Accuracy of direct insertion of TADs in the anterior palate with respect to a 3D-assisted digital insertion virtual planning.

BACKGROUND: Direct and 3D-assisted methods are an available alternative when inserting temporary anchorage devices (TADs) in the anterior palate for orthodontic anchorage. This study aimed to evaluate the differences between a planned insertion versus a direct method on digital models. SETTINGS AND SAMPLE POPULATION: Seventy TADs were inserted by the direct insertion method in 35 patients who needed palatal TADs for orthodontic anchorage. For each patient, placement was independently planned by the superimposition of lateral cephalograms and corresponding plaster models. After mini-implant placement, impressions were taken with scanbodies. For the measurement of both linear and angle deviations, virtual planning models and postoperative oral scans were compared using 3D software for automatic surface registration and calculations. RESULTS: Comparing TADs positioned by the direct method and the digitally planned method, a mean linear distance was found of 2.54 ± 1.51 mm in the occlusal view and 2.41 ± 1.33 mm in the sagittal view. No significant difference has been found between TADs positioned in the right and left palatal sides. A mean distance of 7.65 ± 2.16 mm was found between the tip of the digitally planned TAD and the central incisors root apex. CONCLUSIONS: Both direct and 3D-assisted TAD insertion methods are safe and accurate in the anterior palate. However, the use of insertion guides facilitates TAD insertion, allowing less-experienced clinicians to use palatal implants.

Orthodontic treatment for posterior crossbites.

BACKGROUND: A posterior crossbite occurs when the top back teeth bite inside the bottom back teeth. The prevalence of posterior crossbite is around 4% and 17% of children and adolescents in Europe and America, respectively. Several treatments have been recommended to correct this problem, which is related to such dental issues as tooth attrition, abnormal development of the jaws, joint problems, and imbalanced facial appearance. Treatments involve expanding the upper jaw with an orthodontic appliance, which can be fixed (e.g. quad-helix) or removable (e.g. expansion plate). This is the third update of a Cochrane review first published in 2001. OBJECTIVES: To assess the effects of different orthodontic treatments for posterior crossbites. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched four bibliographic databases up to 8 April 2021 and used additional search methods to identify published, unpublished and ongoing studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults. DATA COLLECTION AND ANALYSIS: Two review authors, independently and in duplicate, screened the results of the electronic searches, extracted data, and assessed the risk of bias of the included studies. A third review author participated to resolve disagreements. We used risk ratios (RR) and 95% confidence intervals (CIs) to summarise dichotomous data (event), unless there were zero values in trial arms, in which case we used odds ratios (ORs). We used mean differences (MD) with 95% CIs to summarise continuous data. We performed meta-analyses using fixed-effect models. We used the GRADE approach to assess the certainty of the evidence for the main outcomes. MAIN RESULTS: We included 31 studies that randomised approximately 1410 participants. Eight studies were at low risk of bias, 15 were at high risk of bias, and eight were unclear. Intervention versus observation For children (age 7 to 11 years), quad-helix was beneficial for posterior crossbite correction compared to observation (OR 50.59, 95% CI 26.77 to 95.60; 3 studies, 149 participants; high-certainty evidence) and resulted in higher final inter-molar distances (MD 4.71 mm, 95% CI 4.31 to 5.10; 3 studies, 146 participants; moderate-certainty evidence). For children, expansion plates were also beneficial for posterior crossbite correction compared to observation (OR 25.26, 95% CI 13.08 to 48.77; 3 studies, 148 participants; high-certainty evidence) and resulted in higher final inter-molar distances (MD 3.30 mm, 95% CI 2.88 to 3.73; 3 studies, 145 participants, 3 studies; moderate-certainty evidence). In addition, expansion plates resulted in higher inter-canine distances (MD 2.59 mm, 95% CI 2.18 to 3.01; 3 studies, 145 participants; moderate-certainty evidence). The use of Hyrax is probably effective for correcting posterior crossbite compared to observation (OR 48.02, 95% CI 21.58 to 106.87; 93 participants, 3 studies; moderate-certainty evidence). Two of the studies focused on adolescents (age 12 to 16 years) and found that Hyrax increased the inter-molar distance compared with observation (MD 5.80, 95% CI 5.15 to 6.45; 2 studies, 72 participants; moderate-certainty evidence). Intervention A versus intervention B When comparing quad-helix with expansion plates in children, quad-helix was more effective for posterior crossbite correction (RR 1.29, 95% CI 1.13 to 1.46; 3 studies, 151 participants; moderate-certainty evidence), final inter-molar distance (MD 1.48 mm, 95% CI 0.91 mm to 2.04 mm; 3 studies, 151 participants; high-certainty evidence), inter-canine distance (0.59 mm higher (95% CI 0.09 mm  to 1.08 mm; 3 studies, 151 participants; low-certainty evidence) and length of treatment (MD -3.15 months, 95% CI -4.04 to -2.25; 3 studies, 148 participants; moderate-certainty evidence). There was no evidence of a difference between Hyrax and Haas for posterior crossbite correction (RR 1.05, 95% CI 0.94 to 1.18; 3 studies, 83 participants; moderate-certainty evidence) or inter-molar distance (MD -0.15 mm, 95% CI -0.86 mm to 0.56 mm; 2 studies of adolescents, 46 participants; moderate-certainty evidence). There was no evidence of a difference between Hyrax and tooth-bone-borne expansion for crossbite correction (RR 1.02, 95% CI 0.92 to 1.12; I² = 0%; 3 studies, 120 participants; low-certainty evidence) or inter-molar distance (MD -0.66 mm, 95% CI -1.36 mm to 0.04 mm; I² = 0%; 2 studies, 65 participants; low-certainty evidence).  There was no evidence of a difference between Hyrax with bone-borne expansion for posterior crossbite correction (RR 1.00, 95% CI 0.94 to 1.07; I² = 0%; 2 studies of adolescents, 81 participants; low-certainty evidence) or inter-molar distance (MD -0.14 mm, 95% CI -0.85 mm to 0.57 mm; I² = 0%; 2 studies, 81 participants; low-certainty evidence).  AUTHORS' CONCLUSIONS: For children in the early mixed dentition stage (age 7 to 11 years old), quad-helix and expansion plates are more beneficial than no treatment for correcting posterior crossbites. Expansion plates also increase the inter-canine distance. Quad-helix is more effective than expansion plates for correcting posterior crossbite and increasing inter-molar distance. Treatment duration is shorter with quad-helix than expansion plates. For adolescents in permanent dentition (age 12 to 16 years old), Hyrax and Haas are similar for posterior crossbite correction and increasing the inter-molar distance. The remaining evidence was insufficient to draw any robust conclusions for the efficacy of posterior crossbite correction.

