Volume 34 (2018): Issue 2 (January 2018)

With minimal manufacturer information, a variety of ‘generic’ orthodontic brackets are available online from overseas distributors. The present study investigated the metal composition of generic orthodontic brackets compared with two well-known ‘proprietary’ brands.

Ranging in price from AU$2.99 to $65, five sets of different generic brackets were obtained directly from China via eBay (G1, G2…G5). Proprietary brackets were obtained from American Orthodontics (P1) and Rocky Mountain Orthodontics (P2). The 11, 12, 13 and 14 brackets from each set were liquefied in an acid solution and subjected to trace element analysis using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) with respect to nickel, chromium, iron, copper, molybdenum, manganese, cadmium, mercury, arsenic and lead. Statistical analysis investigated the compositional consistency within and between each brand.

The composition of P1 and P2 agreed with the manufacturer’s data. The generic groups typically had low molybdenum and higher copper content and approximated either 17-4 or AISI304 stainless steels or a combination of both. No relationship between brand and consistency of manufacture could be identified. The cheapest bracket contained lead.

Generic and proprietary brackets showed differences in their metal composition that may have biocompatibility implications.

To detect age-related morphological changes occurring in the median and transverse palatal sutures that could affect the outcome of rapid maxillary expansion. Determined by Cone-Beam Computed Tomography (CBCT) scans.

CBCT scans were retrospectively analysed of 325 patients aged from 5.9 to 82 years (mean = 27.3 +/-17.9), comprising 144 males and 181 females who underwent CBCT scanning of the maxillary region. The median and transverse palatal sutures were assessed at four topographic points using a grading scale created for the purpose of this study to attempt to assess the shape and the amount of calcified tissue within the examined sutures.

At each of the assessed topographic points, the median palatal suture evolved from a straight/polyline shape to a more tortuous outline with a concomitant increase in the amount of calcified tissue most significantly identified in the middle and posterior regions of the suture. Patients older than 20 years showed significant suture obliteration at all points evaluated. No agedependent increase in the transverse suture calcification could be established.

Patients younger than 15 years should be treated with more predictable effect by means of an RME if no factors other than median palatal suture morphology are considered. Patients between 15 and 20 years old can be described as borderline cases in which an individual assessment by CBCT scans may prove clinically relevant. Patients older than 20 years showed significant suture obliteration at all points evaluated and therefore could be considered as patients at high risk of RME failure.

Anchorage is crucial in controlling tooth movement during orthodontic treatment. Different designs have been introduced to increase the stability of miniscrews. A new miniscrew, The Sydney Mini Screw (SMS), with a hollow chamber and lateral port holes, has been developed to allow the diffusion of an injectable bone graft substitute (iBGS) into cancellous bone. The aim of this study was to analyse the optimum iBGS application with ideal chemo-mechanical properties to be used in conjunction with the novel SMS.

A composite calcium sulphate and calcium phosphate bone graft substitute was examined. The effects of powder particle size, and the powder-to-liquid ratio on the injectability of the iBGS through the SMS were investigated. The viscosity, injectability, and mechanical properties of the new composite mixtures were assessed using rheology and universal compression measurements.

The results showed that the optimised injectable formulation of the bone cement was acquired with the concentration of 2.5 g/ml. This concentration was readily injectable through the SMS, and its setting time was within 2–3 minutes, which is favourable for clinicians. In addition, the resulting structure fractured at 80 kPa compression stress.

The result of this study identified the specific particle size and powder-to-liquid ratio of the iBGS that can be used in conjunction with the new SMS to enhance the primary stability of orthodontic miniscrew applications.

To evaluate the influence of the lateral cephalometric radiograph on orthodontists’ diagnosis and treatment planning decisions.

Five patients with full pre-treatment records were selected to represent a spectrum of malocclusions. The records were provided in a web-based questionnaire emailed to 510 Australian registered orthodontists. Participants were asked to formulate a diagnosis and treatment plan for a randomised patient case. The control group received a lateral cephalometric radiograph whilst the intervention group did not. The two groups’ diagnostic accuracy was determined by a comparison with the formative diagnoses determined by five senior academic orthodontists. Their diagnosis and treatment planning decisions were also compared.

