Pharyngeal obturator in children with cleft lip and palate in the deciduous dentition phase: proposal for the use of stops as an additional retention method

• Ano de defesa: 2024
• Autor(a) principal: Petroni, Vinicius Villas Boas
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Dente decíduo; Insuficiência velofaríngea; Retenção da prótese
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/61/61132/tde-04102024-111331/

Individuals with cleft palate who develop velopharyngeal dysfunction following primary palatoplasty present an undesirable coupling between the oral and nasal cavities, leading to speech symptoms such as hypernasality, nasal air emission, and compensatory articulation disorders. While secondary surgery is the procedure of choice for correcting velopharyngeal insufficiency, there are numerous cases that do not show a favorable prognosis for speech. Alternatively, a pharyngeal obturator may be recommended. One of the challenges encountered in using a pharyngeal obturator, particularly in the rehabilitation of children in the deciduous dentition phase, is the lack of retention of the clasps and the consequent instability of the prosthesis. This study aimed to investigate retention solutions in printed replicas, exploring the hypothesis that the addition of stops would not result in greater retention and stability of the pharyngeal obturator compared to the replica without stops. To test this hypothesis, the objectives were: a) to demonstrate the effectiveness of the retention system obtained by fabricating stops on the vestibular surface of deciduous teeth, and b) to compare which configuration of stops has higher retentive quality under traction and compression forces. The study sample consisted of 40 replicas, which were subdivided into four groups, with 10 replicas each: R1) 10 replicas identical to the original; R2) 10 replicas with the addition of stops on the deciduous canines (53 and 63); R3) 10 replicas with the addition of stops on the second deciduous molars (55 and 65), and R4) 10 replicas with the addition of stops on the deciduous canines and second molars (53, 63, 55, and 65). The stops, created using 3D modeling software, were positioned at a distance between 0.8 to 1.1 mm from the cervical area of the abutment teeth, with a retention depth of 0.5 mm. Each replica was 3D printed using stereolithography technology. Subsequently, a prosthesis was crafted for each printed replica, which underwent clinical traction (T) and compression (C) tests on a universal testing machine, conducted at a speed of 8 mm/min until the total displacement of the prosthesis. Multiple comparisons of significant results between each one of the replicas in the traction and compression groups were conducted using the Benjamini-Hochberg p-value adjustment method. The significance level adopted for these analyses was 5%. The results demonstrated that replicas without stops (R1) showed the lowest median retention values in the compression (0.52 N) and traction (1.87 N) groups. On the other hand, replicas R2, R3, and R4 exhibited significant increases in the median force required to displace the prosthesis in both groups (R2C = 12.86 N; R2T = 8.79 N; R3C = 3.3 N; R3T = 3.68 N; R4C = 9.59 N; and R4T = 9.38 N). The incorporation of stops notably improves the retention of a pharyngeal obturator prosthesis particularly in the rehabilitation of children in the deciduous dentition phase. A polygonal configuration, featuring two anterior and two posterior stops, demonstrates the most favorable performance, justifying its consideration for clinical application.