Colleen M. Kummet

Phenotypic diversity in white adults with moderate to severe Class III malocclusion

INTRODUCTION Class II malocclusion affects about 15% of the population in the United States and is characterized by a convex profile and occlusal disharmonies. The specific etiologic mechanisms resulting in the range of Class II dentoskeletal combinations observed are not yet understood. Most studies describing Class II phenotypic diversity have used moderate sample sizes or focused on younger patients who later in life might outgrow their Class II discrepancies; such a focus might also preclude the visualization of adult Class II features. The majority have used simple correlation methods resulting in phenotypes that might not be generalizable to different samples and thus might not be suitable for studies of malocclusion etiology. The purpose of this study was to address these knowledge gaps by capturing the maximum phenotypic variations in a large sample of white Class II subjects selected with strict eligibility criteria and rigorously standardized multivariate reduction analyses. METHODS Sixty-three lateral cephalometric variables were measured from the pretreatment records of 309 white Class II adults (82 male, 227 female; ages, 16-60 years). Principal component analysis and cluster analysis were used to generate comprehensive phenotypes to identify the most homogeneous groups of subjects, reducing heterogeneity and improving the power of future malocclusion etiology studies. RESULTS Principal component analysis resulted in 7 principal components that accounted for 81% of the variation. The first 3 components represented variation on mandibular rotation, maxillary incisor angulation, and mandibular length. The cluster analysis identified 5 distinct Class II phenotypes. CONCLUSIONS A comprehensive spectrum of Class II phenotypic definitions was obtained that can be generalized to other samples to advance our efforts for identifying the etiologic factors underlying Class II malocclusion.

Comparison of observer reliability of three-dimensional cephalometric landmark identification on subject images from Galileos and i-CAT cone beam CT

OBJECTIVES Recently, there has been increasing interest in the use of cone beam CT (CBCT) for three-dimensional cephalometric analysis and craniofacial reconstruction in orthodontic and orthognathic surgical treatment planning. However, there is a need to redefine the cephalometric landmarks in three dimensional cephalometric analysis and to demonstrate the reproducibility of landmark identification on the type of CBCT machine being used. METHODS CBCT images of 20 subjects aged 15-25 years were selected, ten each from Galileos(®) (Sirona Dental Systems Inc., Bensheim, Germany) and Next Generation i-CAT(®) (Imaging Sciences International, Hatfield, PA). 2 observers located 18 landmarks on each subject twice using Dolphin-3D v. 11 software (Dolphin Imaging and Management Systems, Chatsworth, CA). Inter- and intraobserver reliability was assessed using Euclidean distances and linear mixed models. RESULTS Overall, the intra- and interobserver reliability was excellent for both machines. The landmarks Gonion, Nasion, Orbitale and Anterior Nasal Spine (ANS) showed the greatest median Euclidean distances for both intra- and interobserver measurements. There were significant observer effects in the unified models for Sella, Menton and all six dental landmarks. For Sella, the distances between the measures were significantly smaller (more closely spaced) on the i-CAT machine than on the Galileos in both intra- and interobserver measurements. CONCLUSIONS The intra- and interobserver reliability was excellent for both machines. Some of the landmarks were not as reproducible as others. Which machine produced the highest reliability depended on the landmark considered.

Refinement of Pointwise Linear Regression Criteria for Determining Glaucoma Progression

PURPOSE A variety of pointwise linear regression (PLR) criteria have been proposed for determining glaucomatous visual field progression. However, alternative PLR criteria have only been assessed on a limited basis. The purpose of this study was to evaluate a range of PLR slope and significance criteria to define a clinically useful progression decision rule for longitudinal visual field examinations. METHODS Visual field data for each of 140 eyes (one per participant among 96 cases and 44 controls) were evaluated using the Humphrey Field Analyzer II program 24-2 Swedish interactive thresholding algorithm standard test strategy and Goldmann size III stimuli. The pointwise linear regression A2 (PLRA2) method was used to analyze the data, which included nine visual field examinations performed every 6 months for 4 years. Data from the Ocular Hypertension Treatment Study (OHTS) were used to validate the decision rule. RESULTS Several slope criteria produced specificities of 0.90 or higher, particularly slope criteria of less than -1.2 dB/y. The use of the slope criterion less than -1.2 dB/y at a significance level of P < 0.04 for classification resulted in a hit rate of 0.38, more than a 2-fold increase compared with a commonly used standard slope criterion of less than -1.0 dB/y at a significance level of P < 0.01. A similar increase in the hit rate was shown for a slope of less than -1.2 dB/y and P < 0.04 compared with the standard criterion in the independent OHTS validation data. CONCLUSIONS When systematically evaluating criteria for detecting glaucoma progression, PLR criteria can be refined by requiring a stricter slope criterion such as less than -1.2 dB/y and relaxing the significance criterion to P < 0.04. Increasing the hit rate of PLR will be useful for early detection and treatment of glaucoma.

