The present study aims to compare the efficacy of Twin Block (Removable) and Herbst (Fixed) functional appliances in treating Class II Division 1 malocclusion. The former is a removable appliance, while the latter is a fixed orthodontic appliance attached to the molars using metal bands (Moro et al., 2020). Malocclusion is characterized by a forward positioning of the upper jaw relative to the lower jaw and an overbite (Orthodontic.org, 2021). Malocclusion, or the misalignment of teeth, is a common condition among children and adolescents that can lead to significant issues with chewing, speaking, and even breathing. In some cases, fixed or removable appliances can correct the malocclusion and realign the teeth. One of the most common malocclusion issues is Class II division one, in which the lower teeth are either in a retruded position or the upper teeth are in a protruded position. To treat Class II division 1 malocclusion, two common types of appliances, fixed and removable, are used. Fixed appliances, such as the Herbst, are bonded to the teeth and are meant to be worn all the time. Removable appliances, such as the Twin Block, are designed to be taken in and out of the mouth and can be adjusted as needed. This dissertation aims to compare the efficacy of the Twin Block and the Herbst appliances in treating Class II division 1 malocclusion. Both appliances have advantages and disadvantages, and this research aims to determine which type of appliance is most effective in treating this common condition. The results of this study will provide valuable insight into the best treatment options for Class II division 1 malocclusion.
Orthodontic history and treatment and changes over the years
The history of orthodontic treatment dates back to the ancient Egyptians and Greeks, who used metal bands and wires to help straighten teeth. As the years progressed, so did the technology and materials used for orthodontic treatment. Since then, advances in orthodontic treatments have continued to be made.
In the 1990s, mini-screws were introduced to provide additional anchorage for orthodontic treatment. With these screws, orthodontists can now apply more force to the lower jaw and prevent relapse of the malocclusion. This has enabled faster and more reliable treatment with fewer side effects. In the 2000s, technological advances led to the development of clear braces and aligners, which are now widely used in orthodontic treatment (Tolessa, 2020). These braces and aligners are aesthetically pleasing and much more comfortable than traditional metal braces. In addition, they allow orthodontists to customize the treatment plan for each patient and provide a more efficient and effective treatment.
The oral health of patients with Class II malocclusion is particularly interesting due to the potential risks associated with the condition. Periodontitis, a gum disease, is one of the most common problems associated with Class II malocclusion. It is characterized by inflammation of the tissue and bone around the teeth, resulting in damage to the teeth and loosening of the gums. This can lead to pain, bleeding gums, and tooth loss. Orthodontic treatment is typically the first step in improving oral health for those with Class II malocclusion. The use of fixed and removable appliances can help to correct the misalignment of the teeth, as well as improve overall oral health. Twin Block and Herbst are the most common appliances used to treat Class II malocclusion.
The Twin Block appliance is a removable brace comprised of two connected plates worn to move the lower jaw forward. The Herbst appliance is a fixed appliance used to correct jaw discrepancies by anchoring the lower jaw to the upper jaw. Both appliances are effective in treating Class II malocclusion and improving oral health. However, they differ in cost, comfort, and ease of use. Research has shown that the Twin Block appliance is more economical, more comfortable to wear, and easier to use than the Herbst appliance. Therefore, it may be a better option for patients with Class II malocclusion seeking a more cost-effective and comfortable treatment.
Malocclusion and Angle’s classifications (not too detailed, but outlining the differences between Class I, Class II division 1, and class II division 2 and III).
Malocclusion is a misalignment or incorrect relationship between the upper and lower teeth when the jaws are closed. The severity of malocclusion is classified according to Angle’s Classification System of malocclusion, which is the most widely accepted and used system (Germanò et al., 2019). Class I malocclusion is the most common type of malocclusion. It is characterized by the maxilla and mandible being in normal relationship to each other, with both the maxillary and mandibular teeth occluding normally. The overjet and overbite are within normal limits.
Class II division 1 malocclusion is characterized by a mandibular retrusion and maxillary protrusion, resulting in a deep overbite and an increased overjet. The molar relationship is usually a class II relationship, where the molar relationship of the maxilla is ahead of the mandible. A mandibular retrusion also characterizes class II division 2 malocclusion, but there is a maxillary retrusion instead of a maxillary protrusion. This results in a shallow overbite and a decreased or normal overjet (Germanò et al., 2019). The molar relationship is usually a class II relationship, where the molar relationship of the maxilla is ahead of the mandible.
Class III malocclusion is characterized by a mandibular protrusion and maxillary retrusion, resulting in a decreased overbite and overjet. The molar relationship is usually a class III relationship, where the molar relationship of the mandible is ahead of the maxilla. In the case of Class II division 1 malocclusion, treatment often involves using a fixed or removable functional appliance. Twin block (removable) and Herbst (fixed) are two such appliances commonly used to treat this type of malocclusion (Ling, 2020). The goal of this dissertation is to compare the efficacy of these two appliances in the treatment of Class II division 1 malocclusion.
