Objectives: To assess the effects of orthodontic treatment for Class III incisors in children and adolescents. Design: A Cochrane systematic review. Method: The following databases were searched up to 7th January 2013: Cochrane Oral Health Group Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via OVID, EMBASE via OVID. Selection criteria: All randomised controlled trials of orthodontic treatments to correct Class III incisors. Trials were eligible for inclusion in the review if they recruited children and/or adolescents (aged 16 or less) receiving orthodontic treatment to correct Class III incisors. Trials including patients with a cleft lip and/or palate or other cranio-facial deformity/syndrome were excluded as were trials that had recruited less than 80% children or adolescents or patients who had previously received surgical orthognathic treatment. Active interventions included: orthodontic braces, chin cups, facemasks, reverse headgear, bone-anchored appliances or any other intra or extra-oral appliance aiming to correct Class III incisors. Controls included: No treatment, delayed treatment, other active intervention. Types of Outcome Measures - Primary: Prominence of the lower front teeth (measured in mm or by any index of malocclusion). Secondary: Relationship between upper and lower jaw; psychosocial measures; patient satisfaction; jaw joint problems. Adverse effects: Health of the gums; damage to the teeth e.g. tooth decay. Outcomes were recorded at all ages reported. The results were reported according to the most common endpoints. Adverse effects were recorded and the results reported in descriptive terms. Data collection and analysis: The titles and abstracts of the search results were examined to exclude obviously irrelevant reports. Full text reports of potentially eligible studies were examined for compliance with the eligibility criteria. Screening of references, data extraction and assessment of the risk of bias of included studies, was performed independently and in duplicate by two review authors. The mean differences, with 95% confidence intervals, were calculated for continuous data. Meta-analysis was only used when studies of similar comparisons were reporting comparable outcome measures. A fixed-effect model was used. I2 statistics were used as measures of statistical heterogeneity. Results: Seven randomised controlled trials were included in this review. Of these, four reported on the use of a facemask, two on the chin cup, one on the tandem traction bow appliance and one on mandibular headgear. One study reported on both the chin cup and mandibular headgear appliances. Three trials (n=155) reported ANB differences immediately after treatment with a facemask when compared to an untreated control. The pooled data, for ANB difference, showed a statistically significant mean difference of 3.93 degrees (95%CI 3.46 to 4.39; P<0.0001) in favour of the facemask. There was significant heterogeneity between these studies (I2=82%). One well designed trial, with a low risk of bias, reported outcomes of the use of the facemask compared to an untreated control at 3 years’ follow-up. This showed that improvements in overjet and ANB were still present at 3 years. However, there was no evidence of improved self-concept. The remaining trials each evaluated a different comparison and reported different outcomes so no meta-analysis was possible. Conclusions: There is some evidence that the use of a facemask, to correct prominent lower front teeth in children, is effective when compared to no treatment on a short term basis. However, in view of the general poor quality of the included trials, these results should be interpreted with caution. Further randomised controlled trials, with long follow-up, are required.

Background: Information regarding the various factors that can influence the duration of orthodontic treatment has been investigated before; however, despite the increasing amount of evidence becoming available, controversy still exists. Therefore, this investigation was considered to be useful as additional information to the orthodontic literature. Aim: To determine factors associated with the duration of orthodontic treatment for patients with a Class II malocclusion treated with a functional/fixed appliance approach to treatment. Design: Retrospective, observational study. Setting: Orthodontic Department, Liverpool University Dental Hospital, UK. Method: Data were collected from the records of eligible patients. Inclusion criteria: Patients were included if they had: 1) Undergone a course of orthodontic treatment involving a first phase of treatment with the Twin-Block appliance between the 1st of January 2005 and 31st of December 2008; 2) A Class II dental malocclusion; 3) Required a functional/fixed orthodontic approach to orthodontic treatment; 4) Completed two phases of orthodontic treatment; 5) Records available in a satisfactory condition. Outcome measures: • Duration of the functional appliance phase of orthodontic treatment • Total duration of orthodontic treatment Results: The pre-treatment overjet was the only factor that had a statistically significant influence on the duration of the functional phase of the treatment (p= 0.016). The factors that were statistically significant predictors for the duration of the full course of orthodontic treatment were: the number of treating clinicians (p=0.001), the number of failed appointments (p=0.001), the chronological age of the patient (p=0.002) and whether the patient had extractions or not (p=0.021). Conclusions: 1. The only factor that had a statistically significantly influence on the duration of the functional phase of treatment was the overjet at the start of treatment (positive association). 2. The factors that had a statistically significantly influence on the total treatment duration were the: a) Number of the treating clinicians (positive association); b) Number of appointments the patients failed to attend (positive association); c) Chronological age of the patient (negative association); d) Presence or absence of dental extractions (positive association).

