Comparison of in vivo and in vitro force decay of elastomeric chains/modules: a systematic review and meta analysis.

BACKGROUND: The study evaluated and compared the force decay of orthodontic elastomeric chains/modules in both in vivo and in vitro settings. METHODS: A protocol in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was formulated and registered with the International Prospective Register of Systematic Reviews. A total of 53 articles (44 in vitro and 9 in vivo studies) found via search of the electronic databases of Cochrane and the National Library of Medicine (MEDLINE; PubMed), and manual search of the gray literature from institutional library resources, were selected. Data extraction, quality analysis, risk of bias assessment, and meta-analysis of the level of force decay of elastomeric chains/modules were conducted per standard protocol, and suitable statistical analyses were applied. RESULTS: The mean force decay in the in vivo setting was 41.9% at 24 hours, 42.6% after 1 week, 46.8% after 2 weeks, and 55.0% after 3 weeks. Similarly, the force decay in the in vitro studies was 38.9% at 24 hours, 42.1% after 1 week, 44.6% after 2 weeks, and 51.1% after 3 weeks. However, at the 95% confidence interval, the force decay rates of in vivo and in vitro studies overlap, with a statistically insignificant difference in force decay observed in the in vivo and in vitro settings. CONCLUSIONS: This systematic review and meta-analysis observed more force decay in the in vivo studies versus the in vitro studies (although this difference was statistically insignificant), with the maximum force decay occurring during the initial days, with a reduction to approximately 50% within 3 weeks. Hence, change of the elastomeric chains/module, at intervals of 3 weeks, is advised. (PROSPERO registration no. CRD42020209535).

Management of skeletal class II malocclusion using bimaxillary skeletal anchorage supported fixed functional appliances : A novel technique.

AIM: To evaluate the treatment effects in growing skeletal class II patients subjected to a novel treatment technique, i.e., bimaxillary miniplates supported fixed functional appliance. The null hypothesis was that there is no statistically significant difference in skeletal changes of patients with class II malocclusion treated with bimaxillary skeletal anchorage supported fixed functional appliance and those who were not provided any intervention. METHODS: The sample comprised 32 skeletal class II subjects (17 males and 15 females) with a Cervical Vertebrae Maturity Index (CVMI) demonstrating peak of pubertal growth spurt. Sixteen patients (12.37 ±1.09 years of age) were treated with bimaxillary skeletal anchorage supported fixed function appliance, while 16 well-matched subjects (12.06 ± 1.34 years of age) were included as controls. For both groups, cephalograms (T1, T2) were taken with a matched observational interval of about 7.5 months; 17 linear and 10 angular measurements were recorded. The intraclass correlation coefficient (ICC) was used to determine reliability of measurements recorded. Student t test was carried out to determine the changes produced by the treatment relative to control. RESULTS: When compared with the control group, the treatment group demonstrated significant maxillary retrusion. No significant changes were seen in mandibular growth pattern, whereas mandibular length increased significantly more than in the control group (B-VP: 3.05 mm; Co-Gn: 2.65 mm). Treatment mechanics had minimal effects on maxillary dentition. Mandibular incisors proclined by an average of 3.06°. Maxilla-mandibular relation improved significantly (ANB: -4.29°; NA-Pog: -3.76°). CONCLUSION: The new bimaxillary skeletal anchorage supported fixed functional appliance technique was found to be highly effective in the treatment of class II malocclusion with significant skeletal changes.

De-novo Upper Gastrointestinal Tract Cancer after Liver Transplantation: A Demographic Report.

BACKGROUND: Immunosuppression is essential after liver transplantation (LT). It, however, increases the risk for cancer. OBJECTIVE: To evaluate the prevalence and outcome of upper gastrointestinal (GI) tract cancer in LT patients and assess the perioperative risk of surgery for the upper GI malignancies post-LT. METHODS: 2855 patients underwent LT at our clinic from 1988 to 2018. 20 patients developed upper GI cancer. Data were retrospectively extracted from our database. Analysis included patients' specific data, tumor histopathology and stage, the treatment given and survival. RESULTS: 23 patients developed upper GI malignancies (2 gastric and 18 esophageal cancers; 3 excluded), translating to a incidence of 26.4 per 100,000 population per year. All patients were male. 80% showed alcohol-induced cirrhosis before LT. Most of the tumors were diagnosed at a stage ≥III. 70% underwent surgery and 78.6% developed postoperative complications. One-year-survival was 50%. Total survival rate was 28.6% with a median follow-up of 10 months (range: 0-184). CONCLUSION: Upper GI malignancies are more common after LT compared to the general population. Men after LT, due to alcohol-induced liver cirrhosis, are at a higher risk. Upper GI surgery after LT can be safe, but the severe risk for complications and a poor survival require strict indications.

