ARCHIVE OF ABSTRACTS




2015 Abstracts, Halifax, Nova Scotia


Investigation of Accessory Canals in Primary Molars, A Micro-Computed Tomography Study


Dr. Mark Berscheid, University of Manitoba


Objectives: This study was designed to examine accessory canals in the furcation area of extracted primary molar teeth using micro-computed tomography.

Material and Methods: Extracted primary maxillary and mandibular molars (n=65) were scanned at a resolution of 9.0 µm in a micro-CT scanner (Skyscan 1176). The patient age, as well as type of tooth (maxillary versus mandibular, first versus second molar) were recorded for each tooth and DataViewer v. 1.5.1 was used to interpret scanned images. Presence or absence of canals, canal patency, number of canals, and size of canals was recorded for each tooth. Collected data was analyzed using SPSS 20.0 for Windows. Fisher’s Exact and Kruskal-Wallis tests were used to identify association between variables.


Results: Canals were observed in the furcation area of 83% of molars scanned, and patent canals were found in the furcation area of 8% of molars. The mean number of canals per tooth was found to be 2.6. Second molars were observed to have a significantly higher number of canals than first molars (p<0.05). No significant association was found between patient age and the number of canals present. Also, no significant relation was found between tooth type or patient age and diameter of canals.


Conclusions: The following conclusions can be made based on the results of this study:

1.   While the majority of primary molar teeth have accessory canals in the furcation area, only a minority of primary molar teeth have accessory canals that are patent.

2.   Micro-computed tomography is an effective tool for analyzing accessory canals in the furcation region of extracted primary molars.

3.   Other factors besides accessory canals may be responsible for the interradicular pathological bone resorption observed following pulpal necrosis in primary molars.

 



Survey of Professional Burnout and Depression among Pediatric Dentists in the United States

Dr. Leena Chohan, MSc Candidate, Faculty of Dentistry, University of Toronto

Committee Members: Dr. H Nainar, Dr. C Dewa, Dr. W El-Badrawy


Objectives: 1) To assess the prevalence of occupational burnout and depression among pediatric dentists in the United States and 2) To explore for differences in the prevalence of burnout and/or depression by gender, age, marital status, practice type, geographical location, number of years in practice, and number of hours worked per week.

 

Methods: A self-administered online anonymous survey was sent to all active members of the American Academy of Pediatric Dentistry residing in the United States. Survey Monkey® was used to administer the 37-item online survey. Questionnaire items consisted of three domains: demographic information (7 items); the Maslach Burnout Inventory (MBI) (22 items), including the three dimensions of Emotional Exhaustion, Depersonalization and Personal Accomplishment; and lastly the Patient Health Questionnaire 8 (PHQ-8) (8 items).

 

Results:  A total of 4739 surveys were sent and resulted in 785 responses (response rate = 17%). Nine percent of respondents had occupational burnout based on high scores in 2 dimensions of the MBI, Emotional Exhaustion and Depersonalization. Seven percent of the sample had PHQ-8 scores indicative of depression. Preliminary analyses indicated that those practicing in a group practice were less likely to have Emotional Exhaustion. Those who practiced for 40 or more hours per week were more likely to have Emotional Exhaustion (p<0.05). Prevalence of burnout and depression were correlated.

 

Conclusions: A small but notable number of U.S. pediatric dentists had occupational burnout and depression.



Trends in Caries-Related Emergency Visits to a Paediatric Hospital

M.Sc. candidate: Dr. Molly Ehrlich, DMD

Committee Members: Drs. Edward Barrett, Michael Casas and Carlos Quiñonez


Objectives: The aim of this study was to determine the annual frequency of children who presented to a tertiary care pediatric hospital with a caries-related emergency complaint over a ten-year period. The secondary aims of this study were to determine the demographic characteristics of the families that presented, the types of caries-related emergency complaints, treatment provided and costs associated with treatment.

 

Methods: A retrospective review of the health records of all children who presented to SickKids with caries-related emergency complaints and were seen by a dental resident from January 1, 2003 to December 31, 2012 was completed. A visit for an emergency dental complaint seen within the ED was identified as a registration where the principal diagnosis at discharge was coded using the International Classification of Disease block code equal to K00-K14 (diseases of oral cavity, salivary glands and jaws). Eligibility was determined by reviewing the corresponding health. Records were reviewed and data abstracted on: patient demographics, presenting complaints, co-morbidity, dental treatments, final diagnosis and patient disposition. A cost analysis was provided by SickKids Decision Support Services.

 

Results: During the ten-year period, 2,020 children with caries-related complaints presented to the ED. Visit rates for caries-related complaints increased by 48% (P= 0.0049) over the study period. 68% of the patients were younger than 6 years. Of the 2,020 patients, 1,217 were seen by the dental resident. There were 276 admissions and 85 were treated under general anaesthetic. The mean cost of care within the ED was $248 (CND).  

 

Conclusions: Over the study period there was an increasing trend in caries-related ED visits to a pediatric hospital. EDs have become an important site for people with caries-related sequelae to seek urgent care, particularly for pre-elementary school age group. These visits utilize hospital resources with an average per visit cost of $248.

 


The “W5” of pediatric hospital dental emergencies: A quantitative and qualitative analysis


Dr. Jennifer Park 1*, Campbell, K2

 

1MSc. Candidate, Faculty of Dentistry, University of British Columbia, Vancouver, Canada; 2Faculty of Dentistry, University of British Columbia; Dept. of Dentistry, BC Children’s Hospital, Vancouver, Canada

 

 

Objective:  To explore factors contributing to a reported increase in emergencies presenting to the Department of Dentistry at BC Children’s Hospital over recent years by investigating the “who, what, when, where and why” of their hospital management.

