The effect of bracket slot size on the effectiveness of orthodontic treatment: A systematic review.

OBJECTIVES: To assess, by means of a systematic review, the scientific evidence of the influence of 0.018-inch or 0.022-inch bracket slots on treatment time, efficiency of space closure, efficiency of alignment, quality of orthodontic finishing, level of discomfort, and level of root resorption. MATERIALS AND METHODS: The PubMed, Bireme, Medline, Scopus, Web of Science, Open Grey, and Google Scholar databases were searched, with no date and language restrictions, for randomized clinical trials and controlled clinical trials, using controlled terms related to bracket slots. After the selection and removal of duplicate articles, the risk of bias was assessed, and the data from the included studies were extracted by two independent researchers. RESULTS: The search yielded 2640 studies. After applying the eligibility criteria, eight articles were fully read and four studies were selected for the qualitative systematic review. No randomized clinical trials assessed the duration of treatment in patients treated with 0.018-inch and 0.022-inch bracket slots. Due to heterogeneity of the data available, a meta-analysis could not be conducted. CONCLUSIONS: While most studies indicated a shorter duration of treatment in patients with 0.018-inch bracket slots, no available data confirmed the higher efficiency of one system over the other. The biases in the studies did not allow for a reliable conclusion; therefore, new studies with a better methodologic design are needed.

Validity and reliability of intraoral scanners compared to conventional gypsum models measurements: a systematic review.

BACKGROUND: The development of 3D technology and the trend of increasing the use of intraoral scanners in dental office routine lead to the need for comparisons with conventional techniques. OBJECTIVE: To determine if intra- and inter-arch measurements from digital dental models acquired by an intraoral scanner are as reliable and valid as the similar measurements achieved from dental models obtained through conventional intraoral impressions. SEARCH METHODS: An unrestricted electronic search of seven databases until February 2015. SELECTION CRITERIA: Studies that focused on the accuracy and reliability of images obtained from intraoral scanners compared to images obtained from conventional impressions. DATA COLLECTION AND ANALYSIS: After study selection the QUADAS risk of bias assessment tool for diagnostic studies was used to assess the risk of bias (RoB) among the included studies. RESULTS: Four articles were included in the qualitative synthesis. The scanners evaluated were OrthoProof, Lava, iOC intraoral, Lava COS, iTero and D250. These studies evaluated the reliability of tooth widths, Bolton ratio measurements, and image superimposition. Two studies were classified as having low RoB; one had moderate RoB and the remaining one had high RoB. Only one study evaluated the time required to complete clinical procedures and patient's opinion about the procedure. Patients reported feeling more comfortable with the conventional dental impression method. LIMITATIONS: Associated costs were not considered in any of the included study. CONCLUSIONS AND IMPLICATIONS: Inter- and intra-arch measurements from digital models produced from intraoral scans appeared to be reliable and accurate in comparison to those from conventional impressions. This assessment only applies to the intraoral scanners models considered in the finally included studies. Digital models produced by intraoral scan eliminate the need of impressions materials; however, currently, longer time is needed to take the digital images. REGISTRATION: PROSPERO (CRD42014009702). FUNDING: None.

Tooth angulation and dental arch perimeter-the effect of orthodontic bracket prescription.

OBJECTIVE: The aim of this study was to evaluate the effects of upper incisors and canine angulations introduced by different bracket prescriptions on dental arch perimeter. MATERIALS AND METHODS: Cone beam computerized tomography scans collected using I-Cat (Imaging Sciences International, Hatfield, PA, USA) were selected conveniently from a database of routine exams of a clinical radiology center. Crown and radicular measurements of upper incisors and canines were made and exported to the Autocad 2011 software to create a virtual dental model. The virtual teeth were positioned with an angulation of zero; thereafter, a reference value for the perimeter of the arch was measured. Furthermore, teeth angulations were applied according to the standards of the Edgewise bracket system and the Straight-wire systems: MBT, Capelozza, Andrews, and Roth. The largest linear distances for tooth crown (anterior arch perimeter) and root (radicular distance) were obtained for each bracket prescription. RESULTS: The anterior perimeter for well-aligned incisors and canines without angulation was used as reference (crown: 47.34mm; root: 39.13mm). An increase in the arch perimeter was obtained for all bracket prescriptions evaluated, which ranged from 0.28 and 3.19mm in the Edgewise technique, for the crown and root measurements, respectively, to 1.09 and 11.28mm for the Roth prescription. CONCLUSION: Bracket prescriptions with greater angulation led to an increased use of space within the dental arch, mainly in the radicular region. The consequence of this radicular angular displacement will need to be further investigated.