Effects of surgical mandibular advancement on the upper airways of adult class II patients: A systematic review with meta-analysis

[Comparison of pharyngeal airway space on lateral head radiographs of skeletal class I and II individuals]

Objective

To compare the space of the pharyngeal airway (nasopharynx and oropharynx) through lateral X-ray analysis in skeletal class II individuals with a control group composed of skeletal class I individuals.

Materials and methods

This study was of the observational, descriptive, transversal, and prospective type. The sample was made up by 60 lateral head radiographs distributed between 30 class I (ANB 2°±2° and class I malocclusion) and 30 skeletal class II radiographs (ANB>5° and malocclusion class II-1). Measurements of the airway space in the oropharynx and nasopharynx were taken in mm through the McNamara method on lateral head radiographs.

Results

The average space found in the oropharynx in class I was 11.71mm ± 3.18mm. In the class II group, it was 10.73mm ± 2.36mm. No significant differences were found (p=0.18). The average space found in the nasopharynx in the class I group was 18.45mm ± 4.11mm. In the class II group, it was 19.10mm ± 3.89mm. There were no significant differences found (p=0.53).

Conclusion

The airway space in mm. of the nasopharynx presents similar values in millimeters in subjects with Class I and Class II skeletal malocclusion. There is no difference in the airway spaces of the oropharynx in subjects with Class I and Class II Malocclusions.

Effects of distraction osteogenesis with Le Fort osteotomies on upper airway volumes: a systematic review and meta-analyses

OBJECTIVE

Distraction osteogenesis is one of the treatment options in patients with severe maxillomandibular abnormalities to treat morphological and respiratory problems (obstructive sleep apnea syndrome). The study aimed to evaluate the effect of Le Fort I, II and III distraction osteogenesis (DO) on upper airway dimensions and respiratory function.

METHODS

Electronic search was performed in PubMed, Scopus, Embase, Google Scholar and Cochrane databases. Studies that only involved two dimensional analyses were excluded. Besides, studies that performed DO in conjunction with orthognathic surgery were not considered. NIH quality assessment tool was used to evaluate the risk of bias. Meta-analyses were performed to assess sleep apnea indices and the mean differences in the airway dimensions before and after DO. Gradings of Recommendations, Assessment, Development and Evaluation were used to analyze the evidence level.

RESULTS

Among the 114 studies that went under full-text analyses, 11 articles met the inclusion criteria. Results of the quantitative analyses showed that maxillary Le Fort III DO significantly increased the amounts of oropharyngeal, pharyngeal and upper airway volumes. However, apnea-hypopnea index (AHI) showed a non-significant improvement after this procedure. Besides, the dimensions of the airways increased with Le Fort I and II DO, according to a qualitative analysis. Considering the design of the included studies, our results had a low level of evidence.

CONCLUSION

Maxillary Le Fort DO does not significantly impact AHI, while it significantly increases the airway dimensions. Meanwhile, multicentric studies with standardized evaluation are still required to confirm the effects of maxillary Le Fort DO on airway obstruction.

Three-dimensional comparison between the effects of mandibular advancement device and maxillomandibular advancement surgery on upper airway

BACKGROUND

The efficacy of mandibular advancement devices (MAD) and maxillomandibular advancement (MMA) in improving upper airway (UA) patency has been described as being comparable to continuous positive airway pressure (CPAP) outcomes. However, no previous study has compared MAD and MMA treatment outcomes for the upper airway enlargement. This study aimed to evaluate three-dimensionally the UA changes and mandibular rotation in patients after MAD compared to MMA.

METHODS

The sample consisted of 17 patients with treated with MAD and 17 patients treated with MMA matched by weight, height, body mass index. Cone-beam computed tomography from before and after both treatments were used to measure total UA, superior/inferior oropharynx volume and surface area; and mandibular rotation.