Maximum insertion torque loss after miniscrew placement in orthodontic patients: A randomized controlled trial.

OBJECTIVES: To compare torque recordings of immediately loaded orthodontic miniscrews between insertion time and different post-placement timepoints (2 weeks, 4 weeks and removal time, respectively). SETTING AND SAMPLE POPULATION: Parallel trial with an allocation ratio of 1:1. Eligibility criteria were needs of fixed orthodontic treatment, no systemic disease and absence of using drugs altering bone metabolism. MATERIAL AND METHODS: Patients received miniscrews, 2.0 mm diameter and 10 mm length. All miniscrews underwent inter-radicular placement, and they were placed in the maxilla or in the mandible, palatally or buccally. No pre-drilling was performed. Miniscrews were loaded immediately after the insertion and were used for distalization, intrusion, extrusion, mesialization or indirect anchorage. Patients were randomly divided into three groups. For each patient, Maximum Insertion Torque (MIT) was evaluated at baseline. MIT was measured again after 2 weeks and after 4 weeks by tightening the screw a quarter of turn in Groups 1 and 2, respectively. At the end of the treatment, maximal removal torque was evaluated in Group 3. Torque variation with respect to insertion time was considered as the primary outcome. Baseline and longitudinal differences were tested using the linear mixed-effects (LME) model. RESULTS: Forty seven patients and 74 miniscrews were followed up. An association existed between maximum insertion torque and the observation time. A torque decrease of 26.9% and 30% after 2 weeks was observed for mandibular and maxillary miniscrews, respectively. After 1 month, torque values were similar to the baseline records. The overall success rate was 79.7%. No serious harm was observed. CONCLUSIONS: Maximum insertion torque undergoes a loss during the first 2 weeks, and its values may depend on the insertion site and the anchorage purpose. Removal torque value is almost the same as the initial torque after 1 month.

