5dd MCQs 242 Orthodontic Prof. Mom Sovannrithy 2019

If there is a lot of root resorption, it is important to stop activating the appliance for a period of 6 to 8 weeks. This allows the teeth and roots to rest and recover from the excessive force. Additionally, using a lighter force to move the teeth can help prevent further root resorption and minimize any potential damage. Continuing to apply heavy force or giving medicine may worsen the root resorption and lead to further complications.

In class II division 1 malocclusion, the overjet is increased, which means that the upper front teeth are positioned more forward than the lower front teeth. This can result in a protrusion of the upper front teeth.

In Class II division 1 malocclusion, the overjet is increased. Overjet refers to the horizontal distance between the upper and lower incisors. In this type of malocclusion, the upper front teeth are positioned significantly forward in relation to the lower front teeth, resulting in an increased overjet. This can lead to an overbite and a protrusive appearance of the upper teeth.

The correct answer is "Average". In Class I malocclusion, the upper teeth slightly overlap the lower teeth. This is considered the most common and mild form of malocclusion, where the bite is relatively normal but there may be slight misalignment or crowding of the teeth. The terms "Increase", "Decrease", and "Severe" do not accurately describe Class I malocclusion.

The correct answer is 2-4 degrees. This is the most likely skeletal pattern for ANB normal because it falls within the range of 2-4 degrees, which is considered to be the normal range for this measurement. ANB is a cephalometric measurement used to assess the relationship between the maxilla and the mandible, and a value of 2-4 degrees indicates a balanced skeletal relationship between the two jaws.

The skeletal feature of Class III is when the maxillary (upper jaw) is short or small in relation to the mandible (lower jaw) which is broad. This means that the lower jaw appears larger and more prominent compared to the upper jaw, causing an underbite or a protrusion of the lower teeth. This is a characteristic feature of Class III malocclusion, where the lower jaw is positioned more forward than the upper jaw.

Premature contact or pseudo class III is the cause of anterior cross bite. This refers to a situation where the upper teeth are positioned behind the lower teeth when the jaws are closed. This can occur due to premature contact between the upper and lower teeth, causing an incorrect bite relationship. It can also be caused by a misalignment of the jaws, leading to a pseudo class III malocclusion.

The clinical feature of tongue thrust is the proclination (forward positioning) of the anterior teeth in both arches. This means that the front teeth are pushed forward, causing them to be misaligned and protrude. This can lead to issues with the bite, such as reduced overjet (horizontal overlap of the front teeth), anterior crossbite (misalignment of the upper and lower front teeth), and crowding (lack of space for the teeth to properly align).

Orthodontic treatment of crowding often involves the extraction of teeth. Crowding occurs when there is not enough space in the jaw for all the teeth to properly align. By removing one or more teeth, the orthodontist can create more space and allow the remaining teeth to be properly aligned. Extraction is a common and effective method for addressing crowding and achieving a straighter smile.

The correct answer is 2-4 degrees. This suggests that the ANB angle, which measures the relationship between the upper and lower jaws, is within the normal range. A deviation from this range could indicate a malocclusion or misalignment of the jaws.

The best method to create space is extraction. This involves removing one or more teeth to create room for the remaining teeth to align properly. Extraction is commonly used in orthodontic treatments when there is severe crowding or misalignment of the teeth. By removing the necessary teeth, the orthodontist can create enough space for the remaining teeth to be properly aligned and improve the overall appearance and function of the mouth.

The clinical feature of Class II division 1 is characterized by proclined upper incisors. This means that the upper front teeth are inclined or tilted forward, creating an overbite. This is a common feature seen in individuals with Class II division 1 malocclusion, where the upper teeth are positioned further forward than the lower teeth. This can contribute to an increased overjet (horizontal distance between the upper and lower incisors) and a reduced ANB angle (a measurement used to assess the relationship between the upper and lower jaws). Anterior crossbite may also be present, but it is not the specific clinical feature mentioned in the question.

A space maintainer is used to keep space in the early loss of deciduous teeth. When a deciduous tooth is lost prematurely, a space maintainer is placed to prevent the adjacent teeth from shifting and closing the gap. This helps to ensure that there is enough space for the permanent tooth to erupt properly.

