Persistent pain and neurosensory disturbance after dental implant surgery: prevention and treatment

[Anatomy and function of the canalis sinuosus and its injury prevention and treatment strategies in implant surgery]

The canalis sinuosus, a canal containing the anterior superior alveolar nerve bundle, originates from the infraorbital canal and extends along the maxillary sinus and nasal cavity edges to the anterior maxilla. It was once regarded as an anatomical variation. However, with the widespread application of cone beam computed tomography (CBCT), the detection rate of canalis sinuosus in the population has increased. The canalis sinuosus exhibits diverse courses, branching into multiple accessory canals and terminating at the nasal floor or the anterior tooth region, with the majority traversing the palatal side of the central incisor. The anterior superior alveolar nerve bundle within the canalis sinuosus not only innervates and nourishes the maxillary anterior teeth and the corresponding soft tissues, and the maxillary sinus mucosa, but also relates to the nasal septum, lateral nasal wall, and parts of the palatal mucosa. To minimize surgical complications, strategies for preventing and treating canalis sinuosus injuries need to be investigated. Preoperatively, CBCT is used to identify the canalis sinuosus and to virtually design implant placement at a distance of more than 2 mm from the canalis sinuosus. Intraoperatively, assessing bleeding and patient comfort, complemented by precision surgical techniques such as the use of implant surgical guide plates. Postoperatively, CBCT is used to examine the relationship between the implant and the canalis sinuosus, and treatment of canalis sinuosus injuries can be tailored based on the patient's symptoms. This review summarizes the detection of canalis sinuosus in the population, its anatomical characteristics, and the physiological functions in the anterior maxilla, and discusses strategies for avoiding canalis sinuosus injuries during implant surgery, thereby enhancing clinical awareness and providing references for clinical decision-making.

Assessment of the Anterior Loop and Pattern of Entry of Mental Nerve Into the Mental Foramen: A Radiographic Study of Panoramic Images

INTRODUCTION

The precise location of the mental foramina is an essential landmark in planning the position of dental implants in the anterior mandible. Injury to inferior alveolar nerve during anterior mandibular implant surgery causes altered sensation which greatly affects patient satisfaction.

METHODS

In this study, we assessed the prevalence of anterior loop of mental nerve and the pattern of entry of mental nerve into the mental foramen. Three hundred panoramic radiographs (600 hemimandibles) obtained from records maintained in the Department of Oral Medicine and Radiology were randomly selected for the study. The radiographs were evaluated by two independent observers for the pattern of entry of mental nerve into the mental foramen on either side of the mandible and for the presence or absence of anterior loop of mental nerve.

RESULTS

The most prevalent pattern of mental nerve observed was Straight pattern which totals to 67.5% followed by Anterior loop pattern (18.8%) and then the Perpendicular pattern (13.7%). There was no significant association between the gender and subtypes of looping pattern on the left and right side and a highly significant association between the side of the mandible and loop pattern was observed by Chi square test.

CONCLUSION

The Anterior loop pattern of mental nerve has been found in 18.8% of the population suggesting to accurate planning with three-dimensional imaging techniques to avoid injury to mental nerve during dental implant placement and other surgical procedure involving the interforaminal region of the mandible.

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.

Post-Operative Endodontic Pain Management: An Overview of Systematic Reviews on Post-Operatively Administered Oral Medications and Integrated Evidence-Based Clinical Recommendations

Endodontic treatment comprises the overall management of pre-, intra- and post-operative symptoms, including post-operative endodontic pain, considered as a complication susceptible of chronicization. Post-operative pain is very common and highly unpreventable and has a multi-factorial etiology and a potential pathogenic link to the acute inflammation of the periapical area, secondary to localized chemical, mechanical, host and/or microbial damage occurring during endodontic treatment. Considering the multitude of heterogeneous technical and pharmacological approaches proposed to control post-operative endodontic pain, the present study primarily comprised an overview of systematic reviews of systematic reviews of randomized clinical trials, summarizing findings on post-operatively administered oral medications for post-operative endodontic pain control, in order to note the most effective type and dosage of such drugs. Secondarily, a narrative review of the current evidence on technical solutions to be observed during endodontic treatment procedures, to control post-operative pain, was conducted to provide integrated evidence-based clinical recommendations for optimal post-operative endodontic pain management.

Trigeminal Traumatic Neuroma: a Comprehensive Review of the Literature Based On a Rare Case

PURPOSE OF REVIEW

Traumatic neuromas in general, and trigeminal traumatic neuromas in particular, are relatively rare entities originating from a damage to a corresponding nerve or its branches. This manuscript is a comprehensive review of the literature on trigeminal traumatic neuromas based on an interesting and challenging case of bilateral intraoral lesions.

