Class I malocclusion, bilateral posterior cross bite. Bilateral Posterior Open Bite in permanent dentition.

Treatment: Fixed Therapy.

Time: 21 months.

Lingual Pearl: 8 months before finishing treatment and 2 months after.

Retention: thermoformed splint (upper 3 – 3).

Note: In adult cases, bilateral posterior cross bites with open bite have great tendency to relapse. It is very important to educate tongue trust to achieve stability.