Comparative evaluation of anchorage reinforcement between orthodontic implants and conventional anchorage in orthodontic management of bimaxillary dentoalveolar protrusion.

BACKGROUND: Increased upper lip procumbency is commonly associated with maxillary dentoalveolar protrusion with the major goal of reducing maxillary dentoalveolar protrusion. The treatment plan usually includes extraction of the maxillary first premolars, followed by retraction of anterior teeth with maximum anchorage. Dental implants have been widely accepted as successful adjuncts for obtaining maximum anchorage in orthodontic treatment. METHODS: 50 subjects between the ages of 13 and 17 years having bimaxillary dentoalveolar protrusion were included in the study. The patients were divided into two groups. Both groups received treatment with 0.022″ MBT prescription preadjusted edgewise appliance system. In addition, subjects of Group 'I' received the Nance button and lingual arch as anchorage reinforcement in the upper and lower arches, respectively. Subjects of Group 'II' received self-drilling titanium OI for anchorage reinforcement. RESULTS: Significant retraction was achieved in all cases with good vertical control. Anchor loss was observed in both groups. Anchor loss was much higher in Group I compared to Group II, and an intergroup comparison for anchor loss was highly significant. CONCLUSION: Implants as anchorage, for en masse retraction, can be incorporated into orthodontic practice. The use of orthodontic implants for anchorage is a viable alternative to conventional molar anchorage.

Interdisciplinary Management of Patient with Advanced Periodontal Disease.

This case report describes the interdisciplinary management of an adult patient with advanced periodontal disease. Treatment involved orthodontic and periodontal management. Good esthetic results and dental relationships were achieved by the treatment.

Effect of retraction of anterior teeth on pharyngeal airway and hyoid bone position in Class I bimaxillary dentoalveolar protrusion.

BACKGROUND: To test the hypothesis that the retraction of anterior teeth has no effect on the dimensions of pharyngeal airway and to evaluate the retraction of anterior teeth on each parameter of pharyngeal airway. METHODS: Twenty-two adult patients of Class I bimaxillary protrusion requiring first premolar extractions with maximum anchorage requirements were selected. The pharyngeal airway and dentofacial parameters of the patients were compared using pre- and post-treatment lateral cephalograms with the help of Student's paired t-test (P < 0.05). The relationship between airway size and dentofacial parameters was also evaluated using Pearson correlation coefficient. RESULTS: The upper and lower lips were retracted by 2.25 and 5.4 mm after retraction of the incisors. The tips of upper and lower incisors were retracted by 7.75 and 7.15 mm, respectively. There was a statistically significant decrease in SPP-SPPW (P < 0.05), U-MPW (P < 0.001), TB-TPPW (P < 0.001), and change in HRGN (P < 0.01). A significant correlation was observed between the amount of retraction of lower incisor and decrease in the pharyngeal airway posterior to soft palate (r = 0.102), tongue (r = 0.322), and change in HRGN (r = 0.265). CONCLUSIONS: The size of the pharyngeal (velopharyngeal and glossopharyngeal) airway reduced and hyoid bone position changed after retraction of the incisors in extraction space in bimaxillary protrusive adult patients.

A radiographic study of external apical root resorption in patients treated with single-phase fixed orthodontic therapy.

BACKGROUND: External apical root resorption (EARR) is one of the most common iatrogenic consequences of orthodontic tooth movement. Many factors like gender, duration, orthodontic force and duration of orthodontic treatment have been implicated to cause EARR. METHODS: Pre- and post-treatment OPGs of 60 orthodontic patients (30 males and 30 females) who had undergone treatment with a single phase of fixed orthodontic therapy were randomly selected from institutional archives. The root apices were evaluated for EARR by a single operator on an radiograph viewing box at a standardized source of light using a four-grade ordinal scale. Anterior EARR was measured on the maxillary and mandibular canines. Posterior EARR was measured on premolars, mesiobuccal and distobuccal roots of maxillary first molars and mesial and distal roots of mandibular first molars. The results were compiled and subjected to statistical analysis. RESULTS: The cases in which the patients underwent therapeutic extraction had a relatively higher amount of EARR compared to the cases in which the patients were treated by non-extraction therapy (P < 0.001). Odds ratio indicated that extraction cases had two-fold increased risk of EARR than non-extraction cases (P < 0.001). No statistically significant difference was observed in the distribution of EARR based on gender or duration of orthodontic treatment (P > 0.05). CONCLUSION: Therapeutic extraction is an important determinant of post-treatment EARR. Gender and duration of orthodontic treatment may not be important variables in the causation of EARR according to the findings of this study. However, longitudinal studies with larger sample size are required to validate the results of this study.

