Prevalence of the HLA-B*5701 Allele and Abacavir Hypersensitivity in Saudi HIV Patients: A Multicenter Study.

Introduction Human immunodeficiency virus (HIV) incidence and prevalence are increasing in Saudi Arabia, with a total prevalence of 12,000 in 2020. Treatment of HIV patients includes multiple regimens that may involve abacavir (ABC), which is a potent drug for treating HIV and can be used as a single or combined pill. Unfortunately, its use was limited by the known associated hypersensitivity reaction (HSR). A worldwide literature review over the past decades reported that the incidence of ABC-related HSR is 5-8%. Methods The study was a cross-sectional multicentric study involving five governmental hospitals in Saudi Arabia and included all HIV patients who were following in these centers. Results Out of 3082 patients, 1293 were tested for HLA-B*5701. The prevalence for ABC-HSR is 1.59%, with variability among the five hospitals, with the highest in King Fahad Hospital in Hafuf (KFH-H) at 4.00% and the lowest in Dammam Medical Complex (DMC) at 0.49%. In previous studies, HLA-B*5701 associated with ABC-HSR varied among different ethnic groups. Our study showed that two patients developed ABC-HSR clinically while they were both negative for HLA-B*5701. Conclusion The fact that patients with negative genetic testing are still at risk of developing ABC-HSR makes continuing screening for HLA-B*5701 status essential, as the consequences of missing such a life-threatening HSR could be detrimental.

Rhodococcus equi bacteremia with necrotizing pneumonia and brain abscess in a newly diagnosed HIV patient in Saudi Arabia: A case report and review of literature.

Rhodococcus equi is a Gram-positive coccobacillus that falls within the category of aerobic actinomycetes. The Rhodococcus genus belongs to the nocardioform bacteria group. This microorganism has been found in various settings, including natural environments, animals, and particularly in individuals with compromised immune systems, such as those living with HIV. Notably, there is an increasing number of reports concerning R. equi infections in transplant recipients and even individuals with a normally functioning immune system. Traditionally, R. equi has been primarily associated with pulmonary infections, but there is a growing body of evidence documenting its involvement in extrapulmonary infections. In this report, we present a case involving a newly diagnosed HIV patient who experienced R. equi -induced necrotizing pneumonia, bacteremia, and a brain abscess in newly diagnosed HIV patient. It is important to note that a direct Gram stain may potentially lead to misclassification of such microorganisms as contaminants. Microbiologists should therefore prioritize the careful examination of colony morphology, biochemical reactions, and consider the limitations of automated machine databases. Furthermore, they should correlate their identification findings with clinical data to ensure optimal patient care and management, especially in the context of an immunocompromised state.

An updated review on pathogenic coronaviruses (CoVs) amid the emergence of SARS-CoV-2 variants: A look into the repercussions and possible solutions.

SARS-CoV-2, responsible for COVID-19, shares 79% and 50% of its identity with SARS-CoV-1 and MERS-CoV, respectively. It uses the same main cell attachment and entry receptor as SARS-CoV-1, which is the ACE-2 receptor. However, key residues in the receptor-binding domain of its S-protein seem to give it a stronger affinity for the receptor and a better ability to hide from the host immune system. Like SARS-CoV-1 and MERS-CoV, cytokine storms in critically ill COVID-19 patients cause ARDS, neurological pathology, multiorgan failure, and increased death. Though many issues remain, the global research effort and lessons from SARS-CoV-1 and MERS-CoV are hopeful. The emergence of novel SARS-CoV-2 variants and subvariants raised serious concerns among the scientific community amid the emergence of other viral diseases like monkeypox and Marburg virus, which are major concerns for healthcare settings worldwide. Hence, an updated review on the comparative analysis of various coronaviruses (CoVs) has been developed, which highlights the evolution of CoVs and their repercussions.

Effects of Alt-RAMEC protocol with facemask therapy in cleft lip palate patients in a sample of Pakistani population.

