Predictors of long-term stability of maxillary dental arch dimensions in patients treated with a transpalatal arch followed by fixed appliances

Background: The aim of this retrospective study was to identify which dental and/or cephalometric variables were predictors of long-term maxillary dental arch stability in patients treated with a transpalatal arch (TPA) during the mixed dentition phase followed by full fixed appliances in the permanent dentition. Methods: Thirty-six patients, treated with TPA followed up by full fixed appliances, were divided into stable and relapse groups based on the long-term presence or not of relapse. Intercuspid, interpremolar and intermolar widths, arch length and perimeter, crowding, and upper incisor proclination were evaluated before treatment (T0), post-TPA treatment (T1), post-fixed appliance treatment (T2), and a minimum of 3 years after full fixed appliances’ removal (T3). A binary logistic regression was performed thereafter to evaluate the impact of the dental arch and cephalometric measurements at T1 and the changes between T0 and T1 as predictive variables for relapse at T3. Results: The proposed model explained 42.7 % of the variance in treatment stability and correctly classified 72.2 % of the sample. Of the seven predictive variables, only upper anterior crowding (p = 0.029) was statistically significant. For every millimeter of decreased crowding at T1 (after TPA treatment/before starting the fixed orthodontic treatment), there was an increase of 3.57 times in the odds of having stability. Conclusions: The best predictor of relapse was maxillary crowding before treatment. The odds of relapse increase by 3.6 times for every millimeter of crowding at baseline

B Lymphoblastic Lymphoma Presenting as a Tumor of the Nasopharynx in an Adult Patient

In adults, non-Hodgkin’s lymphoma (NHL) is the second most common neoplasm found in the head and neck region after squamous cell carcinoma. Within this region, primary NHL of the nasopharynx is rare. We report the case of a 28-year-old male diagnosed with a B lymphoblastic lymphoma (CD20−; CD79a+; CD3−; CD10+; PAX5+, CyclinD1−; TdT+) of the nasopharynx extending to the deep and superficial structures of the right hemiface, to the skull base with an intracranial component and a small but detectable bone marrow involvement, who was started on chemotherapy with a complete response. To the best of our knowledge, this is the first case of a primary nasopharynx B-LBL in an adult patient with such aggressive regional spread to be reported in the literature