A systematic review on diagnostic test accuracy of magnetic resonance neurography versus clinical neurosensory assessment for post-traumatic trigeminal neuropathy in patients reporting neurosensory disturbance

Objectives: To perform a systematic review of published studies on diagnostic accuracy of magnetic resonance neurography (MRN) vs clinical neurosensory testing (NST) for post-traumatic trigeminal neuropathy (PTTN) in patients reporting neurosensory disturbances (NSD). Methods: Human studies except case reports, reviews, systematic reviews and meta-analyses were included. PubMed, Embase, Web of Science and Cochrane Library were consulted. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Predetermined data extraction parameters were noted and summarized. Results: 8 studies met eligibility criteria of which 7 were retrospective, representing 444 subjects. Most studies were at high risk of bias with low applicability concerns. Populations and objectives were divergent with a large variation in timing (3 days-17 years post injury) and parameters (multiple coil designs, fat suppression techniques, additional contrast agent) of MRI acquisition. T-2 weighted 3 T imaging with short echo times (2.2-100 ms) and fat suppression was applied in seven studies, techniques varied. Determination of sensitivity and specificity could not be performed due to the methodological variation between studies and lacking comparative data between index and reference tests. Based on limited data, PTTN correlated reasonably well between clinical assessment, intraoperative findings and MRN abnormalities (k = 0.57). Increased signal intensity correlated with persistency of neurosensory disturbances in one study. Intra- (ICC 0.914-0.927) and interobserver (k = 0.70-0.891) MRN variability was considered good to excellent. One retrospective study showed substantial impact of MRN on clinical decision making in one-third of patients. Conclusion: Currently, there is insufficient scientific knowledge to support or refute the use of MRN. Based on limited data, MRN seems promising and reliable in detection and grading of PTTN. Methodological issues underline the importance for prospective blinded studies with standardization of signal intensity calculation and rigorous reporting of MRI acquisition parameters

Case of a cerebral abscess caused by Porphyromonas gingivalis in a subject with periodontitis

We report the case of a 65-year-old man presenting with generalised seizures after developing a right frontal brain abscess. Stereotactic aspiration and subsequent matrix assisted laser desorption/ionisation time-of-flight analyzer (MALDI-TOF) spectrometry revealed Porphyromonas gingivalis as the only causative anaerobe microorganism. Secondary incision and drainage was required due to neurological deterioration with increased dimensions of the abscess, intracranial pressure and formation of a subdural occipitoparietal empyema. Oral imaging was positive for apical periodontitis of multiple elements; therefore, the remaining dentition was removed. Targeted antibiotic treatment included intravenous ceftriaxone and ornidazole. The patient was discharged to our revalidation unit 59 days after admission to make a full recovery. To the best of our knowledge, this is the sixth reported case of P. gingivalis causing an intracranial abscess and the third case of a true intracerebral parenchymal abscess caused by this bacterium.status: publishe

The Biomechanical Effect of the Sagittal Split Ramus Osteotomy on the Temporomandibular Joint: Current Perspectives on the Remodeling Spectrum

The sagittal split ramus osteotomy is a key approach for treating dentofacial deformities. Although it delivers excellent results, the sagittal split ramus osteotomy is believed to induce stress to the temporomandibular joint. Potential stress inducers could be classified as intra- and postoperative factors resulting in an inflammatory response and molecular cascades, which initiate physiological remodeling. Occasionally, this process exceeds its capacity and causes pathological remodeling, through either degenerative joint disease or condylar resorption. Hard evidence on how orthognathic surgery causes inflammation and how this inflammation is linked to the spectrum of remodeling remains scarce. Current concepts on this matter are mainly based on clinical observations and molecular mechanisms are extrapolated from fundamental research in other body parts or joints. This perspective study provides an overview of current knowledge on molecular pathways and biomechanical effects in temporomandibular joint remodeling. It provides research directions that could lead to acquiring fundamental evidence of the relation of orthognathic surgery and inflammation and its role in remodeling. Performing osteotomies in animal models and identifying inflammatory mediators as well as their effect on the joint seem promising. Patients affected by pathological remodeling can also provide samples for histological as well as molecular analysis. Individual susceptibility analysis by linking certain suspect phenotypes to genetic variation could identify the cause and molecular pathway responsible for degenerative joint disease and condylar resorption, ultimately leading to clinically applicable treatment and prevention strategies.status: publishe

Signs and symptoms, quality of life and psychosocial data in 1331 post-traumatic trigeminal neuropathy patients seen in two tertiary referral centres in two countries

BACKGROUND: Post-traumatic trigeminal neuropathy (PTN) is a disturbance of function or pathological change of the trigeminal nerve branches following trauma and has an important impact on patient's quality of life (QoL). OBJECTIVES: To provide diagnostic data on PTN and illustrate differences in aetiology, injured nerve, pain distribution, sensory profile and QoL between PTN subgroups. METHODS: 1331 patients with painful or non-painful PTN were retrospectively reviewed in two centres, extracting demographic data, time and cause of trauma, clinical findings including signs and symptoms, basic neurosensory testing, imaging modalities, treatments, and QoL or psychosocial assessment. RESULTS: More females were represented (70%) than males. The inferior alveolar nerve was most frequently damaged (60%) followed by the lingual nerve (28%). Wisdom teeth removal was considered the main cause (48%). Pain was reported in 63% of patients and pain frequency increased with age without clinically significant gender differences. Numbness was reported in 50% of PTN patients. Neurosensory testing showed larger affected dermatome involvement in persistent injuries, with no differences between the non-painful and painful PTN groups. Patient clustering indicated different sensory profile distributions when stratified according to aetiology or affected nerve branch. High interference with lifestyle was reported (78%), and patients suffering from painful PTN had worse QoL and psychosocial outcomes. CONCLUSION: Patients with painful PTN had different clinical profiles and lower QoL scores than those with non-painful PTN. Sensory profiles may provide important prognostic and therapeutic information; however, more research is needed to assess the clustering procedure and link these clusters to therapeutic guidelines.status: publishe

A systematic review on diagnostic test accuracy of magnetic resonance neurography versus clinical neurosensory assessment for post-traumatic trigeminal neuropathy in patients reporting neurosensory disturbance.

