Challenging the neuralgia-inducing cavitational osteonecrosis concept

The persistently sensitive or painful osseointegrated implant

OBJECTIVE

To determine why some implants can appear to be well osseointegrated with no signs of infection and yet can remain sensitive to percussion and painful and unable to tolerate the weight of a restoration.

STUDY DESIGN

Five patients were identified who between them had 7 implants that met the criteria of being persistently painful and sensitive to percussion while appearing to be well integrated and otherwise disease free. High-definition cone beam computed tomography scans were obtained for all patients. All patients had failed medical treatment.

RESULTS

The cone beam computed tomography scans showed radiolucent channels running from the nearest nerve trunk to the vicinity of the sensitive implants. These may represent neurovascular channels that originally supplied the teeth that were present at the site of the implants, and they may have terminal neuromas that neuromas may be irritated by the implant. In all cases removal of the offending implant caused either substantial or complete relief of discomfort.

CONCLUSION

The presence of terminal neuromas within the jaws may be responsible for persistent pain and sensitivity in an otherwise well-integrated and disease-free implant. Removal of the offending implant appears to be the only treatment.

Neuralgia-inducing cavitational osteonecrosis - A systematic review

OBJECTIVE

To assess the aetiologic factors, proposed diagnostic means and treatment strategies for neuralgia-inducing cavitational osteonecrosis.

METHODS

A search of the literature published up to June 2020 was conducted using Medline, the Cochrane Library, PsycINFO, CINAHL and Web of Science. The scientific quality of the evidence was rated according to NIH Quality Assessment Tools.

RESULTS

4,051 articles were found, 59 were reviewed in full text, and 29 studies were included. With the exception of hereditary coagulopathies, which were identified as potential risk factors in five studies, suggestions concerning the aetiology varied widely. No gold standard diagnostic mean could be identified. Treatment was most often performed by surgical curettage of the affected bone. Surgical treatment outcomes were equally varied: significant facial pain remission was reported in 66%-100% for periods varying between 2 months to 18 years, whereas no or little relief and recurrences were reported in up to ⅓ of cases. All studies were observational in their design. All investigations were rated as poor quality because of high risk of bias and non-transparent reporting.

CONCLUSIONS

Evidence concerning the aetiology, diagnosis and treatment of NICO is poor. Prospective diagnostic and therapeutic studies are needed before the usefulness of invasive therapeutic procedures can be evaluated.

Neuralgia-inducing cavitational osteonecrosis - Fact or myth, the debate persists

Neuralgia-inducing cavitational osteonecrosis (NICO) is a debated condition characterized by cavitary lesions in the maxillary-mandibular region, often missed on conventional radiographs, and the golden standard for diagnostic measures is bone scintigraphy. It may arise secondary to trauma, such as dental extraction and endodontic treatment, and due to a low-grade chronic infection. NICO has been documented as a frequent cause of face pain involving the trigeminal nerve divisions. It may be severe, piercing pain, of short duration or even continuous pain of moderate intensity. It affects females with a greater predilection than males. A lack of awareness of the condition among health professionals is often put into the basket of atypical facial pain. Current studies describe ischemic alveolar bone marrow coagulation disorders as the cause for NICO, which may also be the result of thrombosis with or without hypofibrinolysis, which would obstruct vascular spaces impairing blood flow in the region. Treatment is decided on a case basis, depending on the clinicians’ experience, on previous treatments, on the patient's general status, and more importantly, whether the site is edentulous or dentate. If surgical intervention is chosen, tissue should be sent for pathological examination. Over the years, with the advance of imaging diagnosis processes and the study and detection of genetic changes, one may also include as a cause of NICO the decreased bone marrow blood flow causing bone cavities. All of this was also associated with genetic mutations which would predispose patients to thrombophilia and hypofibrinolysis.

T-786C polymorphism of the endothelial nitric oxide synthase gene and neuralgia-inducing cavitational osteonecrosis of the jaws

OBJECTIVE

We hypothesized that, similar to idiopathic hip osteonecrosis, the T-786C mutation of the endothelial nitric oxide synthase (eNOS) gene affecting nitric oxide (NO) production was associated with neuralgia-inducing cavitational osteonecrosis of the jaws (NICO).

DESIGN

In 22 NICO patients, not having taken bisphosphonates, mutations affecting NO production (eNOS T-786C, stromelysin 5A6A) were measured by polymerase chain reaction. Two healthy normal control subjects were matched per case by race and gender.