Title A randomised controlled crossover trial to assess the effectiveness of, preference for and length of structured reply letters when communicating with referring practitioners Statement “I have made this letter longer than usual as I lack the time to make it short” (Blasie Pascal 1623-1662) Objectives To identify whether : 1. Structured reply letters from consultants were more effective at communicating with and/ or preferred by practitioners when compared to consultants’ standard reply letters. 2. There were differences in the length of the two formats. Null Hypothesis No significant difference exists between practitioner’s awareness of key patient information when receiving either the structured consultant reply letter or the standard consultant reply letter. No significant difference exists between the word counts of the two letter formats. Design Randomised controlled crossover trial. Setting Liverpool University Dental Hospital (LUDH). Participants and methods Participants were recruited from practitioners referring orthodontic patients to LUDH. Seventy five practitioners were stratified by consultant and randomised in blocks to receive either the structured or standard letter first, followed by the alternative format six weeks later. For both groups, the word count was recorded by the secretaries. ‘Knowledge and satisfaction’ questionnaires were dispatched with the letters, completed by practitioners and returned to the department. Outcome measures The primary outcome measure was the practitioners’ awareness of the key information contained within the letter. The secondary outcome measure was the secretarial typing times for the letters. Results The response rate was 87%. There was a statistically significant improvement in practitioners’ awareness of their patient’s status (odds ratio 8.84 95% CI 1.08, 72.52) and the action required (odds ratio 4.13 95% CI 1.10, 15.45) after receiving the structured letter. Practitioners showed a strong preference (p<0.001) for the structured consultant reply letter which were statistically significantly shorter than the standard format with a mean difference of 108 + 10 fewer words (mean difference: 108: 95% CI -118.14, -97.86). Conclusions This trial demonstrated that there was a statistical significant improvement in practitioners’ perceptual and actual awareness of their patient’s status and any action required, having received the structured letter. The structured reply letters had significantly fewer words than the standard letter. Practitioners strongly preferred the structured reply letter format.

BACKGROUND: Demineralisation around orthodontic brackets is a considerable risk of orthodontic treatment. It can occur very early during treatment and involve a large number of teeth with aesthetic and dental health consequences. Early detection of demineralisation is very important in terms of treatment and prevention. The presence of bacteria is one of the requirements for demineralisation to take place and it is unclear whether the type of bacteria in the plaque or the quantity of certain types of bacteria are significant influences on demineralisation. AIM: To identify any general changes in the bacterial composition of dental plaque in adolescents undergoing fixed orthodontic appliance therapy. A secondary aim is to determine the incidence of white spot lesion development and if this was related to the identified red fluorescent plaque. STUDY DESIGN: Prospective longitudinal cohort study. METHODS: Fourteen 11 to 23 year old consecutive patients attending the Orthodontic Department of Liverpool University Dental Hospital were recruited for this study. ToothcareTM and QLF were used to identify red fluorescent plaque and enamel demineralisation on the labial surfaces of the anterior teeth before and after the placement of fixed orthodontic appliances. The bacterial composition of the red fluorescent supragingival plaque was determined by DNA extraction, polymerase chain reaction amplification of the 16r rRNA gene and denaturing gradient gel electrophoresis. 13 RESULTS: The incidence of white spot lesions was recorded as 4.2% of the total surfaces of the teeth included as detected with QLF, the development of white spot lesions was not associated with the presence of red fluorescent plaque. There were differences in the bacterial composition of red fluorescent supragingival plaque in terms of P. gingivalis, S. mutans and S. gordonii between different participants, although changes in the plaque composition between visits for the same participant was not significantly associated with the development of white spot lesions in adolescents. CONCLUSIONS: With the limitations of this study, the placement of fixed orthodontic brackets in adolescents does not significantly change the bacterial composition of red fluorescent supragingival plaque around the brackets and that the development of white spot lesions cannot be correlated to red fluorescent plaque alone.

