This document discusses different types of crowding in the mixed dentition, including simple crowding caused by tooth size-arch length discrepancies and complex crowding caused by additional skeletal or functional factors. It describes methods for measuring arch length and predicting sizes of unerupted teeth to diagnose crowding. Treatment options are provided for different severities of crowding, including space maintenance appliances and orthodontic intervention.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Orthodontic tooth movements and biomechanics.Sk Aziz Ikbal
The document discusses biomechanics principles related to orthodontic tooth movement. It covers topics such as:
- Forces applied to teeth can cause movement through bone remodeling.
- Biomechanics refers to mechanics applied to biological systems. Knowledge of forces is needed to control orthodontic treatment.
- Teeth can move through light forces during normal function but heavier sustained forces over 1 second are needed for orthodontic tooth movement.
- Forces have magnitude and direction, while scalars only have magnitude. Resultant forces and moments from multiple applied forces are calculated.
- Different force systems and moment-to-force ratios produce different types of tooth movement such as tipping, translation, rotation, and torque.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The document discusses different methods of maxillary arch expansion in orthodontics, including slow expansion and rapid maxillary expansion. Slow expansion uses lighter forces over a longer period and can involve dental or skeletal changes. Rapid expansion applies greater force to separate the mid-palatal suture more quickly, but risks relapse. A variety of fixed and removable appliances are described for delivering expansion forces, including quad helix, W-arch, nickel-titanium wires, and expansion screws. The effects, indications, contraindications, and risks of both rapid and slow expansion techniques are compared.
Transient malocclusions are self-correcting developmental variations that occur during dental development. In the pre-dentate period, infants have a retrognathic mandible that corrects over time. In the primary dentition, children commonly have an anterior open bite, deep anterior bite, spacing between teeth, and an edge-to-edge anterior bite that self-correct. In the mixed dentition, a deep bite and crowding are common but resolve with time. The permanent dentition may show increased overjet and overbite during transition that lessen without treatment.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Orthodontic tooth movements and biomechanics.Sk Aziz Ikbal
The document discusses biomechanics principles related to orthodontic tooth movement. It covers topics such as:
- Forces applied to teeth can cause movement through bone remodeling.
- Biomechanics refers to mechanics applied to biological systems. Knowledge of forces is needed to control orthodontic treatment.
- Teeth can move through light forces during normal function but heavier sustained forces over 1 second are needed for orthodontic tooth movement.
- Forces have magnitude and direction, while scalars only have magnitude. Resultant forces and moments from multiple applied forces are calculated.
- Different force systems and moment-to-force ratios produce different types of tooth movement such as tipping, translation, rotation, and torque.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
The document discusses different methods of maxillary arch expansion in orthodontics, including slow expansion and rapid maxillary expansion. Slow expansion uses lighter forces over a longer period and can involve dental or skeletal changes. Rapid expansion applies greater force to separate the mid-palatal suture more quickly, but risks relapse. A variety of fixed and removable appliances are described for delivering expansion forces, including quad helix, W-arch, nickel-titanium wires, and expansion screws. The effects, indications, contraindications, and risks of both rapid and slow expansion techniques are compared.
Transient malocclusions are self-correcting developmental variations that occur during dental development. In the pre-dentate period, infants have a retrognathic mandible that corrects over time. In the primary dentition, children commonly have an anterior open bite, deep anterior bite, spacing between teeth, and an edge-to-edge anterior bite that self-correct. In the mixed dentition, a deep bite and crowding are common but resolve with time. The permanent dentition may show increased overjet and overbite during transition that lessen without treatment.
Crossbite in orthodontics,its types and management with two casessalman zahid
A 9-year-old boy presented with an anterior crossbite of his upper right central incisor and a unilateral posterior crossbite on the right side. A removable appliance with jackscrews was used over 4 months to tip the upper right incisor labially and expand the constricted upper right posterior segment. This successfully corrected both the anterior and posterior crossbites. A retainer was worn long-term to maintain the correction.
This document provides an overview of twin block therapy. It discusses the history, philosophy, design, construction, and stages of treatment using twin blocks. Twin blocks are functional appliances composed of separate upper and lower bite blocks. They are worn 24 hours a day to achieve rapid correction of malocclusions through forces transmitted to inclined planes covering the posterior teeth. Treatment typically involves an initial active phase followed by a support phase to stabilize results.
This document provides information on banding instruments and procedures in pediatric dentistry. It discusses the history of bands, various band materials and sizes, advantages and disadvantages of bands, ideal band material requirements, instruments used for banding, and banding techniques. The key points are:
- Bands are thin metal rings placed on teeth, typically molars, to secure orthodontic appliances. Accurate band placement is important for fitting appliances.
- Stainless steel is commonly used due to properties like resistance to tarnish and springiness. Band sizes vary based on tooth type.