 

Methods: A two-phase study incorporated quantitative (retrospective chart review) and qualitative (personal interview) elements. Phase 1 - Records of 300 emergencies from 2009 to 2013 were systematically selected and reviewed. Patient demographics; source of referral; time/day of visit; nature, scope and management of emergency; and follow-up care were analyzed (Pearson’s Chi-squared Tests and Odds Ratios). Phase 2 - Twenty-five interviews with parents of children who recently experienced dental emergencies were recorded and analyzed for common themes in reported factors/circumstances.

 

Results: Emergencies included dentoalveolar trauma (56.7%), dental pain (20%), swelling from advanced dental disease (13.3%), and ‘other’, unrelated to trauma or caries (10%). Common patients characteristics were: healthy, male, young age (<7 years old), proximity of residence to the hospital and low socioeconomic status. Primary source of referral was the emergency department; emergencies presented equally throughout the week. No immediate intervention was necessary for the majority of cases and follow-up with a community dentist was advised. Factors contributing to a parent’s decision to seek emergent dental care in a hospital included: perception of urgency; concern for their child’s well being; desire for reliable care by a reputable institution; limited understanding of dental disease and consequences of poor oral care; and financial and access to care barriers.

 

Conclusion: Dentoalveolar trauma and untreated advanced dental caries compel families to seek hospital-based dental emergency services. More aggressive efforts to improve awareness of the importance of early dental visits; development of curricula emphasizing management of anxious children and exposure to pediatric emergencies; and reinforcing the ethical responsibility of dentists to provide after-hours emergency care may help to reduce burden on hospital resources.

 

Acknowledgements: Project funding provided by British Columbia’s Children’s Hospital 2012 Telethon Projects Award.



A Retrospective Study of Stainless Steel Crowns as a Posterior Permanent Tooth Restoration Option


Dr. Alison Sigal

Year of Convocation: 2016

Degree: Master of Science, Department of Paediatric Dentistry, University of Toronto


Objectives: This retrospective cohort study was performed to assess the long-term clinical and radiographic outcomes of the stainless steel crown (SSC) as a posterior permanent tooth restoration option.


Methods: Study included 271 patients with at least one SSC restoration of their permanent posterior dentitions registered at the Mount Sinai Hospital’s Dentistry Clinic for Persons with Special Needs. All posterior permanent tooth restorations were documented accounting for 2623 restorations: 766 SSC, 1651 Amalgam, 204 Composite Resin, and 2 Glass Ionomer.


Radiographic analysis of SSC restorations included 61 patients, 127 bitewing (BW) and 118 periapical (PA) radiographs (59 pre and post SSC placement). BW films permitted electronic measurement of interproximal bone levels. Pre/Post-SSC PA films permitted assessment of periapical status utilizing the Periapical Index (PAI) Scoring Scale.


Results: The 10-year survival rate (95% CI) for SSC restorations was 82.6% (78.8%, 86.0%). The median follow-up was 5.1 years with a range of 0-33.1 years. 675 recorded as intact at final chart assessment with 91-recorded true failures (Recementation: 2, Replacement: 33, Extraction: 56). Breakdown of diagnoses at time of failure included: Caries: 8, Loose/Lost SSC: 2, Pulpal Necrosis/pathology: 21 and Other: 25.


The average alveolar bone height recorded from distal and mesial sites of SSC restorations respectively were 1.40mm (0.53 – 3.78mm) and 1.36mm (0.53 – 2.84mm). 92.1% (117/127) of distal and 93.7% (119/127) of mesial sites recorded as healthy, non-resorbed. All 59 Pre-SSC PA had healthy periapical scores (fifty: 1, nine: 2). Post-SSC PA; 13 SSC restorations had PAI score changes recorded over an average duration of 8.4 years (1 – 29.1 years);seven changed from 1 to 2, six from 2 to 1, all consistently representing healthy periapical structure.


Conclusion: A stainless steel crown restoration is an effective long-term treatment option for the permanent posterior dentition with negligible effects on the surrounding periodontal alveolar bone heights and periapical status.



Professional Uncertainty in Providing Dental Care for Special Needs Children

 

Dr. Shan Sun S1*, Bush HM2, Harrison R1, Poon B3, Mathu-Muju KR1

 

1Department of Oral Health Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, Canada; 2
Department of Biostatistics, College of Public Health, University of Kentucky, Lexington, U.S.A.; 3School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, Canada

 

Objective:  The aim of this study was to determine whether scientific (knowledge base), practical (clinical infra-structure) or personal (sense of social justice) sources of uncertainty among British Columbia general dentists posed the greatest barriers to their ability to treat children with special health care needs (CSHCN).

 

Methods: A 74-item self-administered electronic questionnaire was distributed to a random sample of 1200 general dentists registered with the British Columbia Dental Association. Variability in clinical practice (examine, examine and refer, refer) was assessed using three case scenarios featuring CSHCN with a 1) behavioral difficulty (autism spectrum disorder), 2) physical disability (bleeding disorder) or 3) combination (cerebral palsy). Respondents were asked to use a five-point Likert-type scale to rate uncertainty levels from scientific, practical and personal sources in each case scenario. One-sample t-tests were used to compare differences between examination/refer for examination and treat/refer for treatment group pairs. All items in the scientific, practical and personal domains were tested using multivariate analyses (logistic regression) for all three cases. Data was analyzed and classified based on a novel taxonomical approach.

 

Results: The response rate was 20.2% (n=226). A higher percentage of dentists were willing to examine and treat a child with a bleeding disorder (59.7%) or cerebral palsy (63.0%) compared to a child with autism (54.5%). Among those who would refer, the most significant reported sources of uncertainty in general are scientific (knowledge of management, ability to diagnose disease) and practical sources (staff training, inadequate facilities, busy practice).

 

Conclusions: While the majority of general dentists showed interest and desire to provide care for CSHCN, scientific and practical uncertainties are significant factors affecting their ability to provide care.  Recognizing the presence of uncertainty in dental care can inform policy changes to help dentists either decrease reducible uncertainties or cope with those that are irreducible. Implementation of increased undergraduate curriculum hours and hands on experience with CSHCN as well as expanded coverage of public and private dental benefits may help reduce barriers to care for CSHCN, in particular for those with conditions such as autism spectrum disorder.

