The biomechanics of posterior maxillary arch expansion using fixed labial and lingual appliances

Abstract

Objective To compare the biomechanics of straight labial, straight lingual, and mushroom lingual archwire systems when used in posterior arch expansion. Materials and Methods An electro-mechanical orthodontic simulator allowing for buccal–lingual and vertical displacements of individual teeth and three-dimensional force/moment measurements was instrumented with anatomically shaped teeth for the maxillary arch. In-Ovation L brackets were bonded to lingual surfaces, and Carriere SLX brackets were bonded to labial surfaces to ensure consistency of slot dimensions. Titanium molybdenum archwires were bent to an ideal arch form, and the teeth on the orthodontic simulator were set to a passive position. Posterior teeth from the canine to second molar were moved lingually to replicate a constricted arch. From the constricted position, the posterior teeth were simultaneously moved until the expansive force decreased below 0.2 N. Initial force/moment systems and the amount of predicted expansion were compared for posterior teeth at a significance level of α = 0.05. Results Archwire type affected both the expected expansion and initial force/moment systems produced in the constricted position. In general, the lingual systems produced the most expansion. The archwire systems were not able to return the teeth to their ideal position, with the closest system reaching 41% of the intended expansion. Conclusions In general, lingual systems were able to produce greater expansion in the posterior regions when compared with labial systems. However, less than half of the intended arch expansion was achieved with all systems tested.

The in vitro biomechanics of anterior arch expansion using fixed lingual appliances with coil springs or archwire stops

“…Recent finite element simulation studies have considered space closure analysis of the anterior segment with fixed lingual appliances, 14 but work surrounding expansion or space generation is limited. A past study considering posterior arch expansion biomechanics using lingual and labial appliances also found differences between mushroom and straight lingual archwires 15 . The primary differences between the types of lingual archwires occurred near the canine where the first‐order bend between the canine and first premolar exists with mushroom archwires, with expansive forces reducing in mushroom archwires.…”

“…and labial appliances also found differences between mushroom and straight lingual archwires. 15 The primary differences between the types of lingual archwires occurred near the canine where the first-order bend between the canine and first premolar exists with mushroom archwires, with expansive forces reducing in mushroom archwires. While the current study focuses on anterior expansion using stops or coils, the collective outcomes from these studies show that transverse expansion biomechanics in all regions of the mouth may differ between the two archwire types.…”

“…Recent finite element analysis studies have considered lingual mechanics for space closure, but not space generation in crowding cases 14 . Previous research considering posterior transverse expansion of the dental arch using fixed lingual appliances showed significant differences in expansion forces between straight and mushroom lingual archwires, particularly near the first‐order bend between the canine and first premolar 15 . Extending these results to cases of anterior arch expansion, it may be suggested that the same first‐order bend in mushroom archwires may produce biomechanical differences from straight lingual archwires.…”

Application of Cefaclor in Orthodontics through Micro-Implant Anchorage in Patients with Periodontitis

“…In 2015, the First People's Hospital of Yongkang City introduced micro-implant anchorage. This method relies on an embedding force applied to bone tissues for orthodontic treatment [6]. Micro-implant anchorage is safe, and it offers comfortable treatment that involves simple surgery, little trauma, and high stability, which have been unanimously recognized by dentists and patients.…”

Non-Surgical Transversal Dentoalveolar Compensation with Completely Customized Lingual Appliances versus Surgically Assisted Rapid Palatal Expansion in Adults—The Amount of Posterior Crossbite Correction

“…Two things are needed for this tooth movement: torque control to reduce tipping, and an adequate force. This can be accomplished by the use of a completely customized lingual appliance (CCLA), which can accurately achieve the planned tooth position of the initial setup [27][28][29], has a good torque control due to the high precision of the slot-archwire combination [30,31] and offers biomechanical advantages for expansion and compression due to the shorter interbracket distance [32], and therefore a shorter total archwire length.…”