Andrew L. Young

Use of Masseteric and Deep Temporal Nerve Blocks for Reduction of Mandibular Dislocation

A patient presented with a unilateral dislocated condyle that was resistant to reduction by simple manual manipulation because of elevator muscle spasm and severe muscle and temporomandibular joint pain. A technique involving a masseteric nerve block and a temporal nerve block was used, allowing a quick, safe, and minimally painful reduction. The method used for delivering these nerve blocks is described here.

Stellate ganglion block as an early intervention in sympathetically maintained headache and orofacial pain Caused by Temporal Arteritis

INTRODUCTION We report a case of temporal arteritis with a sympathetic component in the orofacial region, which responded to stellate ganglion blocks (SGBs). CASE An 81-year-old woman with limited mouth opening and pain upon chewing was referred to the Orofacial Pain Clinic at Nihon University Dental Hospital. The patient also presented with blurred vision and a burning sensation on the right side of her face. On clinical examination, the temporal artery was tender to palpation, and there was increased sensitivity in the temporal region bilaterally. The patient reported jaw pain and limited mouth opening. Laboratory examination showed elevations in erythrocyte sedimentation rate and C-reactive protein. The burning sensation was due to a sympathetic component, and SGBs substantially reduced both the burning sensation and right temporal pain. Blocking the sympathetic chain on the ipsilateral side also improved jaw movement. The patient was referred to a rheumatologist, after which she was admitted to hospital with a tentative diagnosis of temporal arteritis. Treatment with oral prednisone 30 mg daily was initiated, and the dose was tapered as her symptoms resolved. DISCUSSION The reason for the gradual pain relief after SGB is unclear, but we believe it was effective for ischemia in temporal arteritis because it led to dilation of affected arteries or suppression of inflammation/edema of the vascular wall. CONCLUSION This case demonstrates that SGB may relieve pain related to temporal arteritis and sympathetically maintained headache and orofacial pain by reducing noxious stimulation peripherally and decreasing central pain transmission centrally.

Bite Force and Pattern Measurements for Dental Pain Assessment in the Rat

We present simple method to assess dental pain in the awake rat. Using a sensitive strain gauge we examined changes in bite strength and bite pattern in rats following dental injury. Rats with dental injury displayed a significant reduction in mean peak bite strength and an altered bite cluster pattern. Both changes in the dental injury rats were reversed by an analgesic dose of morphine, and this could be reversed with naloxone. These changes were not observed in naive control animals. This simple method significantly improves our ability to evaluate dental pain syndromes.

Pro and anti-inflammatory cytokine levels (TNF-α, IL-1β, IL-6 and IL-10) in rat model of neuroma

Traumatic neuroma is neuronal tissue proliferation developed in a nerve injury site, often associated with increased sensitivity and spontaneous or evoked neuropathic pain. The mechanisms leading to the disorganized nerve proliferation are not completely understood, though inflammation in the injured nerve vicinity most likely has a role in the process. Inflammatory cytokines are also known to be involved in the maintenance and development of post-traumatic and neuropathic pain. The goal of this study was to quantify and compare pro and anti-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-10) levels in nerves that formed neuromas and nerves that did not, following sciatic nerve transection. A total of 30 rats were used in this study. Twenty rats underwent sciatic nerve transection and 10 underwent sham surgery. Six weeks post-surgery nerve sections were collected and histologically evaluated for neuroma formation. The samples were then classified as neuroma, non-neuroma and sham groups. TNF-α, IL-1β, IL-6 and IL-10 levels were measured in the nerves employing ELISA. TNF-α levels were significantly higher in both neuroma and non-neuroma-forming injured nerves compared to the sham group. IL-1β and IL-6 levels were significantly higher in the neuroma-forming nerves compared to the sham group. IL-10 levels were significantly higher in the non-neuroma group compared to the sham group. In conclusion IL-6, and IL-1 β may have a role in the formation of traumatic neuroma while IL-10 may inhibit neuroma formation.

Internal derangements of the temporomandibular joint: A review of the anatomy, diagnosis, and management.

