The effect of cement versus screw-retained implant positioning in the esthetic zone on emergence angle: A proof of principle.

Choosing between screw-retained and cement-retained restorations in the esthetic zone may have a significant implication on the restorative contour. This study analyzes the effect of facial-palatal implant positioning on the facial emergence angle of implant restorations in the maxillary anterior region. 133 maxillary anterior implant cases were captured with intraoral scans and used to create digital prosthetic designs. The facial emergence angle of the restoration and the depth of the implant were determined using images at the mid-facial cross-section. Simple logistic and linear regression models were used to analyze the interrelation between the emergence angle, depth, and retention methods. The average facial emergence angle for all restorations in this study was 34.4 degrees. A significant difference was found in emergence angle between screw-retained and cement-retained groups, with an average emergence angle of 37.3 degrees and 27.9 degrees, respectively. There is no difference in the mean depth between those two groups. There is a strong negative linear relationship between depth and emergence angle for the screw-retained group. Overall, implant positioning in the anterior maxilla has a significant influence on emergence angle. Facial emergence angle is significantly greater for implants in screw-retained position. This may be partially alleviated by deeper implant placement.

Risk factors and longitudinal regenerative outcomes of sinus membrane perforation during lateral window sinus floor elevation: A retrospective analysis up to 9 years.

BACKGROUND: Lateral-window sinus floor elevation (LSFE) is a reliable procedure to reconstruct the posterior maxilla for implant therapy. This retrospective study aimed to investigate risk factors associated with Schneiderian membrane perforation (SMP) occurrence during LSFE and longitudinal regenerative outcomes following LSFE up to 9 years. METHODS: Patients who had LSFE between 2010 and 2019 were included. All demographic and surgical-related data were retrieved from existing electronic health records. Radiographs were used to evaluate the vertical dimensional changes of ridge and graft materials and the potential anatomic factors of SMP. RESULTS: A total of 122 LSFE procedures in 99 patients were included in the study. Mean ridge height gain and graft shrinkages were 9.5 ± 3.47 and 1.57 ± 2.85 mm. The influence of the healing period on graft shrinkage showed a positive trend; the longer the healing period, the greater the graft shrinkage (p = 0.09). The pathology in the sinus showed a positive correlation with SMP (p = 0.07). However, other anatomical factors did not negatively impact SMP and subsequent ridge height gain (p > 0.05). CONCLUSIONS: With inherent limitation, the findings with up to 9 years of follow-up indicate a consistent ridge remodeling lasting for about 3 years after LSFE procedures. SMP or membrane thickening may not significantly affect the ridge gain following LSFE. The healing period had the most significant influence on graft shrinkage, showing that the longer the healing time between LSFE and implant placement, the greater the graft shrinkage.

A 8-year population-based cohort study of irritable bowel syndrome in childhood with history of atopic dermatitis.

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder affecting a large number of people worldwide. Based on the concept of central sensitization, we conducted a population-based cohort analysis to investigate the risk of IBS in children with atopic dermatitis (AD) as one of the first steps in the atopic march. From 2000 to 2007, 1 20 014 children with newly diagnosed AD and 1 20 014 randomly selected non-AD controls were included in the study. By the end of 2008, incidences of IBS in both cohorts and the AD cohort to non-AD cohort hazard ratios (HRs) and CIs were measured. The incidence of IBS during the study period was 1.45-fold greater (95% CI: 1.32 to 1.59) in the AD cohort than in the non-AD cohort (18.8 vs 12.9 per 10 000 person-years). The AD to non-AD HR of IBS was greater for girls (1.60, 95% CI: 1.39 to 1.85) and children≥12 years (1.59, 95% CI: 1.23 to 2.05). The HR of IBS in AD children increased from 0.84 (95% CI: 0.75 to 0.94) for those with ≤3 AD related visits to 16.7 (95% CI: 14.7 to 18.9) for those with >5 visits (P<0.0001, by the trend test). AD children had a greater risk of developing IBS. Further research is needed to clarify the role of allergy in the pathogenesis of IBS.

