Donald R. Nixdorf

Frequency of persistent tooth pain after root canal therapy: a systematic review and meta-analysis

INTRODUCTION Little is known about the frequency of persistent pain after endodontic procedures even though pain is a core patient-oriented outcome. We estimated the frequency of persistent pain, regardless of etiology, after endodontic treatment. METHODS Persistent tooth pain was defined as pain present > or = 6 months after endodontic treatment. Endodontic procedures included in the review were pulpectomy, nonsurgical root canal treatment, surgical root canal treatment, and retreatment. Four databases were searched electronically complemented by hand searching. Two independent reviewers determined eligibility, abstracted data, and assessed study quality. A summary estimate of persistent all-cause tooth pain frequency was established by using a random-effects meta-analysis. Using subgroup analyses, we explored the influence of treatment approach (surgical/nonsurgical), longitudinal study design (prospective/retrospective), follow-up rate, follow-up duration, initial treatment versus retreatment, and quality of reporting (Strengthening the Reporting of Observational Studies in Epidemiology rankings) on the pain frequency estimate. RESULTS Of 770 articles retrieved and reviewed, 26 met inclusion criteria. A total of 5,777 teeth were enrolled, and 2,996 had follow-up information regarding pain status. We identified 168 teeth with pain and derived a frequency of 5.3% (95% confidence interval, 3.5%-7.2%, p < 0.001) for persistent all-cause tooth pain. High and statistically significant heterogeneity among studies (I2 = 80%) was present. In subgroup analysis, prospective studies had a higher pain frequency (7.6%) than retrospectives studies did (0.9%). Quality of study reporting was identified as the most influential reason for study heterogeneity. CONCLUSIONS The frequency of all-cause persistent tooth pain after endodontic procedures was estimated to be 5.3%, with higher report quality studies suggesting >7%.

Dental Magnetic Resonance Imaging: Making the Invisible Visible

INTRODUCTION Clinical dentistry is in need of noninvasive and accurate diagnostic methods to better evaluate dental pathosis. The purpose of this work was to assess the feasibility of a recently developed magnetic resonance imaging (MRI) technique, called SWeep Imaging with Fourier Transform (SWIFT), to visualize dental tissues. METHODS Three in vitro teeth, representing a limited range of clinical conditions of interest, imaged using a 9.4T system with scanning times ranging from 100 seconds to 25 minutes. In vivo imaging of a subject was performed using a 4T system with a 10-minute scanning time. SWIFT images were compared with traditional two-dimensional radiographs, three-dimensional cone-beam computed tomography (CBCT) scanning, gradient-echo MRI technique, and histological sections. RESULTS A resolution of 100 μm was obtained from in vitro teeth. SWIFT also identified the presence and extent of dental caries and fine structures of the teeth, including cracks and accessory canals, which are not visible with existing clinical radiography techniques. Intraoral positioning of the radiofrequency coil produced initial images of multiple adjacent teeth at a resolution of 400 μm. CONCLUSIONS SWIFT MRI offers simultaneous three-dimensional hard- and soft-tissue imaging of teeth without the use of ionizing radiation. Furthermore, it has the potential to image minute dental structures within clinically relevant scanning times. This technology has implications for endodontists because it offers a potential method to longitudinally evaluate teeth where pulp and root structures have been regenerated.

Randomized controlled trial of botulinum toxin A for chronic myogenous orofacial pain

&NA; The purpose of this study was to determine whether botulinum toxin A (BTX‐A) was efficacious for the treatment of chronic moderate to severe jaw muscle pain in females. This was a randomized double‐blind, placebo‐controlled crossover trial of BTX‐A. Twenty five units injected into each temporalis muscle and 50 U injected into each masseter muscle using three sites per muscle with 0.2 cm3 per site. Data were collected at baseline, 8, 16, 24 weeks, with crossover occurring at 16 weeks. Primary outcome variables were pain intensity and unpleasantness, measured by horizontal visual analog scale (VAS). Secondary outcome variables were maximum interincisal opening without and irrespective of pain, muscle palpation tenderness (12 points), and four general questions. Fifteen female patients were enrolled (18–45 years), but only ten completed the trial. Of those who finished, no statistically significant difference was found in pain intensity (P=0.10), unpleasantness (P=0.40), palpation muscle tenderness (P=0.91), or the three general questions (P=0.64, P=0.66, P=0.67). Statistical significance was achieved for maximum opening without pain (P=0.02) and irrespective of pain (P=0.005) with the BTX‐A arm having a relative decreased opening. No statistically significant difference was observed in any outcome measures except maximum opening, which showed BTX‐A patient opening less wide than placebo. The results do not support the use of BTX‐A in the treatment of moderate to severe jaw muscle pain in this patient population.