 

Acknowledgements: Children with Special Health Care Needs Grant #F13-00854, British Columbia Dental Association.




2014 Abstracts, Montreal, Quebec



 

Evaluating Parents' and Pediatricians' Awareness of the Cariogenicity of Pediasure                                                                       Emily Lin Jun Chen, D.M.D., Janna Danbe, D.M.D., Nuntiya Kakanantadilok, D.M.D.
Montefiore Medical Center, Bronx, New York, U.S.A.       

Objectives:
1) Determine reasons why parents give Pediasure (nutritional supplement) to their children,
2) Investigate how parents use this product, 
3) Determine what information pediatricians provide to their patients for use of the nutritional supplement,
4) Evaluate pediatricians' knowledge of the cariogenicity of the nutritional supplement.

Methods:     
A survey was administered to the parents of patients at the Montefiore Medical Center Pediatric Dental Clinics, who reported their child’s usage of the nutritional supplement. The goal of the survey was to evaluate the parents’ knowledge of the nutritional supplement as a potential caries risk factor, similar to other sugary beverages. The questionnaire helped determine why patients were using the nutritional supplement and what type of professional anticipatory guidance they had received regarding its use, if any. Similarly, a survey was administered to pediatric medicine residents and pediatricians at Montefiore Medical Center (who treat the same patient population) to determine what information and or instructions were given regarding the consumption of the nutritional supplement.

Results and Conclusions:
This study demonstrated the need to discuss nutritional supplement usage at dental visits as part of routine anticipatory guidance, in an effort to reduce patient’s dental caries risk.  Neither parents nor pediatricians were aware of the relative sugar content of the nutritional supplement compared to other beverages known for their high sugar contents. Parents were unaware that this nutritional supplement is cariogenic, and they were giving the nutritional supplement because they were concerned about their child not eating enough. They did not routinely discuss the usage of the nutritional supplement and caries prevention with their child’s pediatrician. Pediatricians did not routinely provide oral hygiene counseling for patients using the nutritional supplement. Pediatricians should include oral hygiene counseling and discuss the cariogenicity of the nutritional supplement, as part of their routine anticipatory guidance. 73% of parents who purchased the nutritional supplement without the pediatrician’s recommendation, were willing to discontinue product usage, when informed of the cariogenicity.

Changes in parental behavior depend on the pediatric dentist providing anticipatory guidance that includes nutritional counseling.  Dentists must ask about the use of these products.


       
Trends in Caries-Related Emergency Visits to a Paediatric Hospital

Molly Ehrlich, DMD
Committee Members: Drs. Edward Barrett, Kathy Boutis, Michael Casas and Carlos Quiñonez

Objectives:
The aim of this study was to determine the annual frequency of children who presented to a tertiary care pediatric hospital with a caries-related emergency complaint over a ten-year period. The secondary aims of this study were to determine the demographic characteristics of the families that presented to the hospital, the types of caries-related emergency complaints, the treatment provided and the costs associated with providing this care.

Methods:
A retrospective review of the health records of all children who presented to SickKids with caries-related emergency complaints from January 1, 2003 to December 31, 2012 was completed. Records were reviewed and data abstracted on: patient demographics, presenting complaints, co-morbidity, dental imaging, dental treatments, final diagnosis and patient disposition.  Patients seen in 2007- 2012 had additional information collected including wait times (total time spent in the emergency department), Comprehensive Ambulatory Classification System (CACS) grouping, Resource Intensity Weight (RIW), catchment area and direct and indirect costs associated with care. Time series analysis will be used to explore trends and patterns within the data. Descriptive statistics will be calculated, including the mean and standard deviation for quantitative measures such as age, neighborhood income quintile and deprivation index quintile. Frequencies of chief complaints, diagnoses and treatments rendered will be calculated and compared by year of presentation. Mean cost of treatment, cumulative total costs and total time spent in the emergency department will be calculated and compared by year of presentation.

Results:
The results are pending.  Data collection is currently underway and planned to be completed by August, 2014.

Conclusions:
Conclusions are pending.
      
      

Oral Inflammatory Load as a Risk Factor for Spontaneous Preterm Birth in Women at Risk of Preterm Delivery


Marie-Lyne Gosselin, DMD
Supervisor: Dr. Michael Sigal, Dr. Howard Tenenbaum, Dr Michael Glogauer
Committee Members: Dr Wendy Whittle, Dr Amir Azarpazhooh, Dr Michael Goldberg
       
Objectives:
The primary aim of this study was to explore the possible association between oral inflammatory load  (OIL) and spontaneous preterm birth (PTB) in pregnant women who are at risk of preterm delivery by evaluating their exposure to indicators of OIL. This study also aimed to compare oral neutrophils counts in pregnant women at risk of spontaneous preterm delivery with oral neutrophil counts in pregnant women with no foreseeable risk of spontaneous preterm delivery.
       
Methods:
Following specific inclusion and exclusion criteria, pregnant women at risk for PTB were recruited to participate in this prospective cohort study. The cells from oral rinse samples provided by the participants were stained with acridine orange, and neutrophil counts (primary exposure variable), were carried out visually by using a fluorescence microscope and a hemocytometer and via spectroscopy. Traditional and non-invasive assessment measures of periodontal health were also recorded and a blood sample was collected to assess the MMP-9 and the fetuin (Ahsg) serum level (secondary exposure variables). Pregnancy outcome along with demographic, dental and medical data were collected using a questionnaire, the antenatal dental chart, the delivery records and a post-delivery phone call questionnaire.

Results:
The results are pending. Statistical measures of risk will be calculated to measure the risk of PTB following the exposure to the observed variables. To control for confounders, a multiple logistic regression analysis will be executed.