Allergic Conjunctivitis and the Associated Risk of Migraine Among Children: A Nationwide Population-based Cohort Study.

PURPOSE: To investigate the risk of migraine in children with allergic conjunctivitis (AC). METHODS: In this population-based cohort study, 309 138 children with AC and 309 138 non-AC controls were included between 2000 and 2007. By 2008 end, the incidences of migraine in both cohorts, and the AC-to-non-AC cohort hazard ratios (HRs) were measured. RESULTS: The incidence of migraine during the study period was 1.92-fold higher in the AC cohort than in the non-AC cohort. The risk was greater for boys with AC and children aged <6 years. The mean time-interval between physician-diagnosed AC to physician-diagnosed migraine was 3.67 years (SD = 2.19).The risk of migraine development in the AC cohort increased with follow-up time and was highest during 4-5 years after AC diagnosis. The children with AC more likely had migraine without than with aura. CONCLUSIONS: Children with AC had a higher incidence and subsequent risk of migraine.

Trend of nocturnal enuresis in children with attention deficit/hyperactivity disorder: a nationwide population-based study in Taiwan.

Attention-deficit/hyperactivity disorder (ADHD) and nocturnal enuresis are common disorders with extensive psychosocial suffering in affected children, and healthcare burden on parents. Whether the childhood psychological disorders and nocturnal enuresis are factors contributing to ADHD have not been clearly established. This study conducted a population-based case-control study using data sets from the National Health Research Insurance database, and identified 14 900 children diagnosed with ADHD. Risk factors that have been associated with or possibly related to ADHD development were included in this study. Performance of in groups of ADHD with enuresis was compared with controls. With adjustment for potential covariates, participants with enuresis exhibited a 2.24-fold greater risk of subsequent ADHD development compared with controls (95% CI 1.84 to 2.73). Participants with enuresis and comorbidity had a significantly greater risk of ADHD than those with no enuresis and no comorbidity (adjusted OR=8.43, 95% CI 4.38 to 16.2). Children who are assessed for ADHD should be evaluated for the presence of enuresis or other neurobehavioral comorbidities. Multidisciplinary treatment may benefit children with ADHD and minimize psychological burden on parents.

Allergic rhinitis and associated risk of migraine among children: a nationwide population-based cohort study.

BACKGROUND: Increased frequency of migraine was reported in adults with allergic rhinitis (AR). Although migraine is less common in children than in adults, it can begin in early childhood and persist into adulthood. We conducted this population-based cohort study to investigate the incidence and subsequent risk of migraine in children with AR. METHODS: From 2000 to 2007, 461,850 children with recently diagnosed AR and 460,718 non-AR controls were included in the study. By the end of 2008, incidences of migraine in both cohorts, the AR to non-AR cohort hazard ratios (HRs), and confidence intervals (CIs) were measured. RESULTS: The incidence of migraine during the study period was 3.2-fold higher in the AR cohort (95% CI, 2.97 to 3.46) than in the non-AR cohort (11.4 vs 3.49 per 10000 person-years). The risk was greater for boys than for girls, and for children aged <6 years. The HR for migraine in children with AR was 1.44 (95% CI, 1.31 to 1.58) for those with ≤2 annual AR-related medical visits, whereas, 14.8 (95% CI, 13.6 to 16.2) for those with >4 visits (p < 0.0001, the trend test). The risk of migraine development in the AR cohort was highest within the first year after AR diagnosis (HR 4.89; 95% CI, 3.98 to 6.00). Children with AR were more likely to have migraine without aura than migraine with aura. CONCLUSION: Children with AR had a higher incidence and subsequent risk of migraine. Physicians should be more aware of migraine in children with AR who complain of headache.

A novel dental implant guided surgery based on integration of surgical template and augmented reality.