The function of a fixed appliance is to allow three-dimensional control of teeth. This means that the appliance is able to move the teeth in various directions, including up and down, side to side, and forward and backward. Unlike other types of appliances, such as removable ones, fixed appliances are not attached to the teeth and can be removed by the patient. The force applied by fixed appliances is typically generated by the muscles and bones in the mouth.

Fixed appliances, such as braces, offer the advantage of allowing multiple tooth movements to be done simultaneously. This means that various teeth can be adjusted and aligned at the same time, which can result in a more efficient and timely treatment process. The other statements provided are not correct for the advantage of fixed appliances.

The auxiliaries' component in a fixed appliance is the power chain. A power chain is a series of elastic or rubber bands that are used to connect the brackets and apply continuous pressure on the teeth. This helps in closing gaps or aligning the teeth properly. Brackets are the small metal or ceramic attachments that are bonded to the teeth, while wires are used to apply pressure and move the teeth. Molar bend is a specific type of wire bend used in orthodontics.

The most likely clinical feature of the given signs is bimaxillary protrusion. This is indicated by the girl's complaint of her front teeth sticking out in both arches, along with incompetent lips and a more convex facial profile. Bimaxillary protrusion refers to the protrusion of both the upper and lower jaws, causing the front teeth to be pushed forward.

The correct answer is to select only patients with good oral hygiene for orthodontic treatment. This is because orthodontic treatment involves the use of braces or other appliances that can make it difficult to maintain proper oral hygiene. Patients with poor oral hygiene may be at a higher risk for developing tooth decay, gum disease, or other oral health issues during treatment. Therefore, it is important to ensure that patients have good oral hygiene habits before starting orthodontic treatment to minimize the risk of complications.

The first premolar is the correct answer for extraction in cases of canine mesially inclined eruption. When a canine tooth is mesially inclined, it means that it is positioned too far towards the midline of the mouth. In such cases, the first premolar is often extracted to create space for the proper eruption and alignment of the canine tooth. Removing the first premolar allows the canine to move into its correct position and prevents any potential crowding or misalignment of the surrounding teeth.

A posterior crossbite occurs when the upper teeth are positioned inside the lower teeth. To correct this, a removable appliance with screw expansion and an anterior bite plane can be used. The screw expansion helps to widen the upper jaw, allowing the upper teeth to align properly with the lower teeth. The anterior bite plane helps to correct the bite relationship between the upper and lower teeth. This combination of appliances helps to correct the posterior crossbite and achieve proper alignment of the teeth. Orthognathic surgery may also be an option for severe cases, but it is not mentioned as the correct answer in this case. A retainer and Class II twin block are not typically used to correct a posterior crossbite.

In class II division 2 malocclusion, the lower facial height (LFH) may be short. This means that the distance between the chin and the base of the nose is shorter than average. This can contribute to a more closed or retruded bite, where the upper front teeth overlap the lower front teeth significantly. The short LFH can affect the overall facial profile and may require orthodontic treatment to correct the malocclusion.

Scissors bite refers to a condition where the upper teeth are placed completely inside the lower teeth when the jaws are closed. This is a dental malocclusion where the upper teeth overlap the lower teeth in a scissor-like manner. It is different from a cross bite, deep bite, or open bite, which all involve misalignments of the teeth but in different ways.

The correct answer is 0.7 mm. This size of wire is being used to make Adam clasp.

Premature contact of deciduous posterior teeth refers to the situation where the back teeth in the baby teeth or primary dentition come into contact before the front teeth. This can lead to a condition known as pseudo class III malocclusion. In this malocclusion, the lower jaw appears to be positioned further forward than the upper jaw, giving the appearance of an underbite. This is different from a true class III malocclusion where the lower jaw is actually positioned further forward. Premature contact of deciduous posterior teeth can cause the lower jaw to shift forward, leading to the development of a pseudo class III malocclusion.

Central Line Shifting refers to the condition when the midline of the upper and lower teeth is not aligned. This misalignment can occur due to various factors such as dental crowding or spacing. Therefore, when the midline of the upper and lower teeth is not in a straight line, it is referred to as Central Line Shifting.