Skeletal and dental changes after maxillary expansion with a bone-borne appliance in young and late adolescent patients.

INTRODUCTION: Rapid palatal expansion is a common therapy during orthodontic treatment and could be a preliminary step for correcting different malocclusions; furthermore, this treatment could be necessary at any age. Different anchorage approaches have been proposed to obtain an effective skeletal result, although every device produces both dental and skeletal effects. This study aimed to compare the dentoskeletal effects of a bone-borne palatal expander considering 2 groups of patients of different ages. METHODS: Twenty-four patients consecutively treated were included in the study; patients were divided into 2 groups according to their age: group 1 with age ≤16 years and group 2 patients >16 years. All patients had a preexpansion cone-beam computed tomography scan; a second scan was required at the end of activations. All patients received a bone-borne appliance anchored on 4 miniscrews. RESULTS: Significant intragroup differences were found for maxillary width and dental diameters. No significant differences were found between groups with regard to longitudinal changes, except for the maxillary right plane. CONCLUSIONS: The use of bone-borne maxillary expansion was effective in generating palatal widening both in growing and young adult patients. No significant skeletal or dental differences were found between groups.

Palatal changes in crossbite patients treated with rapid maxillary expansion vs untreated ones: A geometric morphometric study.

OBJECTIVE: The present study aimed to analyse palatal changes due to rapid maxillary expansion (RME) by using modern geometric morphometric analysis (GMA) on 3D models. SETTINGS AND SAMPLE POPULATION: Forty children with posterior crossbite and maxillary deficiency were selected for this study. Twenty children were treated with RME (mean age 7.4 ± 0.8 years), whereas 20 children were not treated (mean age 7.2 ± 1.1 years). MATERIALS AND METHODS: In the treated group, RME screw was activated until overcorrection was achieved and the RME appliance remained in place for 11 months. Digital dental casts were recorded before treatment and 1 year after the end of active treatment. GMA was performed to compare shape and dimensional variations among groups (between-group principal component analysis). RESULTS: All children in the treated group achieved crossbite correction. None of the control group children achieved crossbite self-correction. No significant shape and dimensional changes were noted in the control group after 1 year. On the other hand, significant shape and dimensional changes were noted in the treated group after 1 year (P < .05). Most of the shape changes in the treated group were similar but more pronounced compared to those observed in the control group. All major changes in palatal morphology occurred on the lateral sides of the palatal vault (widening) and at the height (shortening). Some shape changes were observed in the treated group alone. CONCLUSIONS: Application of GMA to evaluate the effects of RME in crossbite patients revealed significant changes in palatal morphology compared with the absence of changes in the control group.

A multicenter, prospective, randomized trial of pain and discomfort during maxillary expansion: Leaf expander versus hyrax expander.

BACKGROUND: Pain suffered by the young patient is the most frequent symptom during orthodontic treatment and is the one that most frightens children and causes worry in their families. AIM: To investigate pain perception and function impairment during the first week of activation of two palatal expansion screws. DESIGN: A total of 101 subjects were randomly divided into two groups: RME group included patients treated with the standard hyrax expansion screw and LEAF group included patients treated with Leaf Expander appliance. Pain intensity was assessed via the Wong-Baker scale. A questionnaire on oral function impairments was also compiled by the patients. RESULTS: The Pain Scale analysis showed that patients in the RME group suffered from a significantly higher level of pain than those in the LEAF group (88.6% vs 25%, P < .01). RME group showed highest pain indexes from day 1 to day 4 (51.4% RME vs 9.7% LEAF suffered at least once from strong pain in the first 4 days, P < .01). Furthermore, oral functions were similarly affected in both groups. CONCLUSIONS: Pain reported during maxillary arch expansion is influenced by clinical activation protocol and by the screw type. Patients treated with Leaf Expander reported significantly lower pain level in the first 7 days of treatment.