RECENT FINDINGS

The diagnosis for this patient was bilateral trigeminal traumatic neuromas. It is possible that these patients have a genetic predisposition to the development of these lesions. It is a neuropathic pain condition and may mimic dental and other trigeminal pain entities. Topical treatment with lidocaine gel, utilizing a custom-made neurosensory stent, rendered the patient significant and sustained pain relief. Trigeminal traumatic neuromas present a diagnostic challenge even to a seasoned clinician, due to the complex clinical features that may mimic other entities. Topical medications such as local anesthetics may be a good viable alternative to systemic medications to manage the pain associated with the condition. Early identification of the lesion and the associated pain helps in the succinct management of symptomatic trigeminal traumatic neuromas.

Management of Traumatic Trigeminal and Facial Nerve Injuries

In the area of craniomaxillofacial trauma, neurosensory disturbances are encountered commonly, especially with regard to the trigeminal and facial nerve systems. This article reviews the specific microanatomy of both cranial nerves V and VII, and evaluates contemporary neurosensory testing, current imaging modalities, and available nerve injury classification systems. In addition, the article proposes treatment paradigms for management of trigeminal and facial nerve injuries, specifically with regard to the craniomaxillofacial trauma setting.

Pain sensitivity and autonomic nervous system parameters as predictors of dry eye symptoms after LASIK

PURPOSE

Differences in pain processing and autonomic function among patients have been implicated in the development of chronic pain after surgery. This study was designed to evaluate whether pain and autonomic metrics predict severity of chronic dry eye (DE) symptoms after LASIK, as there is increasing evidence that DE symptoms may be manifestations of persistent post-operative ocular pain.

METHODS

Secondary analysis of prospective randomized clinical trial. Patients were treated with either pregabalin or placebo. As no significant differences in DE symptoms were detected by treatment allocation at six months, all participants were grouped together for the present analyses. Subjects were evaluated pre-LASIK with regard to evoked pain sensitivity (utilizing quantitative sensory testing), autonomic metrics and DE and ocular pain symptoms (via validated questionnaires). Measures of DE and ocular pain were assessed post-LASIK, and the Dry Eye Questionnaire 5 (DEQ5) score 6-months after surgery was the primary outcome of interest.

RESULTS

43 individuals were randomized to pregabalin (n = 21) or placebo (n = 22). 42 completed the 6-month visit. Several baseline autonomic metrics correlated with 6-month post-operative DEQ5 scores, including lower systolic (r -0.37, p = 0.02) and diastolic blood pressure (r -0.32, p = 0.04). Ocular pain at 6 months was also negatively correlated with blood pressure (r -0.31, p = 0.047). The presence of painful aftersensations was a significant predictor of chronic DE symptoms at 6 months (mean DEQ5 scores: 8.0 ± 1.9 versus 5.0 ± 5.0, p = 0.009).

CONCLUSIONS

Heightened parasympathetic tone and prolonged pain sensitivity measured prior to surgery predicted greater DE symptom severity 6 months after LASIK.

TRIAL REGISTRATION

NCT02701764.

Effectiveness of low-level laser therapy on recovery from neurosensory disturbance after sagittal split ramus osteotomy: a systematic review and meta-analysis

Background

Orthognathic surgery such as bilateral sagittal split ramus osteotomy (BSSRO) for the treatment of mandibular deformities is one of the most common procedures in maxillofacial operations that may lead to neurosensory disturbance. In this study, we aimed to evaluate the effectiveness of low-level laser therapy (LLLT) on augmenting recovery of neurosensory disturbance of inferior alveolar nerve (IAN) in patients who underwent BSSRO surgery.

Methods

A comprehensive literature search was conducted by two independent authors in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Embase, and Google Scholar electronic databases. Besides, a manual search of all textbooks and relevant articles were conducted. Searches took place in August 2020 and were limited to published and peer-reviewed articles from 2000 to 2020. All analysis was performed using the comprehensive meta-analysis (CMA) and the STATA MP (version:16) software. The weighted mean difference (WMD) using the inverse variance method and the standard mean difference (SMD) was considered for continuous variables.

Results

Seventy-four papers were retrieved after removing duplicate studies and finally, eight studies were assessed for qualitative synthesis and five for meta-analysis. Totally, 94 patients were included in the meta-analysis. Based on the meta-analysis, it was shown that LLLT was not effective in a short interval (0 to 48 h) after surgery, but in a period of more than 1 month after surgery, the positive results of treatment can be observed strikingly. Also, LLLT side/group showed no significant difference in some aspects of neurosensory recovery such as thermal sensation compared to the placebo side/group.