The most likely Overjet (OJ) of Class III malocclusion would be "Upper incisors are Proclined OJ." This means that the upper incisors are tilted forward (proclined) and there is an overjet present, indicating that the upper front teeth are positioned in front of the lower front teeth. This is a common characteristic of Class III malocclusion, where the lower jaw is protruded or the upper jaw is retruded, causing the upper incisors to be proclined and creating an increased overjet.

The vertical plane is used to find overbite. Overbite refers to the vertical overlap of the upper and lower front teeth when the jaws are closed. By examining the vertical relationship between the upper and lower teeth, the vertical plane can help determine the extent of overbite.

Based on the given information, the most likely extraction for this case would be the 4 teeth of 1st premolars. This is because the girl has front teeth that are sticking out in both arches, along with incompetent lips and a more convex facial profile. Extracting the 1st premolars can help create space and allow for proper alignment of the front teeth, improving the overall appearance and function of the girl's teeth and facial profile.

The clinical feature of an anterior open bite is a long face. This means that the patient's face appears elongated, possibly due to the excessive vertical growth of the maxilla or mandible. This can result in a lack of overlap between the upper and lower front teeth, causing an open space between them when the patient bites down. Lips competency refers to the ability to close the lips together at rest, which may or may not be affected in cases of anterior open bite. Deep bite and cross bite are not typically associated with anterior open bite.

When the incisal edge of the lower incisors touches the palate, it is referred to as a traumatic bite. This occurs when there is an abnormal contact between the lower teeth and the palate, causing potential damage or trauma to the teeth and surrounding structures. This condition can lead to various dental problems and may require orthodontic or dental treatment to correct.

The keys of angle's classification are used to determine the relationship between the upper and lower molars. This classification system is based on the relationship between the mesiobuccal cusp of the upper first molar and the buccal groove of the lower first molar. It helps in categorizing dental occlusions and guiding treatment plans.

In class II div 2 malocclusion, the upper incisors are retroclined. This means that they are inclined towards the back of the mouth. This is a common characteristic of this type of malocclusion, where the upper front teeth are positioned further back than normal. Retroclined upper incisors can contribute to an overbite and an imbalanced bite relationship between the upper and lower teeth.

Anterior cross bite is a dental condition where the upper front teeth are positioned behind the lower front teeth when biting down. Skeletal III refers to a class III malocclusion, also known as an underbite, where the lower jaw is protruding or positioned further forward than the upper jaw. This skeletal discrepancy can contribute to the development of an anterior cross bite. Therefore, the presence of a skeletal III feature indicates the possibility of observing an anterior cross bite.

The given correct answer is "Normal". In class I malocclusion refers to a dental condition where the upper teeth slightly overlap the lower teeth. Overjet, on the other hand, is the horizontal distance between the upper and lower front teeth. In a normal class I malocclusion, the overjet is within the normal range, meaning the upper teeth slightly overlap the lower teeth in a normal manner. Therefore, the overjet in class I malocclusion is considered normal.

The correct answer is "OJ increase with Proclined front teeth." In Class II division 1 malocclusion, the overjet (OJ) increases due to the proclination (forward positioning) of the front teeth. This means that the upper front teeth are positioned more forward than the lower front teeth, causing an increased horizontal overlap. This is a common clinical feature of Class II division 1 malocclusion.

Class II division 1 malocclusion is the correct answer because it is a dental condition characterized by the upper front teeth being positioned further forward than the lower front teeth, resulting in an overbite. This condition can cause the lips to appear incompetent, meaning they are unable to fully close or seal properly. The other options, cross bite, long upper lips, and retroclined front teeth, do not specifically relate to the incompetence of the lips.

Extraction is considered the best treatment for crowding because it involves removing one or more teeth to create space and align the remaining teeth properly. This allows for better alignment and prevents further crowding or overlapping of teeth. Other options like closing space, derotation, or proclined upper incisors may not effectively address the issue of crowding and may not provide long-term stability. Extraction is a common and effective treatment approach for crowding, especially in cases where the crowding is severe.