Herbst appliance anchored to miniscrews in the upper and lower arches vs standard Herbst: A pilot study.

INTRODUCTION: The aim of this pilot study was to present the preliminary results of Class II malocclusion treatment using a skeletally anchored Herbst appliance with miniscrews inserted in the maxillary and mandibular arches to improve anchorage control and skeletal effects. METHODS: The treatment group (TG) consisted of 13 patients (10 males [M], 3 females [F]; mean age of 12.8 years) with Class II Division 1 malocclusion who were treated with the Herbst appliance and miniscrews inserted in the maxillary and mandibular arches. They were compared with a control group (CG) of 13 patients (10 F, 3 M, mean age of 12.2 years) with Class II Division 1 malocclusion treated with the standard Herbst appliance without miniscrews. Lateral cephalograms were taken before and after Herbst treatment, and cephalometric analysis was performed. RESULTS: In the TG group SNB (°) increased by 2.9°, whereas in CG group SNB (°) increased by 1.1° (P = 0.017). ANB (°) decreased in both groups: -3.3° in the TG group vs -1.3° in the CG group (P = 0.014). Pg-OLp distance increased in both groups: 5.70 mm in the TG group and 0.8 mm in the CG group (P = 0.022). Mandibular incisors proclined 1.6° in the TG group and 3.7° in the CG group. CONCLUSIONS: Herbst treatment reinforced with 4 miniscrews (2 in each arch) increased the orthopedic effect of treatment in growing patients with Class II malocclusion.

Work-related traumatic dental injuries: Prevalence, characteristics and risk factors.

BACKGROUND/AIMS: The prevalence of work-related oral trauma is underestimated because minor dental injuries are often not reported in patients with several injuries in different parts of the body. In addition, little data are available regarding their characteristics. The aim of this epidemiological study was to determine the prevalence, types, and characteristics of occupational traumatic dental injuries (TDIs) in a large working community. MATERIALS AND METHODS: Work-related TDIs that occurred during the period between 2011 and 2013 in the District of Genoa (Northwest of Italy, 0.86 million inhabitants) were analyzed. Patients' data were obtained from the National Institute for Insurance against Accidents at Work database. RESULTS: During the 2 year period, 112 TDIs (345 traumatized teeth) were recorded. The prevalence was 5.6‰ of the total amount of occupational trauma. The highest prevalence was found in the fourth and fifth decades of life (OR=3.6, P < .001), and males were injured more often than females (70.5% vs 29.5%, OR=2.8, P < .001). Service and office workers represented 52% of the sample, and construction/farm/factory workers and craftsmen were 48%. TDIs involved only teeth and surrounding tissue in 66% of cases, or in combination with another maxillofacial injury in 34%. They were statistically associated with construction/farm/factory workers group (Chi squared P < .01). Crown fracture was recorded in 34.5% of cases, subluxation/luxation in 10.7%, avulsion in 9%, root fracture in 3.8%, and concussion in 3.5%. Thirty-two subjects (28.6%, 133 teeth, OR=4.3, P < .001) presented at least 1 traumatized tooth with previous dental treatment. Among 212 (61.4%) traumatized teeth, 67.5% were upper incisors, 17.5% were lower incisors, 3.3% were upper canines, 1.9% were lower canines, and 9.9% were bicuspids and molars. CONCLUSIONS: Work-related TDIs had a low overall prevalence, and fractures were the most frequent dental injury. Age, gender, and preexisting dental treatments represented risk factors for work-related TDIs.

Trends in Early Childhood Caries: An Italian Perspective.