Conclusion:
This study will bring about a deeper understanding of the possible relation between OIL, related to periodontal inflammation that could include either or both periodontitis and gingivitis, in pregnant women at high risk for PTB and overall birth outcomes.  By relying principally on non-invasive, fast and straightforward tools for assessment of OIL, this approach could be used, even by those without dental training, to identify women at  risk for PTB.

 

 

COMPOSITE BOND STRENGTH OF ONE AND TWO - STEP ADHESIVE SYSTEMS USED FOR RESTORATIONS ON PRIMARY TEETH USING VARYING ACID ETCH APPLICATION TIMES.


Brad Klus, University of Manitoba
The objective of this study was to determine whether the composite bond strength acquired using a single step self-etching bonding system is as or more effective when compared to the two step etch-rinse-bond system at clinically relevant in-vitro standards.


A total of 80 extracted human deciduous with at least one intact smooth surface were collected with parental consent. Collected teeth were randomly assigned to one of four treatment protocols (n=20): single step self-etch (Adper Prompt L-Pop, 3M ESPE), two step etch (15s)-rinse-bond (Optibond Solo Plus, Kerr), single step self etch (Adper Prompt L Pop, 3M ESPE) with 30s pre-etch, and two step etch (30s)-rinse-bond (Optibond Solo Plus, Kerr). A composite cylinder of uniform shape was bonded to each tooth using the designated adhesive system and specimens were tested with a universal testing machine. Descriptive statistics and statistical analysis was performed.


Median shear bond strengths for all specimens, regardless of treatment group, ranged from 3.25 MPa to 43.13 MPa. These values are above suggested minimum clinical required values of 3MPa. A Kruskal-Wallis analysis between treatment groups found statistical significance (p<0.05) for shear bond strength between the groups and both one step system protocols, had higher mean and median shear bond strength values than the two step systems.


An adhesive remnant index (ARI) was analyzed to confirm uniform adhesive fracture between all four treatment groups. Both a Fisher’s exact test, and a Hantel-Haenszel statistic found no significant difference (p<0.05) between the samples.


Based on these findings we concluded that:
1. The ARI score for all treatment groups was not statistically significant, suggesting that the type of bond breakage was consistent regardless of adhesive system used.
2. Both Optibond Solo Plus and Adper Prompt L-Pop systems achieve adequate shear bond strengths as described by current literature.
3. The use of a one-step system to save chair time and aid in patient behavior management may be clinically useful


 

Effect of anticipatory guidance on the presence of cariogenic bacteria in preschool children
       

Nick Lekic, University of Manitoba

Objectives: This study was designed to address whether or not the level (high or low) of Streptococcus mutans in the saliva of preschool children can be used as an indicator of caries risk. 


Material and Methods: Levels of Streptococcus mutans was assessed in saliva of 100 preschool children, before and approximately 6-months after receiving a health promotion intervention known as anticipatory guidance. The S. mutans bacterial level was assessed using an immunoassay system (Saliva-Check MUTANS) based on monoclonal antibody technology. Bacterial counts were determined at baseline as well as at a six month recall examination. Obtained data was analyzed using SPSS 20.0 for Windows to report frequencies and to look for trends and associations between the dependent and independent variables. Bivariate analysis (ANOVA, Chi Square/Fishers/McNemar exact test) was used to identify associations between variables. 


Results: The main finding of this study was that higher levels of Streptococcus mutans were associated with higher caries prevalence at baseline, and caries incidence at follow-up. Furthermore following anticipatory guidance, the levels of Streptococcus mutans were reduced at the subsequent follow-up examination, approaching but not reaching statistical significance, and caries incidence was significantly lower in subjects demonstrating low Streptococcus mutans levels.


Conclusions: Results from this study have shown that anticipatory guidance, offered to caregivers and children at an initial examination, led to a reduction in the proportion of children with high Streptococcus mutans levels upon recall six months later. Children with low Streptococcus mutans levels were also less likely to develop new dental caries. These findings suggest that Streptococcus Mutans counts could be used to assess caries risk and encourages clinicians to provide anticipatory guidance to their patients to help avoid the development of new caries.

 


  “But they stole her teeth.”  Developmentally disabled adults seek dental care

 

Salmasi A*, Harrison R, Brondani M, Rush J

Department of Oral Health Sciences, Faculty of Dentistry, The University of British Columbia, Vancouver


Objectives: Dental services for children and adolescents with special health care needs, such as developmental disabilities, are reasonably accessible in tertiary care hospital dental departments and in the private offices of pediatric dentists.  However, once these young people become  adults, accessing dental care is often problematic.  This qualitative study explored the experiences of adults with developmental disabilities (AWDD) accessing dental services in metro Vancouver. 


Methods: This research used a qualitative, deductive approach.  Recruitment of participants was facilitated by AWDD service organizations and family support groups. Time was devoted to engaging and building relationships with participants before beginning the research.  Consent was obtained from each participant. The focus groups were guided by open-ended questions, audiotaped and then transcribed.  Each focus group lasted, on average, forty minutes. Participants were either “self-advocates” (AWDD who speak or act on behalf of themselves or others on issues that affect people with disabilities) or caregivers (usually parents). Each transcript was read, re-read and coded.  These codes were organized into categories and finally into domains.


Results: Five focus groups with twenty participants were conducted. Seven main domains relating to the experiences of AWDD self-advocate and their family members with dental care providers were identified. These domains were communication, trust, respect, financial issues, transitional services, waiting times and, finally, what makes for a “positive dental experience”.


Conclusions:  The cost of dental care and the need for enhancing government dental benefits for AWDD were concerns expressed primarily by family members. However, problems with communication between dental professionals and AWDDs and respect for the personal autonomy of AWDD  were identified by self-advocates and their carers as issues of concern in the quest for dental care. Ideas for a more positive dental experience were suggested with the hope that these ideas will eventually be communicated to dental providers.