OBJECTIVES: The aim of this study was to evaluate the bond strength of a low fusing veneering porcelain fired on Titanium grade V with different surface treatments. MATERIALS & METHODS: One hundred and twenty bars of Titanium grade V (25±1x 3±0.5x 0.5±0.05mm) were divided randomly into twelve groups: group 1 no surface treatment, group 2 Gold sputter coating, group 3 TiN sputter coating, group 4 Sandblasting Al2O3 125μm, group 5 Sandblasting Al2O3 180μm, group 6 Sandblasting Al2O3 250μm, group 7 Sandblasting Al2O3 125μm then gold sputter coating, group 8 Sandblasting Al2O3 180μm then gold sputter coating, group 9 Sandblasting Al2O3 250μm then gold sputter coating, group 10 Sandblasting Al2O3 125μm then TiN sputter coating, group 11 Sandblasting Al2O3 180μm then TiN sputter coating, group 12 Sandblasting Al2O3 250μm then TiN sputter coating. Vita Titankeramik porcelain was applied for all groups and built up manually with dimensions limited to 8x3x1mm and fired on Ti bars following the manufacturer’s instructions and ISO 9693 recommendations, and tested for bond strength by Schwickerath crack initiation test (ISO 9693) using an Instron universal testing machine (Model: 5566A). The mode of failure and bond interface were evaluated by SEM / EDS. RESULTS: The mean bond strength values of groups 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 were 2.31MPa (±0.2), 24.3MPa (±0.78), 46.94MPa (±1.29), 6.18MPa (±0.98), 9.46MPa (±1.08), 15.14MPa (±0.74), 24.84MPa (±1.73), 36.24MPa (±1.43), 41.49MPa (±2.13), 49.45MPa (±0.96), 69.36MPa (±0.96), 94.45MPa (±1.51), respectively. Two-way ANOVA with Tukey multiple comparisons test was performed to determine the groups that are statistically different. All tested groups (1-12) showed statistically significant difference except groups 2, and 7, P< 0.05. CONCLUSIONS: Within the limitations of this study, the following conclusions can be drawn: 1- Surface finish significantly affects the bond strength of low fusing porcelain to Ti grade V. 2- Larger Al2O3 particle size corresponded to higher bond strengths. 3- Sandblasting in combination with Au or TiN coatings produced the highest bond strength values. 4- Groups 1, 4, 5, & 6 showed Adhesive failure at the ceramic – metal interface; for groups 3, 10, 11, & 12 were found to be Cohesive failure within the porcelain layers; and for groups 2, 7, 8, & 9 were found to be mixed Adhesive / Cohesive failure. / 2018-09-28T00:00:00Z

New CAD/CAM materials are becoming more accepted in veneer restoration. The objective is to investigate the margin integrity of CAD/CAM veneer, their color masking over dark backgrounds and shear bond strength (SBS) to resin cements. Materials and Methods: Four types of CAD/CAM materials shaded A2: Lava Ultimate (LU); IPS Empress CAD (IPS); Vita Enamic (VE); and Vitablocs Mark II (VMII) were sectioned into tiles of different thicknesses: 0.3mm, 0.5mm and 0.7mm (n=7). The color (CIE - L*a*b*) of each specimen was measured against grey background, then against each tooth-shaded background: A3, A4, B3 and C2 acrylic (Coldpac, Motloid). Color differences (ΔE) were calculated. Specimens were measured against black then white background to calculate translucency. Two-way ANOVA was used to compare the differences in ΔE among the groups (a=0.05). SBS values of 2mm thick tile specimens of the same CAD/CAM materials to resin cements, RelyX Ultimate and Varilonik Veneer, were measured using Instron Universal Testing Machine. (n=10). Statistical analysis was performed by ANOVA with Tukey-Kramer HSD multiple comparison test (a=0.05). Qualitative evaluation of margin integrity of the veneers milled from the same CAD/CAM materials in three thicknesses 0.3, 0.5 and 0.7mm were observed under the optical microscope. Results: Significant differences in masking capabilities were found among the tested material for all three thicknesses. In comparison of ΔE values of the tested materials over tooth-shaded backgrounds, specimens over shade A3 background showed the highest color masking ability. LU and VE exhibited better color masking than IPS and VMII. IPS showed significantly higher in translucency than the other groups. IPS showed the highest SBS to resin cements and LU showed lowest SBS. Materials cemented with RelyX showed significantly higher SBS values than those with Variolink. CAD/CAM milled LU and VE veneers show smoother margins when compared to IPS and VMII. Conclusion: LU and VE exhibited higher color masking, lower translucency, lower SBS values, and better margin integrity than IPS and VMI. / 2019-09-26T00:00:00Z