A removable appliance is designed to move teeth in a specific direction. Tipping movements refer to the movement of the tooth in which the apex (tip) of the tooth moves towards the direction of the force applied. This is the most likely movement for a removable appliance as it allows for controlled and predictable tooth movement. Bodily movements involve the entire tooth moving in a parallel manner, which is less likely with a removable appliance. Intrusion refers to the movement of the tooth towards the jawbone, while extrusion refers to the movement of the tooth away from the jawbone, both of which are less likely with a removable appliance.

In Class II division 2 malocclusion, the upper central incisors are more likely to be retroclined, meaning they are tilted towards the back of the mouth. Additionally, the overjet (OJ) is reduced, which refers to the horizontal distance between the upper and lower incisors. This reduction in overjet indicates that the upper incisors are positioned closer to the lower incisors than they should be. This combination of retroclined upper central incisors and reduced overjet is a common clinical feature of Class II division 2 malocclusion.

In class II division 1 malocclusion, the most common feature is an increased overjet. This means that the upper front teeth protrude significantly forward in relation to the lower front teeth. This malocclusion is often characterized by a retruded lower jaw and can result in an anterior open bite, where the upper and lower front teeth do not touch when the back teeth are closed together.

In cases of open bite, the FMA angle may increase. This is because open bite is a condition where there is a lack of vertical overlap between the upper and lower teeth, causing a gap or opening between them. The FMA angle refers to the angle between the Frankfort horizontal plane (a line connecting the external ear canal and the lower margin of the eye socket) and the mandibular plane (a line connecting the lower border of the chin and the lower border of the jaw). In open bite cases, the mandible may rotate clockwise, resulting in an increase in the FMA angle.

The main objective of class II division 1 treatment is to align and retract the upper labial segment. This means that the focus of the treatment is on correcting the alignment and positioning of the upper front teeth. This is important for improving the overall appearance and function of the teeth and jaws.

There are two types of deep bite: skeletal deep bite and dental deep bite. Skeletal deep bite is characterized by a vertical overlap of the upper and lower front teeth due to a discrepancy in the jaw size and position. Dental deep bite, on the other hand, occurs when the upper front teeth excessively cover the lower front teeth due to an over-eruption of the upper teeth or a lack of eruption of the lower teeth.

A removable appliance with Z or T spring can correct an anterior cross bite. This type of appliance applies pressure to the teeth in order to move them into the correct position and align the bite. The Z or T spring design allows for targeted and controlled movement of the teeth, making it effective in correcting an anterior cross bite.

Malocclusion refers to the misalignment of teeth, which can occur due to various factors. One of the main causes of malocclusion is abnormalities in the teeth themselves. This can include overcrowding, uneven spacing, or irregular positioning of the teeth. These abnormalities can result in an improper bite and misalignment of the jaw. Other factors such as abnormal bone growth, abnormal lips, and abnormal tongue posture can also contribute to malocclusion, but the primary cause is the abnormality of the teeth.

Deep bite is a malocclusion where there is excessive vertical overlapping of the upper and lower anterior teeth. In this condition, the upper front teeth cover more than 40% of the lower front teeth when the bite is closed. This can lead to problems with chewing, speech, and esthetics. It may also cause wear and damage to the teeth and gums. Treatment for deep bite may involve orthodontic intervention, such as braces or clear aligners, to correct the alignment of the teeth and improve the bite.

Separators are orthodontic devices used to create space between teeth by breaking the interdental contact. They are typically placed before the placement of braces or other orthodontic appliances to make room for the attachment of brackets. By breaking the interdental contact, separators allow for the proper alignment and positioning of teeth during orthodontic treatment.

The correct answer is "It is a retentive component." This suggests that the Adam clasp is a component that is used to retain or hold something in place. It does not specify what exactly the Adam clasp is used for or how it functions, but it implies that it is a component with a retaining or holding function.

The second bend order refers to the bending of the tip of a fishing rod while casting. It is a measure of the flexibility and responsiveness of the rod. When the rod has a higher second bend order, it means that the tip of the rod bends more easily and has a greater degree of flexibility. This can be beneficial for casting lighter lures or for casting with greater accuracy and control.