BACKGROUND: Stereoscopic visualization concept combined with head-mounted displays may increase the accuracy of computer-aided implant surgery. PURPOSE: The aim of this study was to develop an augmented reality-based dental implant placement system and evaluate the accuracy of the virtually planned versus the actual prepared implant site created in vitro. MATERIALS AND METHODS: Four fully edentulous mandibular and four partially edentulous maxillary duplicated casts were used. Six implants were planned in the mandibular and four in the maxillary casts. A total of 40 osteotomy sites were prepared in the casts using stereolithographic template integrated with augmented reality-based surgical simulation. During the surgery, the dentist could be guided accurately through a head-mounted display by superimposing the virtual auxiliary line and the drill stop. The deviation between planned and prepared positions of the implants was measured via postoperative computer tomography generated scan images. RESULTS: Mean and standard deviation of the discrepancy between planned and prepared sites at the entry point, apex, angle, depth, and lateral locations were 0.50 ± 0.33 mm, 0.96 ± 0.36 mm, 2.70 ± 1.55°, 0.33 ± 0.27 mm, and 0.86 ± 0.34 mm, respectively, for the fully edentulous mandible, and 0.46 ± 0.20 mm, 1.23 ± 0.42 mm, 3.33 ± 1.42°, 0.48 ± 0.37 mm, and 1.1 ± 0.39 mm, respectively, for the partially edentulous maxilla. There was a statistically significant difference in the apical deviation between maxilla and mandible in this surgical simulation (p < .05). CONCLUSIONS: Deviation of implant placement from planned position was significantly reduced by integrating surgical template and augmented reality technology.

Coherent optical memory with high storage efficiency and large fractional delay.

A high-storage efficiency and long-lived quantum memory for photons is an essential component in long-distance quantum communication and optical quantum computation. Here, we report a 78% storage efficiency of light pulses in a cold atomic medium based on the effect of electromagnetically induced transparency. At 50% storage efficiency, we obtain a fractional delay of 74, which is the best up-to-date record. The classical fidelity of the recalled pulse is better than 90% and nearly independent of the storage time, as confirmed by the direct measurement of phase evolution of the output light pulse with a beat-note interferometer. Such excellent phase coherence between the stored and recalled light pulses suggests that the current result may be readily applied to single photon wave packets. Our work significantly advances the technology of electromagnetically induced transparency-based optical memory and may find practical applications in long-distance quantum communication and optical quantum computation.

EIT-based all-optical switching and cross-phase modulation under the influence of four-wave mixing.

All-optical switching (AOS) or cross-phase modulation (XPM) based on the effect of electromagnetically induced transparency (EIT) makes one photon switched or phase-modulated by another possible. The existence of four-wave mixing (FWM) process greatly diminishes the switching or phase-modulation efficiency and hinders the single-photon operation. We proposed and experimentally demonstrated an idea that with an optimum detuning the EIT-based AOS can be completely intact even under the influence of FWM. The results of the work can be directly applied to the EIT-based XPM. Our work makes the AOS and XPM schemes more flexible and the single-photon operation possible in FWM-allowed systems.

Immediate loading of single-tooth restorations: one-year prospective results.

Immediate loading of splinted implant restorations is a growing trend, but limited clinical documentation hampers evidence-based treatment planning for single-tooth applications. This study prospectively evaluated the clinical efficacy of placing implant-supported, single-tooth restorations into immediate, full-occlusal loading. Sixty consecutive patients (intent-to-treat group) with 1 missing tooth between 2 intact teeth were treated with a total of 69 implants. At placement, final impressions were made and implants were provisionalized with nonoccluding prostheses. Definitive prostheses were delivered 2 weeks later. A claim of noninferiority was made with a 95% confidence interval (Mann-Whitney U test) if the success rates between the experimental group and a 97% historical control was > 7%. Standardized radiographs taken at placement and bimonthly intervals were analyzed for crestal bone changes at a type I (alpha) error level of .05; significance levels were not adjusted for multiplicity (Fisher exact tests and Student t tests). Sixteen patients (18 implants) were withdrawn for protocol deviations. The resulting treated-per-protocol group consisted of 44 subjects with 51 implants. Cumulative implant success rates were 98.55% (n = 68/69) for the intent-to-treat group and 98.04% (n = 50/51) for the treated-per-protocol group. There were no significant adverse events or statistically significant differences between the experimental and historical control groups. At 12 months mean crestal bone loss was 1.05 mm, and ranged from 0.38 to 1.5 mm (77%) and 1.6 to 2.69 mm (23%). Immediate full-occlusal loading of single-tooth restorations was safely performed in selected subjects when good primary implant stability and an appropriate occlusal load were achieved.