BACKGROUND: Dental implants have been successful for the restoration of edentulous areas, but current techniques are inadequate in areas lacking sufficient bone volume. Piezoelectric surgery has shown encouraging effects on both osseous healing. A new wedge-shaped titanium PiezoImplant requires piezoelectric osteotomy. This study compares PiezoImplants to conventional threaded cylindrical shaped implants by microcomputed tomography and histology to assess osseointegration, tissue response, and alveolar ridge changes. METHODS: After 3 months post-extraction, 18 conventional cylindrical implants and 18 wedge-shaped PiezoImplants were placed using a split-mouth design in 3 adult mini pigs. The cylindrical implant sites were prepared for osteotomy with rotary instrumentation while the PiezoImplant sites were prepared with piezoelectric surgical inserts. One animal was sacrificed at 4, 8, and 12 weeks post operation. Quantitative µCT and histological analysis evaluated bone volume, osseointegration, and post-operative cellular events. RESULTS: The results of a multivariable linear regression model demonstrated that the PiezoImplants, arch location, and time were significant factors on higher BV/TV percentage. Bone to implant contact (BIC) analysis by high resolution microscopy and histomorphometry indicated osseointegration though intimate contact between implants and adjacent alveolar bone in both groups. The tissue response displayed no evidence of abnormal healing and the PiezoImplant was classified as a non-irritant. CONCLUSION: The combination of piezoelectric osteotomy and newly designed PiezoImplants had favorable effects on wound healing and osseointegration compared to conventional cylindrical implants. These novel wedge-shaped implants may be beneficial for narrow ridge spaces without additional ridge augmentation. Further research is needed to establish clinical validity.

Introduction: Recent studies have utilised cone beam computed tomography (CBCT) for the assessment of the volume of the nasopharyngeal airway space (Guijarro-Martínez and Swennen, 2013, Lenza et al., 2010, Woodside and Linder-Aronson, 1979, Chang et al., 2013). Some of these investigations are based on the analysis of slice data obtained from three dimensional (3D) radiographic images. The usage of a CBCT scan to measure the nasopharyngeal airway volume has drawbacks which include the effect of respiration and tongue position (Abbott et al., 2004), the impact of head posture, lordosis (cranio-cervical inclination) and mandibular morphology on the accuracy of measuring air oro-pharyngeal airways. In addition, published figures to date has not considered the detailed anatomical boundaries of the nasal cavity space, paranasal airway space and other pharyngeal sections collectively (Chang et al., 2013). Aims and objectives: The aim of the study was to assess the validity of the free access software package like ITK Snap in measuring the airways spaces, investigate, using CBCT, the three-dimensional effect of rapid maxillary expansion on the maxillary sinus, the lower part of the nasal cavity, the upper nasopharynx and the upper oropharynx (upper and lower retropalatal spaces), and to correlate the changes in these anatomical spaces with the measured RME appliance split, the dentoalveolar expansion and the gender of the subjects. Materials and methods: This study was carried out on seventeen patients (8 boys, 9 girls; mean age 12.6 + 1.8 years) who required maxillary expansion for the management of narrow upper dental arch. Sample size was calculated using the Researcher’s Toolkit calculator and this indicated that a sample size of 14 patients would produce an Alpha error level or confidence level at 95% and a Beta error level at 20%. Therefore, it was decided to recruit 17 subjects to overcome potential exclusion due to irreproducibility in the head orientation and lordosis. Pretreatment (T1) and immediate post-RME (T2) CBCT images were taken for all the patients. In all CBCT images, head orientation and lordosis were measured using OnDemand 3D software packages. Cases were excluded from the study if the difference in the head orientation and lordosis between the CBCT of T1 and CBCT of T2 was more than 5 degrees. The two scans, T1, T2, were orientated according to a specific protocol and superimposed on the cranial base to standarise the volumteric segemtation and measurements. The impact of RME was assessed by measuring, using ITK snap and OnDemand 3D software packages, the changes in the distance between the intermolar dentoalveolar width at level of molar alveolar crest (IMD), the magnitude of appliance expansion (AE), the volume of respiratory region or the lower part of the nasal cavity (LNC), the volume of the right and left maxillary sinus (RMS and LMS), the volume of the upper nasopharynx (UNP), the subdivisions of the upper oropharynx including the upper and lower retropalatal space (URP and LRP) at T1 and T2. Segmentation of the oro-naso-pharyngeal spaces into multiple segments allows a deailed localisation of the changes and aids in exclusion of any potential masking change of one airway space on adjacent or remote airway space as each segment is associated anatomically and physiologically to different function and/or disorder. The normality of the data was tested using Kolmogorov–Smirnov test. The reproducibility of meaurements was analysed using Paired t-test and interclass correlation coefficient. The volumteric and linear changes was assessed using Student t-test (P < 0.05) and Pearson correlation coefficients was used to test the correlation of these changes. Results: Bonded RME has an effective dentoalveolar expansion effect in growing patients (P=0.001) and produced a significant increase in UNP (P=0.045). There was a statistically significant reduction on the URP space (P=0.042), especially in males. There was strong correlation between the increase of the volume of the right and left maxillary sinuses (PCC=0.86) and between appliance expansion and dentolavelar expansion (PCC=0.75). Conclusions: ITK-SNAP software is a reliable package and a single threshold value (-450 grey) is an accurate value. Additionally, this software can be used to measure the size of bony defect in patient with cleft palate before secondary alveolar bone grafting. Bonded RME was an effective dentoalveolar expander in growing patients and the immediate expansion of LNC and UNP might be associated with a reduction in nasal resistance, improvement in the nasal breathing and it can be considered as an option for treatment of Paediatric Obstructive Sleep Apnea Syndrome. Findings of this dtudy showed that there is a sexual dysmorphisim secondary to RME but did not reach the statistical significance. Generally, the effect of the RME on the upper naso-oro-pharyngeal airway spaces followed a mushroom like pattern with the upper parts expanded, the middle part was significantly narrowed while the lower part was mildly, but insignificantly statistically, reduced. However, it is essential to consider that regardless of the benefit of the increase nasal patency of this orthopeadic procedure, it should not done merely for the above purposes solely but only when it is linked to a right indication for RME. A future studies could include a colour mapping for detailed assessment of changes in different part of the oro-naso-pharyngeal space, as the shape changes of the airway space is as important as volumetric changes. Finally, a further randomised clinical trial or comparative study with larger sample size and long term follow up would be beneficial in estimating the real impact of the RME on the airway confirm the findings of this study.