Effect of surgical mandibular advancement on pharyngeal airway dimensions: a three-dimensional computed tomography study.

The aim of this study was to quantify the changes in pharyngeal airway space (PAS) in patients with a skeletal class II malocclusion managed by bilateral sagittal split ramus osteotomy for mandibular advancement, using three-dimensional (3D) registration. The sample comprised 16 patients (mean age 21.69±2.80 years). Preoperative (T0) and postoperative (T1) computed tomography scans were recorded. Linear, cross-sectional area (CSA), and volumetric parameters of the velopharynx, oropharynx, and hypopharynx were evaluated. Parameters were compared with paired samples t-tests. Highly significant changes in dimension were measured in both sagittal and transverse planes (P<0.001). CSA measurements increased significantly between T0 and T1 (P<0.001). A significant increase in PAS volume was found at T1 compared with T0 (P<0.001). The changes in PAS were quantified using 3D reconstruction. Along the sagittal and transverse planes, the greatest increase was seen in the oropharynx (12.16% and 11.50%, respectively), followed by hypopharynx (11.00% and 9.07%) and velopharynx (8.97% and 6.73%). CSA increased by 41.69%, 34.56%, and 28.81% in the oropharynx, hypopharynx, and velopharynx, respectively. The volumetric increase was greatest in the oropharynx (49.79%) and least in the velopharynx (38.92%). These established quantifications may act as a useful guide for clinicians in the field of dental sleep medicine.

Management of Tooth Size Arch Size Discrepancy (TSASD) in Patients with Sleep Disorder Breathing.

This case report describes the interdisciplinary management of an adult patient with sleep disorder breathing i.e. snoring. Treatment involved combined ortho-surgical management. Marked improvement in general health, good esthetic results, and dental relationships were achieved by the treatment.

Clinical evaluation of immediate loading of titanium orthodontic implants.

BACKGROUND: Skeletal anchorage using dental implants, miniplates, miniscrews and microscrews provides an absolute anchorage for tooth movement. Miniscrew and microscrew implants have many benefits such as ease of placement and removal and immediate orthodontic force application. METHODS: Fifteen subjects in the permanent dentition with an overjet ≥6 mm received treatment with the 0.018-inch pre-adjusted edgewise appliance system (Roth prescription) and extraction of all first premolars. Titanium orthodontic implants were placed in both the upper quadrants and were immediately loaded with elastic chain from the implant head to the sectional arch wire. RESULT: The overall success rate of immediate loaded titanium orthodontic micro implants (OMI) in the present study was 83.33%, with a mean chairside time of 15.33 min of placing two implants in each patient. Peri-implant inflammation was the only complication observed. Most failures were in the initial part of the study. There was no significant difference in the success rate of implants based on sex, side of placement (right or left) and type of malocclusion. CONCLUSION: The OMIs used in the present study proved to be effective and well tolerated in producing immediate orthodontic anchorage for the retraction.

Comparative evaluation of anchorage loss between self-ligating appliance and Conventional pre-adjusted edgewise appliance using sliding mechanics - A retrospective study.

