Biochemical markers of cardiac dysfunction in children with obstructive sleep apnoea (OSA).

OBJECTIVES: We explored relationships between biochemical markers and cardiac responses of children with and without obstructive sleep apnoea (OSA) during exercise. We hypothesised that serum markers of sympathetic nervous system activity and low-grade inflammation would correlate with cardiac responses to exercise in children with or without OSA. METHODOLOGY: The study included 40 of 71 children with previously characterised responses to cardiopulmonary exercise testing. Measures included serum cytokine levels using a multiplex bead-based assay (interleukins IL-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α and IFN-γ). Serum amyloid A (SAA) was quantified by nephelometry, and metanephrine/normetanephrine levels were measured by liquid chromatography, mass-spectroscopy. Comparisons were made between children with and without OSA, and with and without obesity. Relationships between biomarkers and various cardiac parameters were explored by linear regression. RESULTS: Amongst the 40 children in this study, OSA was present in 23. Compared to the 17 children without OSA, those with OSA had higher resting serum IL-6 levels compared to those without (median 3.22 pg/ml vs. 2.31, p < 0.05). Regarding correlations with cardiac function after adjusting for OSA, IL-8 negatively correlated to heart rate (HR) response following exercise (p = 0.03) and IFN-γ negatively correlated with Stroke Volume Index (SVI) (p = 0.03). Both metanephrine and normetanephrine levels positively correlated with SVI (p = 0.04, p = 0.047; respectively) and QI (p = 0.04, p = 0.04; respectively) during exercise when adjusting for OSA. CONCLUSIONS: Children with OSA have raised morning levels of serum IL-6. Separately, higher levels of IFN-γ and IL-8 and lower levels of metanephrine and normetanephrine related to poorer cardiac function during exercise.

Changes in sleep and airway variables in patients with obstructive sleep apnea after mandibular advancement splint treatment.

INTRODUCTION: Obstructive sleep apnea (OSA) is an extensive public health problem that imposes considerable morbidity. Mandibular advancement splint (MAS) therapy is a well tolerated treatment, but success rates are difficult to predict. Our objective was to investigate the relationship of oropharyngeal airway dimensions, sleep characteristics, patient biometrics, and treatment response within an OSA patient sample. METHODS: Records of 33 adults were assessed retrospectively with the use of Dolphin 3D and Image J to measure the airway on pretreatment supine cone-beam computed tomography images and derived lateral cephalograms. The patients used Somnodent (Somnomed; Crows Nest, Australia) MAS appliances, which were titrated over 6-8 weeks. Appliance titration measurements and pre- and posttreatment polysomnograms were assessed. Respiratory disturbance index (RDI), absolute and percentage changes in RDI, non-rapid eye movement (NREM) RDI, rapid eye movement (REM) RDI, supine and nonsupine NREM and REM RDI, and minimal blood-oxygen saturation variables were evaluated. The associations of measurements from 2D and 3D minimal anterior-posterior linear distance and 3D airway variables with MAS treatment response were estimated. RESULTS AND CONCLUSIONS: Combined effects of baseline total airway volume, body mass index, neck circumference, location of minimal cross sectional area, and OSA severity were associated with treatment response. Patients with higher initial OSA and more superiorly located airway constriction showed enhanced treatment response to MAS therapy. Airway constriction due to maxillofacial disproportions rather than soft tissue obstruction also showed better treatment response. No significant relationships were found in lateral cephalogram measurements.

Computerized measurement of the location and value of the minimum sagittal linear dimension of the upper airway on reconstructed lateral cephalograms compared with 3-dimensional values.