Passive Smoke Exposure as a Risk Factor for Oral Clefts—A Large International Population-Based Study

Maternal cigarette smoking is a well-established risk factor for oral clefts. Evidence is less clear for passive (secondhand) smoke exposure. We combined individual-level data from 4 population-based studies (the Norway Facial Clefts Study, 1996-2001; the Utah Child and Family Health Study, 1995-2004; the Norwegian Mother and Child Cohort Study, 1999-2009; and the National Birth Defects Prevention Study (United States), 1999-2007) to obtain 4,508 cleft cases and 9,626 controls. We categorized first-trimester passive and active smoke exposure. Multivariable logistic models adjusted for possible confounders (maternal alcohol consumption, use of folic acid supplements, age, body size, education, and employment, plus study fixed effects). Children whose mothers actively smoked had an increased risk of oral clefts (odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.11, 1.46). Children of passively exposed nonsmoking mothers also had an increased risk (OR = 1.14, 95% CI: 1.02, 1.27). Cleft risk was further elevated among babies of smoking mothers who were exposed to passive smoke (OR = 1.51, 95% CI: 1.35, 1.70). Using a large pooled data set, we found a modest association between first-trimester passive smoking and oral clefts that was consistent across populations, diverse study designs, and cleft subtypes. While this association may reflect subtle confounding or bias, we cannot rule out the possibility that passive smoke exposure during pregnancy is teratogenic.

Complementary and alternative medicine usage by patients of a dental school clinic.

This pilot study investigated the prevalence and specific reasons for usage of complementary and alternative medicine (CAM) among patients of a dental school clinic. Four hundred and two patients completed a 30-page survey on CAM usage. A higher rate of CAM usage was found in this dental school clinic population than rates previously reported in a general population. More than three-quarters (76.1%) of the respondents reported using at least one CAM treatment in the past 12 months; 93.3% reported using at least one CAM treatment at some time in their lives. High rates of chiropractic use were found in this population. Tooth pain was the most frequently reported dental condition motivating CAM use. About 10% of dental school clinic patients use topical oral herbal and/or natural products to treat dental conditions, most frequently for preventive/oral health reasons or for tooth pain.

Use of Intravenous Sedation in Periodontal Practice: A National Survey

BACKGROUND In the early 1990s, much of the periodontal profession perceived an upcoming shift in services performed by periodontists as many patients began to expect sedation for periodontal surgery. As a result, in 1993 the American Academy of Periodontology began encouraging postgraduate periodontal programs to train residents in the use of conscious sedation. The purpose of this study is to investigate trends in the training of intravenous (i.v.) sedation in residency and its use in periodontal practice. METHODS An 18-question survey was mailed to a sample of 1596 active periodontists throughout the United States and Canada. Thirty-seven percent (596) of the surveys were returned. Twenty-two retired periodontists responded and were excluded from the analysis. The data from the remaining 574 surveys were analyzed with a statistical software package. RESULTS Approximately half (49.8%) of the survey respondents offer i.v. sedation in their practices. Among respondents who completed residency prior to 1996, 42.6% offer i.v. sedation compared with 64.2% of respondents who completed residency in 1996 or later. The number of i.v. sedations performed in residency was moderately correlated with the number of i.v. sedations personally performed in periodontal practice (Spearman r = 0.5169, P <0.0001). The largest percentage of periodontists using i.v. sedation (74.0%) was reported from American Academy of Periodontology District 5 (south central United States), whereas District 7 (New Jersey and New York) reported the lowest usage (15.6%). CONCLUSIONS Approximately half of all periodontists provide i.v. sedation, with more recent periodontal graduates more likely to personally offer and administer i.v. sedation services for their patients. Regional differences exist in the use and training of i.v. sedation.

Communication: Antimicrobial Activity of SMAP28 with a Targeting Domain for Porphyromonas gingivalis

