Twin block a simple diagnostic block to differentiate between myogenous and true odontogenic pain
Rutgers School of Dental medicine, USA
: Dent Health Curr Res
Temporomandibular disorders (TMD) encompass dysfunction in the masticatory musculature, the temporomandibular joint (TMJ) and associated structures. TMDs are often associated with muscle pain (myalgia) that may refer, reduced mouth opening, clicking of the TMJ, arthralgia and jaw deviation. Pain in TMD can result from myalgia or arthralgia. Pain in the masticatory muscles is one of the leading causes of non-odontogenic facial pain and is often misdiagnosed as being odontogenic in origin, due to its presentation or referral pattern. Presently, there is no simple diagnostic test available to delineate odontogenic pain from myogenous pain. Peripheral nerve blocks using local anesthetic agents are widely used in medicine for the management of acute pain, chronic pain and headaches. Quek et al. in a retrospective study, demonstrated that the masseteric nerve block may be more effective for managing myogenous facial pain compared to intraoral appliances and trigger point injections. The twin-block is a simple extraoral injection technique that anesthetizes both the masseteric and anterior deep temporal nerves with a single injection and alleviates myogenous pain from this source. In addition to being a potential therapeutic intervention, the twin-block injection could serve as a diagnostic tool to discern pain originating from the masseter and/or temporalis muscles from odontogenic pain. We recently completed a prospective study confirming that the twin-block injection can be used for management of orofacial myogenous pain and as an adjunctive diagnostic tool for myogenous pain in the facial region. We summarize a case series to demonstrate the application of twin block as a successful diagnostic and a therapeutic adjunct in the management of myogenous facial pain supplementing current treatment strategies including palliative home care, orthotic appliance and chairside trigger point injections.
Hafsa Affendi BDS, MDS Center for Temporomandibular joint disorders and Orofacial Pain, Rutgers School of Dental Medicine. She also works at Center for Temporomandibular disorders and Orofacial pain.