Comparison of Two Tooth-borne Expanders in Rapid Maxillary Expansion

Pontifícia Universidade Católica de Minas Gerais

Status: Completed

Conditions: Posterior Crossbite; Malocclusion

Treatments: Device: Hyrax; Device: mini Hyrax

Study type: Interventional

Funder types: Other

Identifiers

NCT03846518

hyraxversusminihyrax

Details and patient eligibility

About

This study will assess the dentoalveolar effects and impact on quality of life of two types of maxillary expanders in orthodontic patients with permanent dentition, from 12 to 16 years old. Half of participants will be treated using the Hyrax expander, while the other half will use the mini Hyrax expander. The null hypothesis is that there is no difference between dentoalveolar effects and impact on quality of life of the two protocols.

Full description

Transverse maxilla deficiency is characterized by narrowing of the maxillary arch with important functional and esthetic impact. In individuals which have not reached bone maturity, a rapid expansion of the maxilla by using tooth-borne expanders as Haas and Hyrax appliance are efficient and safe. A presentation of favorable results for the "mini-Hyrax inverted" expander with a small screw in the transversal correction of the maxilla in patients with cleft lip and palate, besides improving the comfort and the teeth cleaning, provoked an idea of application of this small screw to correct posterior crossbite in individuals without cleft lip and palate. The objective of this study is to compare the dentoalveolar effects and impact on quality of life of two types of maxillary expanders in adolescent patients with permanent dentition and active bone growth. The sample size calculation indicated a total sample of 28 individuals. Taking into account the loss of sample during the study, 34 subjects that have posterior crossbite and age from 12 to 16 years, will be recruited at the Dental School, Pontifical University Catholic of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. These patients will be randomly divided into two groups, Hyrax and mini Hyrax, with 17 patients each. Digital models of both dental arches will be obtained by intraoral scanning precede the procedure (T0) and at the end of the retention period, after appliance removal (T2). OHIP-14 Oral Health Impact Profile Questionnaires, validated in Portuguese, will be applied before expansion (T0), after an expansion (T1) and at the end of the retention period (T2). In digital dental models, maxillary first and second bicuspids and first molar width, and rotation and inclination of maxillary first bicuspids and first molars will be assessed. After the normality test, the appropriate statistical test will be used in the intergroup comparison. A significance level of 5% will be regarded for all tests.

Enrollment: 34 patients

Sex: All

Ages: 12 to 16 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Maxillary permanent dentition, except canines
• Ages ranging from 12 to 16 years old;
• Maxillary constriction associated to posterior crossbite uni or bilateral.

Exclusion criteria

• Cleft lip and palate;
• Craniofacial syndromes;
• Carious lesions;
• History of previous orthodontic treatment.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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34 participants in 2 patient groups

Hyrax group

Active Comparator group

Description:

Seventeen patients will be submitted to rapid maxillary expansion (RME) using the Hyrax expander. The activation protocol will be 2 turns a day up to obtain transverse overcorrection.

Treatment:

Device: Hyrax

mini Hyrax group

Experimental group

Description:

Seventeen patients will be submitted to rapid maxillary expansion (RME) using the mini Hyrax expander. The activation protocol will be 2 turns a day up to obtain transverse overcorrection.

Treatment:

Device: mini Hyrax