Apical root resorption during orthodontic treatment with clear aligners: A retrospective study using cone-beam computed tomography.

INTRODUCTION: We aimed to investigate the incidence and severity of orthodontically induced inflammatory root resorption (OIIRR) on maxillary incisors with clear aligner therapy using cone-beam computed tomography and to identify possible risk factors. METHODS: The root lengths of maxillary incisors were measured on orthogonal images from pretreatment and posttreatment cone-beam computed tomography examinations of 160 patients who received comprehensive orthodontic treatment with clear aligners. RESULTS: Mean absolute reductions in root length varied between 0.47 ± 0.61 mm and 0.55 ± 0.70 mm and were not significantly different between maxillary central and lateral incisors. The prevalence of severe OIIRR, defined as both maxillary central incisors experiencing greater than a 25% reduction in root length, was found to be 1.25%. Potential risk factors included sex, malocclusion, crowding, and posttreatment approximation of apices to the cortical plates. Race, interproximal reduction, previous trauma to the teeth, elastics, age, treatment duration, and pretreatment approximation of apices to the cortical plates did not significantly affect the amount of OIIRR. CONCLUSIONS: Comprehensive treatment with clear aligners resulted in minimal root resorption. Sex, malocclusion, crowding, and posttreatment approximation to the cortical plates significantly affected the percentage of change in root length. Posttreatment approximation of root apices to the palatal cortical plate showed the strongest association for increased OIIRR.

Characteristics of chronic noncancer pain patients assessed with the opioid risk tool in a Canadian tertiary care pain clinic.

BACKGROUND: The Opioid Risk Tool (ORT) is a screening instrument for assessing the risk of opioid-related aberrant behavior in chronic noncancer pain (CNCP) patients. OBJECTIVE: This study aims to compare patient characteristics documented in the original ORT study with those identified in CNCP patients assessed using a physician-administered ORT in a tertiary care pain clinic in Toronto, Canada. METHODOLOGY: This was a descriptive cross-sectional study of 322 consecutive new patients referred over 12 months. Data extraction included ORT scores, demographics, pain ratings, opioid, and other medication use at point of entry, diagnosis, and other variables. Characteristics were compared with those described in the original ORT study. RESULTS: The total mean ORT scores of patients in this study were related to several demographic (gender, age, marital status, and country of birth) and nondemographic variables (employment status, cigarette smoking, and contribution of biomedical and/or psychological factors to presentation). Prevalence of characteristics noted in this patient sample differed substantially from that found in Webster and Webster as the basis for ORT scores. CONCLUSION: Significant differences existed between this study population and the patient sample from which the ORT was derived. Limitations of this study are discussed. We concur with the authors of the original study that the ORT may not be applicable in different pain populations and settings. Based on our findings, we encourage caution in interpreting the ORT in general CNCP settings until further studies are performed.

Systematic review of the quality and generalizability of studies on the effects of opioids on driving and cognitive/psychomotor performance.

INTRODUCTION: The effect of opioids on driving performance has been much debated. Driving is a complex task requiring integration of psychomotor, cognitive, motor and decision-making skills, visual-spatial abilities, divided attention, and behavioral and emotional control. The objective of this systematic review was to assess the quality of studies and to revisit the concept that patients on stable opioids are safe to drive as it applies to everyday practice. METHODS: We searched MEDLINE, EMBASE, PSYCinfo, CENTRAL, TRANSPORT, CINAHL, reference lists of retrieved articles and narrative reviews, for studies on chronic cancer and noncancer pain patients on opioids, tested by driving, driving simulator, or cognitive/psychomotor tests. Methodological quality was assessed with Methodological Index for Nonrandomized Studies, cognitive/psychomotor tests were appraised regarding their sensitivity and validation, and whether confounding variables potentially affecting the study conclusions were recorded. The results were analyzed both quantitatively and qualitatively. RESULTS: We included 35 studies (2044 patients, 1994 controls), 9% of the studies were of poor, 54% of fair, and 37% of high quality; 3 quarters of the studies used high sensitivity cognitive tests. Amount and dose of opioids varied largely in many studies. Mean number of possible but unreported confounders was 2.2 (range, 0 to 4), relating to failure of the studies to mention co-prescriptions with psychotropic effects, pain severity, sleep disorder or daytime somnolence, and/or significant depressive or anxiety-related problems. INTERPRETATION: The commonly held concept that "chronic pain patients on stable opioids are safe to drive" cannot be generalized to all such patients in everyday practice, but may be applicable only to a subset who meet certain criteria.

