Treating Growing Patients With Mandibular Prognathism and Maxillary Constriction

Not Applicable

Completed

• Conditions: Class III Malocclusion

• Registration Number: NCT06762418
• Lead Sponsor: Damascus University

Brief Summary

The intention of this randomized controlled trial is to test the efficacy of two treament protocols in the correction of Class III malocclusion with maxillary constriction. We have to options, either to modify the growth using inter-maxillary traction based on an upper fixed appliance that is used in the same time for rapid maxillary expansion or to inhibit mandibular growth by a removable mandibular retractor (RMR) supplied with an expansion screw.

Detailed Description

Not available

Study Timeline

• Study Start: 2020-07-15
• Primary Completion: 2022-01-15
• Study Completion: 2022-06-15
• Status Verified: 2024-12
• Study First Submitted: 2024-12-31
• Study First Submitted QC: 2024-12-31
• Last Update Submitted: 2024-12-31
• Study First Posted: 2025-01-07
• Last Update Posted: 2025-01-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 26

Inclusion Criteria

1. growing male and female patients aged between 12 and 15 years
2. Angle's class III malocclusion
3. skeletal class III relationship judged clinically and confirmed radiographically (-4 < ANB < + 1)
4. An anterior crossbite involving two or more teeth or an edge-to-edge incisor relationship with or without an anterior shift of the lower jaw upon closure
5. normal inclination of the lower incisors or slightly proclined (i.e., the IMPA between 85° and 100°
6. maxillary constriction requiring expansion judged clinically and confirmed radiographically
7. permanent dentition
8. no previous orthodontic treatment

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Exclusion Criteria

1. skeletal class III malocclusion caused predominantly by maxillary deficiency (SNA<78° with a normal SNB angle)
2. severe skeletal class III presenting mainly due to mandibular protrusion (ANB < - 4° with no functional shift on closure)
3. contraindications for the use of the mini-screws, such as osteoporosis (addressed with cortisone and its derivatives) or those undergoing radiation treatment
4. a convergence between the mandibular canine root and the first premolar root ,which was assessed radiographically
5. facial asymmetry, characterized by a mandibular midline deviation exceeding 2 mm from the facial midline
6. MM angle >35° or SN-MP angle > 40°
7. The existence of cleft lip or craniofacial syndromes and/or palate abnormalities and
8. The existence of supernumerary teeth or missing ones except for the third molars.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Change in the B-H variable	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This variable is the horizontal distance between B point (the mandibular bone point) and the perpendicular plane to the S-N plane through Point S (Sella).
Change in the SNA angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the position of the upper jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken and this angle is going to be measured in degrees
Change in the SNB angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	his angle represents the position of the lower jaw in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken, and this angle will be measured in degrees.
Change in the ANB angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	his angle represents the relationship between the upper and lower jaws in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken, and this angle will be measured in degrees
Change in the SN-GoMe angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the position of the lower jaw in the cephalometric analysis in the vertical direction. Lateral cephalograms will be taken, and this angle will be measured in degrees.
Change in the MM angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the amount of vertical divergence between the upper and lower jaws in the cephalometric analysis. Lateral cephalograms will be taken, and this angle will be measured in degrees.
Change in the mandibular length	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This distance is measured between the mandibular condyle (Co) and the genial point (Gn).
Change in the SN-SPP angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the position of the upper jaw (represented by the spinal plane "SPP") in the cephalometric analysis in the vertical direction. Lateral cephalograms will be taken, and this angle will be measured in degrees.
Change in the Witz appraisal	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	Witz appraisal is measurd by the anteroposterior distance between the projection of Points A and B onto the functioanl occlusal plane. The distance is measured between the two projections in mm. It gives an idea about the sagittal relationship bewteen the upper and lower jaws.
Change in the Co.Go.Me angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle is created by the intersection between the ramus plane (Co.Go) and the mandibular plane (Go.Me). This is called the gonial angle.
Change in the ramus height	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This distance is measured between the mandibular condyle (Co) and mandibular gonial angle (Go).
Change in the lower facial height	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This distance is measured between the anterior nasal spine (ANS) and the lower point on the mandibulr emphysis (Me).
Change in the A-H variable	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This variable is the horizontal distance between A point (the maxillary bone point) and the perpendicular plane to the S-N plane through Point S (Sella).
Change in the SN-U1	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the relationship of the upper anterior teeth with SN in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken, and this angle is going to be measured in degrees
Change in the GoMe-L1 angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the relationship of the lower anterior teeth with the mandibular plane in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken, and this angle will be measured in degrees.
Change in the SPP-U1 angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This angle represents the relationship of the upper anterior teeth with SPP plane in the cephalometric analysis in the anteroposterior direction. Lateral cephalograms will be taken, and this angle is going to be measured in degrees
Change in ls-E Line distance	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	It is the distance between the upper lip point and estheic line of Ricketts.
Change in li-E Line distance	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	It is the distance between the lower lip point and estheic line of Ricketts.
Change in the Gla-Sn-Pog angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	It is the angle between the soft tissue forehead point (Gla) and the subnasal point (Sn) and the most anterior point on the soft tissue chin (Pog).
Change in the naso-labial angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	It is the angle between the upper lip and nasal columella plane.
Change in the labio-mental angle	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	It is the angle between the lower lip and the chin. It is also called the labio-mental fold angle..
Change in the Ag to MZF-j variable	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	Maxillomandibular width right: measured from the Jugal process to the frontofacial plane. This measurement is measured on the frontal cephalogram.
Change in the J-J distance	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	It is the maxillary width measured on the frontal cephalogram.
Change in the molar width at the level of apices (M-MRA)	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This is measured between the apices of the palatal roots of the maxillary first molars (R.RA-L.RA) on the frontal cephalogram.
Change in the molar width at the level of cusps (M-MCT)	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	This is measured between the measured between the mesio-palatal cusps tips of the maxillary first molars (R.CT-L.CT) on the frontal cephalogram.
Change in the inferred molar tipping (M-tip)	At two assessment times: (1) one day before the beginning of the treatment, and (2) at the end of the retention phase which is expected to occur within 12 months	The difference between R.RA-L.RA and R.CT-L.CT variables mentioned above and the difference is given in mm.

Trial Locations

Locations (2)

Adib Al-Lahham Center, Damascus Health Directorate, Ministry of Health; 🇸🇾 Damascus, Syrian Arab Republic

Department of Orthodontics, Faculty of Dentistry, University of Damsacus; 🇸🇾 Damascus, Syrian Arab Republic