OBJECTIVE: The objective of the study is to evaluate the skeletal, dentoalveolar and soft tissue changes before and after treatment with Alt-RAMEC protocol and protraction headgear in comparison to the controls. MATERIAL AND METHODS: A quasi experimental study was conducted in the orthodontic department on 60 patients of cleft lip and palate. These patients were divided into two groups. Group I was the Alt-RAMEC group that underwent Alt-RAMEC protocol followed by facemask therapy while group II was the control group that underwent RME and facemask therapy. Total treatment time in both the groups was approximately 6 to 7 months. Mean and standard deviation was calculated for all the quantitative variables. Pre and post treatment changes between treatment and control groups were made using paired t-test. Intergroup comparison between treatment and control group was analyzed using independent t-test. Significance for all tests was predetermined at a P-value of ≤ 0.05. RESULTS: The Alt-RAMEC group showed significant forward movement of maxilla and improvement in the maxillary base. A remarkable improvement in SNA was seen. The overall outcome was better maxillo-mandibular relationship as shown by positive ANB values and angle of convexity. More effect on maxilla and least effect on mandible was notified with Alt-RAMEC protocol and facemask therapy. Improvement in transverse relationship was also evident in the Alt-RAMEC group. CONCLUSION: Alt-RAMEC protocol in combination with protraction headgear is a better alternative to treat cleft lip and palate patients in comparison to the conventional protocol.

Labial and Palatal Pressure Changes in Extraction Cases Before and After Maxillary Incisor Retraction: A Quasi-Experimental Study.

OBJECTIVE: To evaluate the changes in lip and tongue pressure before and after incisor retraction in patients undergoing orthodontic treatment with premolar extraction and incisor retraction. STUDY DESIGN: A Quasi-experimental study Place and Duration of the Study: Orthodontic Department at Dow University of Health Sciences, Pakistan, from January 2018 to November 2019. METHODOLOGY: The study included 64 patients who were divided into two groups, (32 patients of class I and 32 patients of class II malocclusion). The lip and tongue pressures were recorded before and after incisor retraction with the help of Flexiforce sensor. The collected data were statistically analysed using the SPSS V-24 software. Shapiro-Wilk test was used to test the normality of data. The mean difference between lip and tongue pressure before and after incisor retraction was analyzed by Wilcoxon Signed Ranks Test. The difference in soft tissue pressures between class I and class II treatment groups was carried out using the Mann Whitney test. RESULTS: The mean pressure on the labial surface of incisors was significantly reduced after premolar extraction and incisor retraction (p ≤0.001). On the other hand tongue pressure on the palatal side of incisors was enhanced after incisor retraction (p=0.008) Comparing the differences between Angle's class I and class II malocclusion in mean pressure changes before and after incisor retraction revealed that the difference was not statistically significant on labial (p=0.58) or palatal side (p=0.28) of maxillary incisors. CONCLUSION: Reduced lip pressure and increased tongue pressure were observed after incisor retraction, whereas no significant change was seen in between the class I and class II cases. This signifies that orthodontic extraction affects the pressure changes on incisors and teeth do not remain in balance equilibrium at rest. KEY WORDS: Lip pressure, Tongue pressure, Orthodontic treatment, Flexiforce resistive sensor, Extraction, neutral zone.

Performance of CURB-65 and ISARIC 4C mortality scores for hospitalized patients with confirmed COVID-19 infection in Saudi Arabia.

Background: The COVID-19 pandemic continues with new waves that could persist with the arrival of new SARS-CoV-2 variants. Therefore, the availability of validated and effective triage tools is the cornerstone for proper clinical management. Thus, this study aimed to assess the validity of the ISARIC-4C score as a triage tool for hospitalized COVID-19 patients in Saudi Arabia and to compare its performance with the CURB-65 score. Material and methods: This retrospective observational cohort study was conducted between March 2020 and May 2021 at KFHU, Saudi Arabia, using 542 confirmed COVID-19 patient data on the variables relevant to the application of the ISARIC-4C mortality score and the CURB-65 score. Chi-square and t-tests were employed to study the significance of the CURB-65 score and the ISARIC-4C score variables considering the ICU requirements and the mortality of COVID-19 hospitalized patients. In addition, logistic regression was used to predict the variables related to COVID-19 mortality. In addition, the diagnostic accuracy of both scores was validated by calculating sensitivities, specificities, positive predictive value, negative predictive value, and Youden's J indices (YJI). Results: ROC analysis showed an AUC value of 0.834 [95% CI; 0.800-0.865]) for the CURB-65 score and 0.809 [95% CI; 0.773-0.841]) for the ISARIC-4C score. The sensitivity for CURB-65 and ISARIC-4C is 75% and 85.71%, respectively, while the specificity was 82.31% and 62.66%, respectively. The difference between AUCs was 0.025 (95% [CI; -0.0203-0.0704], p = 0.2795). Conclusion: Study results support external validation of the ISARIC-4C score in predicting the mortality risk of hospitalized COVID-19 patients in Saudi Arabia. In addition, the CURB-65 and ISARIC-4C scores showed comparable performance with good consistent discrimination and are suitable for clinical utility as triage tools for hospitalized COVID-19 patients.