INTRODUCTION: Identifying the location and value of the smallest airway dimension can be useful in screening and planning treatment for patients with obstructive sleep apnea. Our objectives in this study were to (1) objectively identify the vertical location and value of the minimum sagittal linear dimension (MSLD) on 2-dimensional reconstructed lateral cephalograms (RLCs), (2) compare the location and value of the MSLD on RLCs with the vertical location and sagittal dimension of the minimum cross-sectional area (MCSA), and (3) investigate the association between the MSLD on RLCs and both the MCSA and the airway volume. METHODS: Cone-beam computed tomography (CBCT) scans of 91 patients, in 3 age groups (<20, 20-40, and >40 years), were used to perform 3-dimensional assessments of the upper airway and reconstruct lateral cephalograms. Airway volume, MCSA, vertical level, and sagittal dimension of MCSA on the CBCT scans were obtained using Dolphin 3D software (version 11.7; Dolphin Imaging, Chatsworth, Calif). Customized software was used to objectively obtain the location and value of the MSLD of the airway on RLCs. RESULTS: In all age groups, correlation tests showed significant correlations between the MSLD on RLCs and both the MCSA (rs ≥0.59; P <0.001) and the airway volume (rs ≥0.37; P <0.05). Additionally, there were significant correlations between the vertical location of the MSLD and the vertical location of the MCSA (rs ≥0.41; P <0.05) and between the MSLD and the sagittal dimension of the MCSA (r ≥0.61; P <0.001). Bland-Altman plots for the MSLD and the sagittal dimension of the MCSA showed much narrower 95% limits of agreement compared with the Bland-Altman plots for the vertical locations of the MSLD and the MCSA. CONCLUSIONS: Two-dimensional images may be used as a screening tool and to identify the sagittal dimension of the smallest airway dimension. However, comprehensive assessment of airway characteristics is better achieved with CBCT-based 3-dimensional evaluation.

Racial and sex differences in timing of the cervical vertebrae maturation stages.

INTRODUCTION: Our objective was to investigate skeletal maturation of female and male subjects from different racial groups by comparing the cervical vertebrae maturation (CVM) stages. METHODS: The study included 3 racial groups: white, African American, and Hispanic subjects. Each group was subdivided into female and male. The age range of the subjects was between 7 and 18 years. The sample included 60 lateral cephalographs for each subgroup. Skeletal maturation of the cervical vertebrae was assessed according to a method that described 6 CVM stages. RESULTS: Racial differences were evident in the mean ages of CVM stages 2, 3, 4, and 5 (P = 0.002; P = 0.003; P = 0.001; and P = 0.001, respectively) among females; among males, only stage 3 was different (P = 0.001). Sex differences in the mean ages of stages 1, 2, and 3 in Hispanic subjects (P <0.001), and in stages 2 and 3 in African American subjects (P = 0.019 and P <0.001) and white subjects (P = 0.004 and P <0.001) were detected. CONCLUSIONS: In both sexes, racial differences were not apparent between whites and African Americans, but differences were evident between Hispanics vs both whites and African Americans. Sex differences were apparent between the sexes in each of the 3 ethnic groups in CVM stages 2 and 3. No sex differences were detected in stages 4, 5, or 6 in any of the 3 racial groups. It is recommended to consider racial and sex differences when using the CVM stage as a skeletal maturation indicator.

Effects of unilateral premolar extraction treatment on the dental arch forms of Class II subdivision malocclusions.

INTRODUCTION: A retrospective study evaluating posttreatment symmetry in dental arch form and midlines was carried out in Class II subdivision patients treated with unilateral and bilateral maxillary premolar extractions. METHODS: Using Geomagic (version 14; Geomagic, Research Triangle Park, NC) and MATLAB (version 8.4; MathWorks, Natick, Mass) software, best-fit curves expressed as quartic polynomials were generated for 13 Class II subdivisions treated with unilateral extractions and 20 treated with bilateral maxillary premolar extractions. Transverse and sagittal measurements were recorded to assess symmetry. Dental models were superimposed on constructed reference planes to generate average posttreatment arches. Statistical comparisons were performed with the significance level set at P ≤0.05. RESULTS: The unilateral extraction group showed significant differences in transverse arch forms between the right and left sides in the anterior, anterior-middle, and middle segments of the arch, and all regions other than the posterior segment in the sagittal dimension. Significant differences were found between groups in the anterior and anterior-middle segments of the arch transversely, the middle and middle-posterior segments sagittally, and the midline deviation relative to the midsagittal plane. Superimposed average arches showed similar results. CONCLUSIONS: Unilateral maxillary extraction treatment generally results in a narrower and more posteriorly displaced arch form on the extraction side, with a deviated maxillary midline toward the extraction side of the arch.