BACKGROUND: Although a number of studies have been undertaken to evaluate the friction characteristics of self-ligating brackets, there have been only few studies which have actually evaluated the clinical efficiency of these self-ligating brackets. This study was done to evaluate the clinical efficiency of Passive SLB (Smart Clip) in terms of anchorage loss and total treatment duration by comparing it with a Conventional pre-adjusted edgewise (M.B.T.) bracket system. METHODS: This was a retrospective study in which the study sample comprised of ten patients treated with Passive SLB (Smart Clip, 0.022″) and ten patients treated with Conventional pre-adjusted edgewise (M.B.T.) bracket system (0.022″) who required therapeutic extraction of U/L first premolars as a part of their orthodontic treatment plan. Pretreatment and post treatment lateral cephalograms were taken to evaluate the amount of anchorage loss. The total time required to complete the treatment was also recorded. RESULTS: Anchorage loss observed with Passive SLB (Smart Clip) sagittally was 1.90 ± 0.68 mm in the maxilla and 1.90 ± 0.43 mm in the mandible and vertically was 0.52 ± 0.53 mm in the maxilla and 0.70 ± 0.69 mm in the mandible. Anchorage loss observed with Conventional pre-adjusted edgewise (M.B.T.) bracket system sagittally was 2.08 ± 0.43 mm in the maxilla and 1.95 ± 0.44 mm in the mandible and vertically was 0.50 ± 0.49 mm in the maxilla and 0.68 ± 0.53 mm in the mandible. The average time taken for the completion of treatment in Passive SLB (Smart Clip) and Conventional pre-adjusted edgewise (M.B.T.) bracket system was 14.0 ± 2.4 and 17.2 ± 2.6 months respectively. CONCLUSION: There was no statistically significant difference in the quantum of anchor loss between Smart Clip self-ligating bracket system and Conventional pre-adjusted edgewise (M.B.T.) bracket system although Smart Clip self-ligating bracket system is efficient in reducing the overall treatment time.

Self ligating lingual appliance.

Adult demand for orthodontics has grown considerably over the past 10 years propelling increased demand for Esthetic Orthodontics. Lingual appliances are a viable option toward providing Esthetic Orthodontics. The lingual surface of the teeth has a unique morphology that makes it difficult to place brackets in ideal positions. Indirect bonding has become the established methods of overcoming these discrepancies, along with the latest designs of self ligating brackets which offer more efficient mechanics and shorter treatment time.

[Radiofrequency ablation for treatment of colorectal liver metastases: scientific evidence and clinical reality]. / Die Radiofrequenzablation in der Behandlung von kolorektalen Lebermetastasen: Was ist belegt?

Radiofrequency ablation (RFA) of colorectal liver metastases is frequently reported, but, however, lacks clear criteria for indication and reliable, convincing results with 5-year survival ranging from 17 to 48 %. RFA may be the appropriate treatment modality in approximately 3 to 5 % of all patients suffering from colorectal liver metastases. To date, RFA seems to be limited to no more than three metastases, each smaller than 3 cm. The main indication remains irresectability due to number, site, distribution and/or marginal liver function. Tumours in the vicinity of larger vessels (predominantly branches of portal or hepatic veins) are a case for controversy, since advances in hepatobiliary surgery enable a proportion of patients to undergo resections which would have been declared irresectable until most recently, and the oncological value of a thermoablation is questioned, as a certain amount of temperature is lost due to convective heat sinks. RFA is not a curative alternative to hepatic resection unless small tumours appear during open or laparoscopic procedures in a patient with elevated risk for early recurrence or postoperative morbidity following liver resection. The inclusion of RFA into a holistic system of oncological therapy is mandatory. Early RFA followed by systemic (regional?) chemotherapy can rather be recommended than chemo only, RFA only or first-line chemo with subsequent RFA.

[Minimal-invasive microwave coagulation therapy for liver tumours: laparoscopic and percutaneous access]. / Laparoskopische und perkutane Mikrowellenablation maligner Lebertumoren: Anwendbarkeit und Effizienz.

INTRODUCTION: Local ablative treatments play an important role in current surgical treatment strategies. Radiofrequency ablation (RFA) as one of the most popular examples suffers from partly inacceptable local tumour control. Microwave coagulation therapy (MCT) is a comparatively new type of ablation promising several improvements. This series is to the best of our knowledge the first within the central European area, which reports on the successful clinical implementation of MCT in a surgical department. PATIENTS AND MATERIALS: A novel 915 MHz system (MedWaves™, AveCure Inc., SanDiego, CA/U. S. A.) was used to treat 47 patients with 80 tumour nodules in 51 treatment sessions. Average tumour size was 2.6 ± 0.9 cm. Indications were hepatocellular carcinoma in 29 patients and metastases in 14 as well as 4 cholangiocellular carcinomas. The approach was laparoscopic (20) or percutaneous (31). High-risk conditions defined by unfavourable tumour localisation like invisibility in native transabdominal ultrasound, superficial tumour site or risk of heat sink phenomena were found in 28 cases (53 %). RESULTS: Local recurrence rate was 17 % on a per-patient and 12 % on a per-tumour basis (n = 9). One patient died because of incurable upper gastrointestinal bleeding during the postoperative hospital stay. No MCT-associated complication occurred. Median follow-up period was 20 months. Local tumour recurrence was significantly different on comparing laparoscopic to percutaneous MCT (p = 0.032, χ2 test), as was global recurrence (p = 0.011, χ2 test). In a univariate logistic Cox regression, tumour size, access and high-risk localisation were significant prognostic factors for local tumour recurrence, however, in a multivariate reiteration, only the chosen access to MCT (p = 0.012) and tumour size (p = 0.044) remain significant. CONCLUSION: MCT seems to be a useful tool, easy to implement in a surgical environment and may eventually prove to be superior to other local ablative treatment modalities. Even unfavourable tumour localisations could be treated safely and efficiently using MCT without increased risk of local tumour recurrence.

