Superimposition of serial Cone Beam Computed Tomography (CBCT) scans has become a valuable tool for three dimensional (3D) assessment of treatment effects and stability. Voxel based image registration is a newly developed semi-automated technique for superimposition and comparison of two CBCT scans. The accuracy and reproducibility of CBCT superimposition on the anterior cranial base or the zygomatic arches using voxel based image registration was tested in this study. 16 pairs of 3D CBCT models were constructed from pre and post treatment CBCT scans of 16 adult dysgnathic patients. Each pair was registered on the anterior cranial base three times and on the left zygomatic arch twice. Following each superimposition, the mean absolute distances between the 2 models were calculated at 4 regions: anterior cranial base, forehead, left and right zygomatic arches. The mean distances between the models ranged from 0.2 to 0.37 mm (SD 0.08–0.16) for the anterior cranial base registration and from 0.2 to 0.45 mm (SD 0.09–0.27) for the zygomatic arch registration. The mean differences between the two registration zones ranged between 0.12 to 0.19 mm at the 4 regions. Voxel based image registration on both zones could be considered as an accurate and a reproducible method for CBCT superimposition. The left zygomatic arch could be used as a stable structure for the superimposition of smaller field of view CBCT scans where the anterior cranial base is not visible.

No abstract

Objective. We sought to evaluate the possibility of distraction osteogenesis as an alternative to conventional bilateral sagittal split osteotomy. Complications (intraoperative, intradistraction, and postdistraction) were evaluated retrospectively. Study design. Seventy consecutive patients (40 males and 30 females, 11.2-37.3 years old; mean, 14.2 years) underwent distraction osteogenesis to lengthen the mandible. The surgical procedure was carried out with the patient under general anesthesia. After the osteotomy was performed, 2 intraoral monodirectional distraction devices were placed on the mandibular cortex in the third molar region. The rate of distraction was 1 mm/day. The different complications encountered during all phases of the distraction procedure were recorded. Results. A total of 28 complications (40%) were recorded. In 10 patients (14.3%), the complications were techniqueor device-related, or both, and occurred early in the learning period. Five patients (7.1%) had infection occur, and 3 patients (4.3%) had prolonged sensory loss in the distribution of the alveolar nerve. Severe complications occurred in 6 patients (8.6%). Rehospitalization was necessary in 5 patients (7.1%), 4 of whom (5.7% of the series) required further surgery under general anesthesia. Conclusion. Distraction osteogenesis can be considered a safe and predictable procedure for lengthening the mandible, with a low incidence of major complications. The infection rate and the incidence of damage to the inferior alveolar nerve (2.1%) are low. Compliance of both patients and parents during the whole treatment period is of the utmost importance.

BackgroundTraditionally, dental models, facial and intra-oral photographs and a set of two-dimensional radiographs are used for orthodontic diagnosis and treatment planning. As evidence is lacking, the discussion is ongoing which specific records are needed for the process of making an orthodontic treatment plan.ObjectiveTo estimate the contribution and importance of different diagnostic records for making an orthodontic diagnosis and treatment plan.Data sourcesAn electronic search in PubMed (1948–July 2012), EMBASE Excerpta Medica (1980–July 2012), CINAHL (1982–July 2012), Web of Science (1945–July 2012), Scopus (1996–July 2012), and Cochrane Library (1993–July 2012) was performed. Additionally, a hand search of the reference lists of included studies was performed to identify potentially eligible studies. There was no language restriction.Study selectionThe patient, intervention, comparator, outcome (PICO) question formulated for this study was as follows: for patients who need orthodontic treatment (P), will the use of record set X (I) compared with record set Y (C) change the treatment plan (O)? Only primary publications were included.Data extractionIndependent extraction of data and quality assessment was performed by two observers.ResultsOf the 1041 publications retrieved, 17 met the inclusion criteria. Of these, 4 studies were of high quality. Because of the limited number of high quality studies and the differences in study designs, patient characteristics, and reference standard or index test, a meta-analysis was not possible.ConclusionCephalograms are not routinely needed for orthodontic treatment planning in Class II malocclusions, digital models can be used to replace plaster casts, and cone-beam computed tomography radiographs can be indicated for impacted canines. Based on the findings of this review, the minimum record set required for orthodontic diagnosis and treatment planning could not be defined.Systematic review registration number CRD42012002365

No abstract