RESULTS

Homozygosity for the mutant eNOS allele (TT) was present in 6 out of 22 patients (27%) with NICO compared with 0 out of 44 (0%) race and gender-matched control subjects; heterozygosity (TC) was present in 8 patients (36%) versus 15 control subjects (34%); and the wild-type normal genotype (CC) was present in 9 patients (36%) versus 29 controls (66%) (P = .0008). The mutant eNOS T-786C allele was more common in cases (20 out of 44 [45%]) than in control subjects (15 out of 88 [17%]) (P = .0005). The distribution of the stromelysin 5A6A genotype in cases did not differ from control subjects (P = .13).

CONCLUSIONS

The eNOS T-786C polymorphism affecting NO production is associated with NICO, may contribute to the pathogenesis of NICO, and may open therapeutic medical approaches to treatment of NICO through provision of L-arginine, the amino-acid precursor of NO.

Operative treatment of trigeminal neuralgia: review of current techniques

Surgical approaches to pain management are performed when medication cannot control pain or patients cannot tolerate the adverse effects of the medication. Microvascular decompression (MVD) is generally performed when the patient is healthy and relatively young. Partial sensory rhizotomy is performed in addition to, or instead of MVD, in patients in whom significant compression of the trigeminal sensory root does not exist or in whom MVD is technically not feasible. Three percutaneous ablative procedures and gamma knife radiosurgery (GKS) are also performed when MVD cannot be performed. The result of MVD is superior to that of the 3 ablative procedures. GKS is inferior to the 3 ablative procedures in terms of initial pain relief and recurrence, but superior in terms of complications. Peripheral procedures are usually performed in patients not suitable for or not wishing to have other procedures. However, no strict rules exist and each patient should be evaluated individually.

Bisphosphonate Osteochemonecrosis (Bis-Phossy Jaw): Is This Phossy Jaw of the 21st Century?

PURPOSE

Bisphosphonates are being implicated in a growing number of complications of the jaws. A number of terms are being applied to this phenomenon and perhaps the descriptive term bisphosphonate osteochemonecrosis has the most merit. But the eerie similarity of this 21st century disease process with the 19th century disease known as phossy jaw is striking. As the nomenclature continues to evolve, the term used in this article will be bis-phossy jaw. This article will explore historical and current aspects of these diseases. Although there may be other mitigating factors, such as oral health, chemotherapy history, immune status, Karnofsky performance status, or Kaplan-Feinstein index, bisphosphonates appear to be the necessary component in cases of bis-phossy jaw.

MATERIALS

This is primarily a review article on reported cases of bis-phossy jaw, with historical looks at phossy jaw and osteoradionecrosis. Our laboratory has reviewed 20 suspected cases of bis-phossy jaw and the typical histopathologic features of bis-phossy jaw are presented.

RESULTS

Descriptions of phossy jaw and current bis-phossy jaw cases are remarkably similar. Histopathologic features of bis-phossy jaw showed intact vascular channels, even in areas with acute inflammatory infiltrates and bacterial overgrowth. Non-vital bone fragments with reduced evidence of osteoclastic action were also noted.

CONCLUSION

Bis-phossy jaw may have more of a bacterial cofactor risk than osteoradionecrosis, and though altered angiogenesis may yet prove to be a factor, avascularity does not appear to be a major cofactor. The historical disease phossy jaw appears to serve as a possible analogous disease for current research and treatment of bis-phossy jaw. Prevention and early identification of patients at risk should be of prime concern.

Diagnosis and treatment of patients with trigeminal neuralgia

BACKGROUND

The authors review the literature regarding the etiology, diagnosis and treatment of trigeminal neuralgia, or TN. They also describe a patient with the disease.

TYPES OF STUDIES REVIEWED

A MEDLINE search was conducted to identify articles published within the last 10 years regarding current thinking on the etiology, diagnosis and treatment of TN. The authors also reviewed historic articles to gather information about the initial discovery and descriptions of this condition.

RESULTS

The authors identified more than 50 articles on the topic. Generally, there was concordance regarding the diagnosis of this condition; however, some questions and controversy exist regarding the pathogenesis and treatment modality of choice. The authors relied on the most representative and complete articles for this review article.

CLINICAL IMPLICATIONS

TN is the most common form of neuralgia, and patients often visit several clinicians with complaints of pain. Clinicians must recognize this condition and diagnose it correctly for patients to receive proper referral and therapy for this relatively treatable condition.