Placing the maxilla in the most aesthetic sagittal position: validation of several reference lines in relation to the forehead shape

The ideal sagittal position of the maxilla is highly subjective in orthognathic surgical treatment planning. There is no consensus on an analysis to predict the ideal sagittal position of the maxilla. The objective of this study was to determine the preferred maxillary position in relation to the forehead shape, in the Southern Chinese population. The maxilla position of eight patients was simulated based on Steiner's analysis (SA), glabella vertical (GV), Andrews' Element II (AE2), and the Barcelona reference (BR). The simulations were then used in an electronic survey, where respondents ranked the images for each patient from to 1-4 (most to least attractive). A total of 128 responses were collected from dental professionals and laypersons. The most preferred to the least preferred simulation was as follows (mean rank scores for the male and female patients in parenthesis): BR (males 2.06; females 1.98), GV (males 2.11; females 2.21), SA (males 2.59; females 2.40), and AE2 (males 3.24; females 3.41). There was no significant difference in the results according to the sex, age group, or profession of the respondents. The Barcelona reference and glabella vertical are useful in predicting the ideal maxillary position in patients with a flat forehead, and the Barcelona reference is the most preferred in patients with a rounded forehead.

The clinical utility of Nanopore 16S rRNA gene sequencing for direct bacterial identification in normally sterile body fluids

The prolonged incubation period of traditional culture methods leads to a delay in diagnosing invasive infections. Nanopore 16S rRNA gene sequencing (Nanopore 16S) offers a potential rapid diagnostic approach for directly identifying bacteria in infected body fluids. To evaluate the clinical utility of Nanopore 16S, we conducted a study involving the collection and sequencing of 128 monomicrobial samples, 65 polymicrobial samples, and 20 culture-negative body fluids. To minimize classification bias, taxonomic classification was performed using 3 analysis pipelines: Epi2me, Emu, and NanoCLUST. The result was compared to the culture references. The limit of detection of Nanopore 16S was also determined using simulated bacteremic blood samples. Among the three classifiers, Emu demonstrated the highest concordance with the culture results. It correctly identified the taxon of 125 (97.7%) of the 128 monomicrobial samples, compared to 109 (85.2%) for Epi2me and 102 (79.7%) for NanoCLUST. For the 230 cultured species in the 65 polymicrobial samples, Emu correctly identified 188 (81.7%) cultured species, compared to 174 (75.7%) for Epi2me and 125 (54.3%) for NanoCLUST. Through ROC analysis on the monomicrobial samples, we determined a threshold of relative abundance at 0.058 for distinguishing potential pathogens from background in Nanopore 16S. Applying this threshold resulted in the identification of 107 (83.6%), 117 (91.4%), and 114 (91.2%) correctly detected samples for Epi2me, Emu, and NanoCLUST, respectively, in the monomicrobial samples. Nanopore 16S coupled with Epi2me could provide preliminary results within 6 h. However, the ROC analysis of polymicrobial samples exhibited a random-like performance, making it difficult to establish a threshold. The overall limit of detection for Nanopore 16S was found to be about 90 CFU/ml.

Modified maxillomandibular advancement surgery for the treatment of obstructive sleep apnoea: a scoping review

Modified maxillomandibular advancement (MMMA) has been proposed as an alternative to the classic maxillomandibular advancement (MMA) in East and Southeast Asian populations in which bimaxillary protrusion is a prevalent trait. The key difference between MMMA and MMA is the inclusion of anterior segmental osteotomies to reduce the protrusion of the perioral region. The aim of this scoping review was to identify the variations in MMMA and treatment outcomes. A search was conducted in the PubMed, Embase, and Cochrane electronic databases for articles published up to January 2023. Ten articles were included in this review. Three variations of MMMA have been reported in the literature. Treatment outcomes have mostly been favourable for all of these variations. Mandibular advancement of >10 mm and a greater than 50% reduction in the apnoea-hypopnoea index (AHI) have been well reported. Improvements in other outcome measures, such as enlargement of the airway dimension on computed tomography and the Epworth Sleepiness Scale score, have also been shown. Despite additional surgical procedures, complications have been uncommon and mostly minor in nature. It is necessary to be cognizant of MMMA and its variations when providing sleep surgery for East and Southeast Asian patients, tailoring this to the patient's profile and needs.

The role of anterior segmental osteotomies in orthognathic surgery for protrusive faces in a Southeast Asian population: 10-year retrospective data of 51 patients treated in a single centre

Bimaxillary protrusion is a dentofacial deformity common in the East Asian population. It is often difficult to decide between orthodontic and surgical retraction to treat patients with bimaxillary protrusion, especially if surgery to correct skeletal base discrepancies is also required. The objective of this study was to investigate the treatment outcomes of surgical versus orthodontic retraction in patients with bimaxillary protrusion undergoing orthognathic surgery. A retrospective cohort study was conducted, where the medical records and radiographs of 51 patients with bimaxillary protrusion who had an anterior segmental osteotomy concomitant with orthognathic surgery were examined. Patients who had bimaxillary anterior segmental osteotomies were more likely to achieve an inter-incisal angle of 135 ± 5° at the end of treatment, when compared to patients who had orthodontic retraction (P < 0.01). The total treatment duration of patients who had bimaxillary anterior segmental osteotomies was significantly shorter as compared to that of the patients who only had these osteotomies in the maxilla (P < 0.001) or mandible (P = 0.012). Complications and permanent long-term sequelae following anterior segmental osteotomies were uncommon. It is concluded that bimaxillary anterior segmental osteotomies are a viable alternative for patients with concomitant bimaxillary protrusion and skeletal base discrepancies. This allows for a significantly shorter treatment time and greater correction of inter-incisal angles, without a significant increase in complications.

