The effect of surgically assisted rapid maxillary expansion on sleep architecture: an exploratory risk study in healthy young adults

Maxillary transverse deficiencies (MTD) cause malocclusions. Rapid maxillary expansion treatment is commonly used treatment for correcting such deficiencies and has been found to be effective in improving respiration and sleep architecture in children with obstructive sleep apnoea (OSA). However, thus far, the effect of surgically assisted rapid maxillary expansion (SARME) treatment on sleep architecture and breathing of normal subjects has not been assessed. We hypothesised that sleep quality will improve after maxillary expansion treatment. The objective of this study is to access the effect of maxillary expansion treatment on sleep structure and respiratory functions in healthy young adults with severe MTD. This is a prospective and exploratory clinical study. Twenty‐eight consecutive young adult patients (15 males and 13 females, mean age 20·6 ± 5·8 years) presenting with severe MTD at the orthodontic examination were recruited into the study. All the participants underwent a standardised SARME procedure (mean expansion 6·5 ± 1·8 and 8·2 ± 1·8 mm, intercanine and intermolar distance, respectively) to correct malocclusion caused by MTD. An overnight in‐laboratory polysomnography, before and after the treatment, was performed. The mean follow‐up time was 9 months. The main outcome parameters were the changes in sleep architecture, including sleep stages, arousals, slow‐wave activity (SWA) and respiratory variables. Before surgery, young adult patients with MTD presented no evidence of sleep breathing problems. At baseline sleep recording, 7 of 28 (25%) had apnoea‐hypopnoea index (AHI) ≥ 5 events per hour. No negative effect of the SARME was observed in questionnaires or sleep laboratory parameters. In the patients with a higher baseline AHI (AHI ≥ 5 h of sleep), we observed a reduction in AHI after surgical treatment (P = 0·028). SARME did not have a negative effect on any sleep or respiration parameters in healthy young individuals with MTD. It normalised the breathing index in the patients with a mild AHI index.     

Discrepancy between preoperative MRI evaluation and intraoperative or postoperative pathological findings for the extent of local invasion in maxillary squamous cell carcinoma

Preoperative radiological evaluation of the extent of local invasion in maxillary squamous cell carcinoma (SCC) is very important in planning curative surgery. The aim of this study was to examine the accuracy of preoperative radiological evaluation with magnetic resonance imaging (MRI) for the extent of local invasion in maxillary SCC. A retrospective study was conducted of 33 patients who underwent a maxillectomy for maxillary SCC. We compared the MRI findings for 18 structures around the maxillary sinus with intraoperative or postoperative pathological findings. Discrepancies were found between preoperative MRI findings and intraoperative or postoperative pathological findings for 22 patients (66.7%). Overall, the specificity, sensitivity, positive predictive value, and negative predictive value of MRI were 83.4%, 83.0%, 64.5%, and 90.4%, respectively. The receiver operating characteristic curve showed that MRI evaluation of the posterolateral structures including the pterygoid plate, pterygoid muscle, and infratemporal fossa had a lower area under the curve (0.614) and a significantly lower accuracy when compared with the other structures (P = 0.294, 95% confidence interval 0.405–0.822). In conclusion, as the accuracy of preoperative MRI evaluation of the posterolateral structures is low, careful evaluation of local extension to the posterolateral structures is needed when planning curative surgery for maxillary SCC.     

Human infections due to Schizophyllum commune: Case report and review of the literature

Schizophyllum commune is an environmental basidiomycetous fungus, causing occasional, predominantly respiratory, infections in humans. Although S. commune is considered an emerging pathogen, some authors pointed out the possibility that the increase in the diagnosed cases may be also due to recent advances in diagnostic technologies now allowing a more prompt and precise identification at the species level. Here we describe the first Italian case of chronic non-invasive fungal rhinosinusitis due to S. commune in an immunocompetent subject and update the literature review on S. commune sinusitis published between 2012–2019. A timely diagnosis is important to avoid local and systemic complications due to infection with this fungus. In our case, prompt identification at species level was only possible with the use of MALDI-TOF mass spectrometry and confirmed by sequence analysis of ribosomal DNA ITS regions, due to the difficulty in achieving a correct and rapid identification using routine morphological analysis.     

