Apparatus for providing breathing assistance, the apparatus including a body for positioning within an oral cavity of a user, the body defining: a) at least one first opening for allowing airflow between lips of the user; b) two second openings provided in the oral cavity to allow air flow into and out of a posterior region of the oral cavity; and c) two channels, each channel connecting a respective second opening to the at least one first opening and each channel passing at least one of at least partially along the buccal cavity and at least partially between the teeth to thereby provide an airway for the user, the airway at least partially bypassing the nasal passage and acting to replicate a healthy nasal passage and pharyngeal space, characterised in that: i) each channel includes: a first channel portion (113.1) extending through the user's buccal cavity; and a second channel portion (113.2) in fluid communication with the first channel portion and extending between the user's maxillary and mandibular teeth and wherein a cross sectional shape and cross sectional area of at least one of the first and second channel portions varies from the first opening to the second opening; and ii) wherein each channel has a cross sectional area of at least 40 mm 2. a) at least one first opening for allowing airflow between lips of the user; b) two second openings provided in the oral cavity to allow air flow into and out of a posterior region of the oral cavity; and c) two channels, each channel connecting a respective second opening to the at least one first opening and each channel passing at least one of at least partially along the buccal cavity and at least partially between the teeth to thereby provide an airway for the user, the airway at least partially bypassing the nasal passage and acting to replicate a healthy nasal passage and pharyngeal space, characterised in that: i) each channel includes: a first channel portion (113.1) extending through the user's buccal cavity; and a second channel portion (113.2) in fluid communication with the first channel portion and extending between the user's maxillary and mandibular teeth and wherein a cross sectional shape and cross sectional area of at least one of the first and second channel portions varies from the first opening to the second opening; and ii) wherein each channel has a cross sectional area of at least 40 mm 2. i) each channel includes: a first channel portion (113.1) extending through the user's buccal cavity; and a second channel portion (113.2) in fluid communication with the first channel portion and extending between the user's maxillary and mandibular teeth and wherein a cross sectional shape and cross sectional area of at least one of the first and second channel portions varies from the first opening to the second opening; and a first channel portion (113.1) extending through the user's buccal cavity; and a second channel portion (113.2) in fluid communication with the first channel portion and extending between the user's maxillary and mandibular teeth and wherein a cross sectional shape and cross sectional area of at least one of the first and second channel portions varies from the first opening to the second opening; and ii) wherein each channel has a cross sectional area of at least 40 mm 2.