Healthcare workers acquired COVID-19 disease from patients? An investigation by phylogenomics

The increasing number of coronavirus disease 2019 (COVID-19) cases in the community has posed a significant epidemic pressure on healthcare settings. When healthcare workers (HCWs) acquire COVID-19, contact tracing and epidemiological investigation might not be adequate for determining the source of transmission. Here, we report a phylogenetic investigation involving two infected HCWs and nine patients to determine whether patient-to-HCW transmission had occurred in a hospital without a previous COVID-19 outbreak. This is the first study to apply phylogenomics to investigate suspected nosocomial transmission in a region with low prevalence of COVID-19. Our results do not support the occurrence of direct patient-to-HCW transmission.

Evaluation on testing of deep throat saliva and lower respiratory tract specimens with Xpert Xpress SARS-CoV-2 assay

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Testing DTS & LRT specimens by Xpert Xpress SARS-CoV-2 assay with pre-treatment.

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Deep Throat Saliva specimens homogenized with Phosphate-Buffered Saline.

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Lower Respiratory Tract specimens homogenized with maintenance medium.

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Performance of Xpert Xpress SARS-CoV-2 was good & comparable with reference method.

Background

Xpert® Xpress SARS-CoV-2 assay is only validated on nasopharyngeal specimens for detection of SARS-CoV-2. Other specimen types such as deep throat saliva (DTS), also known as posterior oropharyngeal saliva and lower-respiratorytract specimens (LRT) including sputum, tracheal aspirate and bronchoalveolar lavage are not validated. These non-validated specimen types, however, do have significant diagnostic value.

Objective

Evaluate the performance of Xpert Xpress SARS-CoV-2 assay for detection of SARS-CoV-2 from DTS and LRT specimens.

Methods

162 specimens from 158 patients with suspected COVID-19 disease were tested with Xpert Xpress SARS-CoV-2 assay. These included 120 DTS and 42 LRT specimens i.e. 35 sputum, 6 tracheal aspirate and one bronchoalveolar lavage. Results were compared to those by the TIB-Molbiol LightMix® SarbecoV E-gene assay.

Results

Xpert Xpress SARS-CoV-2 assay has satisfactory performance when compared with reference method. The positive percent agreement (PPA) of DTS and LRT specimens were 98.86 % & 100 % respectively while the negative percent agreement (NPA) was 100 % for both DTS and LRT specimens.

Conclusions

This study demonstrated with appropriate sample pre-treatment, Xpert Xpress SARS-CoV-2 assay can be used to test on non-validated specimen types including DTS & LRT specimens.

Changes in bite force after orthognathic surgical correction of mandibular prognathism: a systematic review

Patients requesting treatment for mandibular prognathism seek functional and aesthetic improvements. Improvements in bite force and efficiency are generally used as measures of better function. It is unclear what effect the surgical correction of mandibular prognathism will have on the patient's occlusal forces. The literature was searched using medical subject heading (MeSH) and key word terms 'bite force', 'osteotomy', 'orthognathic surgery', and 'prognathism'. A total of 17 articles were included in this review. These included a total of 697 patients, who ranged in age from 15 to 44 years. Male patients outnumbered female patients in only one study. Five hundred and thirty-two patients underwent bilateral sagittal split osteotomy, 108 patients underwent intraoral vertical ramus osteotomy, and 24 patients underwent extraoral vertical ramus osteotomy (approach unspecified). In general, masticatory efficiency at 3 months after surgery was greater than that found pre-surgically; the increase was significant at 6 months after surgery. The occlusal contact area and points tended to increase from 3 months after surgery, and there was a significant increase at 12 months after surgery. Occlusal forces, although improved, will be lower in corrected prognathic patients than in normognathic patients even at 2 years after surgery.

Biomechanics of mandibular reconstruction: a review

Knowledge of the biomechanics of the mandible allows the surgeon to understand the forces acting on the mandible during function and the resulting deformation that can occur. This allows the appropriate selection and placement of osteosynthesis plates to neutralize these forces. Many methods have been proposed for mandibular reconstruction, each of which has strengths and weaknesses. Most papers evaluating these techniques have focused on survival rates and the quality of the grafted bones, and there have been few studies of the biomechanics (stress distribution and strength) of the various types of reconstructed mandibles. This paper reviews the biomechanics of the mandible and the various methods of reconstruction reported in past studies.