Acknowledgements:  Project funded by BC Dental Association and Canadian Fund for Dental Education.

       

Esthetic Crown Options for the Primary Dentition within Post-Doctoral Residency Programs


Bradford Scheideman, DMD, Jacobi Medical Center

Purpose: To compare the attitude, usage and training of esthetic, full-coverage restorative treatment options in the primary dentition among pediatric dentistry residents and program directors.


Methods: Utilizing an email list from the AAPD, two questionnaires were sent to 907 pediatric dentistry residents and 108 pediatric dentistry program directors. Both surveys investigated the utilization, the learning opportunities provided to the residents, the perceived limitations, and the personal experience of different esthetic, full coverage restorative treatment options. Results were analyzed using standard accepted statistical analysis.


Results: Most pediatric dentistry residencies offer a variety of esthetic, full coverage primary restorative options for anterior teeth, while the majority of programs do not offer any esthetic restorative treatment options for posterior teeth. Residents and dentists both agree that esthetics in the primary dentition are important to parents and pediatric dental residents. There are many barriers to new esthetic primary restorative treatment options. Barriers to zirconia crowns (ZC) include cost, retention, lack of research, lack of personal knowledge/experience, fracture, removal of excess tooth structure, and excess time to place. The major barriers of preveneered SSCs (PVSSC) include patient dissatisfaction and risk of fracture.


Conclusion: Pediatric Dentistry Residencies are adapting to a more esthetic approach for full coverage primary dental restorations. There is a discrepancy between what the director’s state the residents are able to offer in terms of esthetic restorations and what the residents provide to the patients. There is also a discrepancy between the residents’ clinical training and the reported clinical experience in esthetic restorations. The majority of residents are able to learn about PVSSC from faculty members but rely on manufacturer prepared material to educate the residents on ZC. There are several barriers to ZC that need to be addressed before they are universally incorporated into routine restorative procedures by pediatric dentists and residencies.
               

Life-long tooth replacement in the leopard gecko (Eublepharis macularius)
      
Wong, Andrew C.1 Grieco, Theresa M. 1 Richman, Joy M.1

Life Sciences Institute, Faculty of Dentistry, University of British Columbia, Vancouver, Canada

Background: The tooth replacement pattern of the human dentition is characteristic in terms of timing however the understanding of what controls the transition from primary to permanent dentition is lacking. Moreover it is not clear why humans can only replace their teeth once while other animals such as reptiles can replace their teeth throughout life. One potential pathway involved in tooth replacement is the Wingless signalling pathway (Wnt), which leads to uncontrolled budding of supernumerary teeth Gardner’s syndrome in humans.


Objectives: 1) To develop a reptile model, the leopard gecko, in order to study tooth replacement in real-time in vivo. 2) To measure the effect of LiCl, an activator of Wnt signaling, on tooth replacement in longitudinal studies.


Methods: Upper dental arch wax bites of 3 adult leopard geckos were taken weekly. The present/missing teeth were recorded over an 8 month period. The palate was injected bilaterally with LiCl or the control, Sodium Chloride (NaCl), at certain intervals. Post-euthanization, the upper and lower arches were evaluated using Micro CT imaging and with histology.

 

Results: The average replacement frequency per tooth was 7 weeks and there were 42 teeth per quadrant. Slower cycling teeth were interspersed between faster cycling teeth. A posterior-to-anterior wave of replacement emerged but was inconsistent. Additionally, there was limited replacement symmetry between right and left sides. LiCl disrupted the replacement pattern at varying times as the posterior-to-anterior waves became irregular.


Conclusions: Posterior-to-anterior waves of replacement present at certain intervals but repeating coordination of replacement is not readily apparent. LiCl caused irregularity in the replacement wave suggesting Wnt signaling may regulated the natural process of  tooth replacement.


Acknowledgements: Supported by Faculty of Dentistry Research funds and an NSERC Discovery grant to JMR (RGPIN 326908)                             
    
       
Quantifying facial morphogenesis in 3D using Optical Projection Tomography

       

Woo, JM2*, Richman, JM1,2
1Life Sciences Institute, 2Faculty of Dentistry, Division of Pediatric Dentistry. University
of British Columbia


Objectives: In order to study abnormal facial development, reference standards of normal development are required. It is challenging to obtain 3D data on early embryos, since they are comprised of non-differentiated tissue. We used optical projection tomography (OPT) (Bioptonics, UK), which images transparent specimens with UV light. Here we used carefully staged chicken embryos to measure facial morphogenesis over time.

 

Methods: Chicken eggs (n=32) were incubated for 3.5-6 days (stage 20, 24, 28, 29). Embryo heads were fixed in 10% formaldehyde, embedded in agarose blocks, dehydrated in methanol, and then cleared in Benzyl Alcohol Benzyl Benzoate 2:1. Embryos were scanned with the OPT, images were reconstructed, and then the head was digitally resliced in the frontal plane using NRecon and CTan. Resliced files were imported into Amira software, and facial prominences were outlined, and isosurfaces were created. Volumetric measurements were assessed using Amira. Landmarks were applied to the outer surface of each prominence using Landmark. The landmarks were then superimposed from different embryos using MorphoJ, whereby they underwent Procrustes Superimposition (PS), Principal Component Analysis (PCA), Canonical Variate Analysis (CVA), and Discriminant Function Analaysis (DFA).


Results: Traditional morphometrics revealed that the greatest amount of growth was a 24-fold difference in volume of the lateral nasal prominence between stages 20 and 29, followed by the maxillary, mandibular, and frontonasal mass. The ratio length/width shows that there was a 3-fold difference in the frontonasal mass between stages 20 and 29. Geometric morphometrics revealed that embryonic facial prominences grow isometrically until stage 24 except the maxillary prominence which grows till stage 28. Afterwards, facial prominences grew allometrically. Shape changes were observed in all three axes. The frontonasal mass narrowed mediolaterally, and lengthened superioinferiorly and proximodistally. The lateral nasal and maxillary prominences both grew more proximodistally and mediolaterally, and had minimal growth superioinferiorly. The mandibular prominence grew mainly superioinferiorly, and had minimal growth mediolaterally and proximodistally.