Periodontal disease is a chronic inflammatory disease affecting the structures supporting the teeth. It results from the interaction between a microbial biofilm on the tooth surface and a de‐regulated host response in the periodontal tissues of a genetically susceptible host. There are strong correlations between specific ‘red complex’ micro‐organisms within the subgingival biofilm and disease. Dysbiosis, a deleterious shift in the relative abundance of components of the microbiota in disease, is a recognised property of microbiomes at other sites of the GI tract in chronic diseases. Exploring dysbiosis in the oral commensal microbiota using a mouse model of periodontitis, we have shown that a ‘red complex’ organism (Porphyromonas gingivalis) caused significantly more periodontal bone loss in specific pathogen free (SPF) mice than controls and no bone loss in germ free (GF) mice. This confirms the oral commensal microbiota is fundamentally required for periodontal bone loss. In addition, low level colonisation of SPF mice with P. gingivalis led to qualitative and quantitative changes to the microbiota; dysbiosis. The oral commensal microbiota of the SPF mice was stable for our aging population of SPF mice and this led to increased alveolar bone loss with age. Through a series of co‐caging experiments we have shown that the oral commensal microbiota of different strains of mice was transmissible into GF mice and led to periodontal bone loss. We have also demonstrated that a dysbiotic oral commensal microbiota was transmissible into GF mice and led to increased periodontal bone loss. In conclusion, the oral commensal microbiota is fundamental in the pathogenesis of periodontal disease in this mouse model. Moreover, it is dysbiosis of this oral commensal microbiota, brought about by P. gingivalis, that drives accelerated alveolar bone loss. We propose that P. gingivalis be considered as a keystone species.

The complex microstructure and properties of dental enamel have been studied for decades using a variety of quantitative and qualitative techniques in order to gain a greater depth of understanding behind the chemical and physical processes that are associated with the formation and destruction of this biological apatite. Dental enamel is composed of highly ordered carbonated hydroxyapatite crystals which, together with its small organic component, are responsible for its mechanical strength, allowing it to serve its functional purpose. Environmental changes at any stage of the biomineralisation process or post eruption can disrupt the orientation and alter the structure and function, which can have detrimental clinical effects. The aim of this study is to understand and characterise the structural and crystallographic properties of disrupted enamel, and compare this to healthy unaffected tissue. Enamel affected by the genetic disorder, Amelogenesis Imperfecta, alongside enamel disrupted by dissolution and caries were studied using Synchrotron X-ray diffraction, 3D X-ray Microtomography, and Scanning Electron Microscopy techniques to relate these features to the clinically observed characteristics; to the chemistry; and to the known genetics of the tooth. Synchrotron radiation was used to map changes in preferred orientation, while the corresponding mineral density distributions were seen by using an in house developed, non-destructive microtomography system. Structural information on dental enamel at the crystallographic and micron length scales can benefit a variety of different disciplines. This project has the potential to inform early diagnosis, develop a tool for an early recognition of progressive or highly variable medical conditions, and design potential treatment regimes. The comparison of affected enamel to that of healthy enamel will provide a unique opportunity to identify the developmental pathways required for normal tooth development and give insights into the basic principles underlying mammalian biomineralisation.