Transverse changes after surgically assisted rapid palatal expansion

The aim of this retrospective study was to investigate the amount of skeletal and dental expansion in patients submitted to surgically assisted rapid palatal expansion (SARPE). The sample consisted of 21 patients (14 female and seven male) with a mean age of 25.4 years (range 17.4–41.8 years). Postero-anterior (PA) cephalograms were taken pre-expansion (T1), immediately after expansion (T2), and at post-expansion retention of 120 days (T3). SARPE promoted significant transverse skeletal changes, which were maintained from T2 to T3. Dentoalveolar expansion and dental tipping were also observed in the region of the first molars and first premolars; however the net effect at the first molars was significantly less than that at the first premolars. No statistically significant effect on the width of the nasal cavity was observed. The findings indicate that peculiarities inherent to dental effects may influence the clinical options for SARPE. Skeletal expansions with SARPE were significant and stable. Dental changes were different between molars and premolars. The transverse changes after SARPE should be observed for future procedures related to the retention and the completion of orthodontic treatment.     

Determination of canal orifice co-ordinates and MB2 incidence of maxillary first molars in a Turkish sub-population

Objectives. To measure the co-ordinates of the root canal orifices and to determine the incidence of mesiobuccal-2 (MB2) in maxillary first molars in a Turkish sub-population. Materials and methods. Standard digital photographs were taken under a stereomicroscope from the occlusal aspect of each tooth (n = 176) before and after crown removal. Canal orifices were negotiated under moderate magnification using dental loupes. The coordinates of the orifices and the distances of each from the central fossa were measured by using geographic software. Intensity maps of the orifice locations were created by using the co-ordinates of all canal orifices. A representative map was drawn using the mean values of orifice locations and access projection area. Results. In the right maxillary first molars, the mean values for the (X, Y) co-ordinates were (0.67, 2.68) for mesiobuccal-1 (MB1), (0.81, 0.84) for MB2, (?1.12, 1.26) for distobuccal-1 (D1), (?0.89, 0.23) for distobuccal-2 (D2) and (0, ?2.50) for palatinal (P); the corresponding mean values in the left maxillary first molars were (?0.78, 2.56), (?0.98, 0.90), (0.99, 1.18), (0.69, 0.78) and (0.00, ?2.53), respectively. The average MB1–MB2 distance was 1.97 mm. Distobuccalcanal orifices were localized at the distal side of the center in 98.3% of teeth. The incidence of MB2 was 46.02%. Conclusions. The distobuccal canal orifice is mostly located on the distal side of the central fossa. Thus, it should be considered that the access cavity of the maxillary molars may not be always limited mesially. The incidence of MB2 in this sub-population was 46.02%, which is of great importance clinically.     

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??Objective    To evaluate the biomechanical influence of the relationship between implant tip and sinus ?oor cortical bone on posterior maxilla implantation by means of 3-dimensional??3-D??finite element??FE??analysis. Methods        Six 3-D FE models ??M1 to M6?? of standard implants and posterior maxillary region were constructed using CAD software. The thickness of both crestal cortical bone and sinus floor cortical bone were 1mm??according to different heights of the alveolar bone??the relationship between implant tip and sinus floor cortical bone was as follows. M1??the implant tip just broke through sinus cortical bone??the upper surface of sinus cortical bone and the apical surface of the implant were at the same level????M2??the implant tip broke through half the thickness of sinus ?oor cortical bone??M3??the implant tip just made contact with the lower surface of sinus ?oor cortical bone??for the remaining models??the implant tips were 1mm??2mm and 3mm apart from sinus floor??respectively. An inclined force of 129N was applied under immediate loading and conventional loading. The maximum von Mises stress??stress distribution??implant displacement and resonance frequencies were calculated using CAD software. Results    Except the M1 under immediate loading??the maximum von Mises stress of all models were concentrated on the surface of the crestal cortical bone around the implant neck. When the implant tip broke into or through sinus floor cortical bone??the maximum von Mises stress of crestal cortical bone reduced while that of sinus cortical bone increased??and the occlusional resonance frequencies of implants increased significantly while horizontal frequencies decreased??whether under immediate loading or conventional loading. Under immediate laoding??the maximum displacement of implant??especially the maximum displacement of the implant tip??was lower than the other models when the implant tip broke into or through the sinus cortical bone. However??the maximum displacements of both implant neck and tip were  hardly affected by the association between implant tip or sinus floor cortical bone under conventional loading. Conclusion    The association between implant tip and sinus floor cortical bone has effects both on stress distribution of the bone tissues around implant and on the maximum displacement and resonance frequencies of implants. Making the implant tip break into or through the sinus floor cortical bone??bi-cortical anchorage??is beneficial to improve the stress distribution and reduce the maximum displacement of implant??increasing the stability of the implant??especially under immediate loading.