The lower lip and the maxillary central incisor.
D002508:Cephalometry; D006801:Humans; D007180:Incisor / Q000033:anatomy & histology*; D008046:Lip / Q000033:anatomy & histology*; D008310:Malocclusion / Q000473:pathology*; D008311:Malocclusion, Angle Class I / Q000473:pathology; D008312:Malocclusion, Angle Class II / Q000473:pathology; D008313:Malocclusion, Angle Class III / Q000473:pathology