Clinical investigation of patients who develop neuropathic tooth pain after endodontic procedures

Assessing the occurrence and severity of pre- and postendodontic pain in anemic and healthy female patients

OBJECTIVES

The objective of this current survey was to assess both the occurrence and severity of pre- and post-endodontic pain among female individuals, distinguishing between those with anemia and those without.

MATERIALS AND METHODS

In the current study, we included a total of 60 women with anemia (hemoglobin < 11) and those without anemia (hemoglobin > 13). We recorded the occurrence and severity of pain before and at 24, 48, and 72 h following root canal treatment using a visual analog scale (VAS) ranging from 0 to 10. Additionally, we collected data on patient age, tooth type, as well as pulpal and periapical conditions. Statistical analysis was carried out using two-way ANOVA, pairedt-tests, and Pearson correlation coefficient. The significance level for statistical tests was set at p ≤ .05.

RESULTS

The incidence of preoperative pain in both anemic and non-anemic patients was 80%. The total incidence of post-operative pain was recorded as 71.7% (82.2% in anemic and 61.1% in non-anemic women). Compared with the pretreatment pain incidence and intensity, the values increased in 24 h but declined in 48 h and 72 h after treatment. Considering the posttreatment pain intensity, the mean values were higher in the three time intervals (24, 48, and 72 h) in anemic patients. Pulpal and periapical status, in contrast to age and tooth type, significantly contributed to the intensity of posttreatment pain.

CONCLUSION

Regarding the importance of pain phenomenon in human life, it is recommended to consider anemia as an important risk factor for post-endodontic pain. Early diagnosis and analgesic treatment interventions in anemic females, alongside the pain control during root canal treatment, could promote the patient's satisfaction and quality of care.

Post-traumatic Trigeminal Neuropathy Associated With Endodontic Therapy: A Systematic Review

A painful or non-painful trigeminal nerve lesion brought on by trauma that exhibits symptoms and/or clinical evidence of trigeminal nerve dysfunction is known as painful post-traumatic trigeminal neuropathy (PTTN). In relation to this, the term post-traumatic persistent dentoalveolar pain (PDAP) is an idiopathic condition of chronic neuropathic origin that manifests as a diagnostic challenge for dental practitioners. Neuropathic pain is defined by the International Association for the Study of Pain (IASP) as "pain initiated or caused by a primary lesion or dysfunction in the nervous system." PDAP is located primarily in the teeth and jaws. This study systematically reviews how likely it is to get painful PTTN if the patient received endodontic therapy and the duration between doing root canal therapy (RCT) and getting PTTN. A systematic review was carried out using key search terms from PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) with English as the only permitted language. There were strict inclusion requirements. The 10 articles that were included showed a prevalence of an endodontic procedure anywhere from three to 48 months following post-endodontic treatment, and it mainly affects females in their mid-40s with no variation regarding the areas, whether it is in the maxilla or mandible. The lack of information about the association between RCT and PTTN led practitioners to make wrong diagnoses, which made the patient unwilling to seek further help. So, in this review, we identified some visible characteristics that can help in that process.

3-year Outcome of Patients with Persistent Pain after Root Canal Treatment: The National Dental Practice-Based Research Network

INTRODUCTION

We measured the long-term outcomes of patients reporting persistent pain 6 months after root canal treatment (RCT) and assessed the characteristics differing patients with pain chronification from those with pain resolution.

METHODS

Forty-five patients previously found to have persistent pain 6 months post-RCT from the National Dental Practice-Based Research Network were approached for a 3-year follow-up, and 27 participated in the survey. The frequency of self-reported pain, its impact on the ability to perform daily activities, and health care use were measured. The differences between patients whose persistent pain continued and those whose pain resolved were assessed.