Conclusions

The meta-analysis of randomized controlled trials revealed that LLLT generally improves IAN sensory disturbance caused by BSSRO. Further high-quality clinical trials with longer follow-up periods and larger sample sizes are recommended.

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.

Developing evidence-based clinical imaging guidelines of justification for radiographic examination after dental implant installation

Background

This study aimed to develop evidence-based clinical imaging guidelines to assess the proper implant location following implant surgery and identify potential complications during follow-up.

Methods

The guideline development process employed an adaptation methodology in accordance with the Korean clinical imaging guidelines (K-CIG). Core (Ovid-Medline, Ovid-Embase, National Guideline Clearinghouse, and Guideline International Network) and domestic databases (KoreaMed, KMbase, and KoMGI) were searched used to retrieve guidelines, and two reviewers analyzed the retrieved articles. The articles were included in this review using well-established inclusion criteria.

Results

Our online search identified 66 articles, of which 3 were selected for the development of the guidelines. Consequently, based on these three guidelines, we formulated distinct recommendations regarding the appropriate imaging modalities that should be used following implant placement.

Conclusions

Conventional imaging (e.g., periapical or panoramic radiography) should be the first choice for assessing the implant following its placement and osseointegration. The metal artifacts in Cone Beam Computed Tomography (CBCT) should be considered. However, CBCT is recommended for patients with sensory abnormalities following dental implant surgery to evaluate and identify the underlying cause of implant complications and to determine the appropriate treatment.

Prognosis in case of nerve disturbance after mandibular implant surgery in relation to computed tomography findings and symptoms

Purpose

The aim of this study was to evaluate the computed tomography (CT) imaging findings and clinical symptoms of patients who complained of neurosensory disturbances after mandibular implant surgery, and to investigate the relationships of these parameters with the prognosis for recovery.

Methods

CT scans were reviewed in 56 patients with nerve disturbance after mandibular implant surgery. Two oral radiologists classified the imaging findings into intrusion, contact, close, and separate groups according to the distance from the inferior border of the implant to the roof of the mandibular canal (MC). The symptoms of 56 patients were classified into 8 groups and the frequency of each group was investigated. Patients were categorized according to symptom improvement into no recovery and recovery groups, and the relationships of recovery with the CT classification and specific symptom groups were analyzed.

Results

Thirty-eight of the 56 nerve disturbance cases showed improvement. The close and separate groups in the CT classification had a strong tendency for recovery (90.9% and 81.8%, respectively) (P<0.05). Although the lowest recovery rate was found in the intrusion group, it was non-negligible, at 50%. The 6 patients with a worm crawling feeling all improved, while the 8 cases with a tightening sensation showed the lowest recovery rate, at 12.5%, and the symptom of a tightening sensation occurred only in the intrusion and contact groups.

Conclusions

The closer the implant fixture was to the MC on CT images, the less likely the patient was to recover. Regarding paresthesia symptoms, while a worm crawling feeling is thought to be a predictor of recovery, a tightening sensation appeared to be associated with a lower recovery rate.

Are There Contraindications for Placing Dental Implants?

There are few absolute contraindications to dental implant placement. Relative contraindications include cognitive decline, American Society of Anesthesiology patient status IV or higher categories, or medical conditions that may jeopardize the life or lifespan of the patient. Precautions for placing dental implants should be viewed with respect to the evidence-based exposures that can contribute to risk of failure, including but not limited to local, behavioral, and medical factors. Risk for dental implant failure increases in association with (1) past history of periodontal disease, (2) bruxism, (3) smoking, and (4) radiation therapy.

The comparison of dexmedetomidine and ketamine for pediatric dental surgery: A meta-analysis of randomized controlled studies

INTRODUCTION

Dexmedetomidine and ketamine are used for the sedation of pediatric dental surgery. We conduct a systematic review and meta-analysis to compare the sedation of dexmedetomidine and ketamine for pediatric dental surgery.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched. Randomized controlled trials (RCTs) assessing the influence of dexmedetomidine versus ketamine on pediatric dental surgery are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. This meta-analysis is performed using the random-effect model.

