The effect of text message reminders on compliance with Twin Block appliances: A randomised controlled trial.

AIMS: The aim of this study was to evaluate whether text reminders influence patient compliance with Twin Block appliances. The null hypothesis was that there was no statistically significant differences in Twin Block compliance between those who receive text reminders and those that do not. DESIGN: Single-blind parallel randomised controlled clinical trial. SETTING: Health Service Executive (HSE) orthodontic outpatient clinic in Dublin, Ireland. PARTICIPANTS: A total of 59 patients aged 11-15 years with a 5a Index of Orthodontic Treatment Need (IOTN grade) starting treatment with Twin Block appliances. METHODS: A computer-generated unstratified allocation sequence was used to randomise the participants into the control group (CG) or the text group (TG). Both groups were asked to wear their appliances full-time. In addition to the same verbal and written instruction received by the CG, the TG received text message reminders to wear their appliances every 3 days. The primary outcome measure was wear time reported by Theramon® sensors embedded in the appliances. Data on wear time were uploaded from the Theramon® sensors onto cloud software. Participants in both groups were asked to fill out wear diaries and submit these at each visit. Treating clinicians and the primary investigator were blinded to the allocation group. Participants were followed up for 4 months. Participants were not blinded to their treatment group. RESULTS: In total, 29 participants were allocated to the CG and 30 to the TG. The data for 53 participants were analysed, 24 from the CG and 29 from the TG. The median hours/day of wear recorded using the Theramon® sensors was 13.77 (interquartile range [IQR] = 10.19) for the CG and 17.72 (IQR = 5.62) for the TG. The difference in wear time recorded was not statistically significant (P = 0.16). CONCLUSION: The study concluded that text message reminders had no statistically significant influence on patient compliance with Twin Block appliances.

A Decision Analysis Approach to Electronics Standard Development Informed by Life Cycle Assessment Using Influence Diagrams.

Life cycle assessment (LCA) provides holistic information on systems including the trade-offs between environmental impacts and the drivers of such impacts. Coupling life cycle assessment with a decision analysis (DA) method can help ensure that a life cycle assessment is focused on pertinent decision performance measures. In this paper, a framework integrating life cycle assessment with a decision analysis method to enhance the application of life cycle assessment is presented with a real-world case study of developing a material inclusion criterion for sustainable electronics standards. The proposed DA-LCA framework is a five-step process that tracks the flow of information between the steps of decision analysis and life cycle assessment. The case study considered the level of post-consumer-recycled or biobased content in laptop enclosures. Elicitation with a mock stakeholder panel was used to structure a means-ends network and create a utility-based influence diagram to link changes in material inclusion to environmental objectives using life cycle impact scores. Unlike typical life cycle assessment, the decision analysis approach allows for explicit incorporation of non-environmental factors and better constrains product options. Using this approach, the optimum decision for a possible range of 0-30% material content is 5% or 10%, depending on weighting. The DA-LCA framework can provide a blueprint for placing life cycle assessment results in context for decision-makers.

A randomized clinical trial comparing mandibular incisor proclination produced by fixed labial appliances and clear aligners.

OBJECTIVE: To compare the mandibular incisor proclination produced by fixed labial appliances and third generation clear aligners. MATERIALS AND METHODS: Patients underwent a course of orthodontic treatment using either fixed labial appliances or clear aligners (Invisalign). Mandibular incisor proclination was measured by comparing pretreatment and near-end treatment lateral cephalograms. Eligibility criteria included adult patients with mild mandibular incisor crowding (<4 mm) and Class I skeletal bases (ANB, 1-4°). The main outcome was the cephalometric change in mandibular incisor inclination to the mandibular plane at the end of treatment. Eligible patients picking a sealed opaque envelope, which indicated their group allocation, was used to achieve randomization. Data was analyzed using a Welch two-sample t-test. RESULTS: Forty-four patients (mean age, 26.4 ± 7.7 years) were randomized in a 1:1 ratio to either the fixed labial appliance or the clear aligner group. Baseline characteristics were similar for both groups: Fixed appliance mean crowding was 2.1 ± 1.3 mm vs clear aligner mean crowding, 2.5 ± 1.3 mm; pretreatment mean mandibular incisor inclination for the fixed appliance group was 90.8 ± 5.4° vs 91.6 ± 6.4° for the clear aligner group. Fixed appliances produced 5.3 ± 4.3° of mandibular incisor proclination. Clear aligners proclined the mandibular incisors by 3.4 ± 3.2°. The difference between the two groups was not statistically significant (P > .05). CONCLUSION: There was no difference in the amount of mandibular incisor proclination produced by clear aligners and fixed labial appliances in mild crowding cases.

Efficacy of the Nance appliance as an anchorage-reinforcement method.

