No sympathetic nerve sprouting in rat trigeminal ganglion following painful and non-painful infraorbital nerve neuropathy

Following sciatic nerve injury sympathetic invasion and basket formation is seen in dorsal root ganglia. We examined whether this phenomenon occurs in trigeminal ganglion (TG) following axotomy (IOAx) or chronic constriction injury to the infraorbital nerve (IOCCI). The IOCCI rats developed hyperresponsiveness to pinprick stimulation consistent with this model and the IOAx rats remained hyporesponsive for most of the study period. Immunocytochemistry employing antibodies to tyrosine hydroxylase showed no sympathetic invasion or basket formation 2 and 7 weeks post surgery. This study confirms previous work that found no sympathetic invasion of TG following injury, and shows that this finding is unaffected by the presence or absence of nerve injury induced hyperresponsiveness.

Co-localization of N-methyl-D-aspartate receptors and substance P (neurokinin-1) receptors in rat spinal cord

Glutamate, substance P (SP), and their receptors have been implicated in the initiation and maintenance of persistent pain through an interaction at second order spinal cord neurons. Employing well-characterized antibodies to the SP receptor and the N-methyl-D-aspartate receptor (NR1 subunit, splice variant missing exon 22), we demonstrate co-localization of these receptors on second order neurons at cervical, thoracic, lumbar, and sacral spinal cord levels. The co-localization was marked in lamina I of the dorsal horn at all levels and in the intermediolateral nucleus of the thoraco-lumbar spinal cord nuclei associated with autonomic function.

Odontalgia in vascular orofacial pain

A case of episodic, spontaneous odontalgia, aggravated by ingestion of cold food, with no apparent dental pathology is presented. Attempts at alleviating the pain by means of root canal treatment had failed in previous, similar episodes, and pain and pulpal hyperalgesia had shifted to other locations. Primary vascular orofacial pain was diagnosed and effective control obtained by prophylactic treatment with propranolol, a beta-adrenergic blocker. A prophylactic attempt with nifedipine, a calcium channel blocker, failed to alleviate the pain. This diagnostic entity and possible therapeutic approaches are discussed.

Actions of intrathecal diphtheria toxin-substance P fusion protein on models of persistent pain

Substance P (SP) plays a central role in the transduction of second messenger signals from primary afferent nociceptive terminals to second-order neurons in the spinal cord. We have tested a recombinant engineered diphtheria toxin/SP fusion protein (DAB389SP) in acute and chronic pain models in the rat. DAB389SP binds to the SP receptor (SPR) and is internalized and kills SPR-expressing cells by blocking cellular protein synthesis. DAB389SP delivery was by intrathecal infusion, of varying duration, at the lumbar level. In the chronic constriction injury model of neuropathic pain a significant reduction in mechanically induced hyperalgesia was obtained. This effect was less marked in an acute carageenan inflammation model. Although other pain characteristics (mechano-allodynia, cold-allodynia, and heat-hyperalgesia) showed some improvement, these were less pronounced. Immunocytochemistry revealed a toxin-induced reduction in lamina I, of SPR and of NMDA NR1 subunit receptor expressing neurons, and of c-Fos, an inducible molecular marker of persistent nociceptive activity. The use of cytotoxic fusion proteins to target specific cell types may be of considerable benefit in the study of nociception and the treatment of chronic pain.

Neuropathic orofacial pain

Neuropathic orofacial pain (NOP) is a challenging diagnostic problem. In some cases, symptomatology may be similar to that seen with dental pathology, resulting in unwarranted dental treatment. Rarely, NOP can herald serious disease or central tumors, and early diagnosis can be life-saving. The following review outlines the classification, clinical presentation, pathophysiology, and treatment of the more common NOP entities.

Craniofacial pain of myofascial origin: temporomandibular pain & tension-type headache

Craniofacial pain of myofascial origin is a common chronic disorder. When the pain is unilateral and located periauricularly, masticatory myalgia is likely. Tension-type headache is usually bilateral and affects the upper part of the head. The possible interrelationship with generalized myofascial disorders are discussed. Practical approaches to history-taking, diagnosis, and treatment are suggested.

Paroxysmal hemicrania. Case studies and review of the literature

Paroxysmal hemicrania is a vascular-type headache that is characterized by short bouts of severe unilateral pain in the area of the orbit and temple. A chronic and episodic form that has been described is similar to cluster headache and reflects a distinctive temporal pattern. Signs associated with paroxysmal hemicrania include ipsilateral conjunctival injection and tearing with nasal congestion and rhinorrhea. The condition's absolute response to indomethacin pharmacotherapy differentiates paroxysmal hemicrania from cluster headache. Typical symptoms usually make for a relatively straightforward diagnosis of paroxysmal hemicrania, but it may masquerade as pulpitic or temporomandibular-joint-related pain and may even herald systemic disease or malignancy. Paroxysmal hemicrania is a rare syndrome; 111 cases have been reported in the literature thus far. All of these cases have been reported by "headache specialists"; no cases of paroxysmal hemicrania were found in the dental literature. In this review, a relatively large series of seven new cases is reported; all seven were seen in an orofacial pain clinic.

