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The mammalian facial muscles are a subgroup of hyoid muscles (i.e. muscles innervated by cranial nerve VII). They are usually attached to freely movable skin and are responsible for facial expressions. In this study we provide an account of the origin, homologies and evolution of the primate facial muscles, based on dissections of various primate and non-primate taxa and a review of the literat...

Facial expression is a common mode of visual communication in mammals but especially so in primates. Rhesus macaques (Macaca mulatta) have a well-documented facial expression repertoire that is controlled by the facial/mimetic musculature as in all mammals. However, little is known about the musculature itself and how it compares with those of other primates. Here we present a detailed descript...

UNLABELLED Nasal tip ptosis ("drooping" or long nose) occurs when the tip of the nose is more caudal than what is deemed ideal. Intrinsic factors, such as elongated or caudally-rotated lower lateral cartilages, can lead to nasal tip ptosis. Extrinsic factors, such as elongated upper lateral cartilages or excessive caudal anterior septum and heavy nasal skin, can push the nasal tip caudally and ...

BACKGROUND Rhinoplasty remains one of the most challenging operations, as exemplified in the Middle Eastern patient. The ill-defined, droopy tip, wide and high dorsum, and thick skin envelope mandate meticulous attention to preoperative evaluation and efficacious yet safe surgical maneuvers. The authors provide a systematic approach to evaluation and improvement of surgical outcomes in this pat...

In a number of mammals muscle dilator nasi (naris) has been described as a muscle that reduces nasal airflow resistance by dilating the nostrils. Here we show that in rats the tendon of this muscle inserts into the aponeurosis above the nasal cartilage. Electrical stimulation of this muscle raises the nose and deflects it laterally towards the side of stimulation, but does not change the size o...

The facial depressor muscles are an essential component of a full denture smile. In addition, the depressor muscles are actively used to express other human emotions such as sadness, anger, depression, and sorrow. Despite advances in microsurgical techniques, it is surprising how little effort has been directed toward reanimation of the lower lip. This article presents innovative approaches use...

The temporalis, masseter, and depressor muscles of fifteen normal children were studied electromyographically to determine their activities during the position of resting tonus, during various movements of the mandible, and during the act of swallowing. Analysis of our results led to the following conclusions: 1. Resting tonus of the mandible does not depend on neuromuscular activity in the thr...

The upper airway is a complicated structure that is usually widely patent during inspiration. However, on inspiration during certain physiological and pathophysiological states, the nares, pharynx, and larynx may collapse. Collapse at these locations occurs when the transmural pressure (Ptm) at a flow-limiting site (FLS) falls below a critical level (Ptm'). On airway collapse, inspiratory airfl...