Howard Tenenbaum | University of Toronto (original) (raw)

Papers by Howard Tenenbaum

t The enamel matrix derivative Emdogain was recently approved for clinical use in a number of cou... more t The enamel matrix derivative Emdogain was recently approved for clinical use in a number of countries, includin g Canada. It has been shown to stimulate regeneration of periodontal ligament following periodontal surgery i n adults. This paper reviews pertinent clinical and laboratory studies of Emdogain and describes the protocol an d methods used for a longitudinal outcome study of

Reduced neuropsychologic measures as predictors of treatment outcome in patients with temporomandibular disorders

Journal of orofacial pain

To determine via a prospective investigation whether the presence of neuropsychologic or cognitiv... more To determine via a prospective investigation whether the presence of neuropsychologic or cognitive deficiencies could be identified in patients with temporomandibular disorders (TMD) and used to predict treatment outcome. This was based on the theory that measurable reductions in neuropsychologic and cognitive function might have a negative impact on treatment outcome in patients with essentially nontraumatic TMD, as has been shown for patients with posttraumatic TMD. Various neuropsychologic, psychosocial, and clinical parameters (including but not limited to the Peterson-Peterson Consonant Trigram Test and the California Verbal Learning Test) were used to pretest patients suffering from TMD prior to treatment. Patients were then entered into treatment, after which determination of treatment success was made both by the use of visual analog scales for pain and global transitional outcome measures (e.g., "better," responders versus "same/worse," nonresponders). A...

Irritable bowel syndrome patients versus responding and nonresponding temporomandibular disorder patients: a neuropsychologic profile comparative study

The International journal of prosthodontics

This study aimed to assess the use of neuropsychologic tests as a tool to differentiate, or not, ... more This study aimed to assess the use of neuropsychologic tests as a tool to differentiate, or not, between a nonresponding chronic pain condition of nonmuscular origin, irritable bowel syndrome (IBS) (n = 20), versus 2 pain conditions of muscular origin, responding (n = 36) and nonresponding (n = 24) temporomandibular disorders. The neuropsychologic tests used were the simple and multiple-choice reaction-time tests, California Verbal Learning Tests, the Brown-Peterson Consonant Trigram Auditory Memory Test, Sleep Assessment Questionnaire, and Beck Depression Inventory, as well as fatigue and energy level assessments (100-mm visual analog scale). Most of the tests used were capable of significantly differentiating between responding TMD versus IBS patients. Conversely, no statistically significant difference was found between nonresponding TMD versus IBS patients. Overall, the nonresponding TMD and IBS groups did worse in the neuropsychologic assessment than the responding TMD group, w...

Relationship between dental treatment and employment outcomes of welfare recipients

Background: The government of Ontario provides emergency dental care to people on social assistan... more Background: The government of Ontario provides emergency dental care to people on social assistance in order to meet health needs and promote the move from welfare-to-work. The policy community also argues for the expansion of dental services beyond emergency care for similar reasons. However, there is little to no evidence to support the idea that dental care and concomitant improvement in oral health promotes employment outcomes. Objective: To provide policy makers actionable data supporting the idea that improvement in oral health by providing more than emergency dental care can actually enhance employment outcomes among social assistance recipients. Employment outcomes were assessed within twelve months of receiving dental treatment relative to those who did not receive treatment. Method: A retrospective cohort study was designed using dental treatment and social services databases from five Ontario regions. Participants, treatment and non-treatment group, were observed at three...

Oral health-systemic health: what is the true connection? Interviews by Sean McNamara

Journal (Canadian Dental Association), 2007

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 2012

Objective. The aim of this study was to assess the effects of bite splint (BS) treatment terminat... more Objective. The aim of this study was to assess the effects of bite splint (BS) treatment termination in patients treated for temporomandibular disorder (TMD) and sleep bruxism (SB). Study Design. This longitudinal single-cohort study assessed 30 patients (29.5 Ϯ 7.8 years old, 86.7% women) who were successfully treated with BS for SB and TMD for 30 days to 6 months prior to termination of the use of BS. The Research Diagnostic Criteria for TMD Axes I and II, Sleep Assessment Questionnaire, Beck Depression Inventory, and BiteStrip were used to assess TMD signs and symptoms, sleep disorders, depression, and SB at baseline and after 15 days of BS disuse. Results. TMD symptoms, including the disability points, characteristic pain intensity, and present pain at rest, increased significantly (P Ͻ 0.05). After 15 days of BS termination, there were no significant differences in SB and depression levels, sleep quality, and TMD signs.