Clostridium paraputrificum Bacteremia in a Patient with Human Immunodeficiency Virus Infection: A Case Report and Literature Review.

Clostridium paraputrificum (C. paraputrificum) is clinically important due to its association with underlying medical conditions. Infection with C. paraputrificum may worsen HIV prognosis, leading to acquired immunodeficiency syndrome. However, it is not frequently isolated and its susceptibility to antibiotics has not been well studied. Our report examines the case of a patient with human immunodeficiency virus (HIV) infection, who was diagnosed with Clostridium paraputrificum bacteremia. A 59-year-old male was admitted to hospital with a medical history of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and neck pain. Following episodes of high fever, the patient received a full work up to test for sepsis. Blood culture revealed bacterial growth, and MALDI-TOF mass spectrometry confirmed the diagnosis of Clostridium paraputrificum bacteremia. The patient received treatment with meropenem and vancomycin antibiotics, which cleared the infection after 48 hours; however, inflammatory markers remained high. To date, a limited number of reported cases of C. paraputrificum exist; thus, this case report contributes valuable information to the literature to improve our understanding of its action and resistance profiles and aid future bacteremia management.

Does Orthodontics Extractions Negatively Affect The Occlusal Bite Force Of An Individual - A Quasi-Experimental Study.

BACKGROUND: Orthodontics is said to be that branch of dentistry which takes into consideration the facial growth, dentition development as well as occlusion. It is also concerned with the prevention as well as the rectification of the occlusal anomalies. The aim of this study was to determine the occlusal bite force (OBF) changes during fixed orthodontic treatment up to a period of 9 month in Class I patients treated with extraction and non-extraction treatment protocol. METHODS: It was a Quasi-experimental study conducted from 13th March 2018 to 20th March 2019 in the orthodontic department on 90 subjects which were divided into a treatment group {extraction (30), non-extraction (30)} and controls (n=30). Bite force was measured with an OBF gauge at 6 different intervals before starting the treatment to the ninth month of the treatment. The changes in OBF were assessed using r-ANOVA test. Post-hoc Bonferroni was used for multiple comparisons in bite force levels at different treatment stages. The mean difference in OBF between treatment groups was evaluated by independent t-test. Significance for all tests was predetermined at p value of ≤0.05. RESULTS: The mean OBF significantly increased in both the extraction and non-extraction treatment groups (p<0.001) in comparison to the controls. The mean change in OBF was comparatively greater in the non-extraction group as opposed to the extraction group, but the difference was not statistically significant (p=0.468). CONCLUSIONS: Orthodontic treatment has a positive effect with a gradual increase in the OBF values in subjects treated with extraction and non-extraction fixed mechano-therapy. This indicates that well-aligned arches can have an impact on the functional occlusion, hence, enhancing the bite force levels.

COVID-19 vaccine acceptance and associated factors among people living with HIV in the Middle East and North Africa region.

Background: Identifying coronavirus disease 2019 (COVID-19) vaccine acceptance and associated factors among people living with HIV (PLHIV) in the Middle East and North Africa region is important to meet the need for broad-scale vaccination against COVID-19. Objectives: To investigate the COVID-19 vaccine acceptance rate and factors among PLHIV in the Middle East and North Africa region. Method: An online cross-sectional survey was conducted among PLHIV currently living in Egypt, Tunisia and Saudi Arabia between March 2021 and August 2021. Results: Of the 540 respondents, 19.3% reported already being vaccinated against COVID-19 (n = 104), 32.0% responded 'definitely yes' (n = 173), and 13.3% responded 'probably yes' (n = 72) for intention to receive a COVID-19 vaccine, with an overall COVID-19 vaccine acceptance rate of 64.6% among PLHIV in the region. The most significant predictors of COVID-19 vaccine acceptance included feeling less worried about COVID-19 transmission post-vaccination (221.0% higher odds), and believing the disease is vaccine-preventable (160.0% higher odds). Reported barriers to COVID-19 vaccine acceptance include concerns about vaccine effectiveness and belief that HIV medications protect against COVID-19 transmission, living in a rural area and reporting less-frequent engagement with HIV care. Nine out of 10 participants reported that the chances of them getting COVID-19 vaccine would increase if given adequate information and if their doctor recommended it. Conclusion: Findings of the study can help researchers, health officials, and other health system actors understand the predictors and barriers to COVID-19 vaccine acceptance reported by PLHIV. This understanding could inform the future planning of interventions tailored to PLHIV.