When the lower incisor edges lie anterior to the cingulum plateau of the upper, it indicates a Class III malocclusion. In Class III malocclusion, the lower jaw is positioned more forward than the upper jaw, causing the lower incisors to protrude in front of the upper incisors. This is also known as an underbite. Class I refers to a normal occlusion where the teeth are properly aligned, while Class II div 1 and Class II div 2 refer to different types of overbites where the upper teeth protrude over the lower teeth.

Closing space is the best treatment for spacing between teeth. This involves moving the teeth closer together to eliminate the gaps. It can be achieved through various orthodontic techniques such as braces or aligners. Closing space is preferred over extraction because it preserves the natural teeth and maintains a harmonious balance in the dental arch. Derotation and proclined upper incisors are not relevant to treating spacing between teeth.

Spacing is the most common reason for making a crown bridge. This refers to the gaps or spaces between teeth, which can occur due to various reasons such as missing teeth or natural gaps in the dental arch. A crown bridge is a dental restoration that is used to fill in these spaces and improve the appearance and functionality of the teeth. By placing a crown bridge, the gaps can be closed and the patient can achieve a more aesthetically pleasing smile.

In class II div 2 malocclusion, the overjet is decreased and the front teeth are retroclined. This means that the upper front teeth are positioned further back than normal, causing a decreased horizontal overlap between the upper and lower front teeth. This can result in a deep bite and a more retruded appearance of the upper front teeth.

In case of class II division 1 malocclusion, the clinical features include an increased overjet, incomplete overbite, and incompetent lips. This means that the upper front teeth are positioned further forward than the lower front teeth, resulting in a larger horizontal gap between them (overjet). The overbite is not fully overlapping, and the lips are unable to close properly due to the malocclusion.

A clinical feature of class II division 2 malocclusion is a deep bite. This means that the upper front teeth significantly overlap the lower front teeth when biting down. This type of malocclusion is characterized by a retroclined upper central incisor and an excessive overbite. It is often associated with a narrow upper dental arch and a deep curve of Spee.

An open bite refers to a condition where the upper and lower teeth do not come together properly when the mouth is closed. This can result in a visible gap between the upper and lower teeth. It can be caused by various factors such as thumb sucking, tongue thrusting, or skeletal discrepancies. In contrast, a cross bite occurs when the upper teeth are positioned inside the lower teeth, a scissor bite refers to a misalignment of the dental arches, and a deep bite is when the upper front teeth excessively overlap the lower front teeth.

A unilateral cross bite occurs when the maxillary (upper) back teeth are positioned inside the mandibular (lower) teeth on only one side of the mouth. This misalignment can cause difficulty in chewing and can lead to uneven wear of the teeth. It is different from a bilateral cross bite, which occurs when the maxillary back teeth are positioned inside the mandibular teeth on both sides of the mouth. An anterior cross bite refers to a misalignment of the front teeth, while a deep bite refers to excessive overlap of the upper and lower teeth.

There are two types of posterior cross bite. A posterior cross bite occurs when the upper teeth are positioned inside the lower teeth. The two types are unilateral posterior cross bite, which occurs on one side of the mouth, and bilateral posterior cross bite, which occurs on both sides of the mouth.

Heavy force can cause root resorption. When excessive pressure is applied to the teeth, it can lead to the breakdown and destruction of the root structure. This can occur during orthodontic treatment, where the application of heavy force can cause the roots to be reabsorbed. This can result in the shortening of the roots and potential tooth loss if not addressed. Therefore, heavy force is a potential cause of root resorption.

The correct answer is "Concave facial profile." Class III malocclusion refers to a condition where the lower jaw protrudes forward, causing the lower teeth to overlap the upper teeth. This results in a concave facial profile, where the chin appears to be more prominent. Other clinical features of Class III malocclusion may include an increase in the overjet (horizontal distance between the upper and lower front teeth) and a shorter mandible (lower jaw). These features contribute to the characteristic appearance of Class III malocclusion.