Three-dimensional assessment of soft tissue changes associated with bone-anchored maxillary protraction protocols.

INTRODUCTION: The aim of this study was to assess the 3-dimensional soft tissue changes in growing Class III patients with maxillary deficiency associated with 2 bone-anchored maxillary protraction protocols in relation to an untreated control group of Class III patients. METHODS: Growing skeletal Class III patients between the ages of 10 and 14 years participated in this study. In group 1 (n = 10), skeletally anchored facemasks were used with miniplates placed at the zygomatic buttress. In group 2 (n = 10), the patients were treated with Class III elastics extending from infrazygomatic miniplates in the maxilla to symphyseal miniplates in the mandible. Group 3 (n = 10) was an untreated control group. Three-dimensional stereophotogrammetry images were acquired before and after treatment, and then superimposed and analyzed. In addition, lateral cephalometric radiographs were analyzed. RESULTS: The maxilla moved forward significantly in groups 1 and 2 compared with the untreated control group (group 1, 4.87 mm; group 2, 5.81 mm). The 3-dimensional soft tissue analysis showed significant treatment effects; the major changes were observed in the upper lips, cheeks, and middle of the face, which had a significant positive sagittal displacement in both treatment groups. The lower lip and chin area showed significant negative sagittal changes that indicated that the soft tissue growth in this area was restrained with backward displacement especially in group 1 more than in group 2. CONCLUSIONS: The 2 bone-anchored maxillary protraction protocols effectively improved the Class III concave soft tissue profile.

Dentoalveolar and arch dimension changes in patients treated with miniplate-anchored maxillary protraction.

INTRODUCTION: The aim of this study was to evaluate dentoalveolar and arch dimension changes in 2 miniplate-anchored maxillary protraction protocols in relation to an untreated control group using 3-dimensional digital models. METHODS: Thirty growing Class III subjects with maxillary deficiency in the late mixed or early permanent dentition phase were randomly divided into 3 groups. In group 1 (n = 10), patients were treated with skeletally anchored facemasks anchored with miniplates placed at the zygomatic buttress. In group 2 (n = 10), patients were treated with Class III elastics extending from infrazygomatic miniplates in the maxilla to symphyseal miniplates in the mandible. Group 3 (n = 10) was an untreated control group. The decision to discontinue orthopedic treatment was made when the patients had 3 to 4 mm of positive anterior overjet. Pretreatment, posttreatment, and observation 3-dimensional digital models were analyzed, superimposed, 3 dimensionally mapped, and sectioned. RESULTS: In this study, there were no significant changes in maxillary arch depth and maxillary or mandibular intermolar width before and after maxillary protraction or after the observation period in the control group. The mandibular arch depth decreased by a small but statistically significant amount only in groups 1 and 3. Superimposition of the pretreatment and posttreatment or observation maxillary 3-dimensional digital models showed minimal clinically significant dentoalveolar changes. CONCLUSIONS: Miniplate-anchored maxillary protraction protocols can accomplish maxillary advancement by eliminating movements of teeth and dentoalveolar changes. No spontaneous improvement in transverse deficiency was detected after correction of the anteroposterior deficiency at this age. Consequently, patients with transverse maxillary deficiency should have rapid maxillary expansion before or during the miniplate-anchored protraction period to improve the transverse deficiency.

Secular trends in the timing of skeletal maturation as assessed by the cervical vertebrae maturation method.