Internal derangements of the temporomandibular joint are conditions in which the articular disc has become displaced from its original position the condylar head. Relevant anatomic structures and their functional relationships are briefly discussed. The displacement of the disc can result in numerous presentations, with the most common being disc displacement with reduction (with or without intermittent locking), and disc displacement without reduction (with or without limited opening). These are described in this article according to the standardized Diagnostic Criteria for Temporomandibular Disorders, as well as the less common posterior disc displacement. Appropriate management usually ranges from patient education and monitoring to splints, physical therapy, and medications. In rare and select cases, surgery may be necessary. However, in for the majority of internal derangements, the prognosis is good, particularly with conservative care.

Idiopathic condylar resorption: The current understanding in diagnosis and treatment

Idiopathic condylar resorption (ICR) is a condition with no known cause, which manifests as progressive malocclusion, esthetic changes, and often pain. Cone-beam computed tomography and magnetic resonance imaging are the most valuable imaging methods for diagnosis and tracking, compared to the less complete and more distorted images provided by panoramic radiographs, and the higher radiation of 99mtechnetium-methylene diphosphonate. ICR has findings that overlap with osteoarthritis, inflammatory arthritis, physiologic resorption/remodeling, congenital disorders affecting the mandible, requiring thorough image analysis, physical examination, and history-taking. Correct diagnosis and determination of whether the ICR is active or inactive are essential when orthodontic or prosthodontic treatment is anticipated as active ICR can undo those treatments. Several treatments for ICR have been reported with the goals of either halting the progression of ICR or correcting the deformities that it caused. These treatments have varying degrees of success and adverse effects, but the rarity of the condition prevents any evidence-based recommendations.

The twin block: a simple technique to block both the masseteric and the anterior deep temporal nerves with one anesthetic injection

The objective of this article is to describe a new technique to anesthetize the masseter muscle and the temporalis muscle using a single extraoral approach. The block targets both the masseteric and the deep temporal nerves as they leave the infratemporal fossa to innervate the deep surfaces of their respective muscles.

Mouse model demonstrates strain differences in susceptibility to opioid side effects

Individual differences have been observed in responses to opioid drugs, including common side effects. In this study, the inbred mouse strains A/J and C57BL/6J were used to determine whether their specific strain differences correlate with differences in susceptibility to respiratory depression and constipation. To measure the effects of morphine on respiration, morphine at 15 and 40 mg/kg was injected subcutaneously. Respiratory parameters were then measured 30 and 60 min later. To measure the effects on constipation, 5, 15, 40, and 60 mg/kg doses were administered subcutaneously three times daily for three days. Gastrointestinal transit distance was then measured using the charcoal bolus test. C57BL/6J mice showed a greater degree of change in several respiratory parameters, resulting in more pronounced respiratory depression. C57BL6J mice also showed significantly more constipation than A/J mice with 40 and 60 mg/kg morphine doses. This study demonstrates that the strain differences between A/J and C57BL/6J mice have a major effect on opioid-induced constipation and respiratory depression. These correlations are of great clinical interest, as they could lead to the development of methods for reducing side effects.

Painful Trigeminal Neuropathy Attributed to a Space-occupying Lesion Presenting as a Toothache: A Report of 4 Cases

Abstract Painful trigeminal neuropathy attributed to a space‐occupying lesion (code 13.1.2.5 in the International Classification of Headache Disorders, 3rd edition [beta version]) is an orofacial pain condition that has characteristics of classical trigeminal neuralgia but is caused by a space‐occupying lesion. We present 4 cases of intracranial lesions mimicking odontogenic pain as follows: case 1, a 61‐year‐old woman presented with a chief complaint of aching soreness in the right mandibular molar area for 1 year; case 2, a 59‐year‐old man presented with severe pain in the left maxillary and mandibular molars; case 3, a 72‐year‐old man presented with a chief complaint of facial shock–like pain on the left side; and case 4, a 75‐year‐old man presented with a chief complaint of paroxysmal pain and numbness in the buccal gingiva of the right mandibular molar region. Cases 1 and 2 had trigeminal neuralgia, which had previously been incorrectly attributed to osteoma and maxillary sinus retention cyst, respectively, and resulted in inappropriate dental surgical procedures. All patients subsequently underwent magnetic resonance imaging, and the results were consistent with intracranial disease. Magnetic resonance images revealed acoustic neuromas in the cerebellopontine angle in cases 1, 2, and 4 and a small meningioma near the entry to the left Meckel cave in case 3. Cases 1, 3, and 4 had these lesions removed; after which, their pain resolved. Before dental treatment, dental practitioners should focus not only on dental imaging but also on the patients medical history and pain characteristics.