An interventional study of Chincup and Control group in Class III Malocclusion, sponsored by Damascus University. Completed at 1 site in Syrian Arab Republic. Open to participants aged 6 Years to 8 Years. Per ClinicalTrials.gov, last updated 2022-05-04.
Sponsored by Damascus University · Not applicable, Interventional, and Treatment
This in vivo comparative study will evaluate the changes in the mandibular dimensions and the glenoid fossa after skeletal class III subjects' therapy by chincup appliance and compare it with an untreated class III control group. Pre and post-treatment low-dose computed tomography images will be taken before and after achieving positive overjet and undergoing 16 months of active treatment/ observation. Dimensional and volumetric changes in the mandible, condyles, and glenoid fossa will be calculated and compared to those observed in the control group.
Chincup is a usual treatment strategy for growing subjects with skeletal Class III malocclusions due to the mandibular overgrowth. However, the review of the literature reveals controversies and contradictions regarding the efficacy of chincup therapy in the retardation of mandibular growth. Moreover, the adaption of the temporomandibular joint (TMJ) following this treatment isn't clear yet. Two recent systematic reviews recommended the need for high-quality studies.
Computed tomography has been considered an ideal tool for evaluating the TMJ with the possibility of determining the real dimensions of the structures under study. Low-dose computed tomography was introduced as an alternative procedure with an effective dose proximately equal to traditional radiographs. Moreover, the volumetric analysis afforded by 3D imaging has proven reliable and accurate in the evaluation of mandibular and condylar sizes. Therefore, the objective of this randomized control trial is to evaluate the dimensional changes in the mandible, condyles, and glenoid fossa after chin cup therapy for children with mandibular prognathism in comparison with untreated Class III patients
Methods: patients ages between 6 and 8 with anterior crossbite, Class III relationships of the permanent first molars or mesial step relationships of the primary second molars, and short-faced pattern, will be selected from the orthodontic department in the faculty of dentistry at Damascus university. Thirty-eight subjects will be enrolled on the study, who will meet the following radiological inclusion criteria based on cephalometric images: Mild to moderate skeletal class III (4- \<the sagittal skeletal angle\< 0 degree), due to mandibular protrusion (SNB > 80°), and normal or horizontal growth pattern (Bjork's sum ≤396° ±5°).
Patients in the experimental group will receive an individual fabricated bonded bite block and occipital chincup. A 400-500g/side retroactive force will be applied in the direction of the condyles. Patients or panthers will be instructed to wear the appliance /14-16/ hours a day. Pre-(T1) and post-treatment (T2) low-dose computed tomography images will be taken after a positive overjet of 2-4 mm is obtained and undergoing 16 months of active treatment/ observation. The changes in condyle-mandibular volumes and superficial areas and relative positions of the condyles and glenoid fossa will be calculated and compared with those of untreated. Statistical analysis will be done by using the Statistical Package for Social Sciences, Windows version 26.0 (SPSS Inc., Chicago, Illinois, USA) Paired t-test and Wilcoxon signed-rank tests will be used for intragroup comparisons. For the intergroup comparisons, independent t-tests and Mann-Whitney U tests will be carried out.The confidence level is 95% (P\< 0.05).
57 studies on the registry are indexed under Malocclusion, Angle Class III; 11 are open to participants now.
This study's enrollment of 38 is above the median of 32 across 53 interventional studies indexed under Malocclusion, Angle Class III.
Browse Malocclusion, Angle Class III studies →Damascus University is the lead sponsor of 212 studies on the registry; 11 are open to participants now.
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Clinical Inclusion criteria:
Radiological Inclusion criteria:
Exclusion Criteria:
Patients will be treated with occipital chincup and bonded bite block.
Device: Chincup
Patients will not undergone any treatment for 16 months.
Other: Control group
Patients will receive an individual fabricated bonded bite block and occipital chincup. A 400-500g/side retroactive force will be applied in the direction of the condyles. Patients or panthers will be instructed to wear the appliance /14-16/ hours a day.
The changes in condyle-mandibular volumes and superficial areas and relative positions of the condyles and glenoid fossa will be calculated after 16 months of observation.
Change in the mandibular volume and superficial area
After a semiautomatic segmentation will be utilized to isolate the mandibular bone, the mandible will be rendered in high-quality 3D model. Then, the crowns of the teeth will be removed by a plane passing through 1 mm inferior to the alveolar bone and 10 mm distal to the second primary molars. The mandible volumes and surface sizes will be automatically calculated by the software in mm3 and mm2, respectively.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Changes in the condylar volume and superficial area
The condyles will be cut from 3D rendered mandibular model at neck level using a plane parallel to the Frankfort horizontal plane at the most inferior part of the sigmoid notch, the condyle volumes and surface sizes will be automatically calculated by the software in mm3 and mm2, respectively.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the mandibular body (Go-Gn)
Distance between the Gonion point and the Gnathion point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the ramus height (Co-Go)
Distance between the Condylion point and the Gonion point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the total body length (Co-Gn)
Distance between the Condylion point and the Gnathion point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the mandibular angle (GN-Go-CO)
The angle between the Condylion point, the Gonion point and Gnathion point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the vertical position of the condyle (CP-FH)
The measurement will be made on the corrected sagittal view: Distance of Condylar posterior point from Frankfort horizontal plane.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the sagittal position of the condyle (CP-Y)
The measurement will be made on the corrected sagittal view: Distance of Condylar posterior point from Perpendicular plane (Y).
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
change in the vertical position of the mandibular fossa (FP-FH)
The measurement will be made on the corrected sagittal view: Distance of Fossa posterior point from Frankfort horizontal plane (FH).
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the sagittal position of the mandibular fossa (FP-Y)
The measurement will be made on the corrected sagittal view: Distance of point Fossa posterior point from Perpendicular plane (Y).
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Quantitative changes of displacement of superimposed 3D mode
The T1 and T2 3D volumes will be superimposed manually followed by automatic global registration. The point-based analysis will be performed to assess the changes in 3D mandibular models between T1 and T2, and a colour map will be produced. Quantitative mean, minimum, and maximum values of part analyses will be reported for comparative analyses.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Change in the anterior joint space (AJS)
The measurement will be made on the corrected sagittal view: Distance between Condylar anterior point and Fossa anterior point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Chang in the superior joint space (SJS)
The measurements will be made on the corrected sagittal view: Distance between Condylar posterior point and Fossa superior point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Chang in the posterior joint space (PJS)
The measurements will be made on the corrected sagittal view: Distance between Condylar posterior point and Fossa posterior point.
Time frame: (T1) baseline measurement at seven days before the beginning of treatment and (T2) at seven days following the end of treatment
Plan to share: No
Ran from Jan 2019 to primary completion in Jan 2022, 36 months.
Of 37 non-industry interventional studies with no phase under Malocclusion, Angle Class III, half reached primary completion within 13 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 26. This study's 36 months is above that.
Counting every sponsor, half of 38 studies reached it within 13 months; a quarter within 10 and three quarters within 26.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Apr 2022. You cannot join it, but the record below documents what was studied.
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