PURPOSE: To evaluate the prevalence of early childhood caries (ECC) and severe ECC (S-ECC) among Italian preschool children and its predictors regarding children's lifestyle. MATERIALS AND METHODS: A cross-sectional study was carried out involving 563 preschool children. A questionnaire for children's parents and clinical examinations were conducted by calibrated, blinded examiners. The odds ratios (OR) for ECC or S-ECC and co-presence of risk factors were calculated using univariate and multivariate models. Statistical significance was set at p < 0.05 in all analyses. RESULTS: The prevalence of ECC and S-ECC was 14.4% and 5.9%, respectively. According to the multivariate analysis, the predictors for caries were (p < 0.05): age (OR = 2.5; 95% CI = 1.36 - 4.52), non-Italian ethnic origin (OR = 4.3; 95% CI = 2.83 - 7.37), consumption of sugary beverages more than once per day (OR = 2.1; 95% CI = 1.21 - 5.26) and having inadequate oral hygiene status (OR = 3.6; 95% CI = 2.01 - 5.83). CONCLUSIONS: Dietary habits and dental care are important environmental contributing factors in the development of caries in preschool children. Oral health promotion should include an oral hygiene instruction programme and dietary guidelines focused on daily sugar intake for the preschool children themselves as well as for their parents.

Immediate versus delayed loading: comparison of primary stability loss after miniscrew placement in orthodontic patients-a single-centre blinded randomized clinical trial.

INTRODUCTION: The aim of this randomized clinical trial was to compare torque recordings at insertion time and 1 week post-placement between immediately loaded orthodontic miniscrews and an unloaded control group. TRIAL DESIGN: This RCT was designed as parallel with an allocation ratio of 1:1. METHODS: Eligibility criteria to enroll patients were: needs of fixed orthodontic treatment, no systemic disease, absence of using drugs altering bone metabolism. All patients were consecutively treated in a private practice and the miniscrews were placed by the same author. Patients received ORTHOImplant (3M Unitek) miniscrews and they were blindly divided in two groups: group 1 screws were unloaded between T0 and T1, group 2 received immediately loaded screws with NiTi coil. For each patient, maximum insertion torque (MIT) was evaluated at T0. After 1 week, without loading, the screw torque was measured again (T1) and at the end of the treatment maximal removal torque was evaluated (T2). Torque variation in the first week was considered as the primary outcome. RANDOMIZATION: A randomization list was created for the group assignment, with an allocation ratio of 1:1. BLINDING: The study was single blinded in regard of the statistical analysis. RESULTS: Patients enrolled in the clinical trial were 51 for a total of 81 miniscrews. The recruitment started in November 2012 and the observation period ended in August 2014. Twenty-six and twenty-five patients were analysed in group 1 and 2, respectively. The MIT mean in each placement time was 18.25 Ncm (SD = 3.00), 11.41 Ncm (SD = 3.51) and 10.52 Ncm (SD = 5.14) at T0, T1, and T2 time, respectively. In group 1, the torque decrease between T1 and T0 was statistically higher compared to group 2 (P value = 0.003). Statistically significant effects of the placement times on MIT were found (P value <0.0001). No serious harm was observed. LIMITATIONS: This study was performed using only direct force on the miniscrew and not using the miniscrew as an indirect anchorage. It was not possible to obtain quantitative data on bone quality or root proximity to miniscrews. CONCLUSIONS: A significant stability loss was observed in the first week in both groups; Group 1 showed a statistically higher torque loss in the first week when compared to the immediately loaded group. There were statistically significant effects of the measurement times on MIT and of the miniscrew location on MIT. The overall failure rate was 7.4%. TRIAL REGISTRATION: This trial was not registered. PROTOCOL: The protocol was not published before trial commencement.

Efficacy of professional hygiene and prophylaxis on preventing plaque increase in orthodontic patients with multibracket appliances: a systematic review.

BACKGROUND: Plaque increase is a troubling side-effect of fixed orthodontic therapy. This generally arise as a consequence of long-term difficulty in maintaining adequate oral hygiene while wearing multibracket appliances. Demineralization, also known as white spot, causes particular concern as it spoils the aesthetic outcome of the treatment itself, not to mention the integrity of the enamel. OBJECTIVES: To collate the existing literature by evaluating the efficacy of dental hygienist intervention on plaque increase in fixed orthodontics patients. MATERIALS AND METHODS: A targeted search of the Medline database (Entrez PubMed), EMBASE, and CENTRAL using relevant Medical Subject Headings was performed. The articles selected were all published before June 2013 and comprised randomized clinical trials, prospective longitudinal controlled clinical trials, and before/after studies onto the plaque increase of fixed appliances. RESULTS: The search strategy yielded 630 articles. Following the application of inclusion and exclusion criteria, 10 articles qualified for the final review. CONCLUSION: The quality of the retrieved researches ranged from low (one study) to high (one study). Six controlled trials were considered at unknown risk of bias. Data showed that regular patient motivation sessions and mechanical tooth cleaning by a professional dental hygienist help maintaining good oral hygiene during fixed orthodontics.

