Three-dimensional cephalometric analysis in orthodontics: a systematic review

Context – The scientific evidence of 3D cephalometry in orthodontics has not been well established. Objective – The aim of this systematic review was to evaluate the evidence for the diagnostic efficacy of 3D cephalometry in orthdontics, focusing on measurement accuracy and reproducibility of landmark identification. Data Sources – PubMed, EMBASE and the Cochrane library (from beginning to March 13, 2012) were searched. Search terms included: cone-beam computed tomography; tomography, spiral computed; imaging, three-dimensional; orthodontics. Study Selection – Two reviewers read the retrieved articles and selected relevant publications based on pre-established inclusion criteria. The selected publications had to elucidate the hierarchical model of the efficacy of diagnostic imaging systems by Fryback and Thornbury. Data Extraction – The data was then extracted according to two protocols, which were based on the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Next, levels of evidence were categorized into 3 groups: low, moderate and high evidence. Data Synthesis – 571 publications were found by database search strategies and 50 additional studies by hand search. A total of 35 publications were included in this review. Conclusions – Limited evidence for the diagnostic efficacy of 3D cephalometry was found. Only 6 studies met the criteria for a moderate level of evidence. Accordingly, this systematic review reveals that there is still need for methodologically standardized studies on 3D cephalometric analysis.status: publishe

Double vs single primary tooth extraction in interceptive treatment of palatally displaced canines:a randomized controlled trial

Abstract Objectives: To compare the impact of primary canine and primary first molar extractions with extractions of only the primary canine regarding correction of palatally displaced canines (PDCs). Materials and Methods: Thirty-two children aged 9.5–13.5 years with 48 PDCs were randomly allocated to either the double-extraction group (DEG) or single-extraction group (SEG). Clinical and radiographic examinations were performed at baseline and at 6-month intervals until the canine emerged or orthodontic treatment was started. Outcome measures were: emergence of maxillary canine (yes/no), emergence of maxillary canine into a favorable position (yes/no), and maxillary canine positional change (angulation and sector). Factors influencing PDC emergence were analyzed using logistic regression. Results: In the DEG, 64% (16/25) of canines emerged into the oral cavity vs 78% (18/23) in the SEG (P = 0.283). Favorable PDC position at trial end was seen in 64% (16/25) of the DEG vs 57% (13/23) of the SEG (P = 0.600). Significant distal movement of PDCs was recorded in the DEG and SEG, though no significant difference was observed between groups. Significant predictors of canine emergence were initial canine angulation (Angle A) (P = 0.008) and space conditions at T₀ (P = 0.030). Conclusions: Double or single primary tooth extraction procedures are equivalent in supporting PDC eruption into the oral cavity and into a favorable position in the dental arch. Initial canine angulation and space assessments may be used as predictors of successful PDC eruption