RESULTS

Five patients met criteria for pain at 3.4 years (range, 3.1-3.9 years) post-RCT, which was moderate in intensity, occurred for about 3 days in the preceding month, and kept 1 patient from usual activities. Additional health care was received by 4 of 5 patients whose pain continued compared with 7 of 22 patients whose pain resolved. A longer duration of preoperative pain and higher pain intensity and interference at 6 months were found among patients with pain chronification. Of 13 patients with specific diagnoses for the persistent pain derived at 65 ± 41 days (∼8 months) post-RCT, 10 improved regardless of the diagnosis or treatment, and 11 had a temporomandibular disorder and/or headache as comorbid diagnoses (6) or causes (6) of the persistent "tooth" pain.

CONCLUSIONS

Progression of persistent post-RCT pain occurred in 19% of patients. The majority (56%) of patients improved without additional interventions. Both the group that improved and the group that continued to experience pain had a mixture of odontogenic and nonodontogenic etiologies.

Development and preliminary evaluation of a new screening instrument for atypical odontalgia and persistent dentoalveolar pain disorder

AIM

To develop and preliminarily evaluate a new screening instrument for atypical odontalgia (AO) or persistent dentoalveolar pain disorder (PDAP). To evaluate the instrument's performance in detecting AO/PDAP amongst a heterogeneous group of orofacial pain conditions and pain-free controls and empirically compare its performance with an established neuropathic screening instrument (S-LANSS), which is the best available standard.

METHODS

The study design was cross-sectional; subjects recruited included a convenience sample of pain-free controls (n = 21) and four groups of orofacial pain conditions: AO/PDAP (n = 22); trigeminal neuralgia (n = 21); temporomandibular disorder (n = 41); and acute dental pain (n = 41). The instrument's internal reliability and factor structure were examined alongside its sensitivity and specificity and ROC-determined threshold score.

RESULTS

The 9 AO/PDAP-specific items were found to moderately correlate with the S-LANSS (r = 0.58; P < 0.01). The 14-items of the full instrument were examined using exploratory factor analysis and reduced to ten items in a two-factor structure that explained 96% of the variance. This 10-item final instrument had a ROC area of 0.77 (95% CI: 0.67; 0.88), sensitivity of 77% (95% CI: 55; 92%), and specificity of 69% (95% CI: 60; 77%) with an intentionally higher false-positive rate than false-negative rate. In contrast, the S-LANSS exhibited sensitivity of 32% (95% CI: 14;55%) and specificity of 78% (95% CI: 70;85%) with less optimal false-positive versus false-negative rates.

CONCLUSION

This preliminary study confirms the new screening instrument for AO/PDAP merits progression to field testing.

Molecular, cellular and behavioral changes associated with pathological pain signaling occur after dental pulp injury

Persistent pain can occur after routine dental treatments in which the dental pulp is injured. To better understand pain chronicity after pulp injury, we assessed whether dental pulp injury in mice causes changes to the sensory nervous system associated with pathological pain. In some experiments, we compared findings after dental pulp injury to a model of orofacial neuropathic pain, in which the mental nerve is injured. After unilateral dental pulp injury, we observed increased expression of activating transcription factor 3 (ATF3) and neuropeptide Y (NPY) mRNA and decreased tachykinin precursor 1 gene expression, in the ipsilateral trigeminal ganglion. We also observed an ipsilateral increase in the number of trigeminal neurons expressing immunoreactivity for ATF3, a decrease in substance P (SP) immunoreactive cells, and no change in the number of cells labeled with IB4. Mice with dental pulp injury transiently exhibit hindpaw mechanical allodynia, out to 12 days, while mice with mental nerve injury have persistent hindpaw allodynia. Mice with dental pulp injury increased spontaneous consumption of a sucrose solution for 17 days while mental nerve injury mice did not. Finally, after dental pulp injury, an increase in expression of the glial markers Iba1 and glial fibrillary acidic protein occurs in the transition zone between nucleus caudalis and interpolaris, ipsilateral to the injury. Collectively these studies suggest that dental pulp injury is associated with significant neuroplasticity that could contribute to persistent pain after of dental pulp injury.

