Off-Label Therapeutic Usage of Botulinum Toxin Intramuscular Injections in the Head and Neck: A Scoping Review

Clostridium botulinum neurotoxin (BoNT) is widely recognized for cosmetic facial applications, yet its therapeutic value spans a range of craniofacial and cervical neuromuscular disorders. Despite multiple US Food and Drug Administration (FDA)-approved indications across 4 commercial preparations, a comprehensive synthesis of off-label craniofacial and cervical applications remains limited. This scoping review synthesizes current evidence on off-label BoNT-A and BoNT-B use in the craniofacial and cervical region.

A scoping review was conducted using Arksey and O'Malley's framework. Systematic searches of MEDLINE, SCOPUS, and Google Scholar identified English-language US studies published from 1989 to 2025 involving adults ≥18 years. Six reviewers independently screened and extracted data.

Fifty-nine studies met inclusion criteria. Of 103 muscles above the thoracic inlet, 63 were clinically relevant for BoNT treatment, and 61 had at least one documented study. BoNT was used to treat 49 conditions, of which 42 (85.7%) were off-label. Consistent therapeutic benefit was reported for cervical dystonia, myofascial pain, headache disorders, facial synkinesis, oromandibular dystonia, palatal tremor, laryngeal movement disorders, ocular motility conditions, and middle ear myoclonus. Treatment response varied by injection technique and musculature. Adverse events were dose- and region-dependent, with transient dysphagia and neck weakness most associated with cervical injections, while facial and intraoral applications were generally well tolerated.

BoNT is a versatile, anatomically targeted therapy with broad off-label utility in craniofacial and cervical neuromuscular disorders. With careful muscle selection and condition-specific dosing, BoNT maintains a predictable and manageable safety profile. Standardized protocols and expanded clinical trials are needed to optimize off-label applications in the head and neck.