Objective: To investigate the presence of secular trends in skeletal maturation of girls and boys as assessed by the use of cervical vertebrae bones. Materials and methods: The study compared two main groups: the first included data collected from the Denver growth study (1930s to 1960s) and the second included data collected from recent pretreatment records (1980s to 2010s) of patients from the orthodontic clinic of a North American University. The records from the two groups were all for Caucasian subjects. The sample for each group included 78 lateral cephalographs for girls and the same number for boys. The age of the subjects ranged from 7 to 18 years. Cervical vertebrae maturation (CVM) stages were directly assessed from the radiographs according to the method described by Hassel and Farman in which six CVM stages were designated from cervical vertebrae 2, 3, and 4. Results: The mean age of girls from the Denver growth study and girls from the university clinic in each of the six CVM stages was not different at P ≤0.05. However, the mean age of boys from the two groups was not different only in stage 3 (P = 0.139) and stage 4 (P = 0.211). Conclusions: The results showed no evidence to indicate a tendency for earlier skeletal maturation of girls or boys. Boys in the university group started their skeletal maturation later than boys in the Denver group and completed their maturation earlier. Gender was a significant factor affecting skeletal maturation stages in both Denver and university groups.

Objective adherence to positive airway pressure therapy in an Australian paediatric cohort.

PURPOSE: This study aimed to objectively measure adherence (compliance) and effectiveness of CPAP and BiLevel pressure support in an Australian paediatric population and determine factors associated with adherence outcomes. METHODS: Data was collected as part of routine clinical care from 2011 to 2013. Adherence was recorded by downloads from the PAP device. "Adequate" adherence was defined as ≥4 h/night for 70 % of days used. Effectiveness of therapy was measured by polysomnography (PSG) pre- and post-PAP initiation. One year follow-up was undertaken to determine the long-term utilisation of PAP therapy. RESULTS: Ninety-nine children were included (55 CPAP, 44 BiLevel). Mean age and BMI z-score were 6.9 ± 5.5 years and 0.1 ± 2.0 for CPAP and 9.8 ± 5.9 years and -0.5 ± 2.6 for BiLevel, respectively. At initial download, adequate adherence was observed in 75 % of CPAP and 91 % of BiLevel users. Mean hours of use (per night) for all nights used was 6.8 ± 2.8 and 9.3 ± 3.6 h, respectively. PSG demonstrated that CPAP use was associated with >60 % decrease in the obstructive apnoea hypopnoea index (OAHI, 19.0 ± 18.4 to 2.4 ± 3.1; p < 0.001). BiLevel use was associated with improved baseline SaO2 and TcCO2 (SaO2, 92.5 ± 5.4 % to 95.5 ± 2.9 %; p = 0.001 and reduction in TcCO2, 50.0 ± 10.9 mmHg to 44.8 ± 7.6 mmHg; p = 0.01). At follow-up, 22 (40 %) patients on CPAP and 26 (59 %) on BiLevel continued with therapy, and amongst these, adequate adherence was maintained in 76 % of CPAP and 80 % of Bilevel users. CONCLUSIONS: In this Australian paediatric cohort (predominantly non-obese), adherence with BiLevel was greater than for CPAP. Over half of our population continue to utilise PAP therapy 1 year later, and amongst these cases, adequate adherence was maintained.

Demineralization of resin-sealed enamel by soft drinks in a clinically relevant pH cycling model.

PURPOSE: To compare the in vitro protective effect of orthodontic sealants on the enamel demineralization under a soft drink-induced erosive challenge. METHODS: The facial surfaces of bovine incisors were sectioned into 5 mm x 4 mm x 4 mm enamel blocks. Specimens were randomly assigned to three surface protection measures: control (exposed enamel), coating with Transbond XT (unfilled resin primer), or coating with Opal Seal (filled and fluoride releasing primer). Thermocycling was used to simulate aging. The specimens were pH cycled through an acidic buffer, test beverage and a neutral buffer for a total of 7 days. Test beverages included water, Diet Mountain Dew, and Coke Classic. Quantitative light-induced fluorescence (QLF) images were taken at baseline and after aging. Final QLF images were taken to evaluate the demineralization of enamel. Data were analyzed statistically using a two-way ANOVA to compare the interaction between enamel surface protection and beverages as well as one-way ANOVA to compare surface protection and the test beverage levels. RESULTS: A statistically significant interaction was found between the surface protected groups and the test beverage groups (P < 0.05). Statistically significant differences were found among the test beverage groups (P < 0.05) and among the surface protection groups (P < 0.05). Coke Classic went through the sealant layer resulting in high enamel demineralization. Enamel coating with Opal Seal significantly reduced the erosive attack of beverages.