Class II Division I malocclusion
Class II Division I malocclusion is a common condition in orthodontic patients, characterized by a discrepancy between the size of the upper and lower dental arches and/or jaws. This condition is usually caused by an excessive overjet, defined as the horizontal distance between the maxillary and mandibular incisors. It is also known as “buck teeth” or “protrusive maxillary incisors.” The severity of the malocclusion can range from mild to severe, depending on the degree of discrepancy between the upper and lower dental arches and jaws (Ling, 2020). In mild cases, the maxillary incisors may protrude slightly, while in more severe cases, the maxillary incisors may protrude significantly, and the mandibular incisors may be retruded.
The primary goal of treatment for Class II Division I malocclusion is to reduce the overjet and correct the malocclusion. This can be achieved through orthodontic braces, functional appliances, and surgical treatment. The most common type of functional appliance used to treat Class II Division I malocclusion is the Twin Block, a removable appliance (Ling, 2020). The Twin Block and Herbst appliances are commonly used to treat Class II Division I malocclusion. The Twin Block uses a combination of forces to guide the mandible into a more forward position, which helps to reduce the overjet and correct the malocclusion. The Herbst appliance is a fixed appliance that applies a constant downward force to the mandible, guiding the jaw into a more forward position and reducing the overjet (Ling, 2020). Ultimately, the choice of the appliance to treat Class II Division I malocclusion will depend on the severity of the malocclusion and the patient’s and orthodontist’s preferences. The removable Twin Block appliance may be the best option for mild cases, while the fixed Herbst appliance may be the best option for more severe cases.
Fixed functional appliances to treat class II Division I malocclusion.
In the 19th century, Edward Angle developed the first standard classification system for malocclusions, which is still used today (Carvalho et al., 2018). He also improved the technology used for orthodontic treatment by introducing the first archwire and bracket.
Fixed functional appliances are orthodontic devices used to correct the malocclusion of the teeth. They work by repositioning the teeth, jawbone, and muscles, improving dental arch alignment and facial appearance. Fixed functional appliances are commonly used to treat Class II Division 1 malocclusion, characterized by a mandibular retrusion and an excessive overjet of the maxillary incisors. Using fixed functional appliances to treat this malocclusion can result in improved facial symmetry, a better smile, and improved oral health (Ghaffar et al., 2022). This appliance is usually worn for up to one year, and during this time, the patient must maintain good oral hygiene and wear the appliance as instructed by the orthodontist. To treat a Class II Division I malocclusion, a patient must have teeth that do not meet or align correctly.
Fixed functional appliances can be used to correct Class II Division 1 malocclusion, but they do have some drawbacks. They require a commitment to wearing the appliance for the duration of the treatment, and they can cause discomfort and speech impediments. Additionally, they may not be suitable for every patient and have been shown to be less effective in patients with severe malocclusions (Siva, 2021). Fixed functional appliances are popular for treating Class II Division 1 malocclusion. They can effectively correct this malocclusion but can also cause discomfort and speech impediments (Abi, 2020). Discussing all options with an orthodontist is important to determine the best treatment plan for each individual.
Fixed functional appliances correct Class II division 1 malocclusion, characterized by an excessive overjet and a deep bite. Fixed functional appliances aim to reduce the overjet and correct the anterior-posterior and vertical discrepancies in the occlusal relationship. In addition, these appliances can be used to encourage the development of a more normal occlusal relationship and the correction of skeletal discrepancies (Abi, 2020). By encouraging the growth of the lower jaw forward, the appliance can also help promote a more favorable facial profile. Lastly, fixed functional appliances aim to reduce the need for further orthodontic treatment.
When selecting a fixed functional appliance for treating Class II division 1 malocclusion, several critical criteria must be considered:
- The appliance should provide optimal treatment outcomes, such as improved dental alignment, overbite and overjet reduction, and increased facial aesthetics.
- The appliance should be comfortable for the patient, with minimal adverse effects, such as speech and mastication difficulties.
- The appliance should be cost-effective and have a reasonable treatment duration.
- The appliance should be easy for both the patient and the clinician.
Various fixed functional appliances exist, including the Herbst and Twin Block, and each has its advantages and disadvantages. The Herbst appliance is simple and cost-effective, providing a constant force to the mandible and resulting in a rapid improvement in skeletal and dental changes, with minimal patient compliance required (Abi, 2020). The Twin Block has a more excellent range of force applications due to its removable nature. It can correct the dentoalveolar and skeletal components of Class II division 1 malocclusion. However, its removable nature increases the risk of patient noncompliance, and its treatment duration is generally longer than other fixed functional appliances (Abi, 2020). Therefore, the clinician must consider each appliance’s advantages and disadvantages before selecting the most appropriate one for the patient.