Conclusion: Embryonic chicken facial prominences undergo allometric growth. Each prominence varies in dimensional changes with respective stage, with the frontonasal mass and mandibular prominence having the greatest dimensional change.


Acknowledgements: This work was funded by Faculty of Dentistry research funds and CIHR operating grants to JMR.




2013 Abstracts, Vancouver, British Columbia

2nd Year

3rd Year
2011 3M ESPE Graduate Student Research Presentations

Four Canadian graduate students in pediatric dentistry participated in the 3M ESPE Graduate Student Research Presentations, held during the Canadian Academy of Pediatric Dentistry (CAPD) Annual General Meeting in Edmonton in September, 2011. The graduate students presented their research to a panel of judges, and the winning student was awarded a $1000 cash prize.



     
 

Dr. Tabitha Chng, winner of the 3M-ESPE Graduate Student Presentations and Mr. Garrett LeBlanc,

3M-ESPE Representative.

   

Dr. Tabitha Chng, winner

of the 3M-ESPE Graduate Student Presentations,      
Mr. Garrett Leblanc and Dr. Zahra Kurji, Chair of Scientific Committee


2011 Abstracts, Edmonton, Alberta

  • Dr. Tabitha Chng: GLUT2 and TAS1R2 genotype and risk of dental caries
  • Dr. Sabrina Huda: Novel oral rinse assay for the quantification of oral neutrophils and comparison to the standard periodontal exam in pregnant women
  • Dr. Anita Moosani: Evaluation of an Oral Swab Assay as a Quantitative Measure of Periodontal Inflammation in Patients with Special Needs
  • Dr. Lori Waichenberg: A retrospective analysis of the success of fixed space maintainers in a private pediatric dental setting and a survey of the use of fixed space maintainers among pediatric dentists and orthodontists

The following are condensed versions of the abstracts submitted for the 2011 pediatric dental research event.


FIRST PRIZE

Text Box:

Dr. Tabitha Chng

 

Title:  GLUT2 and TAS1R2 genotype and risk of dental caries

Authors: Tabitha Chng, Ahmed El-Sohemy, Daiva Nielsen, Christine Wessman, Karen Eny, Gajanan Kulkarni

 

Introduction: The microbiological and environmental contribution to dental caries has been extensively studied. However, the relative contribution of genetic predispositions has not been clearly defined. Genetic polymorphisms in the TAS1R2 (Ile191Val) and GLUT2 (Thr110Ile) genes have recently been associated with habitual sugar consumption with carriers of the Ile allele of GLUT2 having higher sugar consumption and carriers of the Val allele of TAS1R2 having lower sugar consumption. However, the association between these genetic variants and dental caries has not yet been examined.   

Objectives: To determine whether a common polymorphism in the TAS1R2 and GLUT2 genes is associated with dental caries.

Methods: 80 healthy Caucasian individuals, aged 21-31 years old, who were previously genotyped for the TAS1R2 and GLUT2 polymorphisms through the Toronto Nutrigenomics and Health Study, were recruited.  A clinical and radiographic examination was conducted by a single examiner who was blinded to the genotype of the participants.  To assess caries prevalence, three different caries scores were determined: DMFT (Decayed, Missing, and Filled teeth), DMFT+radiographs and ICDAS (International Caries Detection and Assessment System). Associations between genotype and caries incidence were analysed analyzed Student’s t test.

Results: A significant increase in DMFT scores (mean ± SEM) (4.32±0.43 vs. 6.13±1.24, p=0.04) was shown in carriers of the Ile allele of GLUT2. Carriers of the TAS1R2 gene polymorphism consistently demonstrated lower caries scores: DMFT (4.14±0.47 vs. 5.78±0.89, p=0.05), DMFT+radiographs (4.93±0.57 vs. 7.53±0.91, p=0.01), and ICDAS (19.52±2.15 vs. 26.14±2.82, p=0.03).  

Conclusion: The results suggest that variation in the GLUT2 and TAS1R2 genes are associated with risk of dental caries. Further analysis using the genome-wide association study (GWAS) approach is planned next to identify other polymorphisms associated with caries risk. Further studies targeting children with early childhood caries and validation of the current results in a pediatric population are needed.


 

Dr. Sabrina Huda.jpg

Dr. Sabrina Huda

 

Title:  Novel oral rinse assay for the quantification of oral neutrophils and comparison to the standard periodontal exam in pregnant women

 

Authors: Dr. Sabrina Huda, Dr Howard Tenenbaum, Dr Wendy Whittle, Dr Michael Glogauer, Dr Herenia Lawrence, Dr Michael Goldberg

 

Background:  Current studies suggest that periodontal disease is associated with an increased risk of preterm birth and low birth weight infants. Periodontal diagnosis relies on intraoral visual clinical factors that include redness, bleeding, probing depths, attachment loss and amount of plaque and calculus. A simple test that identifies pregnant women at increased risk of adverse outcome due to periodontal disease would be valuable.

Objectives: To develop a valid and reliable tool to measure periodontal inflammatory disease in pregnant women. To determine the salivary neutrophil counts in pregnant women using a new non-invasive oral rinse assay.  To assess their periodontal health status using this neutrophil quantification assay and conventional methods. To validate the assay as a quantitative measure of periodontal inflammatory disease in pregnant women.

Methods: Periodontal examinations of pregnant women were performed (preliminary n = 36). 10 ml saline rinse for 15 seconds, were collected.  Neutrophils were counted in each rinse.  ABTS, a colour changing redox agent, was added. The intensity of the colour reaction was measured by absorbance. Descriptive statistics and Spearman’s correlation were calculated to assess preliminary results.

