cell-permeable and disrupt Type I PKA-mediated phosphorylation events in the context of live cells. Hence, RI-STAD peptides are versatile cellular tools to selectively probe anchored type I PKA signaling events.

Persistent acute inflammation at the implant-abutment interface

The inflammatory response adjacent to implants has not been well-investigated and may influence peri-implant tissue levels. The purpose of this study was to assess, histomorphometrically, (1) the timing of abutment connection and (2) the influence of a microgap. Three implant designs were placed in the mandibles of dogs. Two-piece implants were placed at the alveolar crest and abutments connected either at initial surgery (non-submerged) or three months later (submerged). The third implant was one-piece. Adjacent interstitial tissues were analyzed. Both two-piece implants resulted in a peak of inflammatory cells approximately 0.50 mm coronal to the microgap and consisted primarily of neutrophilic polymorphonuclear leukocytes. For one-piece implants, no such peak was observed. Also, significantly greater bone loss was observed for both two-piece implants compared with one-piece implants. In summary, the absence of an implant-abutment interface (microgap) at the bone crest was associated with reduced peri-implant inflammatory cell accumulation and minimal bone loss.

Biologic Width around one- and two-piece titanium implants

Gingival esthetics around natural teeth is based upon a constant vertical dimension of healthy periodontal soft tissues, the Biologic Width. When placing endosseous implants, however, several factors influence periimplant soft and crestal hard tissue reactions, which are not well understood as of today. Therefore, the purpose of this study was to histometrically examine periimplant soft tissue dimensions dependent on varying locations of a rough/smooth implant border in one-piece implants or a microgap (interface) in two-piece implants in relation to the crest of the bone, with two-piece implants being placed according to either a submerged or a nonsubmerged technique. Thus, 59 implants were placed in edentulous mandibular areas of five foxhounds in a side-by-side comparison. At the time of sacrifice, six months after implant placement, the Biologic Width dimension for one-piece implants, with the rough/smooth border located at the bone crest level, was significantly smaller (P<0.05) compared to two-piece implants with a microgap (interface) located at or below the crest of the bone. In addition, for one-piece implants, the tip of the gingival margin (GM) was located significantly more coronally (P<0.005) compared to two-piece implants. These findings, as evaluated by nondecalcified histology under unloaded conditions in the canine mandible, suggest that the gingival margin (GM) is located more coronally and Biologic Width (BW) dimensions are more similar to natural teeth around one-piece nonsubmerged implants compared to either two-piece nonsubmerged or two-piece submerged implants.

Influence of the size of the microgap on crestal bone changes around titanium implants. A histometric evaluation of unloaded non-submerged implants in the canine mandible

BACKGROUND

Endosseous implants can be placed according to a non-submerged or submerged approach and in 1- or 2-piece configurations. Recently, it was shown that peri-implant crestal bone changes differ significantly under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of an interface (microgap) between the implant and abutment/restoration in 2-piece configurations. Several factors may influence the resultant level of the crestal bone under these conditions, including movements between implant components and the size of the microgap (interface) between the implant and abutment. However, no data are available on the impact of possible movements between these components or the impact of the size of the microgap (interface). The purpose of this study was to histometrically evaluate crestal bone changes around unloaded, 2-piece non-submerged titanium implants with 3 different microgap (interface) dimensions and between implants with components welded together or held together by a transocclusal screw.

METHODS

A total of 60 titanium implants were randomly placed in edentulous mandibular areas of 5 hounds forming 6 different implant subgroups (A through F). In general, all implants had a relatively smooth, machined suprabony portion 1 mm long, as well as a rough, sandblasted, and acid-etched (SLA) endosseous portion, all placed with their interface (microgap) 1 mm above the bone crest level and having abutments connected at the time of first-stage surgery. Implant types A, B, and C had a microgap of < 10 microns, approximately 50 microns, or approximately 100 microns between implant components as did types D, E, and F, respectively. As a major difference, however, abutments and implants of types A, B, and C were laser-welded together, not allowing for any movements between components, as opposed to types D, E, and F, where abutments and implants were held together by abutment screws. Three months after implant placement, all animals were sacrificed. Non-decalcified histology was analyzed histometrically by evaluating peri-implant crestal bone changes.