INTRODUCTION: The Nance appliance is widely considered to be an efficient method of anchorage reinforcement; however, much of the perceived advantage is based on clinical judgment. The aim of this study was to assess the amounts of anchorage loss and desired tooth movement associated with the Nance appliance. METHODS: The mandibular arches of 7 beagle dogs were used. The first and third premolars were extracted. Reference miniscrews were placed at the first premolar sites as stable references to measure the amounts of anchorage loss and desired tooth movement. Four beagles were fitted with custom-made Nance appliances on the fourth premolars and orthodontic bands on the second premolars (Nance group). Three beagles were fitted with orthodontic bands on the second and fourth premolars with no anchorage reinforcement (control group). The second premolars were retracted over 15 weeks in both groups. The amounts of second premolar movement (desired tooth movement) and fourth premolar movement (anchorage loss) were recorded at 5, 10, and 15 weeks. The percentages of desired tooth movement and anchorage loss to the total space closure were calculated. RESULTS: The mean desired tooth movement was significantly more in the Nance group than in the control group at 10 weeks (P <0.05) but was not significantly different at 5 and 15 weeks. The mean percentages of anchorage loss to the total space closure at 15 weeks were 45.7% in the control group and 28.8% in the Nance group. The Nance group had 16.9% less anchorage loss and 16.6% more desired tooth movement than did the control group at 15 weeks (P <0.05). Most of the anchorage loss (80%) in the Nance group occurred during the first 10 weeks. CONCLUSIONS: The Nance appliance did not provide absolute anchorage, but there was significantly less anchorage loss with it than in the control group. The majority of anchorage loss occurred during the first 10 weeks in the Nance group.

The reliability of Little's Irregularity Index for the upper dental arch using three dimensional (3D) digital models.

AIM: To investigate the inter-examiner variability of contact point displacement measurements (used to calculate the overall Little's Irregularity Index (LII) score) from digital models of the maxillary arch by four independent examiners. METHODS: Maxillary orthodontic pre-treatment study models of ten patients were scanned using the Lava(tm) Chairside Oral Scanner (LCOS) and 3D digital models were created using Creo(®) computer aided design (CAD) software. Four independent examiners measured the contact point displacements of the anterior maxillary teeth using the software. Measurements were recorded randomly on three separate occasions by the examiners and the measurements (n=600) obtained were analysed using correlation analyses and analyses of variance (ANOVA). RESULTS: LII contact point displacement measurements for the maxillary arch were reproducible for inter-examiner assessment when using the digital method and were highly correlated between examiner pairs for contact point displacement measurements >2mm. The digital measurement technique showed poor correlation for smaller contact point displacement measurements (<2mm) for repeated measurements. The coefficient of variation (CoV) of the digital contact point displacement measurements highlighted 348 of the 600 measurements differed by more than 20% of the mean compared with 516 of 600 for the same measurements performed using the conventional LII measurement technique. CONCLUSIONS: Although the inter-examiner variability of LII contact point displacement measurements on the maxillary arch was reduced using the digital compared with the conventional LII measurement methodology, neither method was considered appropriate for orthodontic research purposes particularly when measuring small contact point displacements.

The multidisciplinary conservative management of a vital crown root fracture.

UNLABELLED: This case study reports on the multidisciplinary management of a maxillary canine which sustained an unusual labial crown root fracture, resulting in a large veneer-like fragment.The canine was extruded orthodontically and the fragment was re-attached using adhesive materials.This multidisciplinary solution prevented impingement on the biological width, loss of vitality and loss of tooth structure, leading to an optimal soft and hard tissue aesthetic result. Successful clinical and radiographic results after three years were observed, despite canine protected occlusion. CLINICAL RELEVANCE: Multidisciplinary management can result in an improved prognosis of the tooth and, in time, may be the most cost-effective solution for the patient. When discussing treatment options with the patient, utilization of all dental specialties should be considered and offered to the patient.

Can the intra-examiner variability of Little's Irregularity Index be improved using 3D digital models of study casts?

OBJECTIVES: To compare contact point displacement measurements, used to determine the Little's Irregularity Index (LII) score on study casts and digital models of study casts by an independent examiner. METHODS: The contact point displacement measurements of the six maxillary anterior labial teeth were measured on ten study casts using digital callipers and their associated digital models using Creo Parametric software on five occasions following scanning using a LAVA Chairside Oral Scanner (LCOS) three-dimensional (3D) intra oral scanner. Means, standard deviations and coefficients of variation (CoV) were determined, data analyses (Pearson's correlation coefficients (PCCs) and Intraclass correlation coefficients (ICCs)) and statistical analyses (three and two-way analyses of variance (ANOVAs) and Independent Sample Student's t-tests) were carried out (p<0.05). RESULTS: Significant positive correlations for the contact point displacement measurements were evident between all measurement time points for the study casts (r>0.978; p<0.0001 and ICC>0.910; p<0.0001) and the digital models (r>0.963; p<0.0001 and ICC>0.986; p<0.0001). The CoV results showed that the contact point displacement measurement data from the digital models was more reproducible than the study casts. Of the 50 Independent Sample Student's t-tests, 21 significant increases (p<0.042) were reported in contact point displacement measurements <2.9 mm for the digital models compared with the study casts. CONCLUSION: The use of 3D digital models can improve the reliability of LII measurements by reducing the subjectivity associated with choosing the anatomic tooth contact points and the awkwardness of measuring the contact point displacements on study casts using a cumbersome calliper technique. CLINICAL SIGNIFICANCE: Intra-examiner variability in the measurement of LII is still evident with digital models suggesting that either improved software specifically aimed at the orthodontic community be identified or a new method for measuring anterior incisor crowding be sought.