Prototheca zopfii as a Cause of Pneumonia and Disseminated Infection in Febrile Neutropenia: A Case Report and Literature Review.

BACKGROUND Prototheca spp. are common and found in various environments, including animal and human intestines, on the skin and in respiratory tissues, and colonizing fingernails. Few strains pathogenic for humans have been discovered. Here, we describe an infection by the pathogenic fungus species Prototheca zopfii in a patient. The infection was initially classified as a fungus based on colony morphology, fungal staining results, and growth in some fungi culture media (Sabouraud dextrose agar [SDA]). Reports of Prototheca spp. infections are increasing, often with poor outcomes. The use of matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) technique for identification has been widely described. Phenotypic identification depends on microscopic examination of the direct wet mount and after subculturing in blood and SDA using different stains that show a typical morphological characteristic of Prototheca spp. CASE REPORT A 48-year-old woman was diagnosed with a P. zopfii infection after 22 days of hospitalization in the critical care unit. The patient had profound febrile neutropenia and absolute neutrophil count (ANC) was zero, associated with hypotension and disseminated intravascular coagulation (DIC) 10 days after receiving the first cycle of chemotherapy for metastatic breast adenocarcinoma. Unfortunately, the patient died within 2 days of the initiation of treatment with amphotericin B. CONCLUSIONS This case report highlights algae infections as a possible opportunistic infection type in patients with profound neutropenia, and we discuss the use of MALDI-TOF MS-based technology in detecting such infections and predicting poor prognosis, especially in patients with the disseminated form with underlying febrile neutropenia.

Testing the Sensitivity of Conjunctival Swabs from Confirmed COVID-19 Patients.

OBJECTIVE: To investigate the incidence of COVID-19 viral RNA in the conjunctiva of patients priorly confirmed to have COVID-19, using a conjunctival swab and to determine swab sensitivity. METHODS: This cross-sectional study enrolled patients who tested positive for COVID-19 with PCR via nasopharyngeal swabs. Conjunctival swabs were collected for each patient and subjected to RT-PCR assay. Demographic data and clinical history of patients were investigated and analysed. RESULTS: In this study, 4.9% of the patients tested positive with conjunctival swabs for COVID-19; 29.9%, 28.7%, 20.1%, and 12.2% of the patients had fever, shortness of breath, cough, and red eye, respectively. Among all patients, 18.9% and 73.2% had a history of traveling and contact with positive COVID-19 cases, respectively. There were significant correlations between the conjunctival results and diabetes (P=0.049) and hypertension (P=0.002). Traveling was a risk factor for positive conjunctival swab testing (P=0.016). The sensitivity of the conjunctival swab was 4.8%. CONCLUSION: Among all positive cases of COVID-19, a small percentage had positive results when tested using a conjunctival swab. Conjunctival swabs have very low sensitivity for the detection of COVID-19. However, tears could still be a mode of disease transmission, especially from patients to eye care specialists.

Effect of Natural and Artificial Dentin Conditioners on the Release of Vascular Endothelial Growth Factor.

INTRODUCTION: The purpose of this study was to observe the release of vascular endothelial growth factor (VEGF) after conditioning with etidronic acid (also known as 1-hydroxyethylidene-1 and 1-bisphosphonate [HEDP]) and phytic acid (inositol hexakisphosphate [IP6]) in comparison with EDTA on human dentin disks and cylinders. METHODS: Human dentin disks were disinfected and prepared by the standardized method. Seventeen percent EDTA, 9% HEDP, 1% IP6, and distilled water (5 minutes) were used to immerse dentin disks. The dentin cylinders were prepared by following disinfection and the standardized preparation method to achieve a truncated cone-shaped canal with a 1-mm open apex. The dentin cylinder samples were irrigated with sodium hypochlorite (5 mL/5 minutes) and then rinsed with 17% EDTA, 9% HEDP, 1% IP6 and distilled water (5 mL/5 min). Enzyme-linked immunosorbent essay was performed to measure VEGF release. One-way analysis of variance was used to compare the mean release of VEGF between study groups and controls at a significance level of .05. A post hoc Tukey test was used for multiple comparisons between study groups. RESULTS: Among conditioners, HEDP released more VEGF from both disks and cylinders. In cylinders, VEGF release by HEDP was significantly greater than the other conditioners, whereas in disks the release of VEGF was similar with all conditioners. CONCLUSIONS: The release of VEGF by 9% HEDP and 1% IP6 was comparable with 17% EDTA from dentin disks; however, HEDP demonstrated more release from dentin cylinders than EDTA and IP6.