Use of a modified Comprehensive Pain Evaluation Questionnaire (CPEQ): characteristics and functional status of patients on entry to a tertiary care pain clinic.

BACKGROUND: With increasing knowledge of chronic pain, clinicians have attempted to assess chronic pain patients with lengthy assessment tools. OBJECTIVES: To describe the functional and emotional status of patients presenting to a tertiary care pain clinic; to assess the reliability and validity of a diagnostic classification system for chronic pain patients modelled after the Multidimensional Pain Inventory; to provide psychometric data on a modified Comprehensive Pain Evaluation Questionnaire (CPEQ); and to evaluate the relationship between the modified CPEQ construct scores and clusters with Diagnostic and Statistical Manual, Fourth Edition - Text Revision Pain Disorder diagnoses. METHODS: Data on 300 new patients over the course of nine months were collected using standardized assessment procedures plus a modified CPEQ at the Comprehensive Pain Program, Toronto Western Hospital, Toronto, Ontario. RESULTS: Cluster analysis of the modified CPEQ revealed three patient profiles, labelled Adaptive Copers, Dysfunctional, and Interpersonally Distressed, which closely resembled those previously reported. The distribution of modified CPEQ construct T scores across profile subtypes was similar to that previously reported for the original CPEQ. A novel finding was that of a strong relationship between the modified CPEQ clusters and constructs with Diagnostic and Statistical Manual, Fourth Edition - Text Revision Pain Disorder diagnoses. DISCUSSION AND CONCLUSIONS: The CPEQ, either the original or modified version, yields reproducible results consistent with the results of other studies. This technique may usefully classify chronic pain patients, but more work is needed to determine the meaning of the CPEQ clusters, what psychological or biomedical variables are associated with CPEQ constructs or clusters, and whether this instrument may assist in treatment planning or predict response to treatment.

Referring patients with chronic noncancer pain to pain clinics: survey of Ontario family physicians.

OBJECTIVE: To examine the factors associated with FPs' referrals of patients with chronic noncancer pain to a tertiary care pain clinic. DESIGN: A questionnaire-based survey; data were analyzed using univariate methods. SETTING: A tertiary care pain clinic in Toronto, Ont. Participants All FPs who referred patients to the clinic between 2002 and 2005. MAIN OUTCOME MEASURES: Variables explored included FPs' sex, age, and ethnic background, ethnicity of patient groups seen, and FPs' rationale or barriers influencing referrals to specialized pain clinics. RESULTS: The response rate was 32% (47 of 148 FPs). There were no statistically significant differences between respondents and non-respondents in sex, age, duration of practice, and university of graduation, or between the variables of interest and the referral patterns of those who did respond. The mean age of respondents was 50 years; 47% of the FPs identified themselves as Canadian; and one-third of the respondents indicated that they referred more than 30 patients to pain clinics each year. The 3 most frequently cited reasons prompting referral to pain clinics were requests for nerve blocks or other injections, desire for the expertise of the program, and concerns about opioids; the 3 most prevalent barriers were long waiting lists, patient preference for other treatments, and distance from the clinic. CONCLUSION: Although the results of our survey of FPs identify certain barriers to and reasons for referring patients to pain clinics, the results cannot be generalized owing to the small sample of FPs in our study. Larger studies of randomly selected FPs, who might or might not refer patients to pain clinics, are needed to provide a better understanding of chronic noncancer pain management needs at the primary care level.

Chronic noncancer pain: characteristics of patients prescribed opioids by community physicians and referred to a tertiary pain clinic.