A comparison of the orthodontists’ diagnoses revealed that the lateral cephalometric radiograph did not lead to an increase in the assessment accuracy of dental (p = 0.797) and skeletal (p = 0.273) relationships. Further analysis using logistic regression showed that the orthodontists’ years of experience did not influence the accuracy of skeletal diagnosis (p = 0.177). A comparison between the orthodontists’ dental (p = 0.689) and skeletal (p = 0.321) determinations did not significantly differ between the two groups. An assessment of the vertical growth pattern (p = 0.656) was also unaffected by the omission of the lateral cephalometric radiograph. When the two groups considered treatment planning options, there were no statistically significant differences related to the treatment options of growth modification (p = 0.720), orthognathic surgery (p = 0.101), and/or an extraction decision (p = 0.840).

Lateral cephalometric radiographs did not significantly influence orthodontists’ diagnosis. There was also little evidence to demonstrate the radiograph’s efficacy in treatment planning cases with no skeletal discrepancy or no significant labiolingual incisor movement planned.

To evaluate the dental effects of the Ni-Ti Memoria^® Leaf Spring Activated Expander (MLSAE) in adolescent orthodontic patients presenting with maxillary transverse constriction.

This retrospective controlled clinical study included 22 patients consecutively treated with the Ni-Ti MLSAE (mean age = 12.72 ± 3.07; range = 6–16 yrs). The sample was compared with 22 untreated controls from the University of Michigan Growth Study. Controls were matched by gender, CVM stage and inter-first molar width. Digital dental casts were obtained at pretreatment, one week, monthly and post-expansion time-points. Maxillary dental arch measurements of inter-canine, interpremolar, inter-first molar, arch depth, arch perimeter and molar angulation were evaluated using 3Shape’s OrthoAnalyzer software. Data were analysed using paired sample and modified Student’s t-tests.

Total mean expansion duration was 4.2 ± 1.23 months. Significant increases were observed between baseline and final inter-canine, inter-first and second premolars, inter-first molar, and arch perimeter measurements within the treatment group. No significant differences were found within the controls. Between group analyses showed statistically significant differences between the treatment and control groups for all variables except for arch depth and molar angulation. Average changes for inter-canine, inter-first premolar, inter-second premolar, inter-first molar, and arch perimeter were 1.04, 5.65, 5.80, 4.70 and 2.15 mm, respectively.

The Ni-Ti MLSAE is capable of obtaining adequate expansion in patients, 6–16 years of age, without causing significant dental tipping. It should be considered a slow expansion device that allows for calibrated expansion at a rate of 1–1.5 mm per month when following the suggested protocol.

To evaluate enamel colour change over a period of one year after the completion of fixed appliance treatment and to assess the influence of two different clean-up procedures and the resulting surface roughness.

Seventeen orthodontic patients were debonded and the residual resin removed using tungsten carbide burs followed by enamel polishing with Stainbuster burs or Sof-Lex discs in a split mouth design. A spectrophotometric colour evaluation was performed after clean-up (T0), polishing (T1), and one year later (T2). Colour parameters were measured and enamel colour change (ΔE) was calculated. Surface roughness was determined at T1 and T2 using epoxy replicas. Data were analysed using paired and unpaired t-tests and Pearson’s correlation.

Significant differences in colour change and surface roughness caused by the polishing techniques at T1 were observed. However, this difference was not evident at T2 (p < 0.05). Surface roughness and colour change showed no significant correlation.

Enamel colour changed significantly when evaluated at T2 (one year post-orthodontic treatment). Stainbuster burs resulted in brighter and smoother teeth immediately after orthodontic treatment. The colour and surface roughness were not significantly different after one year and had no significant correlation.

Recent reports have suggested that anomalies involving the maxillary dentition can sometimes occur in combination. The aim of the study was to investigate combinations of maxillary dental anomalies relating to occlusal and skeletal factors which could suggest a ‘syndrome-like’ aetiology.

This report is based on observations of study models and cephalograms of individuals exhibiting dental anomalies or malocclusion traits related to maxillary or maxillary arch development. A series of nine dental and skeletal anomalies was defined. A possible inter-relationship between the dental factors as well as a correlation with the skeletal malocclusion traits and skeletal factors was investigated.

Of the 253 cases examined, 157 demonstrated single dental symptoms; the remainder demonstrated a combination of at least two or more. Dental and occlusal anomalies in maxillary development were usually associated with bi-maxillary jaw retrognathism and a low mandibular ramus height, indicating a vertical mandibular developmental pattern.