Reverse overjet is the correct clinical feature of anterior cross bite. Anterior cross bite refers to a condition where the upper front teeth are positioned behind the lower front teeth when the jaws are closed. Reverse overjet specifically describes the horizontal overlap of the upper and lower front teeth, where the upper teeth are positioned behind the lower teeth. This can lead to functional and aesthetic issues, such as difficulty in biting and chewing, speech problems, and an unbalanced smile. Therefore, reverse overjet is a characteristic feature of anterior cross bite.

A simple anterior cross bite refers to a condition where the upper front teeth sit behind the lower front teeth when the jaws are closed. In this case, a lower incline bite plane can be used to correct the cross bite. The lower incline bite plane helps to reposition the lower jaw and bring the lower teeth forward, allowing them to align properly with the upper teeth. By using a lower incline bite plane, the cross bite can be corrected and the teeth can be aligned in the correct position.

The correct answer is "Appliance not worn full-time and Traumatic occlusion." Abnormal tooth mobility can occur when an orthodontic appliance, such as braces, is not worn full-time as instructed. This can lead to inadequate tooth movement and instability. Traumatic occlusion, or a misalignment of the teeth when they come together, can also cause abnormal tooth mobility. Both factors contribute to the instability of the teeth and can result in increased mobility.

A retainer is a dental appliance that is used to maintain the position of teeth after orthodontic treatment. It is not designed to correct anterior cross bite, which is a misalignment of the upper and lower front teeth. Retainers primarily prevent the teeth from shifting back to their original position. On the other hand, removable appliances with Z or T springs, ice cream sticks/tongue pressure, and fixed appliances are all commonly used to correct anterior cross bite by applying pressure to the teeth and guiding them into the correct position.

A labial bow can be used as a retention component in orthodontics. It is a wire that is placed on the labial surface of the teeth and helps to maintain the position of the teeth after orthodontic treatment. The labial bow applies gentle pressure to the teeth, preventing them from shifting back to their original position. It is commonly used in cases where there is a risk of relapse or to stabilize the final tooth position. The other options, T-spring, Robert retractor, and finger spring, do not serve the same purpose as a labial bow in retention.

Malocclusion refers to the irregularities in the alignment of teeth. It can include various conditions such as overcrowding, crooked teeth, overbite, underbite, or crossbite. These irregularities can cause difficulties in chewing, speaking, and maintaining oral hygiene. Treatment for malocclusion may involve orthodontic procedures such as braces or retainers to correct the alignment of teeth and improve oral function and appearance.

Increased lower facial height cases are a correct example of a contraindication for a bite plane. A bite plane is a dental appliance that is used to treat deep bite cases by opening the bite and reducing the contact between the upper and lower teeth. However, in cases of increased lower facial height, using a bite plane can further increase the vertical dimension of the face, leading to an unbalanced facial appearance. Therefore, it is not recommended to use a bite plane in these cases.

Class II div1 malocclusion is the most likely to cause a fracture of the front teeth. This malocclusion is characterized by the upper front teeth protruding significantly over the lower front teeth, creating an overbite. This overbite can lead to increased stress and pressure on the front teeth, making them more susceptible to fractures or other damage. Class I malocclusion refers to a normal bite, while Class II div.2 and Class III malocclusions involve different types of misalignment that are less likely to result in front tooth fractures.

The more likely diagnosis for the girl's issue of crooked and crossbite front teeth is crowding. Crowding refers to a condition where there is insufficient space in the dental arch to accommodate all the teeth properly, leading to misalignment and overlapping of teeth. This can result in crooked teeth and crossbite, where the upper and lower teeth do not align correctly when biting down. The presence of crowding suggests that the girl's dental arch is not large enough to accommodate all her teeth, leading to the misalignment observed.

A lower incline bite plane is the best treatment for a simple anterior cross bite because it helps correct the misalignment of the upper and lower teeth. By using a lower incline bite plane, the lower jaw is encouraged to move forward, allowing the upper teeth to properly align with the lower teeth. This treatment option is less invasive and less costly compared to orthognathic surgery, which is typically reserved for more severe cases. Fixed appliances and functional appliances may also be used in some cases, but a lower incline bite plane is often the preferred choice for simple anterior cross bite.

