Posterior Crossbite
Conditions
Brief summary
Posterior crossbite is a common clinical condition often associated with transverse maxillary deficiency and functional mandibular shift. This frequent malocclusion is not self-correcting and can lead to the development of craniofacial asymmetries and mandibular dysfunction. The aim of the current study was to evaluate maxillary and mandibular arch widths' response to RME when it is anchored to the upper second deciduous molars or to the upper first permanent molars and to create a decision-making protocol for RME therapy in mixed-dentition patients.
Detailed description
The effects of rapid maxillary expansion (RME) on the maxillary complex have been highly investigated,4 reporting a maximum maxillary intermolar and intercanine width increase of 6.7 mm and 5.3 mm,5 respectively, when RME is banded on upper first permanent molars. Literature also reported cases of periodontal and endodontic damage on RME anchoring teeth; therefore, some authors have suggested banding RME on primary teeth and reporting also different mean intermolar (3.6-4.1 mm) and intercanine width increases (5-5.9 mm). Few studies have investigated the changes in molar dental tipping and inclinations (on average from 3° up to 16.7°) following RME but comprised difficult (ie, barium sulfate solution) and more invasive examinations such as computed tomography and cone beam computed tomography (CBCT) Few articles concerning the indirect effects on mandibular arch following RME reported a low but statistically significant increase of lower intermolar (0.66-0.97 mm) and intercanine width (0.9 mm). Since no studies in the literature have analyzed the differences in permanent vs primary molars as anchoring teeth for RME, the decision to band the permanent deciduous molars did not follow a clinical protocol, but an individual decision was made for each patient based on clinician experience.
Interventions
PROCEDURERapid maxillary expansion
When rapid maxillary expander was in-situ, patients waited 7 days before starting the screw activation of one quarter turn a day (0.22 mm) until overcorrection. Expansion was considered adequate when the occlusal surface of the first maxillary palatal cusp contacted the occlusal surface of the mandibular first molar facial cusp. When was achieved, rapid maxillary expander stayed in place for 10 months.
Sponsors
University of Genova
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
8 Years to 10 Years
Healthy volunteers
No
Inclusion criteria
* Patients in mixed dentition * Unilateral posterior crossbite at least of the first permanent molar * Upper deciduous second molars available as RME anchoring teeth
Exclusion criteria
Primary
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Crossbite correction (binary outcome yes/no: clinical evaluation in vivo and on digital dental casts) | 5 months |
Secondary
| Measure | Time frame |
|---|---|
| Crossbite correction stability (binary outcome yes/no: clinical evaluation in vivo and measured on digital dental casts) | 10 months |
| Canine angulation (degrees of transverse expansion measured on digital dental casts) | 5 months |
| Molar angulation (degrees of transverse expansion measured on digital dental casts) | 5 months |
| Canine Expansion (mm of transverse expansion measured on digital dental casts) | 5 months |
| Upper and lower incisor angulation and rotation (changes in mm and degrees of dental angulation and rotation measured on digital dental casts and Dental digital X-ray) | 10 months |
| Molar expansion (mm of transverse expansion measured on digital dental casts) | 5 months |
Other
| Measure | Time frame |
|---|---|
| Cephalometric evaluation of craniofacial growth (changes in mm and degrees of craniofacial skeletal growth measured on dental digital X-ray) | 10 months |
| Cephalometric evaluation of morphology of the cervical vertebrae (changes in mm and degrees of cervical vertebrae morphology on dental digital X-ray) | 10 months |
Countries
Italy
Outcome results
None listed