- Banding provides strong attachment but risks caries if cement seals fail. Autoclaving is the most reliable steril
This document discusses various fixed appliance techniques for maxillary arch expansion. It begins by classifying expansion appliances based on whether they are fixed or removable, and whether they provide rapid/orthopedic or slow/dentoalveolar expansion. It then describes several common fixed appliances for rapid and slow maxillary expansion, including tooth-borne appliances like Hyrax and tooth/tissue-borne appliances like Haas. The document discusses the effects of rapid maxillary expansion on the maxilla and mandible, as well as indications/contraindications and clinical management of rapid maxillary expansion. It concludes by mentioning bonded rapid palatal expanders as an alternative to banded appliances.
This document discusses adult orthodontics, including biological concepts, history, comparisons between adolescents and adults, objectives, classifications, adjunctive orthodontics, and comprehensive orthodontics. It covers topics like the periodontal ligament, bone, teeth, classifications of adult orthodontic treatment, objectives of treatment for adults, and procedures for adjunctive orthodontics including uprighting teeth, forced eruption, and aligning anterior teeth.
This article reviews different methods of maxillary expansion including rapid maxillary expansion (RME), slow maxillary expansion (SME), and surgically-assisted maxillary expansion. RME uses appliances like Haas or Hyrax expanders to apply heavy forces and separate the midpalatal suture quickly in 2-3 weeks. SME uses appliances like quad helix or coils to apply lighter, continuous forces over months. Surgically-assisted expansion is used when expansion is needed in older patients after suture closure. Maxillary expansion treats transverse deficiencies, crossbites, and improves nasal breathing. Complications can include discomfort, relapse, and tooth tipping.
This document provides information about nasoalveolar molding (NAM) for treating cleft lip and palate. It defines cleft lip and cleft palate, and describes presurgical NAM which reshapes the alveolar and nasal segments before surgical repair. The key steps of NAM include taking an impression, fabricating an acrylic molding plate with a nasal stent, inserting the plate and using tape for retention, and making weekly adjustments to reshape the tissues over 3-5 months before surgery. The goals of NAM are to decrease the cleft deformity and improve symmetry, with benefits such as reducing the need for future bone grafts or surgeries.
This document discusses the management of cross bites in dentistry. It defines cross bites as abnormal occlusions where one or more teeth are positioned lingually or labially in relation to opposing teeth. Cross bites can be classified as anterior, posterior, skeletal, dental or functional. Management depends on the dentition stage and includes techniques like occlusal grinding, arch expansion appliances, and orthodontic tools like elastics or springs. Expansion appliances discussed include quad helix, rapid palatal expander, and hybrid designs. Surgical correction may be used for severe cross bites. The goal is to properly diagnose the cross bite type and address it at early detection for best treatment outcomes.
The document discusses the Pendulum appliance, which is used for distalization of maxillary molars. It has a light construction and produces forces in an arc-like motion. The appliance consists of an acrylic button anchored in the palate and titanium springs extending to bands on the first molars. It can distalize molars by 5mm in 3-4 months with minimal anchorage loss. Modifications include versions that allow expansion or removable springs for extraoral activation to better control distalization.
Dr. Viken Sassouni developed a cephalometric analysis method based on craniofacial x-rays of 100 children. He identified planes, arcs, and points to analyze facial proportions and classify facial patterns. A well-proportioned face has four planes intersecting at point O and equal upper/lower anterior and posterior facial heights. Sassouni found most faces were Type II patterns. His analysis considered vertical and horizontal relationships and classified occlusions, palates, profiles, and dental axes. He concluded that "normal" is relative and proportions are more important than absolute measurements.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document discusses various methods and appliances for distalizing maxillary molars, including removable and fixed options. Removable appliances discussed include extraoral traction using headgear as well as removable appliances with finger springs or sliding jigs. Fixed appliances discussed include intramaxillary devices like Wilson's 3D appliance as well as intermaxillary appliances like Herbst or Jasper Jumper. Factors like the presence of second molars, skeletal pattern, and growth prognosis must be considered when determining whether molar distalization is indicated.
This document discusses the management of open bite malocclusions. It begins by defining open bite and classifying it as either skeletal or dental in nature. Skeletal open bite is caused by excessive vertical growth of the jaws while dental open bite is due to reduced incisor height. Common etiologies of open bite include thumb sucking habits, tongue thrusting, and abnormal skeletal growth patterns. The document outlines various treatment approaches for different open bite classifications and etiologies.
Functional development of dental arches and occlusion /certified fixed orth...Indian dental academy
The document discusses the development of dental occlusion from birth to adulthood. It summarizes that the process involves complex interactions between tooth morphology, muscle functions, bone growth, and forces. It then outlines the key factors that influence occlusion development in more detail, including: bone and tooth relationships, functional eruption, intraoral forces like from muscles and occlusal forces from opposing teeth. It notes that bone adapts to functional forