Frontiers of Oral Biology

No abstract text is available yet for this article.

No abstract text is available yet for this article.

Osteotomies and corticotomies used in combination with orthodontic tooth movement can activate different bone responses that may be exploited to accelerate tooth movement. Segmental osteotomies around dental roots can create a tooth-bearing transport disk that may be distracted and positioned with orthodontic appliances and archwires. In difficult craniofacial repairs, alveolar segments can be guided into position with archwires and orthodontic mechanics. The corticotomy extending into the marrow space can activate bone injury repair mechanisms that accelerate bone turnover as the alveolar bone surrounding the dental roots transitions from a demineralization phase to a fibrous replacement phase and, finally, a mineralization phase...

Photobiomodulation is discussed to be a noninvasive method to accelerate orthodontic tooth movement. The stimulatory effect of low-level laser therapy is well known and includes enhancement in tissue growth and tissue regeneration, resolvement of inflammation and pain. In recent research projects, the effect of laser therapy was tested regarding the stimulatory effect on bone remodeling with the potential to influence the tooth movement rate. The results are divers. The effect of laser regarding the reduction of the postadjustment pain could be proved, but not all authors describe the acceleration of tooth movement...

Orthodontic tooth movement results from applied forces to the teeth evoking cellular responses in the teeth and their surrounding tissues, including the periodontal ligament, alveolar bone and gingiva. It is advantageous for the orthodontist to be well informed of the detailed process of the biological events that unfold during tooth movement, since some of these details may differ from one person to another due to biological differences such as periodontal metabolism or alveolar bone density. This led us to emphasize that orthodontics is a field of endeavor where the integration of mechanics and biology is materialized, and to affirm the fact that tooth movement is conducted in individual human beings, each composed of a unique and intricate physiological system...

Piezocision™-assisted orthodontics is an innovative, minimally invasive surgical procedure designed to help achieve rapid orthodontic tooth movement while correcting/preventing mucogingival defects by adding bone and/or soft tissues. Microsurgical interproximal openings are done in the buccal gingiva to let the piezoelectric knife create the bone injury that will lead to transient demineralization and subsequent accelerated tooth movement. This technique can be used for the whole mouth, the cuts being simultaneously performed at the maxilla and the mandible (generalized Piezocision) or for segments of the dentition (localized Piezocision) to achieve specific localized results (intrusion, extrusion, distalization of teeth, etc...

Surgical techniques for the acceleration of the orthodontic tooth movement have been tested for more than 100 years in clinical practice. Since original methods have been extremely invasive and have been associated with increased tooth morbidity and various other gaps, the research in this field has always followed an episodic trend. Modern approaches represent a well-refined strategy where the concept of the bony block has been abandoned and only a cortical plate around the orthodontic tooth movement has been desired...

While acceleration of the orthodontic tooth movement by surgical techniques has been shown to be effective for decades, noninvasive and nonsurgical methods have always been preferred by both the clinicians and the patients. These techniques have ranged from application of biological molecules to innovative technologies such as resonance vibration, cyclic forces, light electrical currents, magnetic field forces, low-intensity laser irradiation and low-level light therapy. Endogenously produced biologicals have been tested based on their roles in the turnover of alveolar bone in response to orthodontic tooth movement as well as during wound healing...

It is a well-known concept that bone remodeling occurs during orthodontic tooth movement. The orthodontic literature is vastly full of information about the changes occurring on the periodontal ligament level. However, changes occurring in the alveolar bone are being elucidated. The purpose of this chapter is to present some of the studies describing the bone changes associated with orthodontic tooth movement. Initiation of osteoclastogenesis requires inflammation in the adjacent area. Tissue biomarker RANKL responds to the compressive forces...

Pain and discomfort are prevalent symptoms among the vast majority of patients with fixed orthodontic appliances and is the most disliked aspect of treatment. The periodontium is a highly innervated structure that also provides the necessary trophic factors, such as nerve growth factor, which promote neuronal survival, maintenance and axonal growth, via interaction with specific nerve surface receptors, such as TrkA. Various types of nerves are found in the periodontium, including thinly myelinated and unmyelinated sensory fibers that express the neuropeptides substance P and calcitonin gene-related peptide among others...