A labial bow can be used as a retention component in orthodontics. It is a type of wire that is placed on the labial (front) surface of the teeth and helps to maintain the position of the teeth after orthodontic treatment. The labial bow applies gentle pressure to the teeth, preventing them from shifting back to their original position. It is commonly used in removable orthodontic appliances such as retainers. The other options listed (T-spring, Z-spring, Robert retractor) are not typically used for retention purposes.

In class II division 2 malocclusion, the FMPA angle may be reduced. This is because class II division 2 malocclusion is characterized by a retruded mandible and an increased overbite. The FMPA angle measures the relationship between the maxillary and mandibular planes, and a reduced angle indicates a more retruded mandible. Therefore, in this malocclusion, the FMPA angle is likely to be reduced.

The correct statement for bodily movement is that the root and crown move in the same direction. This means that when there is movement in the crown of a tooth, there will also be movement in the root of the same tooth, and they will both move in the same direction. This is an important concept to understand in orthodontics and dental treatment planning, as it helps to determine the desired movement and alignment of teeth.

The correct answer is that the arch wire exerts force to the teeth through the bracket. Arch wires are an important component of orthodontic treatment as they apply pressure to the teeth, helping to align them into the desired position. The force exerted by the arch wire is transmitted to the teeth through the brackets, which are bonded to the teeth. This force is what enables the movement and alignment of the teeth during orthodontic treatment.

Anterior teeth are the front teeth in the mouth, including the incisors. A crossbite occurs when the upper teeth are positioned inside the lower teeth when biting down. Class III malocclusion refers to a condition where the lower jaw is protruded or the upper jaw is retruded, causing the lower teeth to be in front of the upper teeth. This misalignment of the jaws can lead to a crossbite in the anterior teeth. Therefore, the most likely mixed malocclusion associated with anterior teeth being crossbite is Class III.

A very high tongue in the roof of the mouth can cause a wide upper arch and narrow lower arch. When the tongue is positioned too high, it can push against the roof of the mouth, causing it to expand and become wider. At the same time, the pressure from the tongue can restrict the growth and development of the lower arch, leading to a narrower shape. This can result in an imbalance in the size and shape of the upper and lower dental arches, causing issues such as crossbite, crowding, and a median diastema.

In the case of an open bite, the lower facial height (LFH) may increase. An open bite is a dental condition where there is a gap between the upper and lower teeth when the mouth is closed. This can lead to an increase in the lower facial height as the lower jaw may be forced to extend further downwards to compensate for the lack of contact between the upper and lower teeth. This increased lower facial height can affect the overall facial appearance and alignment of the jaws.

In class II division 2 malocclusion, the upper front teeth are significantly protruded and the lower front teeth are inclined backward. This creates a difficult situation for closing space because the position and alignment of the teeth make it challenging to move them into the desired position. Therefore, closing space in class II division 2 malocclusion is considered difficult.

When a lower incisor tooth is traumatized and ends up in the palate, it is referred to as a traumatic bite. This occurs when there is a forceful impact or injury to the tooth, causing it to dislodge and move into an abnormal position. This can result in pain, discomfort, and difficulty in biting and chewing. The other options, open bite, excessive overbite, and deep bite, do not specifically describe the situation of a lower incisor tooth being displaced into the palate.

Abnormal tooth mobility is caused by abnormal resorption of the root, such as in periodontal disease. Periodontal disease is a condition that affects the supporting structures of the teeth, including the gums and bones. When the root of a tooth is affected by abnormal resorption, it can lead to the loosening and mobility of the tooth. This can result in discomfort, difficulty chewing, and potential tooth loss if left untreated.

The clinical feature of an open bite is characterized by the absence of vertical overlapping between the upper and lower teeth. In other words, there is a gap between the upper and lower anterior teeth when the patient bites down. This condition can lead to difficulties in biting, chewing, and speaking, and may require orthodontic treatment to correct.

Tilting movement refers to the movement of the root in the opposite direction of the crown. This means that when the crown of a tooth is tilted in one direction, the root will move in the opposite direction. This movement is important for proper tooth alignment and stability.

