Development of a clinical practice guideline for orthodontically induced external apical root resorption.

OBJECTIVES: To develop a clinical practice guideline on orthodontically induced external apical root resorption (EARR), with evidence-based and, when needed, consensus-based recommendations concerning diagnosis, risk factors, management during treatment, and after-treatment care. MATERIALS AND METHODS: The Appraisal of Guidelines for Research and Evaluation II instrument and the Dutch Method for Evidence-Based Guideline Development were used to develop the guideline. Based on a survey of all Dutch orthodontists, we formulated four clinical questions regarding EARR. To address these questions, we conducted systematic literature searches in MEDLINE and Embase, and we performed a systematic literature review. The quality of evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. After discussing the evidence, a Task Force formulated considerations and recommendations. The drafted guideline was sent for comments to all relevant stakeholders. RESULTS: Eight studies were included. The quality of evidence (GRADE) was rated as low or very low. Only the patient-related risk factors, 'gender' and 'age', showed a moderate quality of evidence. The Task Force formulated 13 final recommendations concerning the detection of EARR, risk factors, EARR management during treatment, and after-treatment care when EARR has occurred. Stakeholder consultation resulted in 51 comments on the drafted guideline. After processing the comments, the final guideline was authorized by the Dutch Association of Orthodontists. The entire process took 3 years. LIMITATIONS: The quality of the available evidence was mainly low, and patient-reported outcome measures were lacking. CONCLUSIONS/IMPLICATIONS: This clinical practice guideline allows clinicians to respond to EARR based on current knowledge, although the recommendations are weak due to low-quality evidence. It may reduce variation between practices and aid in providing patients appropriate information.

Overjet reduction in relation to wear time with the van Beek activator combined with a microsensor.

INTRODUCTION: The aim of this study was to use a microsensor to investigate the association among overjet reduction, treatment duration, and wear time of the van Beek activator. METHODS: The study sample comprised patients (n = 28) with a mean age of 11.60 (±1.25) years at start of treatment treated with the van Beek activator. The prescribed wear time was 12 hours per day. The evaluation period was limited to the first 3 appointments. The wear times during the 3 intervals were assessed. Treatment periods with good compliance were characterized by a wear time of 8 hours or more per day. RESULTS: The medians of overjet were 9.00 mm at the start of treatment and 5.75 mm at the third appointment. The mean total wear time throughout the evaluation period was 7.75 (±3.66) hours per day. Significant correlations were found at the 3 intervals. Patients with a mean wear time of 8 hours or more per day achieved significantly greater overjet reductions. Patients with good compliance of at least 5 months showed significantly greater overjet reductions. CONCLUSIONS: Significant overjet reduction was achieved with a minimum daily wear time of 8 hours for at least 5 months. The level of compliance had a strong tendency to be maintained throughout the treatment period. No patient achieved the prescribed wear time of 12 hour per day.

A case series of wind instrument players with cleft lip and/or palate.

It might be more difficult for patients with cleft lip and/or palate (CL/P) to generate sufficient muscle tension of the upper lip and intraoral air pressure to play a wind instrument. We aimed to explore and describe the key aspects of wind instrument playing with a repaired cleft. An in-depth interview was conducted among ten patients with CL/P and one with a functionally comparable problem and we found that: individuals with CL/P can achieve a professional level on a wind instrument; the oboe and trumpet may be less suitable for patients with CL/P because of the high lip muscle tension and intraoral air pressure that must be generated; air leakage through a fistula, unrepaired alveolus or velopharyngeal insufficiency can be troublesome; and for people with CL/P, a brass instrument with a large mouthpiece is easier than a small mouthpiece. While dentists, doctors and music teachers should discuss the probability that wind instrument playing might be more difficult for patients with CL/P, they should not discourage it.

Corrosion of orthodontic brackets: qualitative and quantitative surface analysis.

OBJECTIVES: To determine and compare surface characteristics and presence of corrosion in new and used brackets with optical light microscopy (OLM) and scanning electron microscopy (SEM), and with elemental chemical analysis with energy-dispersive X-ray spectroscopy (EDS). MATERIALS AND METHODS: OLM and SEM were used to analyze 24 new and 24 used conventional premolar brackets. EDS analysis was performed in six used brackets and four new brackets with corrosion-suspected spots. RESULTS: OLM and SEM images showed wear/abfraction signs, striations, pits/crevices, and adherent material. Used brackets showed more deterioration than new brackets. SEM images disclosed more morphological features than OLM images. EDS analysis revealed a significantly higher phosphorus (P = .001) and sodium (P < .005) weight fraction and significantly lower amounts of chromium (P < .001) in used brackets. The iron, chromium, and nickel weight fractions did not differ significantly between the clean and corrosion-suspected spots. Of the corrosion-suspected spots analyzed by combined SEM and EDS, 44.14% and 6.90% remained corrosion-suspected on used and new brackets, respectively. CONCLUSIONS: Used brackets showed more signs of corrosion than new ones. Combined assessment of SEM and EDS indicates that the bracket surface is affected during orthodontic treatment as a result of corrosion.

Effect of long-term repeated deflections on fatigue of preloaded superelastic nickel-titanium archwires.

INTRODUCTION: The aim of this in-vitro study was to investigate the changes in force delivery of superelastic nickel-titanium archwires used in combination with a self-ligating bracket system after dynamic fatigue-loading in a 3-bracket model under controlled temperature. METHODS: Samples of 2 superelastic nickel-titanium (active austenitic) wires, a conventional nickel-titanium wire, and a stainless steel wire, all 0.014-in round, were divided into 2 groups: static deflection and dynamic deflection. The static specimens were under a constant deflection of 3.0 mm. The dynamic specimens had the same constant deflection of 3.0 mm but were subjected to additional repeated deflections of 0.5 mm, applied by a fatigue tester. The test situation simulates a patient's archwire under deflection and subjected to occlusal contact during 1, 100, 10,000, and 100,000 cycles. Fatigue changes were assessed with a 3-point bending test. RESULTS: Type of wire, loading or unloading, and number of cycles as within-subject factors were statistically significantly different. No statistically significant difference between the test condition, static vs dynamic, was found. The repeated deflections of 0.5 mm were not enough to induce an extra effect of fatigue. CONCLUSIONS: Occlusal forces transferred to a considerably deflected archwire, such as in the large malalignments in the early stages of orthodontic treatment, will have no fatigue effect on the unloading force of that archwire.