OBJECTIVE: To describe the characteristics of patients with chronic noncancer pain (CNCP) prescribed opioids by community physicians and referred to a tertiary pain clinic. DESIGN: Cross-sectional, descriptive study. SETTING: A tertiary care, hospital-based pain clinic in Toronto, Ont. PARTICIPANTS: A total of 455 consecutive patients newly referred to the pain clinic by community physicians. MAIN OUTCOME MEASURES: Data on demographic characteristics, pain ratings, and medication intake were obtained using standardized collection forms and retrospective chart review. Patients were classified by diagnosis: group 1 patients had biomedical disorders only, group 2 patients had biomedical disorders and psychological factors, and group 3 patients had psychological factors only. Patients were also categorized based on opioid use: no opioid use (NOU); low opioid use (LOU), with a daily morphine-equivalent dosage (MED) of 200 mg or less; or high opioid use (HOU), with a daily MED of more than 200 mg. RESULTS: In the general study population, 63% of patients were taking opioids, with 1 in 5 exceeding an MED of 200 mg daily. In group 1, 59% of patients used opioids and 10% had HOU; 66% of patients in groups 2 and 3 were taking opioids, with 21% and 26% classified as having HOU. The mean (SD) daily MED for groups 2 and 3 HOU patients combined was significantly higher than that of group 1 HOU patients: 575.7 (472.9) mg/d versus 284.9 (74.6) mg/d, respectively. Men were twice as likely as women to have HOU; Canadian-born patients were 3 times as likely as foreign-born patients to have HOU. Psychoactive drugs were coprescribed in 61% of LOU patients and 76% of HOU patients. Greater opioid use was associated with group 2 and 3 diagnoses, male sex, Canadian-born origin, and high pain scores. CONCLUSION: Our results indicate that male, Canadian-born CNCP patients presenting with psychological morbidity or comorbidity and reporting higher pain severity ratings were more likely to receive opioids. Additionally, many CNCP patients referred to our tertiary care pain clinic were receiving opioids in excess of a 200-mg/d MED. More studies are needed to determine which factors lead to high-dose opioid prescribing in a subset of this CNCP population.

On the nature of nondermatomal somatosensory deficits.

OBJECTIVES: Nondermatomal somatosensory deficits (NDSDs) not conforming to the distribution of peripheral nerves or dermatomes, and often present after a minor injury or with no known inciting event, have long been associated with "hysteria." This article reviews the modern literature concerning NDSDs associated with chronic pain with regard to their prevalence, phenomenology and clinical presentation, clinical assessment, etiology and pathophysiology, relationship with Conversion Disorder and psychological factors, and their treatment and prognosis. METHODS: Past research and relevant literature concerning NDSDs are reviewed and summarized. Clinical case reports are presented to illustrate the salient features of NDSDs. RESULTS: The prevalence of NDSDs varies between 25% and 50% in samples of chronic pain populations. We describe the temporal, spatial, qualitative, motor, sensory, and behavioral characteristics of NDSDs. Illustrative case reports show the remarkable NDSD phenomenology, variability, and reversibility. NDSDs represent intensely dynamic phenomena that are likely associated with supraspinal mechanisms. Recent functional imaging findings show significant alterations in brain activation patterns in these patients. Similar but spatially and temporally restricted phenomena have been shown in experimental studies with healthy controls and pain patients. NDSDs are associated with certain demographic variables, and possibly psychological factors seem to constitute a poor prognostic sign for response to treatment and return to work and can coexist with structural musculoskeletal or nervous system abnormalities. CONCLUSIONS: NDSDs are important and prevalent clinical phenomena associated with chronic pain. Their prevalence in the general population, primary care settings, and non pain patients is unknown. Research needs to be carried out to elucidate these important phenomena.

Nondermatomal somatosensory deficits: overview of unexplainable negative sensory phenomena in chronic pain patients.