Trigeminal neuralgia with lacrimation or SUNCT syndrome?

An intimate relationship between trigeminal neuralgia (TN) and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) syndrome, based on similar clinical signs and symptoms and on cases demonstrating possible "transformation" from one entity to the other, has been widely accepted. We evaluated the presence of lacrimation in 22 consecutive cases that had been diagnosed as TN. Ipsilateral lacrimation was reported by 6 such cases (5M, 1F). These cases responded to antineuralgic therapy with concomitant resolution of lacrimation and were clinically very similar to TN. The differential diagnosis and the possibility of lacrimation in TN are discussed.

Trigeminal neuralgic-type pain and vascular-type headache due to gustatory stimulus

We present a case of facial pain associated with sweet stimulus. An immediate, electric-like, short, unilateral pain was evoked by strong sweet gustatory stimulation. This was followed 6 to 8 hours later by a bilateral severe headache associated with bilateral tearing, rhinorrhea, periorbital swelling, flushing, and photophobia that lasted up to 2 days. The immediate pain that was experimentally induced with 2.5 grams of sucrose placed on the tongue could be abolished with carbamazepine. However, carbamazepine did not prevent the headache complex that appeared 6 to 8 hours later. Conversely, a trial with indomethacin abolished the late-onset headache, but not the immediate neuralgic-type pain. The independent nature of these pains suggests different pathophysiological mechanisms which are discussed.

SUNCT syndrome: case report and literature review

The case of a woman with short neuralgiform paroxysmal pain of 2 years duration is described. Pain attacks were always accompanied by ipsilateral lacrimation and conjunctival injection. Standard anti-neuralgic therapy, amitriptyline and indomethacin, failed to eliminate or reduce pain. At the end of a 30-month active period the patient seemed to have gone into remission. We believe this to be a case of short-lasting, unilateral, neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), the first reported in the dental literature and the 24th in the general medical literature. The differential diagnosis of the case and relevant literature are discussed.

Orofacial pain with vascular-type features

OBJECTIVE

To examine whether a classifiable primary vascular-type craniofacial pain subgroup exists that predominantly affects intraoral structures.

STUDY DESIGN

Fifty-five patients were chosen prospectively according to the following inclusion criteria; periodic craniofacial pain that was unilateral, pulsatile, severe, and that may wake the patient from sleep. Accompanying phenomena could include local autonomic and/or systemic signs. Twenty-six cases could be further classified into one of the categories of vascular craniofacial pain. The remaining 29, all with predominantly intraoral pain, were not readily classifiable.

RESULTS

Of the 29 patients 70% were women, with an average onset-age of 42.6 years. All reported severe, episodic pain that was usually unilateral and lasted minutes to hours. In all, 55% of patients had autonomic or systemic signs, 48% had pulsatile pain, and 35.4% of patients were awakened by the pain.

CONCLUSION

Although clinical similarities were observed within these patients, further studies are needed to confirm vascular orofacial pain as a clear diagnostic category.

Palatal root hemisections and subsequent tooth restoration: a simple procedure?

This article describes a simple procedure for palatal root hemisection in maxillary molars and their subsequent restoration. Hemisection has several advantages over resection at all stages and allows for simple prosthetic restoration, especially when treating the palatal root.

Diagnosis and treatment of persistent pain after trauma to the head and neck

PURPOSE

A retrospective and prospective study on 22 cases of persistent pain after trauma to the head and neck is presented. According to the predominant symptoms and signs, pain patterns could be divided into musculoskeletal, vascular, and neuropathic, facilitating treatment decisions. Most cases were musculoskeletal in origin, with many demonstrating a combination of two or three pain states.

RESULTS

The variety of pain complaints and their underlying pathophysiology are discussed and treatments for specific pain states are examined.

CONCLUSION

Amitriptyline was the most useful drug in that it provided pain relief in musculoskeletal, vascular, and some neuropathic pain conditions. Multidrug therapy may be indicated in some recalcitrant cases, and drug alternatives are discussed.

