Demystifying posterior crossbite

Vol. 13 – Number 49 – 2020 Case Report Page 69-77 Demystifying posterior crossbite Pedro Henrique Rolim de Oliveira1 Andreia Gomes Moreira2 Tiago Martins da Silva Flora3 Tatianna Miranda Cabral Ferreira4 Victor França Didier5 Maria Jacinta Arêa Leão Lopes Araújo Arruda6 Abstract The posterior crossbite is defined as an abnormally transverse relationship, whose inferior buccolingual dimension is larger than the superior dimension. It has no self-solution and therefore perpetuates itself when left untreated. This malocclusion develops between 19 months and 5 years old. This work proposes to review relevant information regarding the posterior crossbite picture and to demonstrate through a clinical case the effectiveness of the rapid palatal expansion protocol in prepubertal age, providing the reader with a greater safety in the choice of treatment. The present clinical case was performed with a male patient, 7 years old, diagnosed with maxillary atresia, and right unilateral crossbite. The treatment was performed immediately, in the form of rapid maxillary expansion, with the use of modified HAAS device anchored in deciduous second molars. As a result, an intermolar expansion of approximately 6.5mm was obtained, demonstrating success in the treatment with uncrossing of the arches, besides local stability noticed after one year of device removal, without the use of post-disjunction restraints. It was concluded that, when diagnosed, posterior crossbite should be treated interceptably, preferably during the first transient period of the individual, prioritizing rapid maxilla expansion protocol with a modified expander, anchored in primary second molars, avoiding a series of side effects on adjacent permanent teeth, in addition to ensuring greater future occlusal stability. Descriptors: Malocclusion, interceptive Orthodontics, mixed dentition. 1 Specialist in Orthodontics – IOA/IOP, Professor of Orthodontics – IOA/IOP. 2 Post-Doctoral Degree in Pediatric Dentistry – SLMandic, Professor of Orthodontics – IOA/IOP. 3 Specialist in Orthodontics – IOA/IOP, Professor of the course in Orthodontics – IOA/IOP. 4 MSc in Orthodontics – Uniararas), Specialist in Orthodontics – COESP, Professor of the Orthodontics Course – IOA/IOP. 5 PhD student in Dentistry – Unopar, MSc in Orthodontics – USC, Professor of the Orthodontics Course – IOA/IOP. 6 PhD Student in Dentistry – UEPB, Professor of Dentistry – UNIFACISA, Professor of Orthodontics – IOA/IOP.