PURPOSE OF REVIEW: To review the literature and our current understanding of nondermatomal somatosensory deficits (NDSDs) associated with chronic pain in regards to their prevalence, assessment and clinical presentation, cause and pathophysiology, relationship with conversion disorder and psychological factors, as well as their treatment and prognosis. RECENT FINDINGS: NDSDs are negative sensory deficits consisting of partial or total loss of sensation to pinprick, light touch or other cutaneous modalities. Although they had been noted more than a century ago and appear prevalent in chronic pain populations, they are poorly studied. They may be very mild or very dense, may occupy large body areas, are often highly dynamic and changeable or, to the contrary, very stable and long lasting. NDSDs may occur in the absence of biomedical pathology or coexist with structural musculoskeletal or nervous system abnormalities. They appear to be associated with psychological factors and a poor prognosis for response to treatment and return to work. Recent brain imaging studies provide a basis for understanding NDSD pathophysiology. SUMMARY: NDSDs represent prevalent phenomena associated with chronic pain. Further, research is needed to elucidate their origin, response to treatment, and prevalence in the general population, primary care settings, and nonpain patients.

Analysis of complaints to a tertiary care pain clinic over a nine-year period.

BACKGROUND: The present study is the result of an internal audit and examines the profiles of complainants and the sources and nature of complaints toward the staff in a tertiary care pain clinic, the Comprehensive Pain Program of the Toronto Western Hospital in Toronto, Ontario. METHODS: All sources of complaints over a nine-year period were reviewed, which included the following: Toronto Western Hospital Patient Relations (PR) records, with a subset of the files qualitatively analyzed in depth regarding the nature of complaints and complainants; complaints that bypassed PR and were addressed directly to the program director against members of the staff; complaints to the College of Physicians and Surgeons of Ontario; and complaints recorded anonymously at rateMDs.com. RESULTS: Although the prevalence of PR complaints was very low (1.73 complaints per 1000 visits), several other sources of complaints were identified. The typical complainant was a Canadian-born woman acting on her behalf or on behalf of a family member. More than one-half of the complaints were directed against the physicians regarding their opinion of psychological factors augmenting the patient's presentation and/or inappropriate use of opioids. Defensive techniques instituted by the Comprehensive Pain Program staff in reaction to the complaints are discussed, and pertinent literature is reviewed. CONCLUSION: The present study is the first to examine the nature of complaints and complainants from a Canadian pain clinic. Further studies are needed to explore the complex issues of patient and staff interactions, and complaints in the era of 'patient-centred care'.

Skill reacquisition after acquired brain injury: a holistic habit retraining model of neurorehabilitation.

Persistent cognitive, emotional and behavioral dysfunction following brain injury present formidable challenges in the area of neurorehabilitation. This paper reviews a model and practical methodology for community based neurorehabilitation based upon: 1. Evidence from the "automatic learning" and "errorless learning" literature for skills relearning after brain injury; 2. A widely applicable task analytic approach to designing relevant skills retraining protocols; 3. Analysis of organic, reactive, developmental, and characterological obstacles to strategy utilization and relearning, and generation of effective therapeutic interventions; and 4. Procedures for (a) promoting rehabilitative strategy use adapted to acute and chronic neurologic losses, (b) an individual's inherent reinforcement preferences and coping style, (c) reliant on naturalistic reinforcers which highlight relationships to functional goals, utilize social networks, and (d) employ a simple and appealing cognitive attitudinal system and set of procedures. This Holistic Habit Retraining Model and methodology integrates core psychotherapeutic and learning principles as rehabilitation process ingredients necessary for optimal facilitation of skills retraining. It presents a model that generates practical, utilitarian strategies for retraining adaptive cognitive, emotional, behavioral and social skills, as well as strategies for overcoming common obstacles to utilizing methods that promote effective skills acquisition.

Characteristics and period prevalence of self-induced disorder in patients referred to a pain clinic with the diagnosis of complex regional pain syndrome.

