Aetiology and pathogenesis of trigeminal neuralgia: a comprehensive review

Objectives

The aim of present paper was to discuss issues related to trigeminal neuralgia with strong emphasis on the aetiology and pathogenesis of this problem.

Material and Methods

An electronic search of 5 databases (1965 - Oct 2012) and a hand search of peer-reviewed journals for relevant articles were performed. In addition, experience acquired from treating 3263 patients in the Department of Maxillofacial Surgery, Lithuanian University of Health Sciences, were also summarized.

Results

Generally, aetiological factors can be classified into 3 most popular theories that were based on: 1) Related to other disease, 2) Direct injury to the trigeminal nerve, and 3) Propagates the polyetiologic origin of the disease. In addition, two pathogenesis mechanisms of trigeminal neuralgia were proposed. First: the peripheral pathogenetic mechanism that is often induced by progressive dystrophy around the peripheral branches of the trigeminal nerve. Second, central pathogenetic mechanism which often triggered by peripheral pathogen that causes long-lasting afferent impulsation and the formation of a stable pathologic paroxysmal type irritation focus on the central nerve system (CNS).

Conclusions

Patients with susceptive trigeminal neuralgia should be examined carefully by specialists who have expertise in assessing and diagnosing of possible pathological processes and be able to eliminate the contributing factors so the trigeminal neuralgia can be properly managed.

Injury of the Inferior Alveolar Nerve during Implant Placement: a Literature Review

Objectives

The purpose of present article was to review aetiological factors, mechanism, clinical symptoms, and diagnostic methods as well as to create treatment guidelines for the management of inferior alveolar nerve injury during dental implant placement.

Material and Methods

Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were inferior alveolar nerve injury, inferior alveolar nerve injuries, inferior alveolar nerve injury implant, inferior alveolar nerve damage, inferior alveolar nerve paresthesia and inferior alveolar nerve repair. The search was restricted to English language articles, published from 1972 to November 2010. Additionally, a manual search in the major anatomy, dental implant, periodontal and oral surgery journals and books were performed. The publications there selected by including clinical, human anatomy and physiology studies.

Results

In total 136 literature sources were obtained and reviewed. Aetiological factors of inferior alveolar nerve injury, risk factors, mechanism, clinical sensory nerve examination methods, clinical symptoms and treatment were discussed. Guidelines were created to illustrate the methods used to prevent and manage inferior alveolar nerve injury before or after dental implant placement.

Conclusions

The damage of inferior alveolar nerve during the dental implant placement can be a serious complication. Clinician should recognise and exclude aetiological factors leading to nerve injury. Proper presurgery planning, timely diagnosis and treatment are the key to avoid nerve sensory disturbances management.

An analysis of etiological factors for traumatic mandibular osteomyelitis

OBJECTIVE

The aim of this study was to analyze the factors that were associated with the development of osteomyelitis during the treatment of mandibular fractures.

MATERIAL AND METHODS

The data of 3188 patients with mandibular fractures treated during 2002-2009 were analyzed. Traumatic osteomyelitis of the mandible was diagnosed in 207 patients. The background factors of complications were studied and compared with the control group (100 patients) not having complications after treatment of mandibular fractures. The data of clinical, roentgenologic, microbiological, and immunological investigations were analyzed. A logistic regression model was developed to identify the factors for osteomyelitis development.

RESULTS

The treatment in 6.5% of patients was complicated with osteomyelitis; 88.5% of these patients were men, and more than 80% of patients were younger than 50 years. In 86.8% of cases, Staphylococcus species were isolated, with Staphylococcus aureus accounting for 69.1% of cases. The following factors were found to be associated with osteomyelitis development: immunity dysfunction, caries-affected teeth at the fracture line, mobile fractured bones, bone fixation after more than 7 days following trauma, healthy teeth at the fracture line, insufficient bone reposition, and bone fixation after 3-7 days following trauma.

CONCLUSION

Comparative analysis of factors influencing the treatment results revealed a great importance of immunological and dental status and microflora at the affected site. Insufficient or late reposition and fixation of fractured bone fragments play a significant role in the healing process.