Using Little's Irregularity Index in orthodontics: outdated and inaccurate?

OBJECTIVES: Little's Irregularity Index (LII) was devised to objectively score mandibular incisor alignment for epidemiological studies but has been extended to assess the relative performance of orthodontic brackets, retainer or treatment modalities. Our aim was to examine the repeatability and precision of LII measurements of four independent examiners on the maxillary arch of orthodontic patients. The hypothesis was that the reproducibility of individual contact point displacement measurements, used to calculate the LII score, are inappropriate. METHODS: The displacement of the anterior contact points, of the six upper labial segment teeth of the maxillary arch on each of ten casts, were randomly assessed by four examiners at three time-points using LII. RESULTS: Significant correlations were evident between the six examiner-pairs (r > 0.413; p < 0.001) for contact point displacements of >0.5 mm. The coefficients of variation showed that 516 of the 600 individual contact point displacement measurements differed by >20% of the mean. Analyses of variance revealed significant differences (p < 0.047) between examiners for 46% of the contact point displacement measurements. CONCLUSION: The reproducibility of individual contact point displacement measurements, used to calculate the LII score, is poor such that using LII to assess the performance of orthodontic brackets, retainers or treatment modalities must emphatically be discouraged. CLINICAL SIGNIFICANCE: The use of LII by the orthodontic community to predictably determine the outcome of orthodontic treatment modalities in clinical practice cannot be advocated due to the limited accuracy and precision of the technique.

Relationship between bilateral congenital absence of maxillary lateral incisors and anterior tooth width.

INTRODUCTION: The objective of this study was to assess the relationship between anterior tooth width and the presence or absence of maxillary lateral incisors. METHODS: Reference models of 106 subjects, 52 with bilateral agenesis of maxillary lateral incisors and 54 fully dentate controls, were examined. The sample was based on orthodontic patients treated over a 10-year period at Kent and Canterbury Hospital, Canterbury, Kent, United Kingdom. Maximum tooth widths were measured by using digital calipers (Tesa Technology, Renens, Switzerland). RESULTS: Individual tooth dimensions in the maxillary and mandibular anterior segments were reduced by 0.33 to 0.42 mm, respectively, in subjects with agenesis of the maxillary lateral incisors. Linear regression analysis confirmed that these differences have statistical significance (P <0.001). CONCLUSIONS: Isolated bilateral absence of maxillary lateral incisors is associated with reduced mesiodistal tooth widths in both the maxillary and mandibular anterior segments.

Tooth agenesis in patients referred to an Irish tertiary care clinic for the developmental dental disorders.

PURPOSE: This study was carried out to determine the prevalence, severity and pattern of hypodontia in Irish patients referred to a tertiary care clinic for developmental dental disorders. MATERIALS AND METHODS: Details of 168 patients with hypodontia referred during the period 2002-2006 were entered in a database designed as a national record. Tooth charting was completed using clinical and radiographic examinations. The age of patients ranged from 7-50 years, with a median age of 20 years (Mean: 21.79; SD: 8.005). RESULTS: Hypodontia referrals constituted 65.5% of the total referrals. Females were more commonly affected than males with a ratio of 1.3:1. The number of referrals reflected the population density in this area; the majority were referrals from the public dental service. Mandibular second premolars were the most commonly missing teeth, followed by maxillary second premolars and maxillary lateral incisors; maxillary central incisors were the least affected. Symmetry of tooth agenesis between the right and left sides was an evident feature. Slightly more teeth were missing on the left side (n = 725) than on the right side (n = 706) and in the maxillary arch (n = 768) as compared to the mandibular arch (n = 663). Some 54% of patients had severe hypodontia with more than six teeth missing; 32% had moderate hypodontia, with four to six teeth missing. The most common pattern of tooth agenesis was four missing teeth. CONCLUSION: Hypodontia was a common presentation in a population referred to this tertiary care clinic. The pattern and distribution of tooth agenesis in Irish patients appears to follow the patterns reported in the literature.

Orthodontic extrusion in the transitional dentition: a simple technique.

Extrusion of teeth may be necessary in cases of delayed eruption, primary retention, traumatically intruded teeth, or subgingivally fractured teeth. Removable appliances are advantageous, as anchorage is not as tooth-dependant as in the case of fixed appliances. They are cost-effective, operator friendly, and a valuable treatment option to consider in cases where extrusion of anterior teeth in the transitional dentition is necessary. The purpose of this paper was to describe a simple, cost-effective technique using a removable appliance for extrusion of incisors in the transitional dentition.