Toxicity of Orthodontic Brackets Examined by Single Cell Tracking.

Subtle toxic effects may be masked in traditional assays that average or summate the response of thousands of cells. We overcome this by using the recent method of single cell tracking in time-lapse recordings. This follows the fate and behavior of individual cells and their progeny and provides unambiguous results for multiple simultaneous biological responses. Further, single cell tracking permits correlation between progeny relationships and cell behavior that is not otherwise possible, including disruption by toxins and toxicants of similarity between paired sister cells. Notably, single cell tracking seems not to have been previously used to study biomaterials toxicity. The culture medium was pre-conditioned by 79 days incubation with orthodontic brackets from seven separate commercial sources. Metal levels were determined by Inductively Coupled Plasma Mass Spectrometry. Metal levels varied amongst conditioned media, with elevated Cr, Mn, Ni, and Cu and often Mo, Pb, Zn, Pd, and Ag were occasionally found. The effect on human dermal fibroblasts was determined by single cell tracking. All bracket-conditioned media reduced cell division (p < 0.05), while some reduced cell migration (p < 0.05). Most bracket-conditioned media increased the rate of asynchronous sister cell division (p < 0.05), a seemingly novel measure for toxicity. No clear effect on cell morphology was seen. We conclude that orthodontic brackets have cytotoxic effects, and that single cell tracking is effective for the study of subtle biomaterials cytotoxicity.

Trends in the choice of a clinician for orthodontic treatment in the United States.

INTRODUCTION: This study evaluated the trends in orthodontic practitioner choice over the past 15 years and explored the lay public's understanding of different orthodontic practitioner options in the U.S., specifically, orthodontists compared with general dentists. METHODS: A survey was distributed to a representative sample of laypersons in the U.S. The response rate was 90.2%, and 727 completed responses were analyzed. RESULTS: A 28.2% shift away from orthodontists toward general dentists over the last 15 years was significant (P <0.001). The 2 most frequently endorsed ways respondents found their orthodontic practitioners were a recommendation from another dentist (54.2%) and their family's general dentist who offered orthodontic treatment in-house (22.9%). Respondents' knowledge of orthodontists was limited; 85.0% believed that dentists who perform orthodontic treatment are also orthodontic specialists. Only 17.1% of respondents disagreed with the statement that "a dentist who advertises orthodontic treatment is an orthodontic specialist." In addition, 89.7% were not aware that a dentist could not be called an orthodontist without separate training from an accredited residency program. Finally, 64.2% of respondents did not know that an orthodontist must complete more education than a general dentist. CONCLUSIONS: Over the past 15 years, the percentage of orthodontic patients treated by general dentists has increased significantly. The public's ability to differentiate between different types of orthodontic practitioners is poor, showing substantial confusion about orthodontists' qualifications. Most respondents believed that orthodontists are best suited for their orthodontic treatment, but they rely heavily on their general dentists for orthodontic practitioner decisions.

Australian Orthodontists Utilization and Attitude Toward a Government Funded Cleft Scheme.

OBJECTIVES: To (1) survey Australian orthodontists about their involvement with a government-funded scheme for patients with clefts, the Medicare Cleft Lip and Cleft Palate Scheme (MCLCPS) and (2) investigate their attitude toward treating patients with clefts and their training in this respect. DESIGN: A 13-question online survey was distributed to members of the Australian Society of Orthodontists. The survey gathered information regarding respondent demographics, the number of MCLCPS-eligible patients seen in the past 12 months and usual billing practices. RESULTS: A total of 96 complete responses were obtained. About 70% of respondents had treated MCLCPS-eligible patients in the past 12 months and 55% saw between 2 and 5 patients during this time. The likelihood of treating patients with clefts increased by a factor of 4.8 (95% CI: 1.2-18.9) if practicing outside of a capital city and 1.5 times for each decade increase in orthodontist's age (95% CI: 1.0-2.2). The MCLCPS was utilized by 81% of orthodontists with 26% of these respondents accepting rebate only. Most orthodontists felt their university training could have better prepared them to treat patients with clefts. A minority of orthodontists felt that a rebate increase would make them more likely to treat these patients. CONCLUSIONS: Australian orthodontists who treat patients with clefts tend to be older and work outside of capital cities. The decision to treat these patients tends to not be financially motived. Specialty orthodontic training programs could improve the preparedness of their graduates to treat patients with clefts.

The public perception of the differences between specialist orthodontists and general dentists: A comparison between Australia and Sweden.

INTRODUCTION: In Australia and Sweden, orthodontic treatments may be performed by either a general dental practitioner (GDP) or a specialist orthodontist. Evidence suggests that the public may easily confuse a GDP who provides orthodontic treatment with a specialist orthodontist. We conducted a survey of people in Australia and Sweden to assess their understanding of the differences between a specialist orthodontist and a GDP who provides orthodontic treatments. METHODS: The sample comprised 2006 Australian adults and 1010 Swedish adults who completed an online questionnaire. The survey examined the respondents' understanding of the difference between a GDP and a specialist orthodontist. Demographic data and the respondents' preference concerning future practitioner type were also collected. RESULTS: Although most of the responses between the countries were different with statistical significance (P <0.001), many similarities in the responses were observed. More than 90% of the respondents in both countries did not know the difference between a GDP who provides orthodontic treatment and a specialist orthodontist. Almost 75% believed that a specialist orthodontist was the most qualified practitioner to perform orthodontic treatment. Fewer than 10% of the respondents preferred to see a GDP for orthodontic treatment over a specialist. These people tended to be male, have less education, and be younger. Cost was identified as an important factor in choosing an orthodontic practitioner, particularly in the Australian sample. CONCLUSIONS: The clear majority of both Australian and Swedish respondents were unable to identify the difference between a specialist orthodontic and a GDP who provides orthodontic treatments.