Mandibular symphyseal distraction osteogenesis--simplified.

The limb lengthening technique of distraction osteogenesis (DO) used in orthopedic surgery is a well established procedure. DO has been adapted to the facial skeleton to change the anterior-posterior position of the jaws. Historically, the mandibular arch transverse dimension has been considered immutable. Mandibular arch expansion is done with a variety of methods including Schwarz plates, lingual arches, functional appliances and arch wires; these methods produce limited dimensional change with questionable long-term stability. Adapting the Ilizarov treatment protocol to the mandibular symphysis can produce a regenerate bone thereby adding dimension to the innate basal bone. This can then be used to produce a potentially greater effect than the conventional modes of mandibular expansion. The modified mandibular symphyseal distraction device used by the authors is a tooth borne device fabricated with a Schwartz screw and self cured acrylic resin coverage over all the erupted mandibular teeth. The appliance used by the authors has been found to be very economical, easy to fabricate and clinically efficient. The surgical approach used, requiring surgery under local anesthesia in the outpatient department obviates need of hospital admission and the cost and time factors associated with in-patient therapy Mandibular Symphyseal Distraction Osteogenesis (MSDO) with this innovative low cost approach may be compared in a multi centric study with other established methods of MSDO.

Treatment of recurrent hepatocellular carcinoma confined to the liver with repeated resection and radiofrequency ablation: a single center experience.

BACKGROUND: Recurrence of hepatocellular carcinoma (HCC) after surgical treatment is a common problem. It can be treated by radiofrequency ablation (RFA) or repeated hepatic resection (HR). This report compares both in a retrospective, single-institution database. PATIENTS AND METHODS: A prospectively collected database was retrospectively analyzed. RFA was performed under ultrasound control using two different monopolar devices. All kinds of access were used: open surgical (n=10), percutaneous (n=13) and laparoscopic (n=4). HR was performed using an ultrasound aspiration device. Indication for a particular treatment was allocated on a case-by-case basis; the final decision was often made intraoperatively. RESULTS: Survival after RFA (median 40 months) was similar compared to that after HR (48 months, p=0.641, logRank-test). Tumor-free survival was markedly impaired after RFA (15 vs. 29 months). This difference was however not significant (p=0.07, logRank-test). Both groups were different regarding occurrence of cirrhosis, maximal tumor size, time after initial diagnosis and duration of the procedure. CONCLUSION: In this non-randomized retrospective trial, survival and disease-free survival was not significantly different when compared between patients treated by RFA and HR. There was however a tendency towards a longer tumor-free survival in the resected patients.

Low-dose computed tomography to detect body-packing in an animal model.

OBJECTIVE: To assess the possible extent of dose reduction for low-dose computed tomography (CT) in the detection of body-packing (ingested drug packets) as an alternative to plain radiographs in an animal model. MATERIALS AND METHODS: Twelve packets containing cocaine (purity >80%) were introduced into the intestine of an experimental animal (crossbred pig), which was then repeatedly examined by abdominal CT with stepwise dose reduction (tube voltage, 80 kV; tube current, 10-350 mA). Three blinded readers independently evaluated the CT datasets starting with the lowest tube current and noted the numbers of packets detected at the different tube currents used. In addition, 1 experienced reader determined the number of packets detectable on plain abdominal radiographs and ultrasound. RESULTS: The threshold for correct identification of all 12 drug packets was 100 mA for reader 1 and 125 mA for readers 2 and 3. Above these thresholds all 3 readers consistently identified all 12 packets. The effective dose of a low-dose CT scan with 125 mA (including scout view) was 1.0 mSv, which was below that of 2 conventional abdominal radiographs (1.2 mSv). The reader interpreting the conventional radiographs identified a total of 9 drug packets and detected 8 packets by abdominal ultrasound. CONCLUSIONS: Extensive dose reduction makes low-dose CT a valuable alternative imaging modality for the examination of suspected body-packers and might replace conventional abdominal radiographs as the first-line imaging modality.