Congenital agenesis of mandibular second premolars is one of the most prevalent and clinically challenging dilemmas encountered in daily orthodontic practice.
When managing young patients who present without significant maxillary crowding or incisor protrusion, routine compensating maxillary extractions risk overly retracting the profile, flattening facial aesthetics, and compromising functional anterior guidance.
Consequently, orthodontic space closure via lower molar protraction (mesialization) represents an ideal, tooth-preserving alternative that avoids lifelong prosthetic maintenance or costly dental implants.
However, dragging massive mandibular molars mesially through dense cortical bone requires maximum anterior anchorage control to prevent catastrophic reciprocal lingual collapse of the lower incisors.
Traditionally, absolute anchorage demands have positioned Temporary Anchorage Devices (TADs) as the standard modality for lower arch mesialization without patient compliance.
Concurrently, the fixed Herbst appliance—renowned for sagittal Class II orthopedic correction—has demonstrated notable utility as a robust intraoral anchor unit capable of advancing lower posterior dentition while shielding the anterior segment.
Despite their widespread use, comparative evidence regarding protraction rates, overall treatment efficiency, and appliance-specific complications between these two mechanics has remained scarce.
To establish clear clinical parameters, this retrospective case-controlled study by Lamani et al. (Progress in Orthodontics) systematically evaluates the cephalometric, occlusal, and mechanical outcomes of mandibular molar protraction achieved with Herbst appliances versus TADs in patients treated without maxillary extractions.
The authors assess critical endpoints including monthly protraction velocity, overall treatment duration, canine sagittal stability, and emergency failure rates.
By delineating the distinct clinical trade-offs—such as comparable mesialization rates and canine Class I preservation contrasted against the pronounced incidence of appliance debonding in fixed functional setups—this investigation provides clinicians with an indispensable, evidence-based framework to customize anchorage selection based on skeletal pattern, patient tolerance, and chairside biomechanics.
📖 Read the Full Study: To examine the complete cephalometric superimpositions, exact protraction rate calculations, and comparative emergency complication statistics between Herbst appliances and temporary anchorage devices, you can access and download the full article in PDF format on SpringerOpen / Progress in Orthodontics here.