Oral Mucositis Experience in Head and Neck Cancer Patients

ABSTRACT Objective: Validate a recently developed tool for assessing patient reported oral mucosi... more ABSTRACT Objective: Validate a recently developed tool for assessing patient reported oral mucositis (OM), the Patient Reported Oral Mucositis Scale (PROMS) (Kushner ea 2008) amongst head and neck cancer patients undergoing curative therapy. Methods: Patients diagnosed with cancer localized to the head and neck and receiving radiation therapy, with or without concomitant chemotherapy at Princess Margaret Hospital, Toronto, Ontario were invited to partake in a prospective study. The study protocol was approved by the University Health Network Research Ethics Board, ref. 09-0231-CE. Following patient consent, a priori inclusion and exclusion criteria were used for screening purposes. A power calculation identified a need for 20 patients to reach 80% power. The patients were examined clinically once before radiation therapy and thereafter twice weekly during the course of their 6-7 weeks treatments as well as once again six weeks following the completion of the cancer treatment. OM was evaluated clinically according to two commonly used assessment tools, the NCI-CTC-criteria and the OMAS scale. In addition, the participants completed a PROMS VAS questionnaire and submitted a saline rinse for measurements of albumin and polymorphnuclear neutrophils (PMN). Laboratory analyses of the samples were done according to routine procedures. The patient-reported OM experience data were correlated with the clinical and biomarker data and subjected to parametric and non-parametric statistical tests. Results: Of initially 50 consenting participants 36 completed more or less regularly the whole course of clinical examinations. The change from baseline was statistically significant for all markers of oral mucositis as shown in table below. Proportions, averages and min/max values: Before therapy After 3 weeks After 7 weeks Post treatment NCI (n>score 2) 0/36 pat. 8/35 pat. 10/24 pat. 0/29 pat. OMAS (n>score 2) 0/36 pat. 4/35 pat. 8/24 pat. 0/29 pat. PROMS (0-100) 4 (0-12) 26 (0-83) 57 (0-96) 24 (0-80) Oral PMNs in rinse (x104/ml) 30 (1-110) 86 (2-450) 147 (5-550) 37 (1-123) Albumin (mg/L) 8 (3-42) 33 (4-184) 86 (144-451) 16 (3-122) Conclusion: The PROMS tool for self-reported experiences of oral mucositis demonstrate good correlation with currently used clinical examination criteria as well as biomarkers amongst head and neck cancer patients undergoing curative therapy.

Journal of dental education, 2006

The effectiveness of an electronic histology tutorial (EHT) as a mode of learning was assessed by... more The effectiveness of an electronic histology tutorial (EHT) as a mode of learning was assessed by comparing performance on two term tests for an EHT class of sixty-nine students and five prior classes (n=347) who learned by traditional methods. The aims of this study were to 1) develop and introduce a self-instructional, computer-aided approach to guide student learning in the first-year histology course at the University of Toronto Faculty of Dentistry; 2) evaluate the effectiveness of the self-study electronic histology tutorial by comparing students' test scores for the EHT group to students' scores in previous years; and 3) evaluate students' acceptance of this novel mode of learning by means of a satisfaction questionnaire. The EHT group performed significantly better on both the general histology and oral histology term tests than the five prior control years (p<0.001), yet there were no significant differences in overall GPA between the groups, suggesting that ...