Psychiatric comorbidities in patients with Atypical Odontalgia

OBJECTIVE

Atypical Odontalgia (AO) is a condition characterized by tooth pain with no apparent cause. Although psychiatric comorbidity seems to be very common, it has rarely been studied. To clarify the influence of psychiatric comorbidity on the clinical features in patients with AO, we retrospectively evaluated their examination records.

METHODS

Clinical features and psychiatric diagnoses of 383 patients with AO were investigated by reviewing patients' medical records and referral letters. Psychiatric diagnoses were categorized according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). We also analyzed visual analogue scale (VAS), self-rating depression scale (SDS), and the short-form McGill pain questionnaire (SF-MPQ) scores.

RESULTS

Of the 383 patients with AO, 177 (46.2%) had comorbid psychiatric disorders. The most common were depressive disorders (15.4%) and anxiety disorders (10.1%). Serious psychotic disorders such as bipolar disorder (3.0%) and schizophrenia (1.8%) were rare. Dental trigger of AO was reported in 217 (56.7%) patients. There were no significant correlations between psychiatric comorbidities and most of the demographic features. Higher VAS and SDS scores, higher frequency of sleep disturbance, and higher ratings of "Fearful" and "Punishing-cruel" descriptors of the SF-MPQ were found in patients with psychiatric comorbidity.

CONCLUSIONS

About half of AO patients had comorbid psychiatric disorders. Dental procedures are not necessarily causative factors of AO. In AO patients with comorbid psychiatric disorders, pain might have a larger emotional component than a sensory one. VAS, SDS, and SF-MPQ scores might aid in the noticing of underlying comorbid psychiatric disorders in AO patients.

Neuropathic pain in the orofacial region: The role of pain history. A retrospective study

INTRODUCTION

Orofacial neuropathic pain is often difficult to treat, mostly because of still unclear underlying mechanisms. The occurrence of such neuropathic pain varies depending on different factors, of which preexisting preoperative pain seems to be of high importance. The aim of this study was thus to test the hypothesis that prior history of pain could indeed be considered a risk factor for the development of orofacial neuropathic pain in the same region.

METHODS

The study was performed in the dental department of the Groupe Hospitalier Pitié-Salpêtrière (GHPS) in Paris, France. We investigated the presence of prior inflammatory pain before development of orofacial neuropathic pain in 56 patients. For each patient file, the following items were collected: age, gender; medical history; diagnosis; description of the pain (at time of consultation); presence or absence of prior dental treatment; date and type of dental treatment received.

RESULTS

41 patients (73%) of orofacial neuropathic pain patients had a history of pain compatible with an inflammatory condition; 4% (n=2) did not report any prior pain and 23% (n=13) could not remember. Among the patients with documented history of pain prior to neuropathy, 88% (n=36) received surgical treatment; 61%, (n=25) endodontic treatment and 22%, (n=9) restorative treatment. All eventually received endodontic treatment or tooth extraction. These dental treatments are compatible with the hypothesis of prior inflammatory pain in these patients.

CONCLUSION

These results support the hypothesis that prior inflammatory pain could favor the development of orofacial neuropathic pain. Prevention and treatment of inflammatory trigeminal pain may therefore play a key role in preventing future neuropathic pain development.

Amplified Brain Processing of Dentoalveolar Pressure Stimulus in Persistent Dentoalveolar Pain Disorder Patients

AIMS

(1) To determine the brain regions activated by dentoalveolar pressure stimulation in persistent dentoalveolar pain disorder (PDAP) patients, and (2) to compare these activation patterns to those seen in pain-free control subjects.

METHODS

A total of 13 PDAP patients and 13 matched controls completed the study. Clinical pain characteristics and psychosocial data were collected. Dentoalveolar mechanical pain thresholds were determined with a custom-made device over the painful area for patients and were used as the stimulation level during functional magnetic resonance imaging (fMRI) data acquisition. Control subjects received two stimulation levels over matched locations during fMRI scanning: one determined (as above) that evoked equally subjective pain ratings matching those of patients (subjective-pain match) and another nonpainful stimulation level matching the average stimulus intensity provided to patients (stimulus-intensity match). Clinical and psychosocial data were analyzed using independent samples t tests, Mann-Whitney U test, and Spearman rank-order correlation coefficient. fMRI data were analyzed using validated neuroimaging software and tested using a general linear model.

