Does rapid maxillary expansion induce adverse effects in growing subjects?

To assess the scientific evidence that rapid maxillary expansion (RME) causes Adverse Effects on the midpalatal suture, vertical dimension, dental and periodontal structures in growing subjects. MATERIALS AND METHODS: Electronic databases were searched for articles dated through December 2011. The quality of the studies was ranked on a 13-point scale in which 1 was the low end of the scale and 13 was the high end. RESULTS: Thirty relevant articles were identified. The amount of midpalatal suture opening ranged from 1.6 to 4.3 mm in the anterior region and from 1.2 to 4.4 mm in the posterior region. At the end of the active phase, RME resulted in slight inferior movement of the maxilla (SN-PNS +0.9 mm; SN-ANS +1.6 mm), increased tipping of anchored teeth from 3.4° to 9.2° and bending of the alveolar bone from 5.1° to 11.3°. In the long term, RME did not modify the facial growth patterns, and no significant changes on dentoalveolar structures were observed. Of the 30 studies, 2 were medium-high quality, 8 were medium quality, and 20 were low quality. CONCLUSIONS: RME always opened the midpalatal suture in growing subjects. The vertical changes were small and transitory. In the long-term evaluation, an uprighting of anchored teeth was observed and periodontal structures were not compromised

Orthodontic treatment of an impacted dilacerated maxillary incisor: a case report

Dilaceration is one of the causes of permanent maxillary incisor eruption failure. It is a developmental distortion of the form of a tooth that commonly occurs in permanent incisors as result of trauma to the primary predecessors whose apices lie close to the permanent tooth germ. We present a case of post-traumatic impaction of a dilacerated central maxillary left incisor in a young patient with a class II malocclusion

Effects of cervical headgear and pendulum appliance on vertical dimension in growing subjects: a retrospective controlled clinical trial

Summary OBJECTIVE : To analyze the effects on vertical dentoskeletal dimension produced by cervical headgear (CHG) or Pendulum (P) both followed by full fixed appliances in growing patients with Class II malocclusion

Treatment and posttreatment skeletal effects of rapid maxillary expansion studied with low-dose computed tomography in growing subjects

Introduction: The aim of this study was to apply low-dose computed tomography (CT) to evaluate treatment and posttreatment effects produced by rapid maxillary expansion (RME) at the levels of the midpalatal suture and the pterygoid processes. Methods: A sample of 17 subjects (7 boys, 10 girls; mean age, 11.2 years) was analyzed. Multi-slice CT scans were taken before RME, at the end of the active expansion phase, and after a retention period of 6 months. Statistical analysis was performed with ANOVA for repeated measures with post-hoc tests. Results: The amounts of opening of the midpalatal suture during the active phase of expansion were 3.01, 2.17, and 1.15 mm for the anterior, middle, and posterior suture widths, respectively. Pterygoid width also showed a statistically significant increase (1.49 mm). In the postretention period, all transverse measurements had significant decreases except for pterygoid width. Conclusions: At the end of the retention phase after RME therapy, the transverse width of the midpalatal suture was similar to the pretreatment width, whereas the width between the pterygoid processes was significantly increased

Low-dose CT protocol for orthodontic diagnosis.

AIM: This was to correlate the dosimetric evaluation with high diagnostic accuracy by suggesting a protocol that significantly reduces the dose administered by a Dentascan exam without affecting diagnostic accuracy. MATERIALS AND METHODS: 17 patients were selected consecutively (7 males and 10 females) of a mean age of 11.2 (8-14 years) who sought orthodontic treatment. They needed CT control before and after treatment with RME to evaluate impacted canines. The study was performed using a multidetector 16-rows CT with two protocols that provided 2 different KV acquisition parameters: 80 KV or 120 KV. Radiation dose was evaluated in two ways: CTDI and DLP. Image quality was rated and the results were compared to identify significant differences in terms of image quality, radiation exposure and presence of artefacts. RESULTS: The 80 KV scanning has a significantly lower effective radiation dose compared to the 120 KV scanning (p <0.05). The images of all patients were used for comparing the protocols in terms of image quality. The mean scores for the 80 KV scanning images were 4.18 +/-0.81 and 4.41 +/-0.80 for dose obtained by 120 KV scanning. The median image quality was 4 (good) for both protocols. The 80 KV protocol allowed, as well as the 120 KV, a careful analysis by the orthodontist and the dental surgeon that together, based on this images, can choose the best line of treatment between several available options. CONCLUSION: 80 KV protocols compared with 120 KV protocols resulted in reduced total radiation dose without relevant loss of diagnostic image information and quality. The images were good enough to obtain information about the exact position of impacted teeth and to plan the best line of surgical treatment and mechanotherapy strategy

Bonded versus banded rapid palatal expander followed by facial mask therapy: analysis on digital dental casts.

