A crossbite occurs when which of the following is true?

A crossbite is a dental term that refers to a situation in which one or more of the teeth are misaligned in a manner that can cause functional difficulties or aesthetic concerns. The condition occurs when the maxillary teeth (upper teeth) do not properly overlap the mandibular teeth (lower teeth) as they should in a normal bite.

The correct answer accurately describes a situation in which the mandibular teeth are positioned facially, or towards the front of the mouth, in relation to their maxillary counterparts. This positioning indicates that the lower teeth are occlusally more forward than the upper teeth, creating a crossbite scenario. This misalignment can occur with specific teeth or across a dental arch and can lead to incorrect jaw function and can affect the overall oral health of the patient.

The other choices do not correctly depict a crossbite. For example, positioning the maxillary teeth behind the mandibular teeth describes a different form of malocclusion. Similarly, conditions where only molars occlude correctly while the anterior teeth do not are not classified specifically as crossbites but rather highlight other forms of misalignment. Lastly, upper incisors overlapping the lower incisors refers to a normal or potentially overbite relationship, rather than a crossbite, where such