RESULTS

For implants in the laser-welded group (A, B, and C), mean crestal bone levels were located at a distance from the interface (IF; microgap) to the first bone-to-implant contact (fBIC) of 1.06 +/- 0.46 mm (standard deviation) for type A, 1.28 +/- 0.47 mm for type B, and 1.17 +/- 0.51 mm for type C. All implants of the non-welded group (D, E, and F) had significantly increased amounts of crestal bone loss, with 1.72 +/- 0.49 mm for type D (P < 0.01 compared to type A), 1.71 +/- 0.43 mm for type E (P < 0.02 compared to type B), and 1.65 +/- 0.37 mm for type F (P < 0.01 compared to type C).

CONCLUSIONS

These findings demonstrate, as evaluated by non-decalcified histology under unloaded conditions in the canine mandible, that crestal bone changes around 2-piece, non-submerged titanium implants are significantly influenced by possible movements between implants and abutments, but not by the size of the microgap (interface). Thus, significant crestal bone loss occurs in 2-piece implant configurations even with the smallest-sized microgaps (< 10 microns) in combination with possible movements between implant components.

Lateral ridge augmentation using different bone fillers and barrier membrane application. A histologic and histomorphometric pilot study in the canine mandible

Lateral ridge augmentation has become a standard treatment option to enhance the bone volume of deficient recipient sites prior to implant placement. In order to avoid harvesting an autograft and thereby eliminating additional surgical procedures and risks, bone grafting materials and substitutes are alternative filler materials to be used for ridge augmentation. Before clinical recommendations can be made, such materials must be extensively studied in experimental models simulating relevant clinical situations. The present pilot study was conducted in three dogs. Different grafting procedures were evaluated for augmentation of lateral, extended (8 x 10 x 14 mm) and chronic bone defects in the mandibular alveolar ridge. Experimental sites received tricalcium phosphate (TCP) granules or demineralized freeze-dried bone allograft (DFDBA) particles. Barrier membranes (ePTFE) were placed for graft protection. These approaches were compared to ridge augmentation using autogenous cortico-cancellous block grafts, either with or without ePTFE-membrane application. After a healing period of six months, the sites were analyzed histologically and histomorphometrically. Autografted sites with membrane protection showed excellent healing results with a well-preserved ridge profile, whereas non-protected block grafts underwent bucco-crestal resorption, clearly limiting the treatment outcome. The tested alloplastic (TCP) and allogenic (DFDBA) filler materials presented inconsistent findings with sometimes encapsulation of particles in connective tissue, thereby reducing the crestal bone width. The present pilot study supports the use of autografts with barrier membranes for lateral ridge augmentation of extended alveolar bone defects.

Crestal bone changes around titanium implants: a methodologic study comparing linear radiographic with histometric measurements

Generally, endosseous implants can be placed according to a nonsubmerged or a submerged technique and in 1-piece or 2-piece configurations. Recently, it has been shown that peri-implant crestal bone reactions differ significantly radiographically as well as histometrically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of a microgap (interface) between the implant and the abutment/restoration in 2-piece configurations. The purpose of this study was to evaluate whether standardized radiography as a noninvasive clinical diagnostic method correlates with peri-implant crestal bone levels as determined by histometric analysis. Fifty-nine implants were placed in edentulous mandibular areas of 5 foxhounds in a side-by-side comparison in both submerged and nonsubmerged techniques. Three months after implant placement, abutment connection was performed in the submerged implant sites. At 6 months, all animals were sacrificed, and evaluations of the first bone-to-implant contact (fBIC), determined on standardized periapical radiographs, were compared to similar analyses made from nondecalcified histology. It was shown that both techniques provide the same information (Pearson correlation coefficient = 0.993; P < .001). The precision of the radiographs was within 0.1 mm of the histometry in 73.4% of the evaluations, while the level of agreement fell to between 0.1 and 0.2 mm in 15.9% of the cases. These data demonstrate in an experimental study that standardized periapical radiography can evaluate crestal bone levels around implants clinically accurately (within 0.2 mm) in a high percentage (89%) of cases. These findings are significant because crestal bone levels can be determined using a noninvasive technique, and block sectioning or sacrifice of the animal subject is not required. In addition, longitudinal evaluations can be made accurately such that bone changes over various time periods can be assessed. Such analyses may prove beneficial when trying to distinguish physiologic changes from pathologic changes or when trying to determine causes and effects of bone changes around dental implants.