Orthodontic miniscrews: an experimental campaign on primary stability and bone properties.

OBJECTIVE: To evaluate the primary stability of different shaped miniscrews through the acquisition of data regarding maximum insertion torque, pullout force, and a radiodiagnosic evaluation of bone characteristics. MATERIALS AND METHODS: Sixty fresh porcine bone samples were scanned by computed tomography (CT) and cone-beam computed tomography (CBCT). By means of a dedicated software, CT and CBCT images were analysed to measure the insertion-site cortical thickness, cortical density, and marrow bone density. Sixty miniscrews of 12 different types were implanted with no predrilling pilot hole in the bone samples. Every device was tightened by means of a digital torque screwdriver and torque data were collected. Subsequently, pullout tests were performed. Spearman and Pearson correlations were employed to compare any relationship between continuous variables. RESULTS: Different types of miniscrews did not show statistically significant differences in their torque value (P = 0.595), instead a significant difference was revealed by considering their load measures (P = 0.039). Cortical bone thickness resulted strongly correlated both with value of load (P < 0.001), and modestly with torque measures (P = 0.004). A strong positive correlation was found between CT and CBCT both for cortical density (P < 0.001) and marrow bone density (P < 0.001). CONCLUSION: Bone characteristics play the major role in miniscrews primary stability.

Orthodontic treatment for posterior crossbites.

BACKGROUND: A posterior crossbite occurs when the top back teeth bite inside the bottom back teeth. When it affects one side of the mouth, the lower jaw may have to move to one side to allow the back teeth to meet together. Several treatments have been recommended to correct this problem. Some treatments widen the upper teeth while others are directed at treating the cause of the posterior crossbite (e.g. breathing problems or sucking habits). Most treatments have been used at each stage of dental development. This is an update of a Cochrane review first published in 2001. OBJECTIVES: To assess the effects of orthodontic treatment for posterior crossbites. SEARCH METHODS: We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 21 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE via OVID (1946 to 21 January 2014), and EMBASE via OVID (1980 to 21 January 2014). We searched the US National Institutes of Health Trials Register and the World Health Organization (WHO) Clinical Trials Registry Platform for ongoing trials. We placed no restrictions on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomised controlled trials (RCTs) of orthodontic treatment for posterior crossbites in children and adults. DATA COLLECTION AND ANALYSIS: Two review authors, independently and in duplicate, screened the results of the electronic searches, and extracted data and assessed the risk of bias of the included studies. We attempted to contact the first named authors of the included studies for missing data and for clarification. We used risk ratios (RR) and 95% confidence intervals (CIs) to summarise dichotomous (event) data, and mean differences (MD) with 95% CIs to summarise continuous data. We performed meta-analyses using fixed-effect models (we would have used random-effects models if we had included four or more studies in a meta-analysis) when comparisons and outcomes were sufficiently similar. MAIN RESULTS: We included 15 studies, of which two were at low risk of bias, seven were at high risk of bias and six were unclear. Fixed appliances with mid-palatal expansionNine studies tested fixed appliances with mid-palatal expansion against each other. No study reported a difference between any type of appliance. Fixed versus removable appliancesFixed quad-helix appliances may be 20% more likely to correct crossbites than removable expansion plates (RR 1.20; 95% CI 1.04 to 1.37; two studies; 96 participants; low-quality evidence).Quad-helix appliances may achieve 1.15 mm more molar expansion than expansion plates (MD 1.15 mm; 95% CI 0.40 to 1.90; two studies; 96 participants; moderate-quality evidence).There was insufficient evidence of a difference in canine expansion or the stability of crossbite correction.Very limited evidence showed that both fixed quad-helix appliances and removable expansion plates were superior to composite onlays in terms of crossbite correction, molar and canine expansion. Other comparisonsVery limited evidence showed that treatments were superior to no treatment, but there was insufficient evidence of a difference between any active treatments. AUTHORS' CONCLUSIONS: There is a very small body of low- to moderate-quality evidence to suggest that the quad-helix appliance may be more successful than removable expansion plates at correcting posterior crossbites and expanding the inter-molar width for children in the early mixed dentition (aged eight to 10 years). The remaining evidence we found was of very low quality and was insufficient to allow the conclusion that any one intervention is better than another for any of the outcomes in this review.