Comparative evaluation of 2 skeletally anchored maxillary protraction protocols.

INTRODUCTION: The aim of this study was to evaluate and compare the effects of 2 protocols of bone-anchored maxillary protraction with an untreated control group. METHODS: Thirty growing Class III subjects with maxillary deficiency in the late mixed or early permanent dentition were included in the study. In group 1 (n = 10), skeletally anchored facemasks were used with miniplates placed at the zygomatic buttress. In group 2 (n = 10), the patients were treated with Class III elastics extending from infrazygomatic miniplates in the maxilla to symphyseal miniplates in the mandible. Group 3 (n = 10) was an untreated control group. Pretreatment and posttreatment cephalometric radiographs were analyzed. RESULTS: The treatment periods were 8 and 8.9 months in groups 1 and 2, respectively, and the untreated control group was observed for 9.4 months. The maxilla moved forward significantly in groups 1 and 2 compared with the untreated control group (4.87 mm in group 1, 5.81 mm in group 2); overjet and maxillary incisor display were improved without proclination or mesialization of the maxillary teeth relative to the maxillary base. Soft tissue harmony demonstrated the great improvement. However, group 1 showed more opening rotation of the mandible and lingual inclination of the mandibular incisors than did group 2. CONCLUSIONS: The 2 skeletal anchorage protocols for maxillary protraction effectively resolved the severe maxillary deficiently in growing Class III patients. However, vertical changes and retroclination of the mandibular incisors were better controlled by Class III elastics extending from the infrazygomatic miniplates in the maxilla to the symphyseal miniplates in the mandible (group 2).

Nonsurgical approach to Class I open-bite malocclusion with extrusion mechanics: a 3-year retention case report.

Anterior open bite is one of the most challenging malocclusions for orthodontic treatment. The high incidence of relapse is a major concern. Therefore, accurate initial examination, diagnosis, treatment plan, and consideration of habitual risk factors are crucial for a successful outcome without unwanted sequelae. Excellent patient compliance for retainer wear is also a critical factor. This case report shows the 3-year stability of a nonsurgical and nonextraction orthodontic treatment of a 5-mm anterior open-bite malocclusion in a 12-year-old girl with extrusion mechanics and habit modification. After 2 years of orthodontic treatment, excellent outcomes were achieved. With an appropriate retention protocol, the long-term stability of the treatment was favorable.

The Health Effects of 72 Hours of Simulated Wind Turbine Infrasound: A Double-Blind Randomized Crossover Study in Noise-Sensitive, Healthy Adults.

BACKGROUND: Large electricity-generating wind turbines emit both audible sound and inaudible infrasound at very low frequencies that are outside of the normal human range of hearing. Sufferers of wind turbine syndrome (WTS) have attributed their ill-health and particularly their sleep disturbance to the signature pattern of infrasound. Critics have argued that these symptoms are psychological in origin and are attributable to nocebo effects. OBJECTIVES: We aimed to test the effects of 72 h of infrasound (1.6-20 Hz at a sound level of ∼90 dB pk re 20µPa, simulating a wind turbine infrasound signature) exposure on human physiology, particularly sleep. METHODS: We conducted a randomized double-blind triple-arm crossover laboratory-based study of 72 h exposure with a >10-d washout conducted in a noise-insulated sleep laboratory in the style of a studio apartment. The exposures were infrasound (∼90 dB pk), sham infrasound (same speakers not generating infrasound), and traffic noise exposure [active control; at a sound pressure level of 40-50 dB LAeq,night and 70 dB LAFmax transient maxima, night (2200 to 0700 hours)]. The following physiological and psychological measures and systems were tested for their sensitivity to infrasound: wake after sleep onset (WASO; primary outcome) and other measures of sleep physiology, wake electroencephalography, WTS symptoms, cardiovascular physiology, and neurobehavioral performance. RESULTS: We randomized 37 noise-sensitive but otherwise healthy adults (18-72 years of age; 51% female) into the study before a COVID19-related public health order forced the study to close. WASO was not affected by infrasound compared with sham infrasound (-1.36 min; 95% CI: -6.60, 3.88, p=0.60) but was worsened by the active control traffic exposure compared with sham by 6.07 min (95% CI: 0.75, 11.39, p=0.02). Infrasound did not worsen any subjective or objective measures used. DISCUSSION: Our findings did not support the idea that infrasound causes WTS. High level, but inaudible, infrasound did not appear to perturb any physiological or psychological measure tested in these study participants. https://doi.org/10.1289/EHP10757.