To compare the dental effects produced by a bonded versus a banded expander combined with facial mask (FM) in patients with Class III malocclusion by means of digital dental casts. MATERIALS AND METHODS: Two groups of patients with Class III malocclusion and maxillary transverse deficiency in the deciduous or early mixed dentition were selected. The first group consisted of 25 subjects (12 females; 13 males) with a mean age of 7.4 years (SD 1.2 years) treated with a bonded expander and FM. The second group consisted of 25 subjects (13 females; 12 males) with a mean age of 8.1 years (SD 1.3 years) treated with a banded expander and FM. For each subject of the two groups, initial (pre-treatment, T1) and final (post-treatment, T2) dental casts were taken and scanned. Maxillary digital models of T1 and T2 were superimposed on the palatal rugae in order to analyse the maxillary anchorage loss. Significant between-group differences were tested with independent sample t-test (P < 0.05). RESULTS: No statistical differences were found for any of the variables observed. CONCLUSION: Orthopaedic treatment of Class III malocclusion with either a bonded or a banded expander and FM during the deciduous or early mixed dentition induced a significant expansion of the maxillary arch and a slight mesialization of the posterior anchoring teeth with no difference between the two intraoral appliance design

Online user behavioural modeling with applications to price steering

Price steering is the practice of “changing the order of search results to highlight specific products” and products prices. In this paper, we show an initial investigation to quantify the price steering level in search results shown to different kind of users on Google Shopping. We mimic the category of affluent users. Affluent users visit websites offering expensive services, search for luxury goods and always click on the most costly items results at Google Shopping. The goal is checking if users trained in specific ways get different search results, based on the price of the products in the results. Evaluation is based on well known metrics to measure page results differences and similarities. Experiments are automised, rendering large-scale investigations feasible. Results of our experiments, based on a preliminary experimental setting, show that users trained on some particular topics are not always influenced by previous search and click activities. However, different trained users actually achieve different search results, thus paving the way for further investigation

Role of surgical setting and patients-related factors in predicting the occurrence of postoperative pulmonary complications after abdominal surgery

OBJECTIVE: The aim of this retrospective study was to evaluate the role of surgical setting (urgent vs. elective) and approach (open vs. laparoscopic) in affecting postoperative pulmonary complications (PPCs) prevalence in patients undergoing abdominal surgery. PATIENTS AND METHODS: After local Ethical Committee approval, 409 patients who had undergone abdominal surgery between January and December 2014 were included in the final analysis. PPCs were defined as the development of one of the following new findings: respiratory failure, pulmonary infection, aspiration pneumonia, pleural effusion, pneumothorax, atelectasis on chest X-ray, bronchospasm or un-planned urgent re-intubation. RESULTS: PPCs prevalence was greater in urgent (33%) vs. elective setting (7%) (chi(2) with Yates correction: 44; p=0.0001) and in open (6%) vs. laparoscopic approach (1.9%) (chi(2) with Yates correction: 12; p=0.0006). PPCs occurrence was positively correlated with in-hospital mortality (Biserial Correlation r=0.37; p=0.0001). Logistic regression showed that urgent setting (p=0.000), Ariscat (Assess Respiratory Risk in Surgical Patients in Catalonia) score (p=0.004), and age (p=0.01) were predictors of PPCs. A cutoff of 23 for Ariscat score was also identified as determining factor for PPCs occurrence with 94% sensitivity and 29% specificity. CONCLUSIONS: Patients undergoing abdominal surgery in an urgent setting were exposed to a higher risk of PPCs compared to patients scheduled for elective procedures. Ariscat score fitted with PPCs prevalence and older patients were exposed to a higher risk of PPCs. Prospective studies are needed to confirm these result