Unusual Presentation, Relapse, and Metastasis of a Pediatric Testicular Yolk Sac Tumor: Case Report.

Testicular tumors are not uncommon in children and represent 1%-2% of all pediatric malignancies. Prepubertal testicular yolk sac tumor is the most common childhood testicular cancer, accounting for 70%-80% of all cases. The clinical presentation varies from one patient to another; most common presentation is painless scrotal mass. Herein, we present a case of pediatric patient with a testicular yolk sac tumor who had unusual presentation followed by a local relapse and metastasis and continued to have high markers while he was on chemotherapy, then underwent retroperitoneal lymph node dissection and local recurrence excision.

Cardiovascular disease-related mortality risk in end stage renal disease and type 2 diabetes: A systematic review.

BACKGROUND: Patients with uncontrolled type 2 diabetes can have microvascular and macrovascular complications, including renal impairment and cardiovascular diseases. However, it is unknown how diabetes and renal disease could influence cardiovascular mortality. OBJECTIVE: This study aims at examining the medical literature to evaluate the risk of cardiovascular death in concomitant end stage renal disease with type 2 diabetes. METHOD: Medical literature was reviewed through Medline, PubMed, Embase, and Ovid database in the duration between 2009 and 2019. Searching terms included were a combination of "type 2 diabetes mellitus" AND "end-stage renal disease" AND "cardiovascular mortality". Following this, results were filtered to include only original research articles investigating cardiovascular mortality in concomitant diabetes and end-stage renal disease. Selected trials mentioned diabetes control as well as the follow-up duration of the included patients. RESULT: A total of 1508 articles were retrieved. Following the exclusion of articles on animals and including only trials on humans, 32 articles appeared. A total of eight articles were identified as eligible, covering a total of 2,06,492 diabetic patients with end-stage renal disease. All the studies were prospective studies, except for three studies that were retrospective. CONCLUSION: There is an elevated cardiovascular mortality risk in concomitant type 2 diabetes mellitus and end-stage renal disease, especially with uncontrolled blood glucose levels.

Assessing dietary and lifestyle risk behaviours and their associations with disease comorbidities among patients with depression: A case-control study from Bahrain.

OBJECTIVES: In Western populations, patients with depression die 10-25 years prematurely compared to controls, mainly due to lifestyle-related diseases. Tobacco smoking, excessive alcohol intake, poor diets and physical inactivity are among the major contributors to disease comorbidities. The objective of this research is to assess the dietary and lifestyle behaviours for Bahraini patients with depression and to determine their associations with different medical comorbidities. METHODS: A case-control study was conducted from March to December 2019. A sample of 96 diagnosed patients with depression was recruited from the Psychiatric Hospital/Bahrain, and 96 age- and sex-matched controls were recruited from primary health centres. Assessment of anthropometrics, dietary and alcohol intakes, tobacco smoking and physical activity levels were undertaken for both cases and controls. National electronic medical records were reviewed retrospectively for medical comorbidities for the recruited cases. Logistic regression analysis was used to identify associations between lifestyle behaviours and medical comorbidities after controlling for confounding factors. RESULTS: Patients with depression reported higher intakes of energy and energy-yielding macronutrients (e.g., carbohydrates, protein, and fat); three-fold higher rates of tobacco smoking; and significantly lower levels of physical activity. Cases appeared to be at a doubled risk for developing obesity, diabetes type 2, hypertension, and musculoskeletal disorders. The risk for cardiovascular problems was similar for cases and controls. CONCLUSIONS: Poor dietary intakes, increased prevalence of smoking, and low levels of physical activity were evident in patients with depression in Bahrain; these factors were associated with some medical comorbidities.