Predictors of initial stability of orthodontic miniscrew implants.

The purpose of this retrospective study was to elucidate potential confounding factors affecting initial stability of miniscrews inserted to enhance orthodontic anchorage. Four hundred and seven miniscrews inserted in 168 patients treated by 17 orthodontic residents were analysed in a consecutive chart review. The outcome variable was the stability of the miniscrew, measured as a dichotomous variable, 0 if the miniscrew loosened during a 1 week period after insertion to the time of orthodontic force application and a value of 1 otherwise. Potential confounding variables examined were gender, age, jaw, insertion site, tissue type, length and diameter of the miniscrew, and number of previous insertions. Generalized estimating equations (GEE) methods were used to estimate the influence of each factor on stability for the correlated binary outcomes of each patient. A weighted analysis for the GEE approach was also performed for the convergence calculation of the estimation procedure due to a value of 0 in one of the cells. Crude odds ratio (cOR) and adjusted odds ratio (aOR) and their 95 per cent confidence intervals (CI) were calculated for this purpose. The overall success rate after 1 week was 93.1 per cent (379/407). The screws inserted by more experienced clinicians (more than 20 miniscrews) were found to have approximately a 3.6-fold higher success rate of initial stability compared with those inserted by less experienced clinicians after adjusting for the insertion site (aOR = 3.63, P = 0.015). The results of the present study suggest that the initial stability depends on insertion site and clinician experience.

Stability of open bite correction with sagittal split osteotomy and closing rotation of the mandible.

PURPOSE: To determine the long-term stability of bilateral sagittal split osteotomies with counterclockwise (closing) rotation of the mandible combined with rigid internal fixation in the correction of anterior open bite deformities. MATERIALS AND METHODS: A total of 28 patients who had completed orthodontic therapy and had at least 1 year of postoperative follow-up were evaluated using cephalometric analysis for dental and skeletal changes. We evaluated 7 angular and 6 linear measurements cephalometrically at 3 points for each patient: immediately preoperatively, immediately postoperatively, and after a minimum of 1 year of postoperative follow-up. RESULTS: Of the 28 patients, 12 exhibited some degree of opening rotation (range 1% to 64%, mean 16%), and 16 showed no open rotation or continued to experience bite closure. However, all patients had a positive overbite at 1 year of follow-up, indicating that even though skeletal relapse was observed postoperatively, dental compensation resulted in the maintenance of the occlusal relationships. CONCLUSIONS: Bilateral sagittal split osteotomies and closing rotation of the mandible using rigid fixation is a relatively stable procedure and a viable surgical treatment option for the correction of anterior open bite in instances in which maxillary osteotomies are not indicated to improve or enhance facial esthetics.

Developing pediatric three-dimensional upper airway normative values using fixed and interactive thresholds.

OBJECTIVE: To develop and compare pediatric upper airway three-dimensional normative values using the two most commonly used cone beam computed tomography (CBCT) software: Invivo5 (fixed threshold) and Dolphin 3D (interactive threshold). STUDY DESIGN: Out of 3738 CBCT scans, scans of 81 pediatric patients were utilized after applying strict exclusion criteria. The sample was grouped into two age groups (7-11 and 12-17 years). Intra-class correlation coefficient was used to test intra-rater and inter-rater reliability and showed coefficients greater than 0.9 indicating good reliability of the methods used. RESULTS: Paired t tests showed that volumetric and area measurements obtained using Dolphin 3D were significantly larger than those obtained using Invivo5 (p < 0.05). The mean minimal cross-sectional areas (MCSA) for Dolphin 3D were 151 mm2 and 177 mm2 for age groups 1 and 2, respectively. The mean MCSA values for Invivo5 for age groups 1 and 2 were 120 mm2 and 145 mm2, respectively. CONCLUSION: Pediatric upper airway volumetric, area, and linear measurements were reported after applying strict exclusion criteria including a validated sleep questionnaire. Our goal is that clinicians utilize the proposed-here normative values for screening and assist in the timely diagnosis and management of pediatric sleep apnea.

