Radiographic assessment of external root resorption associated with jackscrew-based maxillary expansion therapies: a systematic review.

OBJECTIVE: To evaluate in adolescents and young adults if jackscrew-based maxillary expansion therapies result in external root resorption as measured in vivo via any radiological method. METHODS: The authors conducted a systematic search of several electronic databases (MEDLINE, EMBASE, PubMed, Scopus, CINAHL, Evidence Based Medicine Reviews, LILACS) with the assistance of a senior librarian specialized in Health Sciences database searches through 25 August 2013, as well as a limited grey-literature search (Google Scholar). Human, in vivo studies of adolescents or young adults with transverse maxillary deficiency undergoing non-surgical maxillary expansion therapy through the use of a jackscrew-based maxillary expander with a radiographical assessment of root resorption were selected for full article review. Additionally, manual searches of reference lists of relevant articles were completed to identify additional publications not identified by electronic searches. The lowest levels of evidence accepted for inclusion were case-control studies or consecutively treated series of cases. Two authors independently reviewed and extracted data from selected studies. RESULTS: A total of 83 original articles were identified from the electronic database and limited grey-literature searches. Once selection criteria were applied, only three articles satisfied all inclusion criteria, and individual analysis of the selected articles was undertaken. CONCLUSIONS: Two-dimensional periapical radiographs do not fully reveal the amount of external root resorption associated with maxillary expansion therapy, except for frank apical root resorption. Three-dimensional cone-beam computed tomography radiography displays statistically significant root volume loss associated with maxillary expansion therapy. However, when considering volume-loss percentages, no statistical significance was found.

Comparison of in vivo 3D cone-beam computed tomography tooth volume measurement protocols.

BACKGROUND: The objective of this study is to analyze a set of previously developed and proposed image segmentation protocols for precision in both intra- and inter-rater reliability for in vivo tooth volume measurements using cone-beam computed tomography (CBCT) images. METHODS: Six 3D volume segmentation procedures were proposed and tested for intra- and inter-rater reliability to quantify maxillary first molar volumes. Ten randomly selected maxillary first molars were measured in vivo in random order three times with 10 days separation between measurements. Intra- and inter-rater agreement for all segmentation procedures was attained using intra-class correlation coefficient (ICC). RESULTS: The highest precision was for automated thresholding with manual refinements. CONCLUSIONS: A tooth volume measurement protocol for CBCT images employing automated segmentation with manual human refinement on a 2D slice-by-slice basis in all three planes of space possessed excellent intra- and inter-rater reliability. Three-dimensional volume measurements of the entire tooth structure are more precise than 3D volume measurements of only the dental roots apical to the cemento-enamel junction (CEJ).