Results: Preliminary results showed a significant positive correlation between neutrophils counts and periodontal disease severity as measured by bleeding on probing (rs = 0.70; p <0.01) and the modified gingival index (r = 0.57; p <0.01).

Conclusions: Preliminary results suggest a correlation between neutrophils and periodontal disease in pregnant women. The rinse assay may be used as a screening test for periodontal inflammation in pregnant women.

 

Text Box:Dr. Anita Moosani

 

Title:Evaluation of an Oral Swab Assay as a Quantitative Measure of Periodontal Inflammation in Patients with Special Needs

 

INVESTIGATORS:

Dr. Anita Moosani, Dr. Michael J. Sigal, Dr. Howard C. Tenenbaum, Dr. Michael Glogauer

Dr. Herenia P. Lawrence, Dr. Michael Goldberg

Objectives:

Patients with special needs have a high prevalence of oral disease, which can be difficult to diagnose with conventional dental instruments due to lack of cooperativity, resulting in the use of subjective measures for periodontal disease, unless patients are examined under general anaesthesia. Measurement of oral neutrophil levels may serve as an objective measure of periodontal health status. This study aims to validate and assess the feasibility of using an oral swab assay of oral neutrophils as a quantitative measure of periodontal inflammation in uncooperative patients with special needs.

Methods: Patients scheduled for comprehensive dental treatment under general anaesthesia at Toronto’s Mount Sinai Hospital Dental Program for Persons with Disabilities were included in this study. A periodontal examination using a periodontal probe was done under general anaesthesia and oral swabs were obtained to show that measurable counts of oral neutrophils could be attained. These measurements were then compared to neutrophil counts taken from the oral swabs done later at the patient’s recall examination. Oral neutrophils obtained from the oral swabs were measured using the FLUOstar Optima software.

Results: Sample size calculations indicated that 44 patients are required for this study, and 49 have been assessed under general anaesthesia thus far. Data collection during recall examinations is still in progress, and will allow statistical comparisons between periodontal parameters and oral neutrophil counts taken during the general anaesthetic and recall examinations. Descriptive statistics will be used to determine the evaluators’ ability to acquire the oral swab data in an ambulatory dental clinic for patients with special needs.

Conclusions: Oral neutrophil counts derived from swabs are expected to correlate significantly with conventional parameters of gingival inflammation and provide a standardized method for clinical measurement, thus overcoming the problem of subjectivity encountered with conventional measures in the special needs population.

 

 

Text Box:Dr.  Lori Waichenberg

Title: A retrospective analysis of the success of fixed space maintainers in a private pediatric dental setting and a survey of the use of fixed space maintainers among pediatric dentists and orthodontists

 

Dr. Lori Waichenberg, Dr. Paul Andrews; Dr. Michael Sigal; Dr. Keith Titley; and Dr. Bryan Tompson

 

Space management of the developing dentition is an important part of interceptive and preventive dental care.  Though the published success rates are generally low, many of these studies are based on data from multiple student operators As such, it would be beneficial to present data from a single practitioner on the success and longevity of fixed space maintainers (spms) under a strict protocol in a private practice setting. Furthermore, it would be informative to document the prevailing attitudes of a representative sample of North American pediatric dentists and orthodontists regarding their personal experience with fixed spms.  

Objectives: To evaluate the success and longevity of fixed space maintainers placed by a sole dental practitioner in a private pediatric dental office. To evaluate the use of, attitudes toward, and perceived difficulties with fixed space maintainers by a representative sample of North American pediatric dentists and orthodontists.

Experimental Methods: A retrospective chart review of patients who had fixed space maintainers placed between 2000-2010 at a private pediatric dental practice was conducted.  A total of 898 appliances were included in the study.  A web-based online survey was sent out to a random sample of 1000 pediatric dentists and 1000 orthodontists regarding their use of fixed spms.

Statistical Analyses: For the chart review, descriptive statistics, a Cox regression analysis, and survival curves were generated.  A log-rank test was used to assess the equality of the survival distributions. For the survey study, the results were compiled and analyzed and visual summaries of the responses were generated.

Results: The overall success rate for the spms studied was 86.7%.  The overall survival time for the spms was 205 days, with the band and loop showing the longest survival. The response rate for the survey for the pediatric dentist was 42%, but for the orthodontists was only 6.9%.  The vast majority of pediatric dentists and orthodontists place fixed spms in their practice (99.8% and 97%, respectively). The most common reason for failure was cited as cement loss by the pediatric dentists (47.3%) and breakage was cited as the most common reason by the orthodontists (30.4% ).

Conclusions: Fixed spms had a high success rate and were used by the vast majority of pediatric dentists and orthodontists.  They should be recommended for use in patients whenever indicated.



2009 Abstracts, Victoria, British Columbia
  • Dr. Tim Seto:  Dental Cleanings and pneumonia incidence among Children with Cerebral Palsy
  • Dr. Evan Zaretsky:  Pediatric Dentists' Behaviour Management of Patients with Autism Spectrum Disorder
  • Dr. Ngoc Luong:  Assessment of Parental Satisfaction with Dental Treatment under General Anesthesia in Pediatric Dentistry
  • Dr. Michael Park:  Oral Disease Prevalence and Relationship to Oral Neutrophil Levels and Function in Neutropenia

DENTAL CLEANINGS AND PNEUMONIA INCIDENCE

AMONG CHILDREN WITH CEREBRAL PALSY

Student: Tim Seto (University of Michigan, Ann Arbor, MI)

 

Objectives: Investigate the relationship between pneumonia and dental cleanings in a pediatric population with cerebral palsy (CP) and test the null hypothesis that children with CP are not at increased risk for pneumonia when receiving dental cleanings.

