Objective: Cone-beam computed tomography (CBCT) is a reliable method of assessing the oral cavity and upper airways. We conducted this study to examine the changes introduced by rapid maxillary expansion in the nasal cavity, nasopharynx, and oropharynx as seen with images obtained by CBCT. Materials and Methods: We evaluated 15 patients with maxillary width deficiency treated with RME. Patients were subjected to CBCT at the beginning of RME and after the retention period of 4 months. Results: The nasal cavity presented a significant transverse increase in the lower third, in the anterior (1.08 mm 6 0.15), medium (1.28 mm 6 0.15), and posterior regions (0.77 mm 6 0.12). No significant change occurred in the nasopharynx in volume (P 5 .11), median sagittal area (P 5 .33), or lower axial area (P 5 .29) resulting from the RME. A significant change was noted in the oropharynx in volume (P 5 .05), median sagittal area (P 5 .01), and lower axial area (P 5 .04) before and immediately after the RME. Conclusions: RME is able to increase the transverse width of the nasal cavity, but it does not have the same effect in the nasopharynx. Changes noted in the oropharynx may be due to the lack of a standardized position of the head and tongue at the time of image acquisition. (Angle Orthod. 2012;82:458-463.)

ObjectiveIn order to understand the conflicting information on temporomandibular joint (TMJ) pathophysiologic responses after mandibular advancement surgery, an overview of the literature was proposed with a focus on certain risk factors. MethodsA literature search was carried out in the Cochrane, PubMed, Scopus and Web of Science databases in the period from January 1980 through March 2013. Various combinations of keywords related to TMJ changes [disc displacement, arthralgia, condylar resorption (CR)] and aspects of surgical intervention (fixation technique, amount of advancement) were used. A hand search of these papers was also carried out to identify additional articles. ResultsA total of 148 articles were considered for this overview and, although methodological troubles were common, this review identified relevant findings which the practitioner can take into consideration during treatment planning: 1- Surgery was unable to influence TMJ with preexisting displaced disc and crepitus; 2- Clicking and arthralgia were not predictable after surgery, although there was greater likelihood of improvement rather than deterioration; 3- The amount of mandibular advancement and counterclockwise rotation, and the rigidity of the fixation technique seemed to influence TMJ position and health; 4- The risk of CR increased, especially in identified high-risk cases. ConclusionsYoung adult females with mandibular retrognathism and increased mandibular plane angle are susceptible to painful TMJ, and are subject to less improvement after surgery and prone to CR. Furthermore, thorough evidenced-based studies are required to understand the response of the TMJ after mandibular advancement surgery.

Objective: To compare oral health-related quality of life (OHRQoL) before treatment of adults with unilateral cleft lip and palate (UCLP) and surgical Class III malocclusion, and to consider if clefts needing different orthodontic treatment protocols could influence people’s self-perception. Design: Cross sectional. Setting: Cleft Lip and Palate Center and Clinic of Orthognathic Surgery from a School of Dentistry. Participants: A sample of adults with repaired nonsyndromic UCLP (n = 52) which was age- and sex-matched with a noncleft Class III malocclusion sample seeking orthognathic surgery (n = 51). In turn, the cleft group was subdivided according to treatment planning into nonsurgical orthodontic and surgical orthodontic approaches. Main Outcome Measure: The whole sample was assessed using the short-form oral health impact profile (OHIP-14), with higher scores indicating a poorer OHRQoL. Statistical comparisons were performed with Mann-Whitney U and Kruskal-Wallis tests, and effect size. Bonferroni adjustment was used for post hoc tests ( P < .017). Results: The OHIP-14 scores of the UCLP and Class III groups were significantly different ( P = .001, η2 = 0.108), and higher in Class III. The largest commitment was in the physical disability, physical pain, and psychological disability domains. In addition, no differences were found when the UCLP treatment planning was considered. Conclusion: Surgical Class III malocclusion have a poorer OHRQoL when compared to patients with UCLP, irrespective of whether they are treated surgically or orthodontically. Therefore, the greater commitment of OHRQoL appears to be influenced by the etiology of Class III, and not by treatment plan.

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There is sexual differentiation in the pharyngeal airway morphology for Class III adults. As females present similar pharynx volume compared to a normal skeletal pattern, mandibular setback surgery should be carefully planned because of the risk of airway constriction.

Background/objective Until 2010, adults underwent surgical treatment for maxillary expansion; however, with the advent of micro-implant-assisted rapid maxillary expansion (MARME), the availability of less invasive treatment options has increased. Nevertheless, individuals with severe transverse maxillary deficiency do not benefit from this therapy. This has aroused interest in creating a new device that allows the benefit of maxillary expansion for these individuals. The aim of this study was to evaluate the efficacy of three MARME models according to tension points, force distribution, and areas of concentration in the craniofacial complex when transverse forces are applied using finite element analysis. Materials and methods Digital modeling of the three MARME models was performed. Model A comprised five components: one body screw expander and four adjustable arms with rings for mini-implant insertion. These arms have an individualized height adjustment that allows MARME positioning according to the patient’s palatal anatomy, thereby preventing body screw expander collision with the lateral mucosa in severe cases of maxillary deficiency. Model B was a maxillary expander with screw rings joined to the body, and model C was similar to model B, except that model C had open rings for the insertion of the mini-implants. Through the MEF (Ansys software), the stresses, distribution, and area of concentration of the stresses were evaluated when transverse forces of 7.85 N were applied. Results The three models maintained the following pattern: model C presented weak stress peaks with limited distribution and lower concentration area, model B obtained median stress peaks with better distribution when compared to that of model C, and model A showed better stress distribution and larger concentration area. In model A, tensions were located in the lateral lamina of the pterygoid process, which is an important site for maxillary expansion. The limitation of the present study was that it did not include the periodontal tissues and muscles in the finite element method evaluation. Conclusions Model A showed the best stress distribution conditions. In cases of severe atresia, model A seems to be an excellent option.

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