- May 6, 2026The depressor alae nasi (depressor septi nasi variant) pulls the nasal tip inferiorly during smile animation, producing the characteristic nose…
- May 6, 2026The transverse part of nasalis is the compressor component that narrows the nasal bridge. Combined with the alar part (dilator),…
- May 6, 2026The superficial head is the larger component of the masseter, providing the dominant jaw-closing force. Its fibres run inferomedially from…
- May 6, 2026The deep head of the masseter is smaller and more vertically oriented than the superficial head, retracting the mandible during…
- May 6, 2026The superficial head of the medial pterygoid arises from the maxillary tuberosity and forms the lateral part of the pterygomandibular…
- May 6, 2026The deep head is the larger medial pterygoid component, arising from the medial pterygoid plate. It runs anteroinferiorly to the…
- May 6, 2026The inferior head of the lateral pterygoid is unique in being active during mouth opening rather than closing. It pulls…
- May 6, 2026The anterior belly of the digastric is innervated by the trigeminal nerve (unlike the posterior belly which is facial nerve),…
- May 6, 2026The posterior belly of the digastric is innervated by the facial nerve, reflecting its second branchial arch origin. It forms…
- May 6, 2026The marginal part consists of the fibres immediately adjacent to the vermilion border, responsible for eversion and thinning of the…