Cortical plasticity is thought to occur following continuous barrage of nociceptive afferent sign... more Cortical plasticity is thought to occur following continuous barrage of nociceptive afferent signals to the brain. Hence, chronic pain is presumed to induce anatomical and physiological changes in the brain over time. Inherent factors, some pre-dating the onset of chronic pain, may also contribute to brain abnormalities present in patients. In this study we used structural MRI to examine whether patients with chronic temporomandibular (TMD) pain have abnormalities in gray matter (GM) within brain areas implicated in pain, modulation and sensorimotor function. We found that patients with TMD have cortical thickening in the primary somatosensory cortex (S1), frontal polar and the ventrolateral prefrontal cortex (PFC). These findings provide a structural basis for previous findings of TMD pain and cognitive sluggishness in TMD. We then examined the contribution of TMD characteristics to GM abnormalities. We found that 1) GM in the sensory thalamus positively correlated to TMD duration, 2) cortical thickness in the primary motor (M1) and the anterior mid-cingulate cortices (aMCC) were negatively correlated to pain intensity, and 3) pain unpleasantness was negatively correlated to cortical thickness in the orbitofrontal cortex (OFC). These findings suggest that an individual's TMD pain history contributes to GM in the brain. Lastly, we examined the contribution of a potential pre-existing vulnerability due to neuroticism. In the TMD patients, we found that there was an abnormal positive correlation between neuroticism and OFC thickness, in contrast to the negative correlation found in the healthy controls. Therefore, neuroticism may contribute to TMD pathophysiology. In sum, our data suggest that GM in the brain of patients with chronic TMD pain can be shaped by both personality and pain characteristics.

Consensus Report: Necrotizing Periodontal Diseases

Annals of Periodontology, 1999

Necrotizing ulcerative gingivitis. This is an infection characterized by gingival necrosis presen... more Necrotizing ulcerative gingivitis. This is an infection characterized by gingival necrosis presenting as “punched-out” papillae, with gingival bleeding, and pain. Fetid breath and pseudomembrane formation may be secondary diagnostic features. Fusiform bacteria, ...

Scientific reports, 2011

We present bacterial biogeography as sampled from the human gastrointestinal tract of four health... more We present bacterial biogeography as sampled from the human gastrointestinal tract of four healthy subjects. This study generated >32 million paired-end sequences of bacterial 16S rRNA genes (V3 region) representing >95,000 unique operational taxonomic units (OTUs; 97% similarity clusters), with >99% Good's coverage for all samples. The highest OTU richness and phylogenetic diversity was found in the mouth samples. The microbial communities of multiple biopsy sites within the colon were highly similar within individuals and largely distinct from those in stool. Within an individual, OTU overlap among broad site definitions (mouth, stomach/duodenum, colon and stool) ranged from 32-110 OTUs, 25 of which were common to all individuals and included OTUs affiliated with Faecalibacterium prasnitzii and the TM7 phylum. This first comprehensive characterization of the abundant and rare microflora found along the healthy human digestive tract represents essential groundwork to i...

Microbiome, 2014

Periodontitis is an infectious and inflammatory disease of polymicrobial etiology that can lead t... more Periodontitis is an infectious and inflammatory disease of polymicrobial etiology that can lead to the destruction of bones and tissues that support the teeth. The management of chronic periodontitis (CP) relies heavily on elimination or at least control of known pathogenic consortia associated with the disease. Until now, microbial plaque obtained from the subgingival (SubG) sites has been the primary focus for bacterial community analysis using deep sequencing. In addition to the use of SubG plaque, here, we investigated whether plaque obtained from supragingival (SupG) and tongue dorsum sites can serve as alternatives for monitoring CP-associated bacterial biomarkers. Using SubG, SupG, and tongue plaque DNA from 11 healthy and 13 diseased subjects, we sequenced V3 regions (approximately 200 bases) of the 16S rRNA gene using Illumina sequencing. After quality filtering, approximately 4.1 million sequences were collapsed into operational taxonomic units (OTUs; sequence identity cut...

CONTENTS A MESSAGE TO OUR FRIENDS

So here is a brief overview of the news that reflects the efforts of the incredible partnership t... more So here is a brief overview of the news that reflects the efforts of the incredible partnership that The Help Group comprises - a partnership of our Board of Directors, administration, faculty, governmental colleagues, philanthropic friends working together to support our mission to serve children with special needs and their families. Although this is just a snapshot, we hope that

Value in Health, 2007

Background and Objective: Oral mucositis, a painful condition with potentially life-threatening s... more Background and Objective: Oral mucositis, a painful condition with potentially life-threatening sequelae, often develops in association with allogeneic bone marrow transplantation. This condition has an adverse impact on the oral-health-related quality of life of patients undergoing marrow transplantation therapy. The purpose of this study was to create and validate a Patient-Reported Oral Mucositis Symptom (PROMS) scale. This scale allows evaluation of symptoms of oral mucositis that threaten quality of life.