Factors affecting treatment decisions for Class I malocclusions.

INTRODUCTION: Orthodontic treatment planning requires skill and expertise with considerable practice variations. The aims of this study were to review retrospectively the pretreatment records of patients with Class I malocclusion and to identify variables that could play a role in the treatment decision. METHODS: From the available records of 1500 orthdontic patients, the pretreatment records of 202 patients were selected at random. Inclusion and exclusion criteria were applied, and the surviving records were divided into extraction (n = 92) and nonextraction (n = 92) treatment groups. Skeletal, dental, and soft tissue measurements were obtained from pretreatment lateral cephalograms and dental casts of subjects with bilateral Class I molar relationships. Data were statistically analyzed by binary logistic regression tests. RESULTS: The results showed that the variables of lower anterior facial height, E-plane to upper lip, and maxillary and mandibular incisor inclinations were significantly increased in the extraction group (P <0.05), whereas spacing in the mandibular arch and increased overbite were statistically significant in the nonextraction treatment group (P <0.05). According to the model, the odds of nonextraction treatment are 1.29 and 1.24 times that of extraction treatment for every 1-mm increase in overbite and spacing in the mandibular arch, respectively. CONCLUSIONS: Vertical facial pattern, overbite, mandibular tooth size-arch length discrepancy, lip position, and maxillary and mandibular incisor inclinations are a few of the important variables that should not be overlooked when planning orthodontic treatment. The findings of this study could facilitate the treatment planning process for patients with Class I malocclusion.

Association between hypodontia and Angles malocclusion.

This study was planned to determine the prevalence of hypodontia in permanent dentition and to test whether an association was present between hypodontia and Angle's malocclusion. The retrospective study was conducted at a tertiary care hospital, Karachi, and comprised record of all patients visiting the orthodontic clinics of the hospital from 2005 to 2015. Orthodontic records of 790(79%) subjects, including 189(23.9%) males and 601(76.1%) females, were reviewed. Their mean age was 17 ± 5.06 years. A tooth was considered missing if no evidence of tooth germ was observed on orthopantomograms and dental casts. The total sample was distributed into three groups on the basis of Angle's classification. Chi-square test was applied to determine an association between hypodontia and Angle's malocclusion. Tooth agenesis was observed in 34(4.3%) and a statistically significant difference was found between the genders (p=0.005). A positive association was found between hypodontia and malocclusion groups. Higher frequency of missing teeth was seen in Class III malocclusion which indicates a great need for orthodontic treatment as it has a psychosocial impact on the quality of life.

Stability of Palatal Rugae as a Forensic Marker in Orthodontically Treated Cases.

The palatal rugae have been used as a reference landmark and identification marker by orthodontists and forensic analysts. However, the reliability of palatal rugae as a forensic marker remains questionable once an individual is subjected to orthodontic treatment. This study aimed at evaluating the changes in the rugae pattern after nonextraction, extraction, and maxillary expansion orthodontic treatment. The lengths and shapes of palatal rugae were evaluated on the pretreatment and post-treatment dental casts of 168 subjects using the Thomas and Kotze classification. Extraction treatment significantly reduced the second and third rugae lengths (p < 0.05), whereas the third rugae length was significantly increased after palatal expansion (p < 0.05). The shape of rugae remained consistent in all the study groups which may be used as a reliable forensic marker in subjects undergoing orthodontic treatment. However, the use of the lengths of palatal rugae in forensic odontology must be made with caution.

Effect of Clark's twin-block appliance (CTB) and non-extraction fixed mechano-therapy on the pharyngeal dimensions of growing children.