Idiopathic trigeminal pain associated with gustatory stimuli

We present a unique case of a patient with facial pain evoked by gustatory stimuli. Pain was typically evoked by application of sucrose to the ipsilateral anterior 2/3 of the tongue, but not to the contralateral aspect. Pain was referred to the maxillary tuberosity area and, when stronger, to the infraorbital and supraorbital regions. Sucrose was most effective in eliciting pain, whilst saline, citric acid and water had a minimal effect. Spatial or temporal summation of gustatory stimuli was associated with stronger pain of longer duration and shorter latency. Some of the pain characteristics were similar to those of idiopathic trigeminal neuralgia. Thus, pain was elicited by innocuous ipsilateral stimuli, referred out of the stimulus zone, persisted beyond the period of stimulation and could be controlled with carbamazepine. We proposed a central neural mechanism for pain induction with convergence between gustatory stimuli afferents and pain pathways in the trigeminal system.

Bacterial colonization of the parotid duct in xerostomia

Salivary flow rate and bacterial colonization of the parotid main duct were investigated in 17 patients referred for sialography and in 10 healthy controls. Cultures in the controls were negative whilst the patient group revealed bacterial colonization of the main duct, especially in those with the lowest flow rates. The implications of this finding in patients at high risk of endocarditis who will be undergoing sialography are discussed.

Diagnosis of a sublingual epidermoid cyst using contrast medium radiography: a case report

A case of a sublingual epidermoid cyst is presented. The advantages of contrast medium radiography in diagnosis, localization and surgical treatment planning are exemplified.

The interleukin concept and the periodontal diseases

The interleukins are hormone-like substances found at sites of inflammation such as in rheumatoid arthritis and periodontal disease. The present article analyzes a hypothetical mechanism of periodontal pathogenesis, whose etiology is still unclear despite its high prevalence.

Peripheral T lymphocyte subsets in rapidly progressive periodontitis

The peripheral blood lymphocyte subsets of 10 patients with rapidly progressive periodontitis were investigated with monoclonal antibody. In 4 patients, the T helper/T suppressor ratio was increased. 5 others had a slightly reduced T helper/T suppressor ratio as compared to control group. These findings may indicate a possible cellular immune response in the pathogenesis of rapidly progressive periodontitis.

Lichen planus evoked by periodontal surgery

A case of Lichen Planus (LP) following periodontal surgery in a patient previously free of the disease is described. Genetic predisposition and lymphokine secretion stimulated by local trauma are suggested as a possible mechanism of the phenomenon. It is recommended that LP patients, especially those suffering from the erosive type, should be treated as conservatively as possible, minimizing the possibility of trauma to the oral tissues where local immunity may have been altered by a pathological process.

Development of resistant oral viridans streptococci after administration of prophylactic antibiotics: time management in the dental treatment of patients susceptible to infective endocarditis

The American Heart Association recommends prophylactic administration of penicillin before each dental session to patients susceptible to infective endocarditis. Such preventive treatment, however, may trigger the transient appearance of penicillin-resistant bacterial strains. In order to investigate the behavior of oral streptococci, 29 healthy volunteers who did not harbor penicillin-resistant viridans streptococci received 4 gm of phenoxymethyl penicillin orally over a period of 10 hours. This amount constituted the sole dose of antibiotics administered in the entire experiment. Daily specimens of oral flora were obtained for 14 successive days from each participant and incubated aerobically with a penicillin-saturated disk for 24 hours. Viridans streptococci were considered resistant when bacterial colonies grew adjacent to the disk for 1 day or more. The study population was divided into high- and low-resistance groups, according to the individual antibiograms. Resistant viridans streptococci were already detected at 6 hours after penicillin ingestion in nine (31%) of the subjects. Six months later, oral specimens were taken from ten randomly selected participants; these specimens served as a control. The difference in bacterial resistance between the high- and low-resistance groups was significant for the duration of 9 days, as was that between the high-resistance and control groups (p less than 0.05 in both cases). In order to minimize the odds that penicillin-resistant bacterial strains will develop in patients susceptible to infective endocarditis, elective dental treatments in these persons should be scheduled in intervals of not less than 10 days.

Human leukocyte antigen (HLA) DR4. Positive association with rapidly progressing periodontitis

The relationship between human leukocyte antigens (HLA) determinants and periodontitis has been examined by several authors without showing any particular pattern. However, no study has investigated the HLA-D determinants, which are generally associated with immune disorders, and rapidly progressive periodontitis (RPP). The HLA profile of 10 RPP patients was compared with that of a healthy control population (n = 120). Although no significant difference was found for HLA-A, HLA-B, and HLA-C, HLA-DR4 of the HLA-D group was found in 80% of patients but only in 38.3% of controls. A high frequency of HLA-DR4 has been reported in rheumatoid arthritis (RA) patients. This finding may be significant in light of previous reports highlighting similarities between RA and periodontal disease.