 

Methods: Analyzed pneumonia claims from Michigan State's Medicaid database for a 5-year period (January 2001-December 2005).  Patients aged 3 to 18 years with CP were included.  Outcome of interest was the presence of greater than or equal to 1 claim for pneumonia (International Classification of Disease, Clinical Modification 9th edition - 480 to 486 or 487.0) within 14 days of a prior dental cleaning (Current Dental Terminology 1110, 1120, 4341, 4355).  Multivariate time-dependent logistic regression was used to determine factors associated with pneumonia events.  Potential risk factors evaluated in the regression model include demographic variables: age at entry of study, area of residence (i.e. urban vs. rural), and, the presence of medical conditions: esophagogastric fundoplasty, gastroesophageal reflux, asthma, gastrostomy feeding tube, dysphagia, epilepsy.

 

Results: 7079 children were eligible for this study with the mean age at entry of study of 7.75 years old.  Among these children, 871 (12%) had greater than or equal to 1 claim for pneumonia during the study period.  Only 17 children reported claims of pneumonia within 14 days and 37 children after 30 days of a dental cleaning.  Regression analysis revealed significant risk factors for pneumonia, including dysphagia (OR 2.26), asthma (OR 2.19), gastrosophageal reflux (OR 1.58) and epilepsy (OR 1.43).  Significant non-medical associations with pneumonia include age at entry of study (OR 0.95) and rural area of residence (OR 1.35).

 

Conclusions: No association between dental cleanings and pneumonia events could be demonstrated in CP children aged 3 to 18.  Dysphagia, asthma, gastrosophageal reflux, and epilepsy are more important risk factors than dental cleanings for pneumonia.

 

(Dr. Seto was the first place winner of the 2009 3MESPE prize)



PEDIATRIC DENTISTS' BEHAVIOUR MANAGEMENT OF PATIENTS

WITH AUTISM SPECTRUM DISORDER

zaretskyStudent: Dr. Evan Zaretsky (University of Toronto)

 

Objectives:  The purpose of the present study was to asses which specific behaviour management skills pediatric dentists are using and find effective in working with their patients with Autism Spectrum Disorders, ASD, and to highlight specific influences whether educational, environmental or experiential which contribute to their skills in advanced behaviour management.

 

Methods: Surveys were mailed to all Canadian and select American members of the AAPD, with an invitation to participate in the research either via direct mailing or online.  The survey tool had two sections: Personal and Professional Background; and the Behaviour Management Technique Rating Scale, BMTRS. The BMTRS asks respondents to indicate their frequency of use, and perceived effectiveness of 23 different behaviour management techniques. Responses were collected over 10 weeks and will subsequently be analyzed to describe the previously noted relationships.

 

Results: A total of 837, subjects replied to the survey, a response rate of 50.1%. Although statistical analysis is still pending, several trends were noted. Over 60% of the subjects see autistic patients weekly or more often. Over 40% of respondents say that they use inhalation sedation often or regularly, and more than 2/3 felt it was at best, somewhat useful. Conversely, traditional approaches, such as Tell-Show-Do, are used regularly by 60%, but only 43% considered it useful. Meanwhile, modern techniques, such as filmed modelling, are untried by over 90% of respondents. A resounding 71% believe that more continuing education with regards to ASD would be valuable.

 

Conclusions: Pediatric dentists recognize a need for further education in the field of behaviour management, specifically in regards to ASD. Pharmacologic and traditional techniques, like voice modulation, are widely used, but may not be effective. Many new approaches, such as sensory stimulation, have been documented in the literature, yet remain largely unutilized for reasons, such as time and costs involved.


ASSESSMENT OF PARENTAL SATISFACTION WITH DENTAL TREATMENT

UNDER GENERAL ANESTHESIA IN PEDIATRIC DENTISTRY

 

luongStudent: Dr. Ngoc Luong (University of Toronto)

Supervisors: Dr. B. Saltzman, Dr. M. Sigal, Dr. D. Haas, Dr. M. Casas

 

Objectives: To identify and compare pre-treatment and post-treatment parental expectations and satisfaction concerning their child's dental care under general anaesthesia. Participant characteristics were also investigated.

 

Methods: Questionnaires were administered to 100 parents who had attended the pre-operative anaesthesia consultation (pre-treatment group) and to 100 parents who had returned for post-operative reassessment (post-treatment group). Participants were asked to rate the importance and frequency of each event on a four point Likert Scale. Parents were also asked to complete a participant character information form. A score was calculated for each item in the questionnaires by multiplying the item's mean "importance rating" and the item's mean "expectation rating" and the items were ranked by scores.

 

Results: To date, complete responses were obtained from 69 parents in the pre-treatment group and 77 parents in the post-treatment group. In each group, the highest ranked elements were those representing information and communication. (Additional data and statistical analyses will be reported in the future)

 

Conclusion: Our initial results reinforce the value that parents place in adequate communication and provision of information in dental treatment under general anaesthesia. 

ORAL DISEASE PREVALENCE AND RELATIONSHIP TO

ORAL NEUTROPHIL LEVELS AND FUNCTION IN NEUTROPENIA


parkStudent: Dr. Michael Park (University of Toronto)

Primary Supervisor: Dr. Michael Glogauer

Supervisory Committee: Dr. Yigal Dror, Dr Michael Sigal and Dr. Howard Tenenbaum

 

Historically, case reports and studies that have looked at the oral manifestations of neutropenia have documented advanced periodontal disease, premature loss of teeth and ulcerations upon initial presentation. Patients with neutropenia are treated routinely with granulocyte-colony stimulating factor to increase their levels of circulating neutrophils. However, no follow up studies have been carried out which report on the oral health status of these patients during their active haematological treatment.

 

Objectives: To assess the oral health of children with neutropenia.

 

Methods: Children with neutropenia between the ages of 6-18 attending the Hospital for Sick Children were asked to participate in the study. Participants also underwent an oral and radiographic examination.

 

Preliminary Results: Preliminary data suggest that oral health and neutrophil function are maintained for most patients receiving CSF therapy.


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