Prevalence of neuropathic pain and sensory alterations after dental implant placement in a university-based oral surgery department: A retrospective cohort study

Somatosensory alterations after single-unit dental implant immediate loading: A 1-year follow-up study

OBJECTIVE

This cohort study aimed to assess the incidence of somatosensory alterations after implant surgery using standardized quantitative and qualitative sensory testing.

METHODS

33 participants with single-tooth loss, undergoing immediate implant loading were included. Quantitative Sensory Testing (QST) and Qualitative Sensory Testing (QualST) were conducted at eight time points over a year (baseline to 1 year). Two-Way Repeated Measures ANOVA and post hoc Tukey test were used on QST values and Cochran Q test on QualST.

RESULTS

The study revealed significant increase in thermal thresholds overtime. At the operated side, overall Cold Pain Threshold (extraoral: p = 0.030; intraoral: p < 0.001), and Cold Detection Threshold (intraoral: p < 0.001) increased overtime. In contralateral region, maxilla Cold Detection Threshold (extraoral: p = 0.024; intraoral: p = 0.031), Warm Detection Threshold (extraoral: p = 0.026; intraoral: p = 0.047) and overall Cold Pain Threshold (extraoral and intraoral: p < 0.001) also increased. QualST showed extraoral pinprick (p = 0.032) and intraoral pinprick (p = 0.000), cold (p = 0.000) and touch (p = 0.002) stimuli abnormalities overtime.

CONCLUSIONS

Somatosensory alterations after implant surgery were detected in both quantitative and qualitative sensory assessments, but rapidly decreased during the first follow-ups, and then continuously until 1-year.

CLINICAL SIGNIFICANCE

This study provides clinical and controlled evidence on the real effect of the somatosensory alterations overtime, leading to a better understanding of neurosensory behaviour after single-tooth dental implant rehabilitation.

Do dental implant therapies arouse signs and symptoms of temporomandibular disorders? A scoping review

OBJECTIVE

To delineate and discuss the literature about TMD in the context of dental implantology.

METHODS

The PRISMA-ScR and Joanna Briggs guidelines for scoping reviews were used as methodological parameters. In vivo studies published in the English language showing interplay between dental implant therapy and TMD were included. A systematic screen strategy was applied in two platforms to obtain a broad range of relevant literature published in English.

RESULTS

The literature review indicated that prolonged surgical procedure may be a risk for TMD. Conversely, implant-supported prostheses were found to contribute to the mitigation of some TMD aspects. Empirical principles for the best practice in implant dentistry concerning the TMD were discussed in the present study.

CONCLUSION

The included clinical studies suggest that factors associated with the implant placement, such as long duration of surgical procedures, may represent risk factors for TMD. They also indicate long-term benefits of implant-supported restorations.

Modulation of trigeminal neuropathic pain by optogenetic inhibition of posterior hypothalamus in CCI-ION rat

Posterior hypothalamus (PH), an important part of the descending pain processing pathway, has been found to be activated in trigeminal autonomic cephalalgias. However, there are very few studies conducted and information regarding its implications in trigeminal neuropathic pain (TNP). Therefore, we aimed to ascertain whether optogenetic inhibition of PH could affect the outcomes of a chronic constriction injury in the infraorbital nerve (CCI-ION) rat model. Animals were divided into the TNP animal, sham, and naive-control groups. CCI-ION surgery was performed to mimic TNP symptoms, and the optogenetic or null virus was injected into the ipsilateral PH. In vivo single-unit extracellular recordings were obtained from both the ipsilateral ventrolateral periaqueductal gray (vlPAG) and contralateral ventral posteromedial (VPM) thalamus in stimulation "OFF" and "ON" conditions. Alterations in behavioral responses during the stimulation-OFF and stimulation-ON states were examined. We observed that optogenetic inhibition of the PH considerably improved behavioral responses in TNP animals. We found increased and decreased firing activity in the vlPAG and VPM thalamus, respectively, during optogenetic inhibition of the PH. Inhibiting PH attenuates trigeminal pain signal transmission by modulating the vlPAG and trigeminal nucleus caudalis, thereby providing evidence of the therapeutic potential of PH in TNP management.