INTRODUCTION: Narrow airway dimensions due to mandibular deficiency can predispose an individual to severe respiratory distress. Hence, treatment with mandibular advancement devices at an early age might help improving the pharyngeal passage and reduce the risk of respiratory difficulties. Therefore, the aim of the current study was to evaluate the mean changes in the pharyngeal dimensions of children with mandibular deficiency treated with Clark's twin-block appliance (CTB) followed by fixed orthodontic treatment. METHODS: Orthodontic records of 42 children with mandibular deficiency were selected. Records comprised three lateral cephalograms taken at the start of CTB treatment, after CTB removal and at the end of fixed appliance treatment, and were compared with 32 controls from the Bolton-Brush study. Friedman test was used to compare pre-treatment, mid-treatment and post-treatment pharyngeal dimensions. Wilcoxon signed rank test was used to compare the airway between pre-treatment and post follow-up controls. Mann-Whitney U test was applied to compare the mean changes in pharyngeal dimensions between treatment group and controls from T2 to T0. Post-hoc Dunnet T3 test was used for multiple comparisons of treatment outcomes after CTB and fixed appliances, taking a p-value of ≤ 0.05 as statistically significant. RESULTS: Superior pharyngeal space (p < 0.001) and upper airway thickness (p = 0.035) were significantly increased after CTB, and the change in superior pharyngeal space remained stable after fixed mechano-therapy. CONCLUSION: CTB can have a positive effect in improving pharyngeal space and the resultant increase in airway remains stable on an average of two and a half years.

Effect of Clark's twin-block appliance (CTB) and non-extraction fixed mechano-therapy on the pharyngeal dimensions of growing children

Abstract Introduction: Narrow airway dimensions due to mandibular deficiency can predispose an individual to severe respiratory distress. Hence, treatment with mandibular advancement devices at an early age might help improving the pharyngeal passage and reduce the risk of respiratory difficulties. Therefore, the aim of the current study was to evaluate the mean changes in the pharyngeal dimensions of children with mandibular deficiency treated with Clark's twin-block appliance (CTB) followed by fixed orthodontic treatment. Methods: Orthodontic records of 42 children with mandibular deficiency were selected. Records comprised three lateral cephalograms taken at the start of CTB treatment, after CTB removal and at the end of fixed appliance treatment, and were compared with 32 controls from the Bolton-Brush study. Friedman test was used to compare pre-treatment, mid-treatment and post-treatment pharyngeal dimensions. Wilcoxon signed rank test was used to compare the airway between pre-treatment and post follow-up controls. Mann-Whitney U test was applied to compare the mean changes in pharyngeal dimensions between treatment group and controls from T2 to T0. Post-hoc Dunnet T3 test was used for multiple comparisons of treatment outcomes after CTB and fixed appliances, taking a p-value of ≤ 0.05 as statistically significant. Results: Superior pharyngeal space (p < 0.001) and upper airway thickness (p = 0.035) were significantly increased after CTB, and the change in superior pharyngeal space remained stable after fixed mechano-therapy. Conclusion: CTB can have a positive effect in improving pharyngeal space and the resultant increase in airway remains stable on an average of two and a half years.

Resumo Introdução: a redução nas dimensões das vias aéreas causada pela deficiência mandibular pode predispor um indivíduo a dificuldades respiratórias severas. Assim, o tratamento com aparelhos de avanço mandibular na infância pode contribuir para melhorar a via aérea faríngea e reduzir o risco de problemas respiratórios. Objetivo: o objetivo do presente estudo foi avaliar as alterações médias nas dimensões da faringe de crianças com deficiência mandibular tratada com o aparelho Twin Block (TBC) seguido pelo tratamento ortodôntico fixo. Métodos: a documentação ortodôntica de 42 crianças com deficiência mandibular, consistindo de três telerradiografias de perfil - tiradas ao início do tratamento com TBC (T0), após a remoção do aparelho (T1) e ao final do tratamento ortodôntico fixo (T2) - foi selecionada e comparada à de 32 crianças controle do estudo Bolton-Brush. O teste de Friedman foi utilizado para comparar as dimensões da faringe antes, durante e após o tratamento. O teste de postos de Wilcoxon foi utilizado para comparar as vias aéreas antes do tratamento e depois do acompanhamento das crianças controle. O teste U de Mann-Whitney foi empregado para comparar as alterações médias nas dimensões da faringe entre o grupo tratado e as crianças controle, de T0 a T2. O teste T3 de Dunnett foi utilizado como post-hocpara realizar comparações múltiplas dos resultados do tratamento após o uso do TBC e dos aparelhos fixos, considerando-se como estatisticamente significativo um valor de p ≤ 0,05. Resultados: o espaço faríngeo superior (p < 0,001) e a espessura das vias aéreas superiores (p = 0,035) aumentaram significativamente após o uso do TBC, e a alteração no espaço faríngeo superior permaneceu estável após a mecanoterapia fixa. Conclusão: o TBC pode produzir um efeito positivo no espaço faríngeo, e aumento resultante nas vias aéreas permanece estável, em média, por dois anos e meio.