RESULTS

Four RCTs involving 163 children are included in the meta-analysis. Compared with ketamine for pediatric dental surgery, dexmedetomidine results in comparable sedation level (very low quality, 2 RCTs, n = 40; Std. MD = -0.26; 95% CI = -0.74 to 0.23; P = .31), intraoperative analgesia scores (very low quality, 2 RCTs, n = 98; Std. MD = 0.17; 95% CI = -0.23 to 0.57; P = .40), postoperative analgesia scores (very low quality, 2 RCTs, n = 98; Std. MD = 0.23; 95% CI = -0.17 to 0.62; P = .27), DBP (very low quality, 3 RCTs, n = 123; Std. MD = -0.38; 95% CI = -1.04 to 0.27; P = .25) and SpO2 (very low quality, 3 RCTs, n = 123; Std. MD = 0.24; 95% CI = -0.20 to 0.69; P = .28), but significantly decreases heart rate (very low quality, 3 RCTs, n = 123; Std. MD = -1.51; 95% CI = -2.75 to -0.27; P = .02) and SBP (very low quality, 3 RCTs, n = 123; Std. MD = -0.62; 95% CI = -1.16 to -0.08; P = .02), longer recovery time (very low quality, 3 RCTs, n = 138; Std. MD = 1.74; 95% CI = 0.23 to 3.25; P = .02).

CONCLUSIONS

Dexmedetomidine and ketamine have similar sedation, analgesia scores, and hemodynamic balance, but very low quality of the evidence (GRADE) is revealed in this meta-analysis.

Partial Explantation of Failed Dental Implants Placed in Mandibular Canal: A Case Report

One of the most important concerns during posterior mandibular implant placement is avoiding the mandibular canal. Nerve injury can be very disturbing to the patient, possibly causing mild paresthesia to complete anesthesia. Explantation of a dental implant that gas violated the mandibular canal is the most recommended treatment. However, an osseointegrated implant that placed in the mandibular canal can be left if the patient shows no symptoms. In this case report, we describe a technique to maintain the apexes of the implants while partially removing fractured osseointegrated implants previously placed in the mandibular canal.

Imaging in Orofacial Pain

Imaging usefulness in the diagnosis of orofacial pain includes all modalities that cover the soft tissue and bony structures in the region of the head and neck. Imaging techniques may include 2-dimensional and/or 3-dimensional imaging modalities. Both dentists and physicians should be aware of orofacial pain associated with a variety of sources and select the appropriate imaging technique based on the patient's medical and dental history and the clinical examination. The goal of imaging is to provide the clinician with information that will confirm or deny findings of the clinical examination and allow for the selection of an appropriate treatment.

Role of vitamin C in wound healing after dental implant surgery in patients treated with bone grafts and patients with chronic periodontitis

BACKGROUND

Postoperative wound healing is an important part of the success of the dental implant surgery. However, in case of complex surgery or unfavorable factors, wound healing is often unsatisfactory.

OBJECTIVE

The aim of this study was to explore the effects of vitamin C supplementation in wound healing, following the placement of dental implants with or without bone grafts and patients with chronic periodontitis.

METHODS

This randomized controlled clinical trial included 128 patients requiring dental implants to replace missing teeth. Patients were divided into four groups, group A received dental implants supported by guided bone regeneration (GBR) technique, group B received dental implants with Bio-Oss Collagen, group C received dental implants in patients with chronic periodontitis, and group D received dental implants without any bone grafting or periodontal disease. Each group was divided into an experimental subgroup, who received vitamin C, and a control subgroup. Follow-up appointments were performed at day 3, day 7, and day 14 postsurgery, during which soft tissue healing and pain response scores were evaluated using the Landry index and visual analogue scale, respectively.

RESULTS

The experimental subgroups had significantly higher healing indices than the controls (P < .05) at day 7 postsurgery for group B and day 14 postsurgery for groups A, B, and C. Group D displayed no difference between the experimental and control groups at any time point. In reference to vitamin C for pain relief, there were no statistically significant differences between the study groups.

CONCLUSION

Using vitamin C supplementation improves postoperative healing following dental implant surgery in patients with chronic periodontitis and patients treated with GBR or Bio-Oss Collagen grafts. However, vitamin C supplementation does not decrease the postoperative pain associated with dental implant surgery.

Epidemiology of Persistent Dry Eye-Like Symptoms After Cataract Surgery

PURPOSE

To evaluate the frequency and risk factors for persistent postsurgical pain (PPP) after cataract surgery, defined as mild or greater dry eye (DE)-like symptoms 6 months after surgery.