Neuropathic Pain in Lower Lip after Guided Tissue Regeneration: A Case Report

Post-traumatic trigeminal neuropathic pain is mainly caused by the extraction of third molars or the placement of dental implants. This report describes the treatment of neuropathic pain arising after guided tissue regeneration (GTR). The patient was a 55-year-old woman who had to undergo GTR due to severe periodontitis in the distal aspect of the right mandibular second molar. Postoperatively, the patient had been prescribed mecobalamin for hypesthesia and allodynia in the right lower lip. No improvement was observed in these symptoms after 4 months, however, so she was referred to our Orofacial Pain Center. Preoperative and postoperative cone-beam computed tomography revealed a cyst-like lesion (radiolucent area) close to the right mandibular second molar and canal. Although the results of quantitative sensory examination were normal, rubbing the right lower lip with a cotton swab elicited mechanical allodynia. The diagnosis was post-traumatic trigeminal neuropathic pain for which the patient was given pregabalin and Neurotropin^®. The symptoms improved within approximately 32 weeks, with the medication being terminated at 64 weeks. Although hypoesthesia due to nerve injury may suddenly go into remission, allodynia is often intractable. If symptoms show no improvement after 3 months, possible nerve injury should be investigated. Additionally, the distal root of the mandibular molar may be close to the inferior alveolar nerve, necessitating appropriate diagnostic imaging of the operative field. If the lesion or distal root is close to the inferior alveolar nerve, postoperative hypesthesia or neuropathic pain may occur, even without direct trauma.

Effect of vitamin B complex administration on pain and sensory problems related to inferior alveolar nerve damage following mandibular implant placement surgery

Background. Inferior alveolar nerve damage can lead to mild to severe paresthesia and even facial pain. One of the treatments considered today for the reconstruction and treatment of damaged peripheral nerves is the use of vitamin supplements. This study aimed to evaluate the effect of vitamin B complex supplementation on pain and sensory problems following mandibular implant placement surgery. Methods. In this single-blind clinical trial, 46 patients applying for implant placement, who were eligible for the study, were evaluated. All the patients were examined for sensory facial injury and inferior alveolar nerve injury within 24 hours after implant placement. The nerve damage was recorded by AI (asymmetry index) in the initial examination. Patients who reported clinical and radiographic signs of nerve damage due to implant or drill impingement of the nerve canal were excluded from the study and promptly treated with anti-inflammatory protocols. Then the patients were randomly divided into control (n=23) and intervention (n=23) groups. Patients in the control group received routine treatment after implantation, and patients in the intervention group received vitamin B complex pills in addition to routine treatment. A placebo was used to eliminate the inductive effect of the drug in the control group. Follow-up of patients was performed at intervals of 14 days and 1, 2, and 3 months after treatment. Data analysis was performed using SPSS 24 and Kruskal-Wallis, Wilcoxon, and chi-squared tests. Results. In both groups, a decreasing trend in pain intensity was observed for up to three months. There were no significant differences between the mean pain intensity in the intervention and control groups at all the follow-up intervals. In both groups, a decrease in the rate of paresthesia was observed during the 3-month follow-up. The mean of paresthesia in the two groups was not significantly different at any follow-up interval. Conclusion. Vitamin B complex might not affect pain intensity and paresthesia after implant surgery.

Pain complications of oral implants: Is that an issue?