Classifying orofacial pains: a new proposal of taxonomy based on ontology.

We propose a new taxonomy model based on ontological principles for disorders that manifest themselves through the symptom of persistent orofacial pain and are commonly seen in clinical practice and difficult to manage. Consensus meeting of eight experts from various geographic areas representing different perspectives (orofacial pain, headache, oral medicine and ontology) as an initial step towards improving the taxonomy. Ontological principles were introduced, reviewed and applied during the consensus building process. Diagnostic criteria for persistent dento-alveolar pain disorder (PDAP) were formulated as an example to be used to model the taxonomical structure of all orofacial pain conditions. These criteria have the advantage of being (i) anatomically defined, (ii) in accordance with other classification systems for the provision of clinical care, (iii) descriptive and succinct, (iv) easy to adapt for applications in varying settings, (v) scalable and (vi) transferable for the description of pain disorders in other orofacial regions of interest. Limitations are that the criteria introduce new terminology, do not have widespread acceptance and have yet to be tested. These results were presented to the greater conference membership and were unanimously accepted. Consensus for the diagnostic criteria of PDAP was established within this working group. This is an initial first step towards developing a coherent taxonomy for orofacial pain disorders, which is needed to improve clinical research and care.

Influence of headache frequency on clinical signs and symptoms of TMD in subjects with temple headache and TMD pain

&NA; The relationship of the frequency of temple headache to signs and symptoms of temporomandibular joint (TMJ) disorders (TMD) was investigated in a subset of a larger convenience sample of community TMD cases. The study sample included 86 painful TMD, nonheadache subjects; 309 painful TMD subjects with varied frequency of temple headaches; and 149 subjects without painful TMD or headache for descriptive comparison. Painful TMD included Research Diagnostic Criteria for Temporomandibular Disorders diagnoses of myofascial pain, TMJ arthralgia, and TMJ osteoarthritis. Mild to moderate‐intensity temple headaches were classified by frequency using criteria based on the International Classification of Headache Disorder, 2nd edition, classification of tension‐type headache. Outcomes included TMD signs and symptoms (pain duration, pain intensity, number of painful masticatory sites on palpation, mandibular range of motion), pressure pain thresholds, and temple headache resulting from masticatory provocation tests. Trend analyses across the painful TMD groups showed a substantial trend for aggravation of all of the TMD signs and symptoms associated with increased frequency of the temple headaches. In addition, increased headache frequency showed significant trends associated with reduced PPTs and reported temple headache with masticatory provocation tests. In conclusion, these findings suggest that these headaches may be TMD related, as well as suggesting a possible role for peripheral and central sensitization in TMD patients. Subjects with painful temporomandibular disorders (TMD) showed significant trends for increased signs and symptoms of TMD associated with increased frequency of concurrent temple headaches.

Dental magnetic resonance imaging

INTRODUCTION Clinical dentistry is in need of noninvasive and accurate diagnostic methods to better evaluate dental pathosis. The purpose of this work was to assess the feasibility of a recently developed magnetic resonance imaging (MRI) technique, called SWeep Imaging with Fourier Transform (SWIFT), to visualize dental tissues. METHODS Three in vitro teeth, representing a limited range of clinical conditions of interest, imaged using a 9.4T system with scanning times ranging from 100 seconds to 25 minutes. In vivo imaging of a subject was performed using a 4T system with a 10-minute scanning time. SWIFT images were compared with traditional two-dimensional radiographs, three-dimensional cone-beam computed tomography (CBCT) scanning, gradient-echo MRI technique, and histological sections. RESULTS A resolution of 100 μm was obtained from in vitro teeth. SWIFT also identified the presence and extent of dental caries and fine structures of the teeth, including cracks and accessory canals, which are not visible with existing clinical radiography techniques. Intraoral positioning of the radiofrequency coil produced initial images of multiple adjacent teeth at a resolution of 400 μm. CONCLUSIONS SWIFT MRI offers simultaneous three-dimensional hard- and soft-tissue imaging of teeth without the use of ionizing radiation. Furthermore, it has the potential to image minute dental structures within clinically relevant scanning times. This technology has implications for endodontists because it offers a potential method to longitudinally evaluate teeth where pulp and root structures have been regenerated.