OBJECTIVES: To perform a systematic review of published studies on diagnostic accuracy of magnetic resonance neurography (MRN) vs clinical neurosensory testing (NST) for post-traumatic trigeminal neuropathy (PTTN) in patients reporting neurosensory disturbances (NSD). METHODS: Human studies except case reports, reviews, systematic reviews and meta-analyses were included. PubMed, Embase, Web of Science and Cochrane Library were consulted. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Predetermined data extraction parameters were noted and summarized. RESULTS: 8 studies met eligibility criteria of which 7 were retrospective, representing 444 subjects. Most studies were at high risk of bias with low applicability concerns. Populations and objectives were divergent with a large variation in timing (3 days-17 years post injury) and parameters (multiple coil designs, fat suppression techniques, additional contrast agent) of MRI acquisition. T2 weighted 3 T imaging with short echo times (2.2-100 ms) and fat suppression was applied in seven studies, techniques varied. Determination of sensitivity and specificity could not be performed due to the methodological variation between studies and lacking comparative data between index and reference tests. Based on limited data, PTTN correlated reasonably well between clinical assessment, intraoperative findings and MRN abnormalities (k = 0.57). Increased signal intensity correlated with persistency of neurosensory disturbances in one study. Intra- (ICC 0.914-0.927) and interobserver (k = 0.70-0.891) MRN variability was considered good to excellent. One retrospective study showed substantial impact of MRN on clinical decision making in one-third of patients. CONCLUSION: Currently, there is insufficient scientific knowledge to support or refute the use of MRN. Based on limited data, MRN seems promising and reliable in detection and grading of PTTN. Methodological issues underline the importance for prospective blinded studies with standardization of signal intensity calculation and rigorous reporting of MRI acquisition parameters.status: Published onlin

Orofacial quantitative sensory testing: Current evidence and future perspectives

BACKGROUND AND OBJECTIVE: Orofacial quantitative sensory testing (QST) is an increasingly valuable psychophysical tool for evaluating neurosensory disorders of the orofacial region. Here, we aimed to evaluate the current evidence regarding this testing method and to discuss its future clinical potential. DATA TREATMENT: We conducted a literature search in Medline, Embase and Scopus for English-language articles published between 1990 and 2019. The utilized search terms included QST, quantitative, sensory testing and neurosensory, which were combined using the AND operator with the terms facial, orofacial, trigeminal, intraoral and oral. RESULTS: Our findings highlighted many methods for conducting QST-including method of levels, method of limits and mapping. Potential stimuli also vary, and can include mechanical or thermal stimulation, vibration or pinprick stimuli. Orofacial QST may be helpful in revealing disease pathways and can be used for patient stratification to validate the use of neurosensory profile-specific treatment options. QST is reportedly reliable in longitudinal studies and is thus a candidate for measuring changes over time. One disadvantage of QST is the substantial time required; however, further methodological refinements and the combination of partial aspects of the full QST battery with other tests and imaging methods should result in improvement. CONCLUSIONS: Overall, orofacial QST is a reliable testing method for diagnosing pathological neurosensory conditions and assessing normal neurosensory function. Despite the remaining challenges that hinder the use of QST for everyday clinical decisions and clinical trials, we expect that future improvements will allow its implementation in routine practice.status: publishe

Metal debris after dental implant placement: A proof-of-concept study in fresh frozen cadavers using MRI and histological analysis

PURPOSE: This report originated from the finding of metal artefacts on magnetic resonance images (MRI) which were not detected on panoramic radiography or cone beam computed tomography (CBCT) imaging. It was hypothesised that drills or implants might release metal particles during surgical procedures in the jawbones. Therefore, the aim was to assess whether dental implants or surgical drills might cause metal debris in the surrounding tissues. MATERIALS AND METHODS: The experiment consisted of a postmortem and an antemortem model. A split-mouth design was carried out in a postmortem fresh frozen cadaver head. In the left mandible only the drill preparation sequence was performed, whereas in the right mandible, the drill sequence was followed by implant placement. Before surgery, the postmortem model underwent a baseline MRI acquisition. A second MRI (MRI2) was acquired after performing the osteotomies on both sides and implant placement on the right side. Finally, the implants were carefully removed, and a final MRI (MRI3) was acquired. Bone blocks containing the implant and osteotomy sites were isolated. For the antemortem model, a fresh frozen cadaver head was selected that already had implants in place. An implant in the anterior maxilla was removed and the surrounding bone block was isolated as well. A histological analysis was prepared for both models. RESULTS: In the antemortem model, histological analysis showed irregular-shaped dark particles near the bone-implant interface consistent with metal debris. Additionally, in the postmortem model, both sites showed metal artefacts on MRI2 and MRI3, and by using a balanced fast field echo sequence, and histological analysis, the suspected particles of metal debris were confirmed on both sides of the mandible. CONCLUSIONS: Further studies should investigate the origin and extent of the metal debris following implant placement, as well as its clinical significance, possible risk factors and preventive measures.status: publishe