The use of oral implants as a form of replacing missing teeth in partial or total edentulous patients is considered the gold standard in oral rehabilitation. Although considered a history of success in contemporary dentistry, surgical complications may occur, as excessive bleeding, damage to the adjacent teeth and mandibular fractures. Persistent pain and abnormal somatosensory responses after the surgery ordinary healing time are also potential problems and may lead to the development of a condition named posttraumatic trigeminal neuropathic pain (PTNP). Though relatively rare, PTNP has a profound impact on patient's quality of life. Appropriated previous image techniques, effective anaesthetic procedures and caution during the surgical procedure and implant installation are recommended for the prevention of this condition. In case of the PTNP, different management modalities, including antidepressant and membrane stabilizer medications, as well as peripheral strategies, as the use of topical medication and the botulin toxin are presented and discussed.

Accuracy and the role of experience in dynamic computer guided dental implant surgery: An in-vitro study

BACKGROUND

To compare the accuracy of implant placement using the conventional freehand method and a dynamic navigation system; to assess the role of the surgeon's experience in implant placement using these two methods.

MATERIAL AND METHODS

A randomized in-vitro study was conducted. Six resin mandible models and 36 implants were used. Two researchers with differing clinical experience (novice and experienced) placed implants using either the Navident dynamic navigation system (navigation group) or the conventional freehand method (freehand group). Accuracy was measured by overlaying the real position in the postoperative CBCT on the virtual presurgical placement of the implant in a CBCT image. Descriptive and bivariate analyses of the data were performed.

RESULTS

The navigation group showed significantly higher accuracy for all the variables studied except 3D entry and depth deviation. This system significantly enhanced the accuracy of the novice professional in several outcome variables in comparison with the freehand implant placement method. However, when the implants were placed by the experienced clinician the dynamic navigation system only improved angulation deviation. Significant differences were found between the 2 professionals when the freehand method was employed. Similar deviations were observed for the implants placed with the navigation system.

CONCLUSIONS

Dynamic computer assisted surgery systems allow more accurate implant placement in comparison with the conventional freehand method, regardless of the surgeon's experience. However, this system seems to offer more advantages to novice professionals, since it allows them to reduce their deviations significantly and achieve similar results to those of experienced clinicians.

A randomized controlled trial comparing nerve block and mandibular infiltration techniques in posterior mandible implant surgeries

Background

To compare global surgical pain under nerve block and mandibular infiltration anesthesia techniques, and to evaluate pain during drilling and the distance to the mandibular canal in posterior mandible implant surgeries.

Material and Methods

A prospective, randomized, controlled, double-blind, clinical trial was conducted to compare nerve block (Group A) to mandibular infiltration (Group B) techniques for dental implant placement. Global surgical pain (VAS = visual analogue scale), pain during drilling or implant placement (MPQ = McGill pain questionnaire) and distance to the mandibular canal (Image J) were statically analyzed. Age, gender, anxiety levels, tooth to be replaced, implant size, adjacent teeth and duration of surgery were also analyzed.

Results

172 patients were included and 283 dental implants were analyzed. VAS values were significantly higher in Group B (p<0.05). In Group A, 99% of the surgeries were performed painlessly during drilling and implant placement, but in Group B, 11.6% of implant placements (17 implants) felt pain during these surgical steps. Mean distance to mandibular canal (3.8 mm, range: 0.0 to 7.0) in those 17 implants placed under mandibular infiltration was clinically and statistically similar to the mean distance (3.0 mm, range: 0.0 to 9.0) of 130 implants placed painless (p=0.10). Pain during drilling under mandibular infiltration was significantly associated with the duration of surgery (p<0.05) and to both adjacent teeth being present (p<0.05).

Conclusions

Although both techniques are safe and effective for placing implants in the posterior mandible, nerve block provides a more profound analgesia than mandibular infiltration. When placing implants under mandibular infiltration, as getting closer to the canal does not increase the feeling of pain, it is not recommended to use the presence of pain as a preventive resource to avoid inferior alveolar nerve injuries. Key words:Dental implant, mandibular infiltration anesthesia, nerve block, pain, nerve injury.