Frequency of Nonodontogenic Pain after Endodontic Therapy: A Systematic Review and Meta-Analysis

INTRODUCTION Little is known about ill-defined pain that persists after endodontic procedures, including an estimate of the problems magnitude. We conducted a systematic review of prospective studies that reported the frequency of nonodontogenic pain in patients who had undergone endodontic procedures. METHODS Nonodontogenic pain was defined as dentoalveolar pain present for 6 months or more after endodontic treatment without evidence of dental pathology. Endodontic procedures reviewed were nonsurgical root canal treatment, retreatment, and surgical root canal treatment. Studies were searched in four databases electronically, complemented by hand searching. A summary estimate of nonodontogenic tooth pain frequency was derived using random-effects meta-analysis. RESULTS Of 770 articles retrieved and reviewed, 10 met inclusion criteria, and nine had data on both odontogenic and nonodontogenic causes of pain. A total of 3,343 teeth were enrolled within the included studies and 1,125 had follow-up information regarding pain status. We identified 48 teeth with nonodontogenic pain and estimated a 3.4% (95% confidence interval, 1.4%-5.5%) frequency of occurrence. In nine articles containing data regarding both odontogenic and nonodontogenic causes of tooth pain, 56% (44/78) of all cases were thought to have a nonodontogenic cause. CONCLUSIONS Nonodontogenic pain is not an uncommon outcome after root canal therapy and may represent half of all cases of persistent tooth pain. These findings have implications for the diagnosis and treatment of painful teeth that were previously root canal treated because therapy directed at the tooth in question would not be expected to resolve nonodontogenic pain.

Diagnostic criteria for headache attributed to temporomandibular disorders

Aims: We assessed and compared the diagnostic accuracy of two sets of diagnostic criteria for headache secondary to temporomandibular disorders (TMD). Methods: In 373 headache subjects with TMD, a TMD headache reference standard was defined as: self-reported temple headache, consensus diagnosis of painful TMD and replication of the temple headache using TMD-based provocation tests. Revised diagnostic criteria for Headache attributed to TMD were selected using the RPART (recursive partitioning and regression trees) procedure, and refined in half of the data set. Using the remaining half of the data, the diagnostic accuracy of the revised criteria was compared to that of the International Headache Society’s International Classification of Headache Diseases (ICHD)-II criteria A to C for Headache or facial pain attributed to temporomandibular joint (TMJ) disorder. Results: Relative to the TMD headache reference standard, ICHD-II criteria showed sensitivity of 84% and specificity of 33%. The revised criteria for Headache attributed to TMD had sensitivity of 89% with improved specificity of 87% (p < 0.001). These criteria are (1) temple area headache that is changed with jaw movement, function or parafunction and (2) provocation of that headache by temporalis muscle palpation or jaw movement. Conclusion: Having significantly better specificity than the ICHD-II criteria A to C, the revised criteria are recommended to diagnose headache secondary to TMD.

What is the impact of acute and chronic orofacial pain on quality of life

OBJECTIVES Orofacial pain (OFP) is thought to substantially reduce oral health-related quality of life (OHRQoL). Little has been reported about the impact of acute dental pain and persistent (chronic) orofacial pain conditions, other than temporomandibular disorders (TMD), on OHRQoL. The aim of this study was to examine and compare OHRQoL impairment among four OFP conditions: TMD, acute dental pain (ADP), trigeminal neuralgia (TN) and persistent dentoalveolar pain disorder (PDAP). METHODS OHRQoL was measured using the OHIP-49 in a convenience sample of subjects with four OFP conditions (TMD (n=41), ADP (n=41), TN (n=21), PDAP (n=22) and a pain-free control group (n=21)). The mean OHIP-49 summary score described the level of impact and inferential and descriptive statistics were used to examine any differences inter-condition. The mean of the OHIP-14 and 5 were also measured by extracting the corresponding items from the OHIP-49. RESULTS All pain conditions presented with statistically significant (P<0.001) and clinically relevant (measured by effect sizes and the OHIPs minimal important difference) impairment when compared to the control group (P<0.001). The OHRQoL for the four OFP conditions had similar levels of impairment (TMD=62.3, ADP=55.5, TN=58.1 and PDAP=69.8). CONCLUSION TMD, ADP, TN and PDAP have substantial impact on OHRQoL as measured by the OHIP-49 and the extracted items for the OHIP-14 and 5. Differences among the four groups of orofacial pain conditions are likely not to be substantial.

Persistent dento-alveolar pain disorder (PDAP): Working towards a better understanding.

• New terminology, persistent dento-alveolar pain disorder (PDAP), and diagnostic criteria have been put forward to address the shortcomings of existing nomenclature, which are associated with unclear criteria. • Arriving at an accurate diagnosis of PDAP is based on excluding other possible aetiologies, and may involve different care providers. • Synthesis of published data suggests that PDAP has a frequency of occurrence following root canal therapy of around 1.6%. • The putative risk factors involved in PDAP are largely unknown, but seem to be similar to those being identified with other post-surgical chronic pain disorders. • The underlying mechanisms involved in the development of and/or perpetuating PDAP are unknown and the approach to treatment remains empiric in nature.