Evolution of Orthodontic Anchorage Techniques: A Comparative Analysis Using the Latent Dirichlet Allocation Algorithm

INTRODUCTION

Anchorage is an issue of tooth movement that has been discussed and scrutinized many times. Without an anchor, teeth cannot be moved. Newton’s law of “for every action there is an equal and opposite reaction” must be remembered. The American Heritage College Dictionary defines anchorage as “a means of securing or fixing”.^[1,2]

Edward Angle’s Sixth Edition was published in 1900. In Chapter X of this edition, he discussed the principles of anchorage. Angle wrote, “According to the laws of physics, their movement in conformity with the line of obstruction can only be accomplished by applying force from a fixed anchorage base in three ways: pulling, pushing, or bending.”^[3]

The use of implants in dentistry has found a wide range of uses, from the treatment of tooth loss to plate fixation in surgery, while in orthodontics, they are used for skeletal anchorage to achieve tooth movement.^[4,5]

The resistance against undesired tooth movements in orthodontics is called anchorage and controlling the anchorage is important for the success of orthodontic treatment, and the bone-supported devices used for this purpose are mini screws.^[6,7]

John Hunter, a Scottish surgeon, introduced the idea of implanting human teeth in the 1700s. Gainsforth and Higley (1945) provided the earliest documentation of the skeletal anchorage concept when they suggested the possibility of orthodontic anchorage to the basal bone by distalizing a maxillary canine tooth by placing Vitallium screws in the ramus of a dog. However, the use of force led to the loss of the screws within 16 to 31 days.^[8,9]

Reviewing the literature in the relevant field is a very important step in scientific studies. When the literature is searched manually, it is not possible to conduct a comprehensive review, or such a search takes a very long time. On the other hand, automatic searches of the literature do not enable in-depth semantic search.^[10,11]

The Latent Dirichlet Allocation (LDA) Algorithm is a probabilistic topic modelling method. The model generates topics from a set of documents based on word weight. The basis of LDA is that topics have a probability distribution over words, and text documents have a probability distribution over topics. Each topic has a distribution over the word sequence. For each document, it has a working principle that randomly assigns topics to the words in the document.^[12-15]

MATERIAL AND METHODS

In this study, the use of miniscrews providing skeletal anchorage in orthodontic treatments before and after the year 2000 was analyzed with the LAD algorithm.

In the pre-2000 period, when the subject modelling analysis was examined, a structure focusing on orthodontic treatment, growth, and bone structures was seen. While words such as “treatment,” “implant,” “wire,” “maxillary,” “orthodontic,” “bone,” “force,” “movement,” “anchorage,” and “periodontal,” come to the fore, topics such as titanium implants, stainless steel wires, and osseointegration attract attention. Words such as “titanium,” “endosseous,” “stainless steel,” “osseointegrated,” “inserted,” and “placed” show the importance of the materials used in orthodontic appliances in this period. In addition, the presence of words such as “friction,” “force,” “anchorage,” “expansion,” “movement,” and “extraction” reveals that orthodontic treatment techniques were the focus. In general, the materials used in orthodontic treatments, tooth movements, and growth processes seem to be more important in this period.

Topic 1: Orthodontic Treatment Processes and Appliance Use

Topic 2: Dental Implants and Osseointegration

Topic 3: Orthodontic Braces and Friction Mechanisms

Topic 4: Upper and Lower Jaw Movements

Topic 5: Tooth Movements and Anchoring Mechanisms

In the post-2000 period, significant changes were observed in orthodontic treatment approaches. Words such as “molar,” “bone,” “treatment,” “retraction,” “force,” “implant,” “skeletal,” “movement,” “anchorage,” “cortical,” “appliance,” “miniscrews,” and “surgical” come to the fore, and the use of skeletally supported systems, miniscrews and cortical bone is more emphasized. The words “finite,” “miniscrews,” “cortical,” “stability,” “screw,” “palatal,” “device,” and “surgical,” indicate the increased use of more invasive and advanced technologies in orthodontic treatments. During this period, words such as “distalization,” “intrusion,” “retraction,” “movement,” “loss,” “stability,” “significant,” and “maximum” became more prominent, indicating that more specific and mechanically controlled movements gained importance in orthodontic treatments. In general, it is seen that after 2000, orthodontic treatment approaches were supported by more advanced engineering techniques and new technologies such as mini screws and cortical bone support were more widely used.

Topic 1: Molar Tooth Movements and Anchorage Systems

Topic 2: Bone Density and Implant Stability

Topic 3: Orthodontic Treatment Mechanics and Skeletal Supported Movements

Topic 4: Miniscrews and Retrospective Orthodontic Movements

Topic 5: Force Distribution and Computer Aided Analysis

DISCUSSION

Table 1 shows the data before 2000 and Table 2 shows the data after 2000. As in Table 3, the period before 2000 can be evaluated as a period focusing more on material sciences and basic tooth movements in orthodontic treatments, while the post-2000 period stands out as a period in which the use of miniscrews, cortical assisted movements and surgically assisted treatment techniques gained importance. As in Table 3, the period before 2000 can be evaluated as a period focusing more on material sciences and basic tooth movements in orthodontic treatments, while the post-2000 period stands out as a period in which the use of miniscrews, cortical-assisted movements, and surgically assisted treatment techniques gained importance. With the impact of new technologies, more mechanical and engineering principles have started to be used in orthodontic treatments, which has led to significant changes in treatment methods. In particular, miniscrews, skeletal-assisted movements, finite element analysis, and surgically assisted orthodontics have become more popular, indicating that more controlled and stable treatment approaches have been adopted.

CONCLUSION

The evolution of orthodontic anchorage techniques over the years highlights the significant advancements in both materials and treatment methodologies. Before 2000, orthodontic approaches focused primarily on basic tooth movement mechanics, material sciences, and traditional anchorage systems, such as stainless steel wires. However, post-2000, a paradigm shift occurred with the integration of miniscrews, skeletal anchorage, and surgically assisted treatments, allowing for more controlled and stable orthodontic movements. The application of computational tools like finite element analysis has further enhanced precision in force distribution and treatment planning. This transition demonstrates the increasing reliance on engineering principles and innovative technologies to improve orthodontic outcomes, ensuring greater efficiency and patient comfort. As research continues, further developments in anchorage techniques are expected to refine and optimize orthodontic treatment strategies.