INTRODUCTION: Although there have been a few case reports in the literature of self-inflicted symptoms presenting as complex regional pain syndrome (CRPS), there has been no systematic study. This report investigates the period prevalence and characteristics of self-induced disorders in patients referred to a comprehensive pain clinic with a diagnosis of CRPS. METHODS: Retrospective chart review was conducted for all cases referred as "neuropathic pain" to a comprehensive pain clinic over a period of 2 years. RESULTS: Out of 175 consecutive neuropathic pain referrals over a 2-year period, 41 were specifically referred as CRPS. Application of (modified) 1994 IASP CRPS criteria confirmed the diagnosis of CRPS in 11/15 men and in 15/26 women. Four of the 15 women had evidence of active self-induced signs and symptoms (eg, ligation of the limb, ulcerations, bizarre migrating wounds), which abated with casting, strict observation, discussion with the patient, or other intervention. The characteristics of these cases are presented and compared with other similar cases seen in previous years. CONCLUSIONS: This is the first report of a case series of patients diagnosed as CRPS with self-induced symptoms. We discuss in detail limitations of the study, factors that contribute to the index of suspicion, and the complex nature of the behavior including the overlap between factitious disorder, somatoform disorders, and malingering, whereas we stress the legitimacy of CRPS as a diagnosis.

The problem of pain.

Pain problems, especially posttraumatic headache, are very common following head trauma. Pain may be the most significant problem, more disabling than any brain or other injuries, and interfering with aspects of cognition or other function. However, posttraumatic headache and most other chronic posttraumatic pain problems remain poorly understood. This article reviews fundamental issues that should be considered in understanding the nature of chronic pain including the distinction between acute and chronic pain; neurobiological distinctions between the lateral and medial pain system; nociceptive versus neuropathic or other central pain; sensitization effects; the widely accepted view of chronic pain as a multidimensional subjective experience involving sensory, motivational-affective and cognitive-behavioral components; the problem of mind-body dualism; the role of psychosocial factors in the onset, maintenance, exacerbation or severity of pain; plus issues of response bias and malingering.

Psychological, neuropsychological, and medical considerations in assessment and management of pain.

Pain is a common yet challenging problem, particularly following traumatic injuries to the head or neck. It is a complex, multidimensional subjective experience with no clear or objective measures; yet it can have a significantly disabling effect across a wide range of functions. Persisting misconceptions owing to mind-body dualism have hampered advances in its understanding and treatment. In this article, a conceptualization of pain informed by recent research and derived from a more useful biopsychosocial model guides discussion of relevant medical, psychological, and neuropsychological considerations. This pain process model explains chronicity in terms of hyperresponsiveness and dysregulation of inhibitory or excitatory pain modulation mechanisms. Related neurocognitive effects of chronic pain are examined and recommendations for minimizing its confounding effects in neuropsychological evaluations are offered. A biopsychosocial assessment model is presented to guide understanding of the myriad of factors that contribute to chronicity. A brief survey of general classes and samples of the more useful pain assessment instruments is included. Finally, this model offers a rational means of organizing and planning individually tailored pain interventions, and some of the most useful pharmacologic, physical, and behavioral strategies are reviewed.

Posttraumatic painful torticollis.

The development of abnormal posturing of the neck or shoulder after local injury has been termed posttraumatic cervical dystonia (PTCD). Certain features seem to distinguish a unique subgroup of patients with this disorder from those with features more akin to typical idiopathic cervical dystonia, such as onset and maximum disability that occurs very quickly after injury, severe pain and a fixed abnormal posture. In an attempt to clarify the nature of this syndrome further, we evaluated 16 such patients (8 men, 8 women). Motor vehicle accident and work-related injuries were common precipitants, with posturing usually developing shortly after trauma, and little progression occurring after the first week. A characteristic, painful, fixed head tilt and shoulder elevation were present in all but one patient, who had a painless elevated shoulder and painful contralateral shoulder depression, as well as nondermatomal sensory loss in 14 patients. Additional abnormalities included dystonic posturing in a limb (2 patients) or jaw (1 patient), limb tremor (3 patients) and "give-way" limb weakness (8 patients). The tremor and the jaw dystonia demonstrated features suggestive of a psychogenic movement disorder, most commonly distractibility. Litigation or compensation was present in all 16 patients. Intravenous sodium amytal improved the posture, pain or both in 13 of 13 patients; in 7 of 13 the sensory deficit either markedly improved or normalized. General anesthesia demonstrated full range of motion in all 5 patients assessed. Psychological evaluations suggested that psychological conflict, stress, or both were being expressed via somatic channels in 11 of 12 tested patients. Our results suggest an important role of psychological factors in the etiology or maintenance of abnormal posture, pain and associated disability of these patients. The role of central factors triggered in psychologically vulnerable individuals after physical trauma is discussed. We propose that the disorder be referred to as "posttraumatic painful torticollis" rather than characterize it as a form of dystonia until further information on its pathogenesis is forthcoming.