When it comes to using removable appliances to treat Class II Division 1 malocclusion, there are several potential risks associated with their use. Firstly, the patient may be at risk of developing soft tissue irritation due to the pressure applied by the appliance against the inside of the cheeks and lips. This can cause discomfort and difficulty with eating and speaking. Secondly, the appliance must be taken out for eating and cleaning, and the patient must be diligent in ensuring they wear the appliance for the prescribed amount of time each day (Abi, 2020). If they do not, the treatment may fail to be effective. Another potential risk with removable appliances is that the patient may not be compliant with the treatment. This can occur due to discomfort or lack of motivation, and is a common reason why removable appliances are not successful in treating Class II Division 1 malocclusion. The patient must be willing to follow the instructions provided by the orthodontist for the treatment to be successful.
Finally, the patient may be at risk of developing gingival irritation due to the pressure of the appliance against the gums. This can lead to inflammation and discomfort, and should be monitored by the orthodontist. In conclusion, there are several risks associated with the use of removable appliances to treat Class II Division 1 malocclusion. These include soft tissue irritation, lack of patient compliance, and gingival irritation (Abi, 2020). Therefore, it is important for the patient to be aware of these risks prior to beginning treatment, and for the orthodontist to monitor these issues during the course of treatment.
The Herbst appliance consists of a metal framework custom-made to fit the patient’s teeth and a metal joint that connects the upper and lower parts of the appliance, which controls the movement of the lower jaw (Moro et al., 2020). It is worn 24 hours daily, generally well-tolerated by patients, and highly effective in correcting malocclusion by guiding the lower jaw into the correct position (Orthodontic.org, 2021). The treatment with the Herbst appliance is usually divided into two phases, with the appliance worn continuously for 6-12 months in the first phase, the active phase of treatment (Moro et al., 2020).
The Herbst appliance, developed by Emil Herbst early twentieth century, marked the beginning of the modern era of fixed functional appliances. This appliance was designed to correct Class II malocclusions in growing patients, and it was the first to move both the upper and lower jaws simultaneously (Carvalho et al., 2018). Although it was re-popularised by Hans Pancherz in the early twentieth century, the Herbst appliance was difficult to install and had limitations in its ability to control the lower jaw and prevent relapse of the malocclusion.
The Herbst appliance is a fixed functional appliance attached to the braces. It consists of a metal framework custom-made to fit the patient’s teeth. The metal joint that connects the upper and lower parts of the appliance is a crucial component of the Herbst appliance (Moro, A. et al. 2020). This joint helps to control the movement of the lower jaw, which is the main issue that needs to be addressed in Class II malocclusion. By encouraging the forward growth of the lower jaw, the Herbst appliance helps to correct the malocclusion, thereby improving the bite and jaw alignment.
The Herbst appliance is highly effective in treating Class II malocclusion as it guides the lower jaw, allowing it to grow into the correct position. It also helps to distribute the forces of biting and chewing evenly across the jaw, reducing the pressure on individual teeth and the risk of further damage (Orthodontic.org, 2021). Furthermore, the Herbst appliance is designed to be worn 24 hours daily. It is generally well-tolerated by patients, making it an ideal choice for individuals looking for an effective and convenient way to correct their malocclusion.
The treatment with the Herbst appliance is usually divided into two phases to ensure optimal results and a successful correction of Class II malocclusion. The appliance is worn continuously for 6-12 months in the first phase (Bishara et al. 2000). This is the active phase of treatment, where the Herbst appliance controls the movement of the lower jaw and encourages the forward growth of the jaw into the correct position. This period of continuous wear is crucial to achieving the desired correction and is why the Herbst appliance is popular among orthodontic professionals.
The second phase of treatment with the Herbst appliance involves the patient wearing the appliance at night time only for 6-12 months. This phase is designed to maintain the correction achieved during the first phase, ensuring that the lower jaw remains in the correct position. It is also a time for the patient to get used to the new jaw position and for the surrounding soft tissues to adapt to the changes. This phase of night-time wear is essential for ensuring long-lasting results and preventing malocclusion from reoccurring. Overall, the two-phase treatment with the Herbst appliance provides a comprehensive and effective solution for individuals seeking to correct Class II malocclusion.
The treatment time with the Herbst appliance is typically 12-24 months, making it a relatively short-term solution for correcting Class II malocclusion. However, it is important to note that this time frame can vary depending on several factors, such as the severity of the malocclusion and the patient’s compliance with the treatment plan (Orthodontic.org, 2021). In some cases, where the malocclusion is more severe, the treatment may take longer, while in other cases, where the patient is highly compliant and the malocclusion is mild, the treatment may be completed in a shorter time frame.