Antibiotic therapy is often used with mechanical therapy to treat periodontal disease. However, complications associated with antibiotic use can occur. A ‘bacteria-specific’ targeted approach would eliminate some of these complications and kill specific periodontopathogens without harming the commensal bacteria. One such approach is to couple antimicrobial peptides to a ligand, pheromone, or antibody specific for the periodontopathogen, Porphyromonas gingivalis. To assess the feasibility of this approach, we attached PQGPPQ, a peptide from proline-rich protein 1 to either the N-terminus of SMAP28 (peptide ZS37-37) or the C-terminus of SMAP28 (peptide ZS37-38) to see whether it has potential as a carrier ligand to deliver SMAP28 to the surface of P. gingivalis. For Escherichia coli and Aggregatibacter actinomycetemcomitans, the median minimal inhibitory concentration (MIC) of ZS37-37 was higher than the median of SMAP28 alone, although the median MIC of ZS37-38 was lower than that of SMAP28 alone. For P. gingivalis, there was no difference in the median MIC values. For S. aureus, the median MIC was higher for ZS37-37 and ZS37-38 compared to SMAP28 alone, particularly for ZS37-38. For Fusobacterium nucleatum, the median MIC values were equal for ZS37-37 and ZS37-38 and higher than the median MIC for SMAP28 alone. Attaching PQGPPQ to SMAP28 did not greatly increase the antimicrobial activity of ZS37-37 or ZS37-38 for P. gingivalis nor substantially decrease the antimicrobial activity of ZS37-37 or ZS37-38 for the four other microorganisms tested. This is an initial step to develop a selective antimicrobial agent that has ‘targeted’ antimicrobial activity without adverse reactions often associated with the use of broad-spectrum antibiotics.

Patterns of complementary and alternative medicine (CAM) use among dental patients.

OBJECTIVES Complementary and alternative medicine (CAM) is a diverse collection of approaches used to prevent or treat diseases. The goal of this study was to examine relationships between dental patient characteristics and current usage of CAM therapies. METHODS The CAM definition encompassed 24 therapies excluding prayer. Associations and trends in usage were assessed for gender, income, education, and age. Multivariable logistic and negative binomial models were used to identify factors impacting the use and number of CAM therapies used. RESULTS In dental patients (n = 402), nearly 67 percent of subjects reported at least one CAM treatment. Gender was significantly associated with recent utilization of CAM, biological, manipulative (all P < 0.01), and mind-body (P = 0.04) therapies, as well as the number (P < 0.01) of therapies used. Higher education levels were significant in usage of any CAM, biological, and mind-body therapies (P < 0.01). CONCLUSION A large proportion of dental patients reported use of CAM therapies. While CAM therapies and those who use them are diverse, given their widespread use, they clearly have potential impacts on the oral health of the public. Knowledge of the characteristics of dental patients who use CAM therapies is a first step in developing a broader understanding how CAM therapies and associated beliefs may affect oral health and public health programs.

Candidate gene study for smoking, alcohol use, and body weight in a sample of pregnant women

Abstract Objective: Prenatal smoking, alcohol use, and obesity have significant effects on maternal and fetal health. However, not much is known about the genetic contributions to these risk factors among pregnant women. We evaluate the associations between several candidate genes and smoking, alcohol use, pre-pregnancy body weight, and weight gain during pregnancy in a sample of pregnant women. Methods: The study analyzes a sample of about 1900 mothers from the Danish National Birth Cohort. We test the association between 1450 SNPs in/near 117 genes/loci and various risk factor measures. Results: Only a few SNPs in FTO were significantly associated with pre-pregnancy obesity and body mass index (4 and 2 SNPs, respectively) after SNP-level correction for multiple testing. A few loci were significantly related to various smoking measures (any smoking, quitting and cigarette number) with gene/locus-level correction for multiple testing, but not after SNP-level correction. Similarly, some loci were significant for the alcohol measures at the gene/locus-level but not at SNP-level correction. Conclusion: The study suggests that the majority of the evaluated candidate genes may not play an important role in influencing these risk factors among pregnant women, highlighting the importance of other genetic factors and non-genetic contributors to their etiology.

Noninvasive Neurally Adjusted Ventilatory Assist in Premature Infants Postextubation

Background Neurally adjusted ventilatory assist (NAVA) has distinct advantages when used invasively compared with conventional ventilation techniques. Evidence supporting the use of noninvasive NAVA is less robust, especially in the very low birth weight (VLBW) population. Objective To determine whether synchronized noninvasive ventilation via neurally adjusted ventilatory assist (NIV NAVA) supports ventilation postextubation in premature infants. Methods A retrospective analysis of a cohort of twenty‐four former VLBW (<1.5 kg) infants from July 2011 to October 2012. Decreased or unchanged capillary pCO2 after increasing NAVA support was used as a marker for adequately supported noninvasive ventilation. The Wilcoxon signed‐rank test was used to compare pre‐ and post‐NAVA intervention (&agr; = 0.05). Results Ventilation improved after an increase in NIV NAVA level in 83% of the premature infants studied (20/24) with a decrease in median pCO2 by 5 mm Hg (p = 0.0001). Conclusion NIV NAVA can provide synchronized postextubation ventilatory support as measured by decreased pCO2 in premature infants.