An overview of pain problems associated with lesions, disorder or dysfunction of the central nervous system.

This paper will present an overview of pain problems associated with lesions, disorder or dysfunction of the central nervous system (CNS). The incidence, qualities of the pain experience, associated sensory abnormalities, and other characteristics will be discussed. Particular attention will be paid to central pain (CP) associated with stroke as the most prominent and best studied of the many CP problems. In general, there is poor understanding of the pathophysiology of CP, problems are often severe and intractable, and treatment is typically difficult. The concept of CP is increasingly being invoked to account for various presentations not traditionally considered, e.g. fibromyalgia. It is suggested that processes associated with CP might also contribute to the presentation in psychiatric Pain Disorders or other atypical pain problems. Finally, although perhaps not as problematic, a number of CNS disorders or lesions may be associated with reduced sensitivity to pain.

At the crossroads: Pain in the 21st century.

This paper, written from the perspective of a psychologist working in a tertiary care chronic pain program, presents an overview of chronic pain with suggestions as to what may be important directions for research and treatment in the future. It is suggested that the monumental problem of chronic pain needs to be better appreciated, that both biological and psychosocial factors contributing to presentation need to be better understood, and that the most fruitful avenue of research may be an exploration of the interface between psychosocial and biological components, i.e., the neurobiological substrate mediating psychological effects or the nature of brain-behavior relationships involved in chronic pain. A method to assist in the differentiation of central from peripheral and organic from psychosocial components, and the outline of a novel neuropsychobiological model are described.

Pain, cognition and traumatic brain injury.

There has been considerable controversy concerning the problem of the persisting post-concussive syndrome and whether cognitive or other sequelae might be attributed to the effects of brain injury or other causes. Headache is the predominant problem in virtually all surveys of the post-concussive syndrome. It is suggested that pain and related problems may account for most of the difficulties in those presenting with the persisting post-concussive syndrome or other cases in which mild to moderate brain injury is suspected. A survey of the literature concerning the relationship of pain, cognition and traumatic brain injury indicates that cognitive difficulties are common in acute or chronic pain, with or without any indication of brain injury. However, numerous methodological problems are apparent and there is clearly need for further study. Consideration is given both to psychosocial and neurobiological effects underlying any such relationships.

A brief introductory guide to chronic pain resources on the Internet.

The expanding Internet has become an increasingly valuable tool for world wide sharing of information. Health care professionals, patients, lay persons, family members and others are afforded instant access to masses of information and almost unlimited resources on virtually any topic, as well as an almost seamless vehicle for communication. This new medium offers tremendous implications for health care. However, the absence of a single clearinghouse, a single search procedure or guarantee of accuracy often make information access efforts challenging, confusing and frustrating. The present paper provides a brief introduction aimed at increasing appreciation of the Internet and enhancing its utility with regard to chronic pain and its management and offers rudimentary guidelines for efficient accessing of information. Finally, it presents the results of a comprehensive search including nearly 200 useful Internet web links for professionals, patients, family members and other interested persons who assess, treat or cope with chronic pain. Identified resources include numerous organizations, medical, psychological assessment and practical treatment strategies, assessment and treatment reviews, support groups, list serve groups for patients and professionals, advocacy resources, news and assistive technology resources. Special emphasis is given to useful resources to assist professionals treating persons with chronic pain, as well as resources that can assist persons challenged by chronic pain.