Microflora of the oral cavity in patients with xerostomia

OBJECTIVE

The aim of this study was to evaluate the dependence of the condition of the microflora of the oral cavity on the etiology of xerostomia, patients' sex, age, degree of hyposalivation, and duration of the sense of dryness.

MATERIAL AND METHODS

A total of 64 patients with complaints of oral dryness referred to the Clinic of Oral and Dental Diseases, Hospital of Lithuanian University of Health Sciences, for consultation during the period from 2003 to 2005 were selected for the study. The etiological factors of xerostomia were as follows: radiotherapy (PRT) to the maxillofacial area, Sjögren's syndrome (SS), and xerogenic medications, tricyclic antidepressants (TCAs).

RESULTS

There were 50 women and 14 men. Their mean age was 60.5 ± 1.6 years. All the patients in the PRT group had high counts of Candida spp. as compared with percentages of patients in the TCA and SS groups (100% vs. 66.7% and 56.2%, P<0.05). Patients' age and sex in different etiology groups had no significant impact on the condition of their oral microflora. There were equal percentages of patients with deficient and normal salivation in the TCA group (44% in both the groups; P<0.01). All the patients in the PRT group had pronounced hyposalivation (P<0.002). A significantly greater percentage of patients with severely reduced salivation had high counts of Lactobacillus spp. (P<0.01). Significantly greater percentages of patients with the clinical duration of xerostomia of up to 6 months had high counts of Lactobacillus spp. and Candida spp. colonies.

CONCLUSIONS

In patients with xerostomia, the condition of the microflora of the oral cavity and impairment of major salivary gland function varied according to the etiology of the disease. The level of hyposalivation and the duration of xerostomia were found to have a significant impact on the microflora of the oral cavity.

Anatomy of mandibular vital structures. Part I: mandibular canal and inferior alveolar neurovascular bundle in relation with dental implantology

Objectives

It is critical to determine the location and configuration of the mandibular canal and related vital structures during the implant treatment. The purpose of the present study was to review the literature concerning the mandibular canal and inferior alveolar neurovascular bundle anatomical variations related to the implant surgery.

Material and Methods

Literature was selected through the search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were mandibular canal, inferior alveolar nerve, and inferior alveolar neurovascular bundle. The search was restricted to English language articles, published from 1973 to November 2009. Additionally, a manual search in the major anatomy, dental implant, prosthetic and periodontal journals and books were performed.

Results

In total, 46 literature sources were obtained and morphological aspects and variations of the anatomy related to implant treatment in posterior mandible were presented as two entities: intraosseous mandibular canal and associated inferior alveolar neurovascular bundle.

Conclusions

A review of morphological aspects and variations of the anatomy related to mandibular canal and mandibular vital structures are very important especially in implant therapy since inferior alveolar neurovascular bundle exists in different locations and possesses many variations. Individual, gender, age, race, assessing technique used and degree of edentulous alveolar bone atrophy largely influence these variations. It suggests that osteotomies in implant dentistry should not be developed in the posterior mandible until the position of the mandibular canal is established.

Anatomy of Mandibular Vital Structures. Part II: Mandibular Incisive Canal, Mental Foramen and Associated Neurovascular Bundles in Relation with Dental Implantology

Objectives

The purpose of the present study was to review the literature of how to identify the mental foramen, mandibular incisive canal and associated neurovascular bundles during implant surgery and how to detect and avoid the damage of these vital structures during implant therapy.

Material and Methods

Literature was selected through a search of PubMed, Embase and Cochrane electronic databases. The keywords used for search were mandibular incisive canal, mental foramen, mental nerve, anterior mental loop. The search was restricted to English language articles, published from 1979 to November 2009. Additionally, a manual search in the major anatomy, dental implant, and periodontal journals and books was performed.