Lateral ridge augmentation and implant placement: an experimental study evaluating implant osseointegration in different augmentation materials in the canine mandible

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.

Crestal bone changes around titanium implants. A histometric evaluation of unloaded non-submerged and submerged implants in the canine mandible

BACKGROUND

Today, implants are placed using both non-submerged and submerged approaches, and in 1- and 2-piece configurations. Previous work has demonstrated that peri-implant crestal bone reactions differ radiographically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on the location of the interface (microgap) between the implant and abutment/restoration in 2-piece configurations. The purpose of this investigation was to examine histometrically crestal bone changes around unloaded non-submerged and submerged 1- and 2-piece titanium implants in a side-by-side comparison.

METHODS

A total of 59 titanium implants were randomly placed in edentulous mandibular areas of 5 foxhounds, forming 6 different implant subgroups (types A-F). In general, all implants had a relatively smooth, machined coronal portion as well as a rough, sandblasted and acid-etched (SLA) apical portion. Implant types A-C were placed in a non-submerged approach, while types D-F were inserted in a submerged fashion. Type A and B implants were 1-piece implants with the rough/smooth border (r/s) at the alveolar crest (type A) or 1.0 mm below (type B). Type C implants had an abutment placed at the time of surgery with the interface located at the bone crest level. In the submerged group, types D-F, the interface was located either at the bone crest level (type D), 1 mm above (type E), or 1 mm below (type F). Three months after implant placement, abutment connection was performed in the submerged implant groups. At 6 months, all animals were sacrificed. Non-decalcified histology was analyzed by evaluating peri-implant crestal bone levels.

RESULTS

For types A and B, mean crestal bone levels were located adjacent (within 0.20 mm) to the rough/smooth border (r/s). For type C implants, the mean distance (+/- standard deviation) between the interface and the crestal bone level was 1.68 mm (+/- 0.19 mm) with an r/s border to first bone-to-implant contact (fBIC) of 0.39 mm (+/- 0.23 mm); for type D, 1.57 mm (+/- 0.22 mm) with an r/s border to fBIC of 0.28 mm (+/- 0.21 mm); for type E, 2.64 mm (+/- 0.24 mm) with an r/s border to fBIC of 0.06 mm (+/- 0.27 mm); and for type F, 1.25 mm (+/- 0.40 mm) with an r/s border to fBIC of 0.89 mm (+/- 0.41 mm).

CONCLUSIONS

The location of a rough/smooth border on the surface of non-submerged 1-piece implants placed at the bone crest level or 1 mm below, respectively, determines the level of the fBIC. In all 2-piece implants, however, the location of the interface (microgap), when located at or below the alveolar crest, determines the amount of crestal bone resorption. If the same interface is located 1 mm coronal to the alveolar crest, the fBIC is located at the r/s border. These findings, as evaluated by non-decalcified histology under unloaded conditions, demonstrate that crestal bone changes occur during the early phase of healing after implant placement. Furthermore, these changes are dependent on the surface characteristics of the implant and the presence/absence as well as the location of an interface (microgap). Crestal bone changes were not dependent on the surgical technique (submerged or non-submerged).

