An implantable system for treating obstructive sleep apnea, 'OSA', in a subject, the system comprising: a power source; and a neuromuscular stimulator configured for implantation in a mandible of the subject, the neuromuscular stimulator being in electrical communication with the power source, the neuromuscular stimulator comprising: a housing, a controller contained within the housing, an electrical lead that is connected to the housing, and at least one intramuscular electrode included in the lead, the controller being configured to receive certain power and stimulation parameters associated with a therapy signal from the power source, and the system being characterised in that: the controller is hermetically sealed; the lead is flexible so as to not hinder regular tongue movement; the lead is of a length suitable to pass through both cortices of the mandible into electrical communication with one or more sublingual muscles that control the anterior positioning of the tongue base when contraction occurs; and all or only a portion of the lead includes one or more deployable anchoring elements to facilitate secure placement of the lead and the electrode in one or more muscles of an anterior lingual musculature of the subject such that the at least one electrode is configured to deliver the therapy signal directly to the one or more muscles of an anterior lingual musculature of the subject. a power source; and a neuromuscular stimulator configured for implantation in a mandible of the subject, the neuromuscular stimulator being in electrical communication with the power source, the neuromuscular stimulator comprising: a housing, a controller contained within the housing, an electrical lead that is connected to the housing, and at least one intramuscular electrode included in the lead, a housing, a controller contained within the housing, an electrical lead that is connected to the housing, and at least one intramuscular electrode included in the lead, the controller being configured to receive certain power and stimulation parameters associated with a therapy signal from the power source, and the system being characterised in that: the controller is hermetically sealed; the lead is flexible so as to not hinder regular tongue movement; the lead is of a length suitable to pass through both cortices of the mandible into electrical communication with one or more sublingual muscles that control the anterior positioning of the tongue base when contraction occurs; and all or only a portion of the lead includes one or more deployable anchoring elements to facilitate secure placement of the lead and the electrode in one or more muscles of an anterior lingual musculature of the subject such that the at least one electrode is configured to deliver the therapy signal directly to the one or more muscles of an anterior lingual musculature of the subject. the controller is hermetically sealed; the lead is flexible so as to not hinder regular tongue movement; the lead is of a length suitable to pass through both cortices of the mandible into electrical communication with one or more sublingual muscles that control the anterior positioning of the tongue base when contraction occurs; and all or only a portion of the lead includes one or more deployable anchoring elements to facilitate secure placement of the lead and the electrode in one or more muscles of an anterior lingual musculature of the subject such that the at least one electrode is configured to deliver the therapy signal directly to the one or more muscles of an anterior lingual musculature of the subject.