The best tooth movement in orthodontic treatment is achieved through gentle force. This is because applying excessive force can lead to tissue damage and discomfort for the patient. Gentle force allows for a controlled and gradual movement of the teeth, minimizing the risk of complications and ensuring a more comfortable experience for the patient. Additionally, using gentle force over a longer duration of time is preferred over short durations, as it allows for better stability and long-term results.

The correct statement for removable appliance is "Tiping movement". This means that the appliance allows for tilting or tipping movements of the teeth. It suggests that the appliance can be adjusted to apply pressure on specific areas of the teeth to achieve desired movement. The other statements are not correct as they are either not applicable or contradictory.

Rectangular and round wires are commonly used in fixed appliances because they provide stability and strength. Rectangular wires are often used for added control and torque, while round wires are used for general alignment and movement. The combination of these two types of wires allows for effective and efficient functioning of fixed appliances.

The most likely Over jet of Class II division1 malocclusion is when the upper incisors are proclined and the overjet is greater than 4mm. This means that the upper front teeth are positioned too far forward in relation to the lower teeth, resulting in a significant horizontal gap between the upper and lower incisors. This is a common characteristic of Class II division 1 malocclusion, where the upper jaw is protruded and the lower jaw is retruded.

When the lower incisor edges occlude into the cingulum plateau of the upper incisors, it indicates a Class I occlusion. In Class I occlusion, the upper and lower teeth are properly aligned, with the upper incisors slightly overlapping the lower incisors. This is the ideal occlusion where the teeth fit together correctly and there is no malocclusion present.

Crowding or anterior cross bite is more likely for orthodontic treatment because both conditions involve misalignment of the teeth. Crowding occurs when there is not enough space in the mouth for all the teeth to fit properly, resulting in overlapping or crooked teeth. Anterior cross bite, on the other hand, refers to a misalignment of the upper and lower front teeth, where the lower teeth are positioned in front of the upper teeth when the bite is closed. Both conditions can cause functional and aesthetic issues, and orthodontic treatment is often necessary to correct them.

The clinical dental feature of Class III malocclusion is characterized by a decreased or reversed overjet. This means that the lower front teeth are positioned more forward than the upper front teeth, causing the lower jaw to protrude. This can result in a crossbite and an improper bite alignment. Other features of Class III malocclusion may include a broad upper arch with crowding and bimaxillary protrusion.

The correct components for reducing OJ (overjet) are the Robert retractor and the Bucal canin retractor. These instruments are commonly used in orthodontics to help adjust the position of the teeth and correct overjet issues. The Z-spring and T-spring mentioned are not typically used for reducing OJ, so they are not the correct components for this purpose.

Extruding molars is necessary in deep bite cases when the Lower Facial Height (LFH) reduces. This means that the distance between the nose and chin decreases. By extruding the molars, the vertical dimension of the bite can be increased, helping to correct the deep bite.

Coffin spring is a possible component for correcting posterior cross bite. It is a type of orthodontic spring that is used to expand the upper arch and correct a posterior cross bite. By applying gentle pressure, the coffin spring helps to widen the upper jaw and align the upper and lower teeth properly. This correction can improve the bite and overall alignment of the teeth, leading to better oral health and function.

Cross bite refers to a condition where the upper and lower teeth do not align properly when the jaws are closed. This misalignment can lead to asymmetrical development of the jaw. When the jaw grows unevenly, it can cause various problems such as difficulty in chewing, speaking, and even breathing. Therefore, it is important to correct cross bite immediately to prevent further complications and promote proper jaw development.

In open bite cases, the FMPA (Functional Mandibular Plane Angle) may be increased. This means that the angle between the functional mandibular plane (a line connecting the condylion and gonion) and the cranial base (a line connecting sella and nasion) is larger than normal. This increased angle indicates a more posteriorly positioned mandible, which can contribute to the open bite condition where the upper and lower teeth do not properly meet when the mouth is closed.

Severe rotation is a condition that requires long-term retention because it involves the misalignment of teeth, where a tooth is rotated or twisted in its position. In order to correct this condition, orthodontic treatment is required, which often involves braces or other appliances. After the treatment, the teeth need to be retained in their corrected positions for a prolonged period of time to prevent them from shifting back to their original rotated positions. This is why severe rotation requires long-term retention.