RESULTS

Both groups showed a significant increase in the superior oropharynx volume after the treatments (p = 0.003) and the MMA group showed greater increase (p = 0.010). No statistical difference was identified in the MAD group considering the inferior volume, while the MMA group showed a significantly gain (p = 0.010) and greater volume (p = 0.024). Both groups showed anterior mandibular displacement. However, the mandibular rotation were statistically different between the groups (p < 0.001). While the MAD group showed a clockwise rotation pattern (-3.97 ± 1.07 and - 4.08 ± 1.30), the MMA group demonstrated a counterclockwise (2.40 ± 3.43 and 3.41 ± 2.79). In the MAD group, the mandibular linear anterior displacement was correlated with superior [p = 0.002 (r=-0.697)] and inferior [p = 0.004 (r = 0.658)] oropharynx volume, suggesting that greater amounts of mandibular advancement are correlated to a decrease in the superior oropharynx and an increase in the inferior oropharynx. In the MMA group, the superior oropharynx volume was correlated to mandibular anteroposterior [p = 0.029 (r=-0.530)] and vertical displacement [p = 0.047 (r = 0.488)], indicating greater amounts of mandibular advancement may lead to a lowest gain in the superior oropharynx volume, while a great mandibular superior displacement is correlated with improvements in this region.

CONCLUSIONS

The MAD therapy led to a clockwise mandibular rotation, increasing the dimensions of the superior oropharynx; while a counterclockwise rotation with greater increases in all UA regions were showed in the MMA treatment.

Class II Malocclusion in Adult Patients: What Are the Effects of the Intermaxillary Elastics with Clear Aligners? A Retrospective Single Center One-Group Longitudinal Study

Aim: To evaluate the dental effects of the treatment with clear aligners and intermaxillary elastics in adult patients with Class II malocclusion. Material and methods: A sample of 20 Class II patients treated with Invisalign aligners (5 M and 15 F; mean age of 27.6 ± 6.3 years) was included in this single-center one-group longitudinal study. Dental cast and cephalometric records were analyzed before (T0) and after treatment (T1). Data were analyzed with a t-test for paired data (p < 0.05). Results: There was a significant reduction of the Overjet (OVJ= −1.4 ± 0.2; p ≤0.001) and a retroposition of upper incisors (U1-NPo = −1.3 ± 1.7; p < 0.001). Furthermore, distalization of upper molars with an improvement of molar class (U6-PT Vertical = −0.93 ± 0.97; p < 0.001; Molar Relation = −0.75 ± 0.45; p < 0.001) was observed. A good control of the lower and upper incisor inclination was present, highlighted by the non-significant changes in these values (L1-GoGn = −0.12 ± 5.4; p = 0.923; U1-AnsPns = −1.1 ± 8.1; p = 0.551). In the lower arch, an increase in the intermolar diameter (0.6 ± 1.0; p = 0.01) was present. Finally, there were no statistically significant changes in all the skeletal variables (ANPg = 0.005 ± 0.687; p = 0.974; SN/MP = −0.47 ± 1.9; p = 0.298). Conclusions: Treatment with Invisalign aligners shows a reduction of the Overjet, a retroposition of the upper incisors, good control of the lower incisors, and an improvement of the molar relationship.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of the 2021 dental literature in restorative dentistry to inform busy dentists regarding noteworthy scientific and clinical progress over the past year. Each member of the committee brings discipline-specific expertise to coverage of this broad topical area. Specific subject areas addressed, in order of the appearance in this report, include COVID-19 and the dental profession (new); prosthodontics; periodontics, alveolar bone, and peri-implant tissues; implant dentistry; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine and oral and maxillofacial surgery; and dental caries and cariology. The authors focused their efforts on reporting information likely to influence daily dental treatment decisions with an emphasis on future trends in dentistry. With the tremendous volume of dentistry and related literature being published daily, this review cannot possibly be comprehensive. Rather, its purpose is to update interested readers and provide important resource material for those interested in pursuing greater details on their own. It remains our intent to assist colleagues in negotiating the extensive volume of important information being published annually. It is our hope that readers find this work useful in successfully managing the patients and dental problems they encounter.