PLoS ONE, 2013

Osteoclasts are large multinucleated cells that arise from the fusion of cells from the monocyte/... more Osteoclasts are large multinucleated cells that arise from the fusion of cells from the monocyte/macrophage lineage. Osteoclastogenesis is mediated by macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kB ligand (RANKL) and involves a complex multistep process that requires numerous other elements, many of which remain undefined. The primary aim of this project was to identify novel factors which regulate osteoclastogenesis. To carry out this investigation, microarray analysis was performed comparing two pre-osteoclast cell lines generated from RAW264.7 macrophages: one that has the capacity to fuse forming large multinucleated cells and one that does not fuse. It was found that CD109 was up-regulated by.17-fold in the osteoclast forming cell line when compared to the cell line that does not fuse, at day 2 of the differentiation process. Results obtained with microarray were confirmed by RT-qPCR and Western blot analyses in the two cell lines, in the parental RAW264.7 cell line, as well as primary murine monocytes from bone marrow. A significant increase of CD109 mRNA and protein expression during osteoclastogenesis occurred in all tested cell types. In order to characterize the role of CD109 in osteoclastogenesis, CD109 stable knockdown cell lines were established and fusion of osteoclast precursors into osteoclasts was assessed. It was found that CD109 knockdown cell lines were less capable of forming large multinucleated osteoclasts. It has been shown here that CD109 is expressed in monocytes undergoing RANKL-induced osteoclastogenesis. Moreover, when CD109 expression is suppressed in vitro, osteoclast formation decreases. This suggests that CD109 might be an important regulator of osteoclastogenesis. Further research is needed in order to characterize the role played by CD109 in regulation of osteoclast differentiation.

PAIN, 2011

Patients with temporomandibular disorder (TMD) perform poorly in neuropsychological tests of cogn... more Patients with temporomandibular disorder (TMD) perform poorly in neuropsychological tests of cognitive function. These deficits might be related to dysfunction in brain networks that support pain and cognition, due to the impact of chronic pain and its related emotional processes on cognitive ability. We therefore tested whether patients with TMD perform poorly in cognitive and emotion tasks and whether they had abnormal task-evoked brain activity. Seventeen female subjects with nontraumatic TMD and 17 age-matched healthy female subjects underwent functional magnetic resonance imaging while performing counting Stroop tasks comprising neutral words, incongruent numbers, or emotional words, including TMD-specific words. Group differences in task-related brain responses were assessed. Connectivity between 2 pairs of coupled brain regions during the cognitive and emotional tasks (prefrontal-cingulate and amygdala-cingulate) was also examined. The patients had sluggish Stroop reaction times for all Stroop tasks. Furthermore, compared to controls, patients showed increased task-evoked responses in brain areas implicated in attention (eg, lateral prefrontal, inferior parietal), emotional processes (eg, amygdala, pregenual anterior cingulate), motor planning and performance (eg, supplementary and primary motor areas), and activation of the default-mode network (medial prefrontal and posterior cingulate). The patients also exhibited decoupling of the normally correlated activity between the prefrontal and cingulate cortices and between the amygdala and cingulate cortex. These findings suggest that the slow behavioral responses in idiopathic TMD may be due to attenuated, slower, and/or unsynchronized recruitment of attention/cognition processing areas. These abnormalities may be due to the salience of chronic pain, which inherently requires attention.

Journal of Periodontology, 2010

Background: The purpose of this review was to evaluate the effectiveness of photodynamic therapy ... more Background: The purpose of this review was to evaluate the effectiveness of photodynamic therapy (PDT) for periodontitis in adults as a primary mode of treatment or as an adjunct to non-surgical treatment of scaling and root planing (SRP) compared to a conventional non-surgical SRP treatment.

Journal of Periodontology, 2005

Background: Cementum formation is deemed to be instrumental for the successful regeneration of pe... more Background: Cementum formation is deemed to be instrumental for the successful regeneration of periodontal tissues, and thus events and modifiers of cementum formation and mineralization need to be determined. This study aimed to determine whether the bisphosphonate 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) altered the behavior of immortalized cementoblasts (osteocalcin-cementoblasts [OCCM]).

Journal of Periodontology, 2014

Background: The effect of glycemic control on severity of periodontal inflammatory parameters in ... more Background: The effect of glycemic control on severity of periodontal inflammatory parameters in patients with prediabetes is unknown. The aim of the present study is to assess the effects of glycemic control on self-perceived oral health, periodontal parameters, and marginal bone loss (MBL) in patients with prediabetes.