Clinical association between teeth malocclusions, wrong posture and ocular convergence disorders: an epidemiological investigation on primary school children.

BACKGROUND: As the various systems in the body are inter-connected to form a single structural unit, a pathological condition in one area can also affect other areas. There are many known correlations between the visual and motor system. The importance of visual function, particularly the paracentral peripheral field of view, in motor coordination, ambulation and the maintenance of balance has been amply demonstrated.In line with current medical principles, which are moving towards a more holistic view of the human body, this study aims to investigate, in an interdisciplinary manner, the incidence of dental malocclusions together with posture and eye convergence disorders. METHODS: Six hundred and five children attending at the 3rd, 4th and 5th years of seven Genoa primary schools were examined. Each child underwent the following examinations: (i) dental/occlusal; (ii) orthoptic; and (iii) postural. Occlusal data concerned the presence of cross-bite, midline deviation with a mandibular shift, bad habits and deep or open bite.Postural assessment involved frontal and lateral inspection, investigation during trunk flexion and ambulation, and note of any asymmetry in the lower limbs. The recorded orthoptic data included those pertaining to ocular dominance, a cover test, convergence and the Brock string test. RESULTS: A prevalence of cases with an unphysiological gait was found in patients with overjet (14.70%) or overbite (14.87%), while the percentage of patients with normal occlusion that showed an unphysiological gait was 13.08%. Also, about 93.8%-94.2% of children showed normal legs without dysmetry, with no difference in respect to the type of occlusion. Subjects with an open bite or deep bite showed a slightly different distribution of right or left dominant eyes. CONCLUSION: About 13% of children showed a pathological gait and, among them, vertical anomalies of occlusion (deep bite or open bite) were prevalent with respect to the other occlusal defects. The vertical dimension of occlusion revealed a slight relationship with the proper dominant eye. Postural, orthoptic, osteopathic and occlusal variables were often clinically associated, and therefore these disorders appear to request a multidisciplinary medical approach for their treatment.

Biomarkers of periodontal tissue remodeling during orthodontic tooth movement in mice and men: overview and clinical relevance.

Biologically active substances are expressed by cells within the periodontium in response to mechanical stimuli from orthodontic appliances. Several possible biomarkers representing biological modifications during specific phenomena as simile-inflammatory process, bone resorption and formation, periodontal ligament changes, and vascular and neural responses are proposed. Citations to potentially published trials were conducted by searching PubMed, Cochrane databases, and scientific textbooks. Additionally, hand searching and contact with experts in the area were undertaken to identify potentially relevant published and unpublished studies. Selection criteria were as follows: animal models involving only mice and rats undergoing orthodontic treatment; collection of gingival crevicular fluid (GCF) as a noninvasively procedure for humans; no other simultaneous treatment that could affect experimental orthodontic movement. The data suggest that knowledge of the remodeling process occurring in periodontal tissues during orthodontic and orthopedic therapies may be a clinical usefulness procedure leading to proper choice of mechanical stress to improve and to shorten the period of treatment, avoiding adverse consequences. The relevance for clinicians of evaluating the rate of some substances as valid biomarkers of periodontal effects during orthodontic movement, by means of two models of study, mice and men, is underlined.

Probabilistic graphical modelling of early childhood caries development.