Results

In total, 47 literature sources were obtained and reviewed. The morphology and variations of the mandibular incisive canal, mental foramen and associated neurovascular bundles were presented as two entities. It suggested that clinicians should carefully assess these vital structures to avoid nerve/artery damage.

Conclusions

The mandibular incisive canal, mental foramen and associated neurovascular bundles exist in different locations and possess many variations. Individual, gender, age, race, assessing technique used and degree of edentulous alveolar bone atrophy largely influence these variations. It suggests that the clinicians should carefully identify these anatomical landmarks, by analyzing all influencing factors, prior to their implant surgical operation.

[Xerostomia: clinic, etiology, diagnosis and treatment]

The aim of this article is to review the problem of xerostomia considering its clinical, etiological, diagnostic and treatment features, basing on the today's tutorials and scientific articles found in databases on the Internet. Recent epidemiologic data on the prevalence of xerostomia in different countries are introduced. There are analyzed the main aspects of clinical manifestations of xerostomia, according to the different etiology analyzed. The most common etiological factors causing xerostomia, especially the main three of them: radiation therapy, Sjögren's syndrome, and drugs, are pointed out. The most popular and accepted clinical and laboratory assays for measuring and evaluating the function of salivary glands are represented. Attention is paid to xerostomia as substantiation of the separate diagnosis and its role in diagnosing other diseases. The concept of possible treatment modalities and prognosis are discussed. The main and most common problems concerning xerostomia are revealed.

Comparative analysis of the effectiveness of the mandibular angle fracture treatment methods

425 patients with mandibular angle fractures were treated at the Hospital of Kaunas University of Medicine (HKUM) Clinic of Maxillo-Facial Surgery. Treatment included the application of closed fracture fragments fixation methods (wire splint fixation, and Kirschner wire osteosynthesis), and methods of open fixation--osteosynthesis using the supra-periosteal miniplate, and osteosynthesis using supra-osseous Zes Pol plate (the latter method was modified by the authors). Relative computerized densitometry showed that closed fixation methods result in a faster healing of fractures. The findings of the pain threshold testing showed that open fixation methods more severely damage the function of the lower alveolar nerve. Using closed fixation methods, osteomyelitis occurred in 5.3% of cases, while using open fixation methods--in 15.3% of cases. Thus, the authors of the article maintain that when mandibular angle fractures, in the presence of suitable conditions, closed fracture fragments fixation methods should be given a priority.

[Acute and chronic facial pain due to injured neural plexus of the upper teeth]

The general causes of upper dental plexus injury are tooth disturbances and the periodontal tissues diseases, the pathology of maxillary sinus, various traumatically manipulations in the area of tooth and maxilla as well. The main symptom of upper tooth neural plexus injury is acute and chronic pain in the alveolar sprout of maxilla, gums or in the area of singly tooth, which rarely spreads into neighboring maxillofacial areas. The authors recommend that the acute pain syndrome would be called the inflammation of upper tooth plexus, and the chronic pain syndrome--plexopathia of upper tooth. Study presents the differential diagnosis according to character of facial pain syndrome and the data of sensority disorders research and investigation of pain thresholds as well. The recommendations for treatment tactic and methods of analyzed indispositions are suggested.

[Post-traumatic infraorbital nerve neuropathy]

The authors have investigated functional state of infraorbital nerve of 479 patients with zygomatic fractures. The degree of nerve damage was evaluated according to changes of pain threshold during damaged nerve stimulation. It was estimated that in 64.3% of zygomatic fractures the infraorbital nerve was affected. The nerve damage degree could be mild, moderate and severe. In 43.18% of moderate and severe nerve damage cases the neuropathy develops. The symptoms, signs and treatment of neuropathy have been described. The neuropathy with clinical symptoms as permanent soreness and paresthesias (itch, "running ant", fibrillations of cheek tissues etc.) in the infraorbital nerve innervation zone occur to 43.18% of the patients after moderate and severe damage of the nerve. The treatment of neuropathy was analysed. In cases of moderate and severe nerve damages, authors recommend to perform decompression of the nerve, because if not applied, the function of nerve does not recover.