Patients need to understand that the length of treatment with the Herbst appliance will depend on their case and that the time frame provided is an estimate. Orthodontic professionals will assess the patient’s needs and provide a more accurate estimate of the treatment time based on their specific case. Patients are also encouraged to ask questions and raise any concerns regarding the treatment process and time frame to ensure they are fully informed and prepared for their journey towards a corrected bite and improved jaw alignment.
Removable functional appliances for treating Class II Division 1 malocclusion
Removable functional appliances are a popular option for treating Class II Division 1 malocclusion, as they offer a non-invasive and convenient solution for correcting bite and jaw alignment issues (Orthodontic.org, 2021). The main aim of these appliances is to encourage the forward growth of the lower jaw and reposition the upper jaw relative to the lower jaw, which helps to correct the malocclusion. This treatment is ideal for individuals looking for a less intrusive option than traditional orthodontic treatments such as braces.
Some of the most common types of removable functional appliances used to treat Class II Division 1 malocclusion include the Twin Block, the activator, and the MARA. These appliances work by applying gentle force to the jaw and teeth, which helps to guide the jaw and teeth into their correct positions r(Kim et al. 2005). The appliances are designed to be worn for specified periods each day. They are easy to remove, making them a convenient and practical option for individuals looking to correct their malocclusion (Moro A. et al., 2020). Furthermore, the removable functional appliances are typically well-tolerated by patients, making them a popular choice among orthodontic professionals and patients.
Twin Block (Removable)
The Twin Block is a popular type of removable functional appliance used to treat Class II Division 1 malocclusion. It is a non-invasive and convenient solution that is well-tolerated by patients and can be easily removed for eating and brushing.
The Twin Block appliance consists of two acrylic plates designed to fit over the upper and lower teeth. The plates are connected by a metal bar, which helps to control the lower jaw’s movement and encourages the lower jaw’s forward growth (Kim et al. 2005). The metal bar is a critical component of the appliance, providing the necessary force to reposition the jaw and teeth into their correct positions. The appliance is designed to be worn continuously, except when eating and brushing teeth, for 6-12 months. This duration can vary depending on the severity of the malocclusion and the patient’s case.
The Twin Block is a highly effective appliance for correcting Class II Division 1 malocclusion and has been used successfully by orthodontic professionals for many years. The removable nature of the appliance makes it a convenient option for patients, as they can remove it for eating and brushing, which can help reduce any discomfort or inconvenience associated with other orthodontic treatments (Orthodontic.org, 2021). Additionally, the Twin Block is typically well-tolerated by patients and is considered a safe and effective option for individuals looking to correct their malocclusion.
The treatment with the Twin Block appliance is usually divided into two phases. The first phase is a crucial stage of the treatment, during which the appliance is worn continuously for a period of 6-12 months (Day & Lander 2007). This continuous wear allows the appliance to work effectively in controlling the lower jaw’s movement and encouraging the lower jaw’s forward growth. The appliance applies gentle pressure to the jaw, which helps to reposition the jaw and teeth into their correct positions, resulting in a corrected Class II Division 1 malocclusion.
In the second phase, the patient must wear the appliance at night for 6-12 months to maintain the correction. This phase is important to ensure that the correction is stable and that the lower jaw does not revert to its original position. The patient will typically only need to wear the appliance at night, which can help reduce any discomfort or inconvenience associated with continuous wear. The total treatment time with the Twin Block appliance is typically 12-24 months, and this time frame can vary depending on the severity of the malocclusion and the patient’s case (Moro, A. et al. 2020). However, the patient must adhere to the treatment plan and wear the appliance as directed by their orthodontic professional to ensure the best outcome.
The time frame for treatment with the Twin Block appliance can vary depending on several factors, including the extent of the malocclusion and the patient’s level of cooperation with the treatment plan. On average, most patients wear the Twin Block for 12-24 months, but this can be extended or shortened depending on the individual’s needs and progress. The goal of the treatment is to correct the bite and align the jaws properly, and the length of treatment will be determined by the amount of time needed to achieve these results (Day & Lander 2007). Consistently wearing the appliance as directed and following the recommended treatment plan is crucial for ensuring a successful outcome and reducing the overall treatment time.
In conclusion, the Herbst and Twin Block appliances are two of the most commonly used orthodontic devices for treating Class II Division 1 malocclusion. The main goal of these appliances is to realign the bite and position of the jaws in a manner that promotes a proper and functional bite. They work by guiding the growth of the lower jaw forward and repositioning the upper jaw about the lower jaw, which helps to correct the overbite and improve the overall alignment of the jaws. Both appliances are highly effective in treating Class II Division 1 malocclusion and have been used with great success by orthodontic professionals worldwide. The choice between the Herbst and Twin Block will depend on various factors, including the patient’s needs and the orthodontist’s recommendations. Regardless of the specific appliance chosen, the ultimate goal is to achieve a straight, healthy, and functional bite.
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