Dental arch

The dental arches are the two arches (crescent arrangements) of teeth, one on each jaw, that together constitute the dentition. In humans and many other species, the superior (maxillary or upper) dental arch is slightly larger than the inferior (mandibular or lower) arch, so that in the normal condition the teeth in the maxilla (upper jaw) slightly overlap those of the mandible (lower jaw) both in front and at the sides. The way that the jaws, and thus the dental arches, approach each other when the mouth closes, which is called the occlusion, determines the occlusal relationship of opposing teeth, and it is subject to malocclusion (such as crossbite) if facial or dental development was imperfect. The dental arches are the two arches (crescent arrangements) of teeth, one on each jaw, that together constitute the dentition. In humans and many other species, the superior (maxillary or upper) dental arch is slightly larger than the inferior (mandibular or lower) arch, so that in the normal condition the teeth in the maxilla (upper jaw) slightly overlap those of the mandible (lower jaw) both in front and at the sides. The way that the jaws, and thus the dental arches, approach each other when the mouth closes, which is called the occlusion, determines the occlusal relationship of opposing teeth, and it is subject to malocclusion (such as crossbite) if facial or dental development was imperfect. Because the upper central incisors are wider than the lower ones, the other teeth in the upper arch are arrayed somewhat distally, and the two sets do not quite correspond to each other when the mouth is closed: thus the upper canine tooth rests partly on the lower canine and partly on the lower first premolar, and the cusps of the upper molar teeth lie behind the corresponding cusps of the lower molar teeth.