Maxillary anomalies based on the finding of aplasia, eruption problems or crossbite could occur in combination and be associated with constricted skeletal development of the palate or atypical mandibular morphology. It is proposed that these findings suggest the existence of a Maxillary Deficiency Syndrome which should be considered carefully when orthodontic treatment planning.

A Class II malocclusion is a common orthodontic problem that may affect social acceptance and the self-esteem of the patient. The aim of the present study was to evaluate the effect of functional appliance therapy on the oral health-related quality of life (OHRQOL) of patients presenting with a skeletal Class II malocclusion due to mandibular deficiency.

Forty-nine patients (11 to 14 years old) with a Class II malocclusion due to mandibular deficiency were included as the experimental group. A control group of 49 subjects was selected from school children without malocclusion. The Child Oral Impact on Daily Performance (Child-OIDP) index was administered, repeated and differences were evaluated following functional therapy using the Clark Twin Block appliance.

At baseline, the most common oral impact on daily performance in the experimental group was emotional stability (35 patients, 71.4%) and smiling without shame (34 patients, 69.4%), which respectively decreased to 12.2% (six cases) and 20.4% (10 cases) after functional therapy. The mean (±SD) of the Child-OIDP Overall Impact score in the experimental group at baseline was 25.94 (±17.84), which significantly decreased to 2.77 (±2.09) after therapy (p < 0.001).

Functional therapy using the Clark Twin Block appliance had a significant effect in improving OHRQOL of children presenting with mandibular deficiency.

In Australia, orthodontic treatment may be performed by either a general dental practitioner (GDP) or a specialist orthodontist. However, the titles ‘specialist’ and ‘orthodontist’ are restricted to dentists who have undertaken an additional three years of full-time training in an accredited institution. Considering the increase in popularity of GDP orthodontic courses, an assessment was worthwhile of the public’s understanding of the difference between a specialist orthodontist and a GDP who provides orthodontic treatment.

Two thousand and six Australian adults registered with a survey organisation and completed an online questionnaire. Participants were chosen to reflect age and state demographic data provided by the 2016 Australian Census. The survey questions examined the respondents’ understanding regarding the difference between a GDP and a specialist orthodontist related to training and qualifications. Furthermore, factors influencing respondents’ preferences for choosing an orthodontic practitioner as well as demographic data were collected.

Sixty-six percent of respondents felt that a dentist who provided orthodontic treatment must also be a specialist orthodontist whilst 27% were unsure. Seventy-four percent of respondents felt that a specialist orthodontist was the most qualified person to provide orthodontic treatment. The most popular factor in deciding which type of practitioner to see for orthodontic treatment was whether they were a specialist, followed closely by cost. A GDP was more likely to be chosen as an orthodontic practitioner by respondents who were male, less educated, had a lower income or had seen a GDP for orthodontic treatment in the past.

Although the respondents generally appeared to appreciate the value of seeing a specialist for orthodontic treatment, a significant proportion did not appear to understand the difference between a specialist orthodontist and a GDP. The present findings support further education of the public.

To evaluate the effect of the cervical headgear on the development of obstructive sleep apnoea and subsequent alterations of oropharyngeal dimensions.

An electronic database search of published and unpublished literature was performed (MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Clinical Trials.gov and National Research Register). Search terms included obstructive sleep apnoea, sleep disorders, pharyngeal dimensions and headgear. A risk of bias assessment was conducted using the ACROBAT-NRSI tool for non-randomised studies.

Of the 51 articles initially retrieved, only three were eligible for inclusion, while the remainder were retrospective cohort studies presenting serious risk of bias primarily due to undetected confounding factors or selection bias. No quantitative synthesis was possible. One study assessed the potential effect of isolated headgear treatment on apnoeic indices, while two studies described pharyngeal airway dimensions after the use of headgear alone or in combination with an activator appliance. Overall, increased apnoeic indices and the oxygen desaturation index were detected for headgear users. Dimensional changes in the posterior airway space were comparable after headgear or activator use, while combined headgear-activator treatment led to an increase in posterior pharyngeal area when compared with isolated fixed appliance therapy.

Due to methodological inconsistencies and apparent risk of bias of the existing studies, no robust conclusions can be drawn. Prospective controlled or randomised controlled trials are deemed necessary to provide evidence on the effect of headgear treatment on sleep apnoea or pharyngeal airway dimensions.