Long-term three-dimensional effects of orthognathic surgery on the pharyngeal airways: a prospective study in 128 healthy patients

OBJECTIVE

To investigate volumetric and circumferential pharyngeal airway space (PAS) changes and stability over time as evaluated with cone beam computed tomography (CBCT) before and after orthognathic surgery 2 years postoperatively.

MATERIALS AND METHODS

One hundred twenty-eight patients underwent bimaxillary orthognathic surgery at the Department of Maxillofacial Surgery of University Hospitals, Leuven, Belgium, were recruited prospectively. Patients were divided into 4 groups based on the amount of mandibular advancement in 5 mm increments (< 0 mm, 0-5 mm, 5-10 mm, or > 10 mm). CBCT data was acquired preoperatively and 1-6 weeks, 6 months, 1 year, and 2 years postoperatively. Patients with a history of maxillofacial trauma or surgery, obstructive sleep apnoea syndrome, or craniofacial anomalies were excluded. Nasopharyngeal, oropharyngeal, and hypopharyngeal PAS volumes and constriction surface areas (mCSA) were measured and compared between each time point with a paired t-test.

RESULTS

The largest significant increase in oropharyngeal volume and mCSA were observed in the 5-10 mm (+ 13.3-21.7%, + 51.3-83.0%)) and > 10 mm (+ 23.3-44.6%, + 92.3-130.0%) mandibular advancement groups. This increase only remained stable 2 years postoperatively in the > 10 mm group. In other mandibular advancement groups, short-term oropharyngeal volume and mCSA increases were noticed, which returned to baseline levels 6 months to 1 year postoperatively.

CONCLUSION

Bimaxillary advancement osteotomy significantly increases oropharyngeal volume and mCSA, which remains stable between 6 months to 1 year postoperatively.

CLINICAL RELEVANCE

Long-term stable volumetric and mCSA enlargements were found with > 10 mm mandibular advancements over a period of 2 years. Return towards baseline levels was observed in the other mandibular advancement groups.

Efficacy and Safety of Qingfei Paidu Decoction for Treating COVID-19: A Systematic Review and Meta-Analysis

Background: Qingfei Paidu decoction (QFPD) has been widely used in treating COVID-19 in China. However, there is still a lack of comprehensive and systematic evidence to demonstrate the effectiveness and safety of QFPD. This study aims to evaluate the efficacy and safety of QFPD in patients with COVID-19.

Methods: We searched seven databases up to 5 March 2021. Two reviewers independently screened studies, extracted data of interest, and assessed risk of bias. The Cochrane risk of bias tool was used to assess the risk of bias of randomized controlled trials. The Newcastle–Ottawa scale was used to assess the risk of bias of cohort and non-randomized trials. The “Quality Assessment Tool for Before-After (Pre-Post) Studies With No Control Group” was adopted for controlled pre–post studies. We used the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) to assess the certainty of evidence. We carried out a random effect meta-analysis using RevMan 5.3. For outcomes that could not be meta-analyzed, we performed a descriptive analysis.

Results: We identified 16 studies with 11,237 patients, including one RCT, six non-randomized trials, two cohort studies, and seven pre–post studies. The certainty of evidence was low to very low because of the observational study design. QFPD combined with conventional treatment might decrease the time for nucleic acid conversion (MD = −4.78 days, 95% CI: −5.79 to −3.77), shorten the length of hospital stay (MD = −7.95 days, 95% CI: −14.66 to −1.24), shorten the duration of symptoms recovery of fever (MD = −1.51 days, 95% CI: −1.92 to −1.09), cough (MD = −1.64 days, 95% CI: −1.91 to −1.36) and chest CT (MD = −2.23 days, 95% CI: −2.46 to −2.00), improve the overall traditional Chinese medicine symptom scores (MD = 41.58 scores, 95% CI: 32.67 to 50.49), and change the laboratory indexes, such as WBC, AST, and CRP.

Conclusion: QFPD combined with conventional treatment might be effective for patients with COVID-19. No serious adverse reactions related to QFPD were observed. Further high-quality studies are still needed in the future.