Correction of anterior crossbite performed in the public service of the city of São Paulo (SUS). Clinical case report using the pam class III guide

This clinical case report examines the efficacy of the GUIA PAM III (Marinho’s Posterior-Anterior Guide), a functional jaw orthopedic appliance, in treating Angle Class III malocclusion with anterior crossbite. The study focuses on a 3-year-old male patient treated within the Brazilian public health system (SUS), presenting with functional mandibular projection and deleterious parafunctional habits. The PAM III appliance was selected for its cost-effectiveness, high patient acceptance, and its unique design that eliminates the need for a constructive bite registration, which is particularly beneficial for very young patients. Treatment objectives centered on promoting therapeutic postural changes and neuromuscular reprogramming to stimulate maxillary growth while controlling mandibular development. Over the clinical follow-up period, bioprogressive activations were utilized to achieve balanced stomatognathic function and a harmonious facial profile without exerting excessive pressure on the dental arches. Cephalometric analyses post-active treatment revealed significant improvements, including an increase in the ANB angle and successful correction of the crossbite, effectively avoiding the need for future orthognathic surgery. The results demonstrate that the GUIA PAM III is a highly effective, comfortable, and simple tool for interceptive orthopedic intervention in growing patients.