In order to develop a statistical model for complex interactions among factors affecting early childhood caries development (ECC), 234 children from the "XXXX oral growth longitudinal study" were analysed at ages 3, 4 and 5. A questionnaire for children's parents (clinical history, nutritional and oral hygiene habits) and clinical oral examinations were recorded each year. The probabilistic dependence structure on the most significant factors was modelled with an Undirected Graphical Model (UGM or Markov random fields) which provides a probabilistic reasoning approach for the establishment of multi-way associations. The best fitting UGM was estimated through the maximum likelihood principle and two-way factor associations were verified through Fisher's exact statistical hypothesis tests for count data. The effect of sugar intake on caries incidence is mediated by oral hygiene; for caries incidence, oral hygiene quality is more relevant than toothbrushing time; the effect of pacifier on caries incidence is statistically significant only when considered in combination with breastfeeding time. Among behavioural ECC risk factors, the quality of oral hygiene, and not the toothbrushing frequency, is a primary factor that modulates the sugar intake in his primary role of the ECC developer. School-based oral health programs for ECC prevention should be improved with supervised toothbrushing program. UGM analysis could improve the school-based oral health programs with more effective and efficient prevention strategies based on the hierarchical interactions among the ECC risk factors. Oral hygiene plays a pivotal role in early childhood caries and can modulate positively or negatively their development. Supervised toothbrushing is a crucial intervention to be included in the daily educational and clinical practice and in the school-based oral health promotion programs. Trial registration: Clinical trial registration number: NCT02798809.

Miniscrew design and bone characteristics: an experimental study of primary stability.

INTRODUCTION: The purpose of this study was to evaluate the correlations between bone characteristics, orthodontic miniscrew designs, and primary stability. METHODS: Four different miniscrews were placed in pig ribs. The miniscrews were first scanned with a scanning electron microscope to obtain measurable images of their threads. Subsequently, the maximum insertion torque of the screws and the maximum load value in the pullout force tests were measured; furthermore, bone specimen characteristics were analyzed by using cone-beam computed tomography. For each bone sample, the insertion site cortical thickness as well as both cortical and marrow bone density were evaluated. The nonparametric Kendall rank correlation (tau) was used to evaluate the strength of the associations among the characteristics measured. The nonparametric Kruskall-Wallis test was used to evaluate the differences among the groups, and post-hoc comparisons were assessed by using the Nemenyi-Damico-Wolfe-Dunn test. RESULTS: A significant dependence was found between pitch and maximum insertion torque (tau, -0.49). Positive correlations were also found between pullout force and maximum insertion torque (tau, 0.64), cortical thickness (tau, 0.36), and marrow bone density (tau, 0.35). CONCLUSIONS: In this in-vitro experimental study, strong correlations were observed among miniscrew geometry, bone characteristics, and primary stability.

In vitro determination of the mechanical and chemical properties of a fibre orthodontic retainer.

The aim of this study was to analyse, in vitro, the chemical and mechanical properties of a new fibre retainer, Everstick, comparing its characteristics with the requirements for an orthodontic retainer. Chemical analysis was used to examine seven fibre bundles exposed to a photocuring lamp and then to different acids and resistance to corrosion by artificial saliva fortified with plaque acids. The mechanical properties examined were tensile strength and resistance to flexural force. Ten fibre samples were tested for each mechanical analysis and the mean value and standard deviation were calculated. Wilcoxon signed rank test was used to evaluate change in weight after treatment in each group. To determine changes over time between the groups for each acid considered separately, both repeated measures analysis of variance (ANOVA) on original data and on rank transformed data were used. If the results were different, ANOVA on rank-transformed data was considered. Acetic acid was found to be the most corrosive and caused the most substance loss: both pure and at the salivary pH value. Hydrofluoric acid was the most damaging. For all acids analysed in both groups (lactic, formic, acetic, propionic), changes after treatment were statistically different between two groups (P < 0.001 for lactic, acetic, propionic; P = 0.004 for formic acid).The mean Young's modulus value was 68 510 MPa. Deformation before the fibre separated into its constituent elements (glass fibre and composite) was 3.9 per cent, stress to rupture was 1546 MPa, and resistance to bending was 534 MPa. The deflection produced over a length of 12 mm was 1.4 mm. The fibre bundle was attacked by acids potentially present in the oral cavity; the degree of aggressiveness depending on the acid concentration. To preserve fibre bundles long term, careful plaque control is necessary, especially in the interproximal spaces, to avoid acid formation. The tested product was found to be sufficiently strong to oppose flexural and occlusal forces.