Biologic width around titanium implants. A physiologically formed and stable dimension over time

Research in implant dentistry has mainly focused on hard tissue integration with much less data available with regards to soft tissue integration involving epithelium and connective tissue. In the present study, the implantogingival junction of unloaded and loaded non-submerged titanium implants has been analyzed histometrically in the canine mandible. In 6 foxhounds, 69 implants were placed. Dogs in the unloaded group were sacrificed 3 months after implant placement. Loaded implants were restored with gold crowns and those dogs were sacrificed after 3 months and 12 months of loading. Non-decalcified histologic sections were analyzed histometrically measuring the dimensions of the Sulcus Depth (SD), the Junctional Epithelium (JE), and the Connective Tissue Contact (CTC). Histometric evaluation revealed that significant changes within tissue compartments (SD, JE, CTC) occurred over time (P < 0.05). Sulcus Depth had a mean of 0.49 mm and 0.50 mm after 3 months and 6 months of healing, but after 15 months was 0.16 mm which was significantly different. Similarly, the length of the Junctional Epithelium after 3 months and 6 months of healing was 1.16 mm and 1.44 mm, respectively, and these values were significantly different from measurements taken after 15 months (1.88 mm). The area of Connective Tissue Contact showed a different pattern of change in that after 3 months of healing (1.36 mm) it was significantly different from the same area after 6 months and 15 months which were 1.01 mm and 1.05 mm, respectively. Interestingly, the sum of SD, JE, and CTC, forming the Biologic Width, did not change over the observation period (P > 0.05). These data indicate that the Biologic Width is a physiologically formed and stable structure over time in the case of non-submerged, one-piece titanium implants as evaluated histometrically under unloaded and loaded conditions. Dynamic changes did occur, however, within the overall Biologic Width dimension. Thus, the use of non-submerged, one-piece implants allow for stable overall peri-implant soft tissues as evaluated under loaded conditions for up to 12 months.

Comparison of bioactive glass to demineralized freeze-dried bone allograft in the treatment of intrabony defects around implants in the canine mandible

BACKGROUND

The purpose of this study was to evaluate and compare the healing of different bone grafting materials adjacent to titanium plasma-sprayed (TPS) endosseous dental implants.

METHODS

Implant osteotomy sites were prepared and standardized 3-walled intrabony defects (3 mm x 5 mm x 5 mm) were created at the mesial of each implant site. Thirty-two TPS implants were placed in edentulous mandibular ridges of the 4 dogs. Periodontal dressings were placed in the defect sites so as to create a defect simulating bone loss around an implant. After 3 months, the periodontal dressing was removed, the defect sites debrided and evaluated for size, and intramarrow penetration performed. The graft materials tested were 1) canine demineralized freeze-dried bone allograft (cDFDBA); 2) bioactive glass granules of a broad size range 90 to 710 microns (BRG); and 3) bioactive glass granules of narrow size range 300 to 355 microns (NRG). One site on each side of the mandible was not filled and served as a control. Dogs were sacrificed 4 months after graft placement.

RESULTS

Histologically, differences in percent bone-to-implant contact in the defect area were observed between the treatment groups. cDFDBA>control=BRG=NRG with statistical significance found between cDFDBA and control (P = 0.0379), but no statistically significant difference between control or either bioactive glass material. When comparing percent bone height fill of the defect in the grafted area, cDFDBA (65.7%) was significantly better than the control (48.9%; P < or = 0.05) with no statistically significant difference between control, broad range bioactive glass (57.3%) and narrow range bioactive glass (56.6%). When total bone area was measured, the percentage of new bone in the grafted area was cDFDBA (42.1%), broad range glass (33.1%) and narrow range glass (22.6%) with significance found between cDFDBA and NRG (P = 0.0102). The content of residual graft particles in soft tissue was significant (P = 0.0304) between cDFDBA (1.4%) and NRG (11.4%) with no significant difference between graft material for residual particle content in bone tissue.