CTX-M type beta-lactamases among fecal Escherichia coli and Klebsiella pneumoniae isolates in non-hospitalized children and adults

We investigated the occurrence and diversity of extended-spectrum beta-lactamase (ESBL) enzymes among antibiotic-resistant Escherichia coli and Klebsiella pneumoniae isolates obtained from human feces. All ESBL-positive isolates were characterized at the molecular level by polymerase chain reaction, sequencing and pulsed-field gel electrophoresis (PFGE). Eight of 46 antibiotic-resistant E. coli (6 from children and 2 from adults) and 4 of 8 K. pneumoniae (all from adults) isolates were found to be ESBL-positive by the double-disk synergy test. Seven isolates were found to have CTX-M-14, 2 each had CTX-M-24 and CTX-M-38, and 1 had CTX-M-9. In addition, 8 isolates were found to carry TEM-1b or TEM-1c. No SHV-type enzyme was found among the E. coli strains. In 9 strains, the plasmidic bla(CTX-M) determinants were transferable to E. coli by conjugation. Analysis by PFGE showed evidence of clonal and non-clonal spread. The present study shows fecal carriage of organisms producing bla(CTX-M) determinants and underscores the role that commensals could play as a reservoir for their dissemination.

Alveolar haemorrhage in anti-glomerular basement membrane disease without detectable antibodies by conventional assays

Anti-glomerular basement membrane (anti-GBM) disease represents the spectrum of disease attributable to circulating anti-GBM antibodies. While active anti-GBM disease in the absence of circulating anti-GBM antibodies has been described, it is considered rare with the use of current routinely available assays. We report four subjects with features consistent with active anti-GBM antibody disease without detectable antibodies by routinely available enzyme linked immunosorbent assay (ELISA) and immunoblot techniques. All were smokers who presented with diffuse alveolar haemorrhage, minimal renal involvement, and undetectable anti-GBM antibodies. Seronegative anti-GBM disease with predominant pulmonary involvement may be more common than previously appreciated and should be part of the differential diagnosis for otherwise unexplained diffuse alveolar haemorrhage. Renal biopsy with immunofluorescent studies should be considered in the diagnostic evaluation of such subjects, including those with idiopathic pulmonary haemosiderosis.

A comparison of 13 guinea pig and human anti-tissue transglutaminase antibody ELISA kits

AIMS

Tissue transglutaminase (tTG) is a major autoantigen recognised by IgA anti-endomysial antibodies (IgA EMA). Enzyme linked immunosorbent assays (ELISA) for IgA anti-tissue transglutaminase antibodies (IgA tTG) have therefore been developed as an alternative serological screening test to IgA EMA for coeliac disease (CD). The use of human tTG (h-tTG), as opposed to guinea pig liver tTG (gpl-tTG), in these assays has been reported to produce superior results. This study compared 13 commercial IgA tTG ELISA kits to ascertain their performance characteristics in the diagnosis of CD in patients with biopsy confirmed disease compared with controls. All patients and controls were adults aged 21 years or older.

METHODS

Sera from the following groups of patients were tested in each kit: (1) 49 patients with CD confirmed on small bowel biopsies (all IgA EMA positive); (2) 34 patients with small bowel biopsies that were not consistent with CD; and (3) 30 patients with biopsy confirmed inflammatory bowel disease. All controls were negative for IgA EMA and were not IgA deficient. Sensitivities and specificities were determined using both the manufacturers' recommended cut off points and receiver operating characteristic (ROC) analysis derived decision thresholds. The area under the curve (AUC) for each ROC plot was also calculated and compared between kits.

RESULTS

In general, the h-tTG based IgA tTG ELISA kits demonstrated superior performance (especially specificity) compared with the gpl-tTG based kits, although 100% sensitivity and specificity (comparable to the IgA EMA assay) was obtained in only one recombinant h-tTG based kit.

CONCLUSIONS

The use of h-tTG in IgA tTG ELISA kits is generally, but not universally, associated with superior performance. Factors other than antigen source are important in determining kit performance.

Detection of the CD56+/CD45- immunophenotype by flow cytometry in neuroendocrine malignancies

AIMS

Antibodies against CD56 are primarily used in flow cytometric studies to detect natural killer cells. However, they may be useful in the identification of neuroendocrine malignancies, especially if the cells do not express CD45, indicating a non-leucocyte origin.

METHODS

A retrospective review was conducted on all solid tissue flow cytometric studies performed between January 1997 and September 2001, to identify all cases with a CD56+/CD45- immunophenotype.

RESULTS

Twelve neuroendocrine malignancies (five metastatic small cell carcinomas, three Merkel cell carcinomas, two metastatic undifferentiated neuroendocrine carcinomas, one metastatic pancreatic neuroendocrine carcinoma, and one neuroblastoma) were identified.

CONCLUSIONS

CD56+/CD45- neuroendocrine malignancies are only rarely detected in the flow cytometric analysis of solid tissue samples. However, the recognition of this immunophenotype is important to avoid their misclassification as natural killer cell malignancies. Furthermore, flow cytometry assists in the rapid identification of such cases, so that appropriate immunohistochemical studies can be performed to facilitate their correct diagnosis.