Beverly Crusher slapping Wesley on the cheek
The cheek or jowl was a part of one's face, extending from below the eyes to the jaw. The bones of one's cheek were referred to as cheekbones. (VOY: "The Q and the Grey")
Kisses were often given on one's cheek, often to signify greeting or dismissing, (TNG: "We'll Always Have Paris", "Legacy") sometimes goodnight. (ENT: "Dear Doctor") Klingons preferred biting each other on the cheek. (TNG: "Reunion") Slaps could also be given on one's cheek, in an impulsive moment. (TNG: "Sarek")
In 2366, while under the influence of strong Vulcan emotions, Beverly Crusher uncharacteristically slapped her son on the cheek, after he mouthed off to her. (TNG: "Sarek")
In 2371, while bemoaning the trivial ailments he had been reduced to treating, The Doctor complained, "Every runny nose, stubbed toe, pimple on a cheek becomes my responsibility." (VOY: "Parallax")
In 2374, while an imposter was assuming the identity of Tom Paris, Seven of Nine noted vascular congestion in his cheeks and asked if he was intoxicated. (VOY: "Vis à Vis")
In 2376, according to the holographic character Seamus, Seven of Nine had fair cheeks. (VOY: "Fair Haven")
Tom Paris noticed that Harry Kim's cheeks were redder than usual when the ensign had a crush on Irina in 2377. (VOY: "Drive")
In the writers' second draft script of ENT: "Breaking the Ice", Trip Tucker received a bruise on his cheek as a result of T'Pol hitting him while they had been sparring.