Effects of rapid jaw expansion on teeth and periodontium

Author(s)

Fabio Santos Bottacin

• Document type: Master's Dissertation
• Press: Ribeirão Preto.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Ribeirão Preto (PCARP/BC)
• Defense date: 2017-06-01

Examining board members

Mario Taba Junior; Luciane Macedo de Menezes; Luiz Carlos Pardini; Luiz Andre Freire Pimenta

• Advisor: Mario Taba Junior

Abstract

Introduction: The upper dental arch of patients with posterior crossbite is usually atresic and rapid maxillary expansion is indicated for these cases during the mixed dentition, promoting the opening of the medial palatine suture and transverse increments in the posterior region of the dental arch. Objective: The purpose of this study was to evaluate the effects of rapid maxillary expansion using the acrylic cover breaker, through clinical and radiographic monitoring. Material and Method: The study sample consisted of 21 patients with posterior crossbite, uni or bilateral and upper dental arch atresia. The rapid maxillary expansion procedure was performed in the late mixed dentition using the expansion apparatus with acrylic occlusal cover. Cone beam tests were performed prior to appliance installation and 06 months after the McNamara circuit breaker was installed at the time of removal. Computed tomography images were measured using On Demand 3D software (Version 1.0, Cybermed Inc., Seoul, South Korea). Computed tomography images were analyzed for the thickness of the buccal and lingual bone plates, the level of the buccal bone crest of the first permanent molars, the width of the hard palate, the transverse distance between the first maxillary first molars. Clinical parameters were obtained monthly until the end of the treatment: visible dental plaque index (IPV), gingival bleeding index (ISG), probing depth (PS), clinical insertion level (NIC) and bleeding probing index SS). Pre- and posttreatment measurements were submitted to paired t-test (p <0.05). Results: There were no statistically significant differences between the initial and final time for IPV, ISG, ISS, PS and NIC, but there was a significant increase for PS and CIN during the 30, 60 and 150 day periods. The results of the measurements made through the CBCT did not show statistically significant differences between the times for the height of the buccal bone crest. The thickness of the buccal bone plate decreased in the permanent and deciduous molars, which was only significant in the permanent molars (p <0.05), whereas on the palatine side it increased significantly (p <0.001) in all teeth analyzed. There was no reduction of the buccal bone crest. At the bi-molar distance showed a significant increase (p <0.001) in both the cervical region and the apical region. The same significant increase (p <0.001) was found for the width of the palate. Conclusion: The results of the clinical parameters and the measurements made by means of the computerized tomography allowed to verify the orthopedic effect of the acrylic breaker in the occlusal of the teeth in the rapid expansion of the maxilla. The observed changes do not suggest significant damage to the teeth and to the periodontal structures evaluated. (AU)

• FAPESP's process: 15/20095-1 - EFFECTS OF RAPID MAXILLARY EXPANSION IN TEETH AND PERIODONTIUM
• Grantee: Fabio Santos Bottacin
• Support Opportunities: Scholarships in Brazil - Master