CONCLUSIONS

The results of this study indicate that percent bone-to-implant contact and percent bone height fill in an intrabony defect around titanium plasma-sprayed implants are statistically significantly higher with the use of DFDBA when compared to bioactive glass material.

Evaluation of three different dental implants in ligature-induced peri-implantitis in the beagle dog. Part II. Histology and microbiology

The purpose of this study was to evaluate experimental peri-implant breakdown microbiologically, radiographically and histologically. Hydroxyapatite-coated, titanium plasma-sprayed, and titanium alloy surfaces were investigated. Eighty-four implants were placed in 14 beagle dogs. Standardized radiographs and microbiologic samples (DNA) were obtained. Dogs were sacrificed at 3 and 6 months. Undecalcified histologic sections were prepared. Thickness of hydroxyapatite coating, changes in crestal bone height, and marginal changes in osseointegration were measured. Vertical bone loss was computed. Radiographs were analyzed using computer-assisted densitometric image analysis (CADIA). Microbial analysis (DNA) did not clearly favor any of the examined surfaces. CADIA did not show differences among implant surfaces. No significant differences among the three implants were noted for histometry, except the experimental titanium plasma-sprayed surface showed an increase in vertical bone loss 6 months (P < .05). Thickness of hydroxyapatite was decreased in active peri-implantitis sites (P < .05). Clinical attachment level was shown to be the most sensitive clinical parameter for detecting histologic changes. All implants were equally susceptible to peri-implantitis.

Crestal bone changes around titanium implants. A radiographic evaluation of unloaded nonsubmerged and submerged implants in the canine mandible

Current implant placement utilizes both nonsubmerged and submerged techniques. However, the implications of the location of a rough/smooth implant interface as well as the location of a microgap between implant and abutment on crestal bone changes are not well understood. The purpose of this study was to radiographically evaluate crestal bone changes around unloaded nonsubmerged and submerged titanium implants in a side-by-side comparison. Fifty-nine (59) implants were placed at different levels to the alveolar crest in 5 foxhounds. Standardized radiographs were taken at baseline and at monthly intervals until sacrifice at 6 months. Radiographic assessment was carried out by measuring the distance between the top of the implant/abutment and the most coronal bone-to-implant contact (DIB), and by evaluation of bone density changes using computer-assisted densitometric image analysis (CADIA). DIB measurements revealed that in 1-part, nonsubmerged implants, the most coronal bone-to-implant contact followed at all time points the rough/smooth implant interface. In all 2-part implants, nonsubmerged and submerged, the most coronal bone-to-implant contact was consistently located approximately 2 mm below the microgap. In addition, CADIA values for all 2-part implants were decreased in the most coronal area-of-interest (AOI). All bone changes were statistically significant and detectable 1 month after implant placement in nonsubmerged implants or 1 month after abutment connection in submerged implants. Neither implant position nor individual dog effects were statistically significant. These results demonstrate that the rough/smooth implant interface as well as the location of the microgap have a significant effect on marginal bone formation as evaluated by standardized longitudinal radiography. Bone remodeling occurs rapidly during the early healing phase after implant placement for non-submerged implants and after abutment connection for submerged implants.

Evaluation of three different dental implants in ligature-induced peri-implantitis in the beagle dog. Part I. Clinical evaluation

The purpose of this study was to clinically evaluate experimental peri-implant breakdown. Hydroxyapatite-coated, titanium plasma-sprayed, and machined titanium-alloy surfaces were investigated. Eighty-four implants were placed in 14 beagle dogs. Pocket probing depths and clinical attachment level and mobility measurements were made. Dogs were sacrificed at 3 and 6 months. All experimental implants showed a significant loss in clinical attachment level (P < .05). Increased pocket probing depths for experimental implants occurred during the first 2 months, after which a plateau was reached. At the 3- and 6-month evaluation, pocket probing depths at experimental implants were significantly increased (P < .05). No differences among the three implant types were noted for clinical attachment levels and pocket probing depths. In general, greater mobility was found with the titanium-alloy implants than with hydroxyapatite-coated and titanium plasma-sprayed implants (P < .025). In addition, mobility measurements were significantly greater for experimental titanium-alloy implants during the first 3 months (P < .05). Clinical attachment level measurements were most sensitive to peri-implant status. All implants were equally susceptible to ligature-induced peri-implant breakdown. Consequently, meticulous oral hygiene and regular maintenance care are prerequisites for successful implantology.

