Definition of New Three-Dimensional Cephalometric Analysis of Maxillomandibular Sagittal Relationship for Orthodontics and Orthognathic Surgery: Normative Data Based on 700 CBCT Scans.

The objective of the study was to define the norm of new 3-dimensional cephalometric analysis of maxillomandibular sagittal relationship with the patient in Natural Head Position. A cross-sectional study was performed using 700 consecutives cone beam computed tomography datasets of pre-orthodontic patients received for three-dimensional craniofacial analysis. To stablish the clinical norm of the new sagittal reference (linear distance A-B), the correlation with the gold standard (ANB angle) was estimated with the Pearson's correlation coefficient. Subsequently, the prognostic values of the linear distance A-B was calculated to define the clinical norm. The sample was composed by 463 women (66.1%) and 237 men (33.9%). The mean age was 30 ± 14,5 years old (range 6-71 y old). According to the skeletal class classification (ANB), 46.1% (323) were class I, 42% (294) class II, and 11.9% (83) class III. The regression model found that each additional grade of the ANB angle imply a mean increase of 1.24 mm of the distance A-B ( P <0.001). The normative value of the linear distance A-B was obtained through the prognostic values of the distance for the limits of the ANB norm 0 to 4. These values were on the range of 0.52 to 5.48 mm. Therefore, the clinical norm for cephalometric maxillomandibular sagittal relationship using linear distance from point A-B is: 3±2.48 mm. With this new approach, we can define the skeletal sagittal relationship of the patient in natural head position overcoming the limitations of using intracranial or occlusal plane references improving the diagnosis and orthognathic surgical planning process.

Aesthetic perception of smile in long face pattern patients who underwent maxillary impaction with miniplates or orthognathic surgery.

INTRODUCTION: The gummy smile is perceived in 10% of the population aged 20 to 30 years old, and it causes an aesthetic imbalance in the smile. This study investigated the existence of differences in the aesthetic perception of the smile after correcting the gummy smile using two different techniques: orthognathic surgery for maxillary impaction and miniplate-aided orthodontic impaction. METHODS: Photographs of 16 Long Face Pattern female patients were evaluated by 56 oral and maxillofacial surgeons, 56 orthodontists, and 56 laypeople before and after the treatment with one of the two techniques. These photographs were standardized using the Photoshop program, randomly organized, and then presented to the evaluators via the Google Meeting® application in the PowerPoint® program. To evaluate the attractiveness of the smile, the Visual Analogue Scale (VAS) was used. To analyze the intra and inter-examiner concordances, Spearman's correlation and Kendall's concordance tests were used, respectively. For intergroup comparison, the Friedman test was used, with a 5% significance level. RESULTS: For all three groups of evaluators, the post-treatment evaluation results were superior to the results before the treatment: surgeons and orthodontists assigned higher scores for surgical cases and laypeople for orthodontic cases. CONCLUSION: From a clinical point of view, there was no difference between the results of both techniques with regard to the aesthetic perception of smiles. A gingival exposure ranging from zero to two millimeters was considered the most aesthetic for all evaluators.

Effect of orthodontic maxillary posterior en masse intrusion anchored with miniplates on maxillary sinuses volume. Retrospective CBCT study.

OBJECTIVE: To evaluate, by means of cone beam computed tomography (CBCT), the volume change of maxillary sinuses in patients that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates. MATERIALS AND METHODS: The sample consisted of pretreatment (T1) and posttreatment (T2) CBCT scans obtained from 14 patients (4 male and 10 female), with a mean age of 32.4 years, that underwent orthodontic maxillary posterior en masse intrusion anchored with miniplates in the zygomatic crest. The mean treatment duration was 20 months and the mean intrusion movement was 2.4 mm. Maxillary sinus volume was measured by means of the software ITK SNAP (version 3.8.0) in T1 and T2 CBCT scans. The changes in sinuses volume were calculated by T1-T2 values. Data were analyzed statistically with Wilcoxon test at 5% of level of significance and the method error was analyzed with Wilcoxon test, intraclass correlation and Dahlberg's formula. RESULTS: The mean difference (T1-T2) was -242.85 mm³ (p = 0.396) for the right sinus and -32.5 mm³ (p = 0.875) for the left sinus. A slight increase in the volume of the sinuses was shown although these results were not statistically significant. CONCLUSION: The orthodontic maxillary posterior en masse intrusion anchored with miniplates did not influence significantly the maxillary sinus volume.