RESULTS

PDAP patients had greater anxiety (P<.0001) and depression scores (P=.001), more jaw function impairment (P<.0001), and greater social impact (P<.0001) than controls. No significant differences were found for brain activation spatial extent (PDAP X Controls subjective pain: P=.48; PDAP X Controls stimulus intensity: P=.12). Brain activations were significantly increased for PDAP patients compared to control subjects when matched to stimulus intensity in several regions related to the sensory-discriminative and cognitive components of pain perception, including the primary and secondary somatosensory cortices, inferior parietal lobule, insula, premotor cortex, prefrontal cortex, and thalamus. When matched to subjective pain ratings, increased brain activations were still present for PDAP patients compared to controls, although to a lesser extent.

CONCLUSION

The present results suggest that dentoalveolar pressure is processed differently in the brain of PDAP patients, and the increased activation in several brain areas is consistent with amplified pain processing.

Orofacial pain after invasive dental procedures: neuropathic pain in perspective

BACKGROUND

The neurologist is very familiar with the painful neuropathies of the trunk and extremities but, generally, to a lesser extent with those of the head and face. Of the latter, the neurologist is particularly familiar with ophthalmic zoster and trigeminal neuralgia.

REVIEW SUMMARY

This review deals with neuropathic orofacial pain: (1) to highlight its presentation; and (2) to contrast it with that of neuropathic pain elsewhere in the body, including the head, from which it seems to differ significantly. The reason for the difference is also discussed as well as its implications for the diagnosis of orofacial pain as neuropathic. In the cases of neuropathic orofacial pain presented, the pain followed invasive dental procedures, making it relatively homogenous in terms of its etiology. The cases are contrasted with those of cranial nonorofacial and of noncranial painful neuropathy.

CONCLUSIONS

It is suggested that the presence of abnormal sensory responses to touch, in the sense of paresthesia, dysesthesia, or allodynia, is a prerequisite for the diagnosis of neuropathic pain, when other, motor or sensory, signs of nerve injury ordinarily guiding the diagnosis are lacking, as is often the case in the face.

Prevalence of persistent pain 3 to 5 years post primary root canal therapy and its impact on oral health-related quality of life: PEARL Network findings

INTRODUCTION

The frequency of persistent pain 3-5 years after primary root canal therapy and its impact on the patient's perceived oral health-related quality of life was determined in a practice-based research network.

METHODS

All patients presenting to participating network practices who received primary root canal therapy and restoration for a permanent tooth 3-5 years previously were invited to enroll. Persistent pain was defined as pain occurring spontaneously or elicited by percussion, palpation, or biting. The patient also completed an oral health-related quality of life questionnaire (Oral Health Impact Profile-14).

RESULTS

Sixty-four network practices enrolled 1323 patients; 13 were ineligible, 12 did not receive a final restoration, and 41 were extracted, leaving 1257 for analysis. The average time to follow-up was 3.9 ± 0.6 years. Five percent (63/1257) of the patients reported persistent pain, whereas 24 of 63 (38%) exhibited periapical pathosis and/or root fracture (odontogenic pain). No obvious odontogenic cause for persistent pain was found for 39 of 63 (62%). Teeth treated by specialists had a greater frequency of persistent pain than teeth treated by generalists (9.3% vs 3.0%, respectively; P < .0001). Sex, age, tooth type, type of dentist, and arch were not found to be associated with nonodontogenic persistent pain; however, ethnicity and a preoperative diagnosis of pulpitis without periapical pathosis were. Patients reporting pain with percussion tended to experience pain with other stimuli that negatively impacted quality of life including oral function and psychological discomfort and disability.

CONCLUSIONS

These results suggest that a small percentage (3.1%) of patients experience persistent pain not attributable to odontogenic causes 3-5 years after primary root canal therapy that may adversely impact their quality of life.

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 problem's 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.