Barcelona line. A multicentre validation study of a facial projection reference in orthognathic surgery.

The purpose of this study was to validate an already published facial anteroposterior reference: upper incisor (UI) to soft tissue plane or so-called Barcelona line (BL) to trace the most aesthetic sagittal position of the maxilla. A cross-sectional multicentre evaluation of Caucasian patients from Spain and Brazil with different anteroposterior maxillary positions was designed. Sagittal images in natural head orientation of grouped patients according to the horizontal distance from the UI to BL were ranked by healthcare professionals and non-professional Caucasian raters according to the aesthetic perception of each profile, using a digital survey. Seventy-four raters (50 laypeople, 12 orthodontists, and 12 maxillofacial surgeons) rated 40 profiles. The best-rated profile corresponded to group 3 (0-4 mm UI-BL) with 61.8% of positive evaluations, followed by group 4 (≥ 4 mm UI-BL): with 61.1%. On the other hand, group 1 (≤-4 mm UI-BL) was the worst-ranked profile with 71.8% of negative evaluations, followed by group 2 (-4-0 mm UI-BL): with 59.6% of negative evaluations. The correlation between the mean assessment score and UI-BL showed a moderately-strong association (r = 0.68, p < 0.001). The inter-rater reliability of assessment (74 evaluators) was moderate (k = 0.49, 95% CI: 0.39 to 0.59). The results suggest that protrusive middle-third facial profiles are preferable. The BL is proposed as a simple, individualised, and reproducible tool to trace an aesthetic sagittal position of the maxilla in orthognathic surgery.

Semi-Automated Three-Dimensional Condylar Reconstruction.

The objective was to validate a semi-automated segmentation method for 3-dimensional (3D) reconstruction of the mandibular condyle from cone beam computed tomography (CBCT) data and illustrate its application in volumetric analysis of the condyle.Ten CBCT datasets were used to validate the proposed semi-automatic method for 3D rendering of mandibular condyles. First, a standardized orientation protocol of the skull was applied. After defining the volume of interest, a grey-scale cut-off value was selected to allow an automatic reconstruction of the condyle's surface. Subsequently, condylar contour was optimized manually. The whole process was repeated twice by 2 independent investigators. Volumetric measurements of the condyle were used as a measure of conformity between both investigators. The reproducibility of condylar volume reconstruction was excellent for intra-examiner measurements (CV = 3.65%, intraclass correlation coefficient = 0.97) and good for inter-examiner measurements (CV = 7.15%, ICC = 0.89). The overall mean time required for the segmentation process was 6.31 + 2.78 minutes. The proposed protocol provides an accurate and reproducible tool for 3D reconstruction of the mandibular condyle using CBCT data. Its implementation will enable adequate follow-up of morphological changes in bone tissue with a Hounsfield unit-based imaging segmentation method.

Bone grafting with granular biomaterial in segmental maxillary osteotomy: A case report.

INTRODUCTION: Segmental maxillary osteotomy enables correction of anterior open bites. However, the outcome can be somewhat unstable, particularly if pseudarthrosis occurs. Bone grafts can be used to prevent this complication. Among the many biomaterials available for grafting, Bio-oss(®) has been used successfully in a range of modalities, with studies to support several indications. This report describes a case of segmental maxillary osteotomy in which Bio-oss(®) granules were used as bone grafts in the surgical gap. PRESENTATION OF CASE: A 24-year-old female presented with anterior open bite, Angle class III posterior occlusion, and Angle class II anterior occlusion. Virtual surgical planning of the procedure predicted a gap of approximately 5mm in the region of the osteotomy, which was bridged with Bio-oss(®) granules. DISCUSSION: Although autogenous bone grafting is the gold standard due to its osteoconductive, osteoinductive, and osteogenic properties, it involves increased morbidity for the patient, unpredictable resorption rates, increased operative time, and risk of infection at the donor site. Use of the Bio-oss(®) material can provide good bone stability, osteoconduction, and biocompatibility, while reducing operative time and surgical morbidity. CONCLUSION: This is the first report of bone grafting with a granular biomaterial in segmental maxillary osteotomy. Successful formation of new bone with density greater than that of the surrounding tissue was achieved, preventing pseudarthrosis and postoperative instability.