An interventional study of Lower molar distalization and Class III elastics in Class III Malocclusion, sponsored by Saint Camillus International University of Health Sciences. Completed at 1 site in Italy. Open to participants aged 19 Years and older. Per ClinicalTrials.gov, last updated 2025-03-05.
Sponsored by Saint Camillus International University of Health Sciences · Not applicable, Interventional, and Treatment
Distalizing mandibular molars may be indicated for patients with minor skeletal Class III discrepancies or in Class III subjects with mild crowding. Traditionally, mandibular molar distalization was accomplished using elastics, open coils, and the multiloop edgewise archwire technique. In recent years, several techniques have been developed to reduce the dependence on patient compliance, such as skeletal anchorage. Recently, several reports have been published on mandibular distal movement using miniscrews and some case reports have shown the possibility of obtaining Class III correction with sequential mandibular distalization in non-growing subjects by means of clear aligners. However, a sound clinical judgment should always be made on the basis of a higher level of evidence. Therefore, the purpose of the present prospective study is to provide a detailed analysis of the underlying skeletal and dental changes determined by mandibular distalization therapy with the sequential Invisalign protocol in permanent dentition. This will be accomplished by testing the following null hypothesis: mandibular molar distalization is not achievable with aligners without the application of TADs.
Class III malocclusion is considered one of the most challenging maxillofacial disorders in clinical practice characterized by an antero-posterior discrepancy with mandibular protrusion, maxillary retrusion, or a combination of both. In adult patients, managing this condition is further complicated by the absence of residual skeletal growth, limiting therapeutic options to orthodontic interventions and, in some cases, surgical procedures. Diagnosis in Class III adult patients requires distinguishing between skeletal malocclusion and dento-alveolar discrepancy. The combination of orthognathic surgery and orthodontic therapy represents the gold standard for more severe skeletal Class III disharmonies, leading to an improvement of both function and aesthetics. On the other hand, in Class III cases characterized by a prevalent dental component or mild skeletal discrepancy, the malocclusion can be addressed with a dento-alveolar compensation. In these cases, the clinical objectives are to achieve a correct sagittal, canine and molar Class I relationship, as well as ideal values of overjet and overbite. The non-surgical orthopedic approach involves the application of Class III elastics or the distalization of the lower molars, which can improve the sagittal occlusal relationship. As a matter of fact, mandibular distalization allows the increase of lower arch length along with the achievement of the necessary space to correct a Class III relationship. However, bone density and root anatomy make lower molar distalization difficult to achieve. In addition, one of the most frequent adverse effects is represented by the anterior anchorage loss with a worsening of lower incisor proclination and overjet values. Traditional appliances feature the use of open coil springs, inter arch elastics, and lip bumper device combined with fixed appliances. Nowadays, the development of clear aligner technology provides new opportunities even in the management of complex malocclusion cases, including Class III discrepancies. In particular, molar distalization movements and intermaxillary elastics have been proposed as a valid clinical strategy to improve the occlusal relationship without requiring skeletal anchorage devices. During the sagittal mechanics, over-corrected movements should be planned in order to obtain more bodily movements of the lower molars. Moreover, the best accuracy and predictability of distalization movements are supported by the sequential staging and the presence of attachments on the tooth surfaces. Nowadays, scientific evidence on this topic is limited and it is influenced by restrictions in terms of sample size, retrospective design, and lack of long-term observation. Hence, the aim of the present study was to evaluate the efficacy and efficiency of intermaxillary elastics combined with lower molar distalization by means of clear aligners in the treatment of Class III malocclusion in adult patients. More specifically, a randomized controlled trial (RCT) was conducted to evaluate the antero-posterior correction induced by Class III elastics combined with lower distalization movements and the application of Class III elastics alone. The possibility of achieving satisfying clinical outcomes without the use of skeletal anchorage was considered to avoid an invasive orthodontic approach
57 studies on the registry are indexed under Malocclusion, Angle Class III; 11 are open to participants now.
This study's enrollment of 30 is close to the median of 32 across 53 interventional studies indexed under Malocclusion, Angle Class III.
Browse Malocclusion, Angle Class III studies →Saint Camillus International University of Health Sciences is the lead sponsor of 4 studies on the registry; 1 is open to participants now.
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Exclusion Criteria:
In Group 1 (Lower Distalization Protocol), all subjects underwent lower molar distalization combined with Class III elastics.
Other: Lower molar distalization
In Group 2 (Non-Distalization Protocol) all subjects were treated with dento-alveolar expansion and Class III elastics
Other: Class III elastics
Lower Distalization Protocol included extraction of the lower third molars before starting treatment and a 50% sequential lower distalization with two teeth being distalized at a time. The distalization started with the movement of lower second molars, followed by the first molars halfway through the process, and so on. Once the canine reached the right position, the "en masse" retraction of the four incisors completed the treatment plan. The protocol comprised the use of Class III intermaxillary elastics to support the distalization movement and to control the proclination of lower incisors
Non-Distalization Protocol featured extraction of the lower third molars before starting treatment, transversal dento-alveolar coordination, strategic interproximal reduction (IPR) in the anterior segment of the lower arch, and the addition of Class III elastics
Lower molar positional changes expressed by means of linear and angular measurements (L6-MP mm; L6-MP angle; L6 - CoGo mm; L6 apex - CoGo mm)
L6-MP mm: linear distance between the mesial cusp of lower first molar and Mandibular plane L6-MP angle: angle between long axis of lower first molar and Mandibular plane L6 - CoGo mm: linear distance between the mesial cusp of lower first molar and CoGo line L6 apex - CoGo mm: linear distance between the apex of lower first molar and CoGo line
Time frame: from the start of treatment to the end at 24 months
Changes in inclination of the lower incisors (IMPA angle)
IMPA angle: angle between long axis of the lower incisor and mandibular plane
Time frame: from the start of treatment to the and at 24 months
Changes in position of the lower incisors (L1-CoGo mm; L1apex - CoGo)
L1-CoGo mm: linear distance between the tip crown of the lower incisor L1apex - CoGo mm: linear distance between the apex of the lower incisor and CoGo line
Time frame: from the start of treatment to the and at 24 months
Sagittal skeletal changes (SNA angle, SNB angle, ANB angle)
SNA angle: maxillary sagittal position SNB angle: mandibular sagittal position ANB angle: maxillomandibular sagittal discrepancy
Time frame: from start of treatment to to the end at 24 months
Sagittal skeletal changes (Wits appraisal)
Wits appraisal: maxillomandibular sagittal discrepancy
Time frame: from start of treatment to to the end at 24 months
Vertical skeletal changes (SN^MP angle, Gonial Angle)
SN-MP angle between Sella/Nasion plane and Mandibular plane Gonial angle, angle between Ar-Go plane and Go-Me plane
Time frame: from the start of treatment to the end at 24 months
Changes of upper incisors inclination
Incisor inclintion: angle between long axis of upper incisor and Sella Nasion
Time frame: from the start of treatment to the and at 24 months
Overbite and Overjet values
Overbite mm: horizontal distance between the upper and lower incisors on the occlusal plane Overjet mm: vertical distance between the upper and lower incisors on the occlusal plane
Time frame: from the start of treatment to the and at 24 months
Plan to share: Undecided
Ran from Dec 2022 to primary completion in Dec 2024, 24 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 24 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.
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This study is completed, as verified in Mar 2025. You cannot join it, but the record below documents what was studied.
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Saint Camillus International University of Health Sciences