A comparison of miniplates and teeth for orthodontic anchorage.

INTRODUCTION: In this study, we investigated orthodontic space closure of premolar extraction sites with miniplate anchorage compared with conventional tooth-borne anchorage in 8 adult beagle dogs. METHODS: A split-mouth design with all 4 quadrants was used. Four premolars were extracted to create adequate space for premolar retraction. Retraction was performed with nickel-titanium coil springs. In the control side, the premolars were retracted against other teeth, and, in the experimental side, the premolars were retracted against miniplates. Each quadrant received 2 additional bone screws as bone markers for cephalometric superimposition. Lateral cephalograms were taken at initial activation, 6 weeks, and 12 weeks. Three parameters were measured and evaluated: linear space closure, angular tipping, and amount of anchorage slippage. RESULTS: Overall, the miniplates had a high success rate of 93.8% (15 of 16) during the 12-week period of orthodontic loading. Similar amounts of space closure were observed in the control and the experimental sites. A statistically significant difference was observed for the amounts of tipping and anchorage slippage of miniplates vs tooth-borne anchorage. In the maxilla, the mean miniplate tipping was 0.1 degrees , whereas mean tipping of the anchor teeth was 9 degrees (P = .01). In the mandible, the miniplates tipped an average of 3.4 degrees , whereas the mean tipping of the anchor teeth was 13.3 degrees (P = .02). In the maxilla, the miniplates had 1% anchorage loss, whereas the tooth anchors had 37.1% anchorage loss (P = .001). In the mandible, the miniplates had a mean anchorage loss of 4.5%, whereas the tooth anchors had a mean anchorage loss of 31.1% (P = .001). CONCLUSIONS: Although the total amount of space closure was similar in both the control and the experimental groups, the mechanism of space closure was different. In the control group, slippage of the anchor teeth accounted for approximately a third of the space closure. In the experimental group, the miniplates had minimal movement, and space closure was achieved almost entirely by movement of the target teeth. These results confirm that miniplates provide virtually absolute anchorage.

Adjunctive periodontal therapies.

In general, systemic and local chemotherapeutic treatments offer a variety of options as adjuncts to traditional mechanical therapy, but they should not be used routinely for every patient. In fact, initial debridement to disrupt the biofilm and remove calculus prior to drug treatment may enhance results. Dentists will need to use their clinical judgment based on disease nature and severity to make treatment decisions, with the knowledge that these therapies may be best utilized in the few localized persistent lesions present following thorough scaling and root planing.

Mandibular growth following implant restoration: does Wolff's law apply to residual ridge resorption?

This study measured bone height under a fixed detachable cantilever restoration supported by five or six endosseous implants in 60 consecutively treated patients. Panoramic films were made at surgery and 1, 2, 3, and 4 years postrestoration. A computer-enhanced method was used to measure mandibular height 5, 10, 15, and 20 mm distal to the last implant, which was used as a length. standard to correct for variation in film magnification. Implant restoration resulted in a significant growth of the mandible (baseline: 7.25 +/- 0.25 mm, 4 years: 8.18 +/- 0.18 mm; P = .05). The growth in dimension appears to occur during the first year of function.