Stability of tooth position in the broader sense considers all the forces that may act on the tooth. Reitan reported that significant forces remained in the periodontium after tooth movement, and he carried out research that demonstrated residual stretching of the crestal periodontal fibers more than 7 months after tooth movement. Brain demonstrated that severing the fibers reduced the relapse in tooth position in dogs. Edwards published a series of papers exploring the effects of surgical transection of the gingival fibers on tooth stability, recommending that circumferential fiberotomy be performed in order to increase posttreatment tooth stability...

The earliest report on orthodontic tooth movement in the English literature was published in 1911. Oppenheim carried out studies on baboons to determine what histologic changes occurred during tooth movement. Reitan and many others carried out research into the nature of tooth movement. The pressure-tension model of tooth movement developed from these studies, whereby the two sides of the tooth responded to forces as if in isolation. A second theory, proposed by Stuteville in 1938, was the hydraulic theory of tooth movement...

Tissue reaction to orthodontic force has been a subject of research with the purpose of providing the orthodontists with information necessary for the application of a force system that can generate a maximum of tooth movement and modeling of the alveolar process with a minimum of damage. Traditionally, the studies of bone biological reactions have been distinguishable from those performed by bone biologists. This has led to a controversy regarding both the terminology and perception of the reaction to mechanical perturbation...

The regional acceleratory phenomenon (RAP) is a tissue reaction to a noxious stimulus that increases the healing capacities of the affected tissues. It is typical not only of hard tissues such as bone and cartilage, but also of soft tissues. The RAP is characterized by acceleration of the normal cellular activities, as an 'SOS' phenomenon of the body that has to respond to the new perturbation. In the alveolar bone, the RAP is characterized, at a cellular level, by increased activation of the basic multicellular units (BMUs), thereby increasing the remodeling space...

Bone is masterfully programmed to repair itself through the coupling of bone formation following bone resorption, a process referred to as coupling. In inflammatory or other conditions, the balance between bone resorption and bone formation shifts so that a net bone loss results. This review focuses on four pathologic conditions in which remodeling leads to net loss of bone, postmenopausal osteoporosis, arthritis, periodontal disease, and disuse bone loss, which is similar to bone loss associated with microgravity...

Bone remodeling is a highly coordinated process responsible for bone resorption and formation. It is initiated and modulated by a number of factors including inflammation, changes in hormonal levels and lack of mechanical stimulation. Bone remodeling involves the removal of mineralized bone by osteoclasts followed by the formation of bone matrix through osteoblasts that subsequently becomes mineralized. In addition to the traditional bone cells (osteoclasts, osteoblasts and osteocytes) that are necessary for bone remodeling, several immune cells such as polymorphonuclear neutrophils, B cells and T cells have also been implicated in bone remodelling...

The periodontal ligament (PDL) and alveolar bone are two critical tissues for understanding orthodontic tooth movement. The current literature is replete with descriptive studies of multiple cell types and their matrices in the PDL and alveolar bone, but is deficient with how stem/progenitor cells differentiate into PDL and alveolar bone cells. Can one type of orthodontic force with a specific magnitude and frequency activate osteoblasts, whereas another force type activates osteoclasts? This chapter will discuss the biology of not only mature cells and their matrices in the periodontal ligament and alveolar bone, but also stem/progenitor cells that differentiate into fibroblasts, osteoblasts and osteoclasts...

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Reconstruction of maxillofacial bones has proven to be complex due to the aesthetic requirements and functional demands of the jaw. Although autogenous bone grafts and a wide range of biomaterials are routinely used for facial bone reconstruction, these methods are associated with a number of drawbacks, including the limited availability of autogenous grafts and the morbidity associated with bone graft harvesting, whilst biomaterials are also linked with a high failure rate. These limitations have inspired the search for innovative techniques for bone bioengineering and the development of more reliable biomaterials...

Periodontitis is a chronic inflammatory disorder affecting nearly 50% of adults in the United States. If left untreated, it can lead to the destruction of both soft and mineralized tissues that constitute the periodontium. Clinical management, including but not limited to flap debridement and/or curettage, as well as regenerative-based strategies with periodontal membranes associated or not with grafting materials, has been used with distinct levels of success. Unquestionably, no single implantable biomaterial can consistently guide the coordinated growth and development of multiple tissue types, especially in very large periodontal defects...