Biologic width around titanium implants. A histometric analysis of the implanto-gingival junction around unloaded and loaded nonsubmerged implants in the canine mandible

The use of endosseous dental implants as transmucosal devices necessitates the successful integration of three different tissues: bone, connective tissue, and epithelium. So far, studies have predominantly focused on hard tissue integration. Much less is known about soft tissues. This study examined the dimensions of the implantogingival junction in relation to clinically healthy unloaded and loaded nonsubmerged implants. In total, 69 titanium plasma-sprayed (TPS) and sandblasted acid-etched (SLA) implants were placed in an alternating fashion in six foxhounds and allowed to heal for 3 months. Two dogs were sacrificed after the initial healing period. The remaining four dogs had crowns fabricated that were allowed to function for up to 12 months. These animals were sacrificed after 3 and 12 months of loading. Histometric analysis of undecalcified histologic sections included the evaluation of the sulcus depth (SD), the dimensions of the junctional epithelium (JE), and the connective tissue contact (CTC). Mean values in the 3 month unloaded group were 0.49 mm for SD, 1.16 mm for JE, and 1.36 mm for CTC. These dimensions were 0.50 mm for SD, 1.44 mm for JE, and 1.01 mm for CTC for the 3 month loaded group. After 12 months of loading, these values were 0.16 mm for SD, 1.88 mm for JE, and 1.05 mm for CTC. The sum of these measurements was similar for the different time points and similar to the same dimensions around teeth. TPS and SLA surfaces had no influence on the evaluated parameters (P > 0.05). The data suggest that a biologic width exists around unloaded and loaded nonsubmerged one-part titanium implants and that this is a physiologically formed and stable dimension as is found around teeth.

Evaluation of an endosseous titanium implant with a sandblasted and acid-etched surface in the canine mandible: radiographic results

Previous studies have demonstrated in short-term experiments that sandblasted and acid-etched (SLA) titanium implant had a greater bone-to-implant contact than a titanium plasma-sprayed (TPS) implant in non-oral bone. In the present study, an SLA implant was compared radiographically to a TPS implant under unloaded and loaded conditions in the canine mandible for up to 15 months. 69 implants were placed in 6 foxhounds. Standardized radiographs were taken at baseline, preload, 3, 6, 9, and 12 months of loading. Loaded implants were restored with gold crowns similar to the natural dentition. Radiographic assessment of the bone response to the implants was carried out by measuring the distance between the implant shoulder and the most coronal bone-to-implant contact (DIB) and by evaluated of bone density changes using computer-assisted densitometric image analysis (CADIA). 5 different areas-of-interest (AOI) were defined coronally and apically along the implant. DIB measurements revealed that SLA implants had significantly less bone height loss (0.52 mm) than TPS implants (0.69 mm) at the preload evaluation (p = 0.0142) as well as at 3 months of loading (0.73 mm/1.06 mm; p = 0.0337). This difference was maintained between the implant types during the 1-year follow-up period. The same trend was also evident for CADIA measurements with SLA implants showing higher crestal bone density values when comparing preload to baseline data (p = 0.0890) and 3 months to baseline data (p = 0.0912). No measurable bone density changes were apparent in the apical areas of either implant. These results suggest that SLA implants are superior to TPS implants as measured radiographically in oral bone under unloaded and loaded conditions.