The effect of raisin-containing cereals on the pH of dental plaque in young children.

PURPOSE: The purpose of this study was to investigate the effect of raisins and raisin-containing cereals on plaque acidogenicity in young children. METHODS: Twenty 7- to 11-year-olds participated in this randomized controlled study. The test food groups were raisins, bran flakes, commercial raisin bran cereal (cRB) and experimental raisin bran cereal (eRB). Ten percent sucrose and sorbitol were used as positive and negative controls. The in vivo plaque pH was measured with a touch microelectrode (Beetrode) prior to (baseline) and 2, 5, 10, 15, 20, and 30 minutes after consuming a test food or rinsing with a control solution. RESULTS: All test foods reduced plaque pH over the 30-minute period, with the largest reduction noted between 10 to 15 minutes. Consumption of cRB produced the largest pH drop compared to the other food groups at 10 minutes (P < .001). Addition of raisins to bran flakes (eRB) promoted a less pronounced pH drop beyond 10 minutes when compared to bran flakes alone (P < .001). Consumption of raisins or eRB did not reduce plaque pH below 6 over the 30-minute testing period. CONCLUSION: The ranking in order of study test foods in promoting plaque acidogenicity is: (1) commercial raisin bran cereal; (2) bran flakes; (3) raisins; and (4) experimental raisin bran cereal.

Marfan syndrome-an orthodontic perspective.

Marfan syndrome is a heritable disorder of connective tissue that can affect the heart, blood vessels, lungs, eyes, bones, and ligaments. It is characterized by tall stature, elongated extremities, scoliosis, and a protruded or caved-in breastbone. Patients typically have a long, narrow face. A high-arched palate produced by a narrow maxilla and skeletal Class II malocclusion due to mandibular retrognathia are other common features. For a patient with no family history of the disorder, at least three body systems must be affected before a diagnosis can be made. Individuals affected by the syndrome routinely seek orthodontic treatment to correct the orofacial manifestations. In this report, the authors present the records of three patients with Marfan syndrome who were treated at a dental school. Two patients had severe periodontal disease in the absence of significant contributing local factors. The presentation of systemic symptoms and typical physical characteristics varied. The syndrome thus went unnoticed in one patient for many years. We discuss here the observed intraoral findings and the progress of orthodontic treatment to provide a brief overview of the challenges involved in treating such patients.

Relationship between rapid maxillary expansion and nasal cavity size and airway resistance: short- and long-term effects.

INTRODUCTION: The availability of new, reliable, objective, and 3-dimensional techniques to assess the effects of rapid maxillary expansion on the morphology of the maxillary dental arch, nasal cavity dimensions, and nasal airway resistance led to the development of this research. METHODS: Thirty-eight subjects participated in this study (mean age, 13 years). Data were collected before expansion, when the expander was stabilized, when the expander was removed, and 9 to 12 months after the expander was removed. Subjective assessment of improvement in nasal respiration was obtained when the expander was stabilized. Three-dimensional imaging and acoustic rhinometry were used to assess the virtual cast and the nasal cavity, respectively. RESULTS AND CONCLUSIONS: The statistically significant short-term effects of RME were (1) mean increases in palatal area, volume, and intermolar distance; (2) a mean reduction of nasal airway resistance; and (3) mean increases in total nasal volume and nasal valve area. Our long-term findings were the following: (1) mean palatal area and intermolar distance were reduced, while palatal volume was stable, and (2) nasal airway resistance was stable, whereas mean nasal cavity volume and minimal cross-sectional area increased. Additionally, 61.3% of our subjects reported subjective improvement in nasal respiration. Weak correlations were found between all variables analyzed.