METHODS

This single-center study included 86 individuals who underwent cataract surgery between June and October 2016 and had DE symptom information available 6 months after surgery. Patients were divided into 2 groups: controls were defined as those without DE symptoms 6 months after surgery (defined by a Dry Eye Questionnaire 5 (DEQ5) score <6), cases were defined as those with mild or greater DE-like symptoms 6 months after surgery (DEQ5 ≥6).

RESULTS

Mean age of the study population was 71 ± 8.6 years; 95% (n = 82) were men. DE-like symptoms were reported in 32% (n = 27) of individuals 6 months after cataract surgery; 10% (n = 8) reported severe symptoms (DEQ5 ≥12). Patients with DE-like symptoms after cataract extraction also had higher ocular pain scores and specific ocular complaints (ocular burning, sensitivity to wind and light) compared with controls with no symptoms. A diagnosis of nonocular pain increased the risk of DE-like symptoms after cataract surgery (odds ratio 4.4, 95% confidence interval 1.58-12.1, P = 0.005).

CONCLUSIONS

Mild or greater PPP occurred in approximately 1/3 of individuals after cataract surgery. Prevalence of severe PPP is in line with that of refractive surgery, dental implants, and genitourinary procedures.

Systematic Review and Meta-Analysis on Incidence of Altered Sensation of Mandibular Implant Surgery

Altered sensation (including paresthesia, dysesthesia and hypoesthesia) after mandibular implant surgery may indicate transient or permanent injury of the inferior alveolar nerve and the mental branch, and considerably lower patients’ satisfaction about the therapy. Previous studies have shown a great degree of variability on the incidence of altered sensation. We here reported the incidence of altered sensation after mandibular implant surgery based on a meta-analysis of 26 articles published between 1990.1.1 and 2016.1.1. Study quality and risk of bias was assessed and the studies with a lower score were excluded in the meta-analysis. Data synthesis was performed using the logistic-normal random-effect model. The meta-analyses revealed that the short-term (10 days after implant placement) and long-term (1 year after implant placement) incidence was 13% (95% CI, 6%-25%) and 3% (95% CI, 1%-7%), respectively. (2) For the patients who initially reported altered sensation, 80% (95% CI, 52%-94%) of them would return to normal sensation within 6 months after surgery, and 91% (95% CI, 78%-96%) of them would return to normal sensation one year after surgery. We concluded that dentist-patient communication about the risk of altered sensation is critical to treatment planning, since the short-term incidence of altered sensation is substantial (13%). When a patient reports altered sensation, regular assessment for 6 months would help tracing the changes of symptoms. In terms of long-term follow-up (1 year after surgery), the incidence is much lower (3%) and most patients (91%) would return to normal sensation.

Continuous neurophatic orofacial pain: A retrospective study of 23 cases

Background

To determine the clinical characteristics of Continuous Neuropathic Orofacial Pain in patients that suffer Persistent Idiopathic Facial Pain (PIFP), Painful Post-Traumatic Trigeminal Neuropathy (PPTTN) or Burning Mouth Syndrome (BMS) and to describe their treatment.

Material and Methods

A retrospective observational study was made, reviewing the clinical history of the patients diagnosed with Continuous Neuropathic Orofacial Pain between 2004 and 2011 at the Orofacial Pain Unit of the Master of Oral Surgery and Implantology of the University of Barcelona and at the Orofacial Pain Unit of the Teknon Medical Center of Barcelona.

Results

The average age of the patients with Continuous Neuropathic Orofacial Pain was 54.5, with a clear female predominance (86.9%, n=20). Of all patients, 60.9% (n=14) were suffering a PIFP, 21.7% (n=5) had a BMS and 17.4% (n=4) were presenting a PPTTN. The pain quality described by the patients with Continuous Neuropathic Orofacial Pain was oppressive (43.47%, n=10), widely represented by patients with PIFP, and burning (39.13%, n=9) being the only quality that described patients with BMS. The treatment carried out with the patients was only pharmacologic. The most used drugs for the treatment of PIFP and PPTTN were clonazepam (50%, n=9) and amitriptyline (44.44%, n=8). However, a 55.5% (n=10) of the patients with PIFP or PPTTN required the association of two or more drugs for a correct pain control. All the patients with BMS responded satisfactorily to clonazepam.

Conclusions

Continuous Neuropathic Orofacial Pain is a little known condition among the general population, physicians and dentists. This favors a late diagnosis and inaccurate treatments which entail unnecessary suffering. It is important to inform both the general population and health professionals concerning this painful condition.

Key words:Continuous neuropathic orofacial pain, persistent idiopathic facial pain, painful post-traumatic trigeminal neuropathy, burning mouth syndrome, atypical odontalgia.