Dehydroepiandrosterone sulfate, cholesterol, hemoglobin, and anthropometric measures related to growth in male adolescents

Sixty-four white boys between 10.6 and 14.3 years old participated in an adolescent nutrition assessment study evaluating dehydroepiandrosterone sulfate (DHEAS) as a measure of maturation. DHEAS, an adrenal androgen, is low in childhood and rises with the development of secondary sexual characteristics. Biochemical measures included plasma DHEAS assessed by radioimmunoassay, cholesterol assessed by an enzymatic method, and hemoglobin assessed by the cyanmethemoglobin method. Midarm muscle area (MAMA) was calculated from midarm circumference and triceps fatfold measurements. DHEAS was correlated significantly with height, weight, MAMA, and hemoglobin. By age, significant differences were found for height, weight, and MAMA, but not for any of the biochemical measures. For boys with DHEAS concentration less than 3 mumol/L, values for height, weight, body mass index, MAMA, and hemoglobin were significantly different from those for boys with higher DHEAS concentrations. No significant differences were found for age or nutrient intakes by DHEAS concentration groups. Mean plasma cholesterol concentrations decreased with increases in age and with maturation evidenced by higher DHEAS concentration. Cholesterol concentration was negatively correlated with height and MAMA. Mean nutrient intakes estimated by a quantitative food frequency questionnaire met or exceeded the Recommended Dietary Allowances for these age groups. DHEAS identified maturation differences in male adolescents.

Paretic thyroid myopathy

Reports of vertical deviation in Graves' disease in recent years have always been associated with restrictive phenomena and positive forced duction testing, usually related to a tight inferior rectus. Two cases of medically proven Graves' diseased of ten-year duration are presented with increasing vertical disparity. Forced duction testing showed no restriction. Saccadic velocity tests using electro-oculography confirmed paresis of the inferior rectus in both cases. No cases of "true" vertical extraocular muscle paresis in chronic Graves' disease have been reported in the American literature.

Masked bilateral superior oblique paresis

Masked bilateral superior oblique paresis which was unsuspected occurred in 9 out of 57 cases. In every case of superior oblique paresis, bilaterality should be presumed until proven otherwise. Maximum attention on multiple examinations should be utilized to elicit the slightest contralateral inferior oblique overaction.

Surgical therapy of convergence insufficiency

Fourteen cases of intractable convergence insufficiency were surgically treated by resection of both medial rectus muscles. All 14 patients showed dramatic relief of severe asthenopic symptoms. Temporary diplopia due to consecutive esotropia is a necessary part of this surgery and is relieved by fresnel prisms. Exophoria at near will return, occasionally to the original angle of deviation, but the symptoms do not return. The preoperative symptoms can be of severity out of proportion to the deviation. Bimedial resection is a most efficacious surgical method for treatment of intractable convergence insufficiency.

Antipodean squint

Strabismic cases which are exotropic fixing with one eye, and esotropic fixing with the other eye are rare and a result of anisometropia, unequal accommodation, paresis or restriction, and previous ocular muscle surgery. Three cases of antipodean squint are reported without known etiology factor. An extensive survey of experts in the field of strabismus was unable to document other similar cases where a cause could not be determined.

Acquired Brown's syndrome of inflammatory origin. Response to locally injected steroids

In a recent large series of tendon sheath syndrome, Brown reported only five cases of the pure acquired type that were not intermittent and in which the patients did not undergo spontaneous recovery. The origin of acquired Brown's syndrome is varied and includes trauma of the orbit, direct trochlear trauma, orbital or muscle surgery, frontal sinusitis or sinus surgery, and inflammation of the superior oblique tendon and sheath, namely a stenosing tenosynovitis. The differential diagnosis and possible causes of the acquired Brown's syndrome were reviewed, and two cases of presumptive tenosynovitis of the superior oblique tendon and sheath are presented in detail. In both cases, the condition of each patient was notably improved by a series of direct injections of methylprednisolone acetate into the trochlear region. This form of treatment for acquired Brown's syndrome of inflammatory origin has never, to my knowledge, been reported in the literature.