A clinical review of crossbite in an orthodontic population.

BACKGROUND: Crossbite is a common occlusal anomaly. It may occur either anteriorly or posteriorly and may be either dental or skeletal in origin.

OBJECTIVE: To determine the pattern and frequency of crossbite occurrence in an orthodontic population.

METHODS: This was a retrospective study of 633 patients, 288 males (45.5%) and 345 (54.5%) attending a Lagos orthodontic clinic over a five-year period. Information obtained on each patient included age, sex and occlusal variables such as overjet, overbite and tooth-bone ratio.

RESULTS: Out of the 633 patients seen 189 (29.9%) were recorded to have at least one tooth in crossbite. Anterior crossbite occurred in 125 (66.1%) of the affected patients while posterior crossbite was recorded in 37 (19.6%). Patients presenting with anterior and posterior crossbite constituted 27 (14.3%) of patients. Unilateral crossbite was slightly more frequently than bilateral crossbite. A total of 445 teeth were recorded in crossbite with the permanent maxillary lateral incisor being the most frequently affected tooth constituting 33.9% of the teeth in crossbite. The number of teeth in crossbite per patient ranged from 1 to 8, a single tooth in crossbite being most commonly occurring. Crossbite was most frequently seen in patients presenting with Class I malocclusion.

CONCLUSION: Crossbite was a frequently occurring anomaly in the Lagos population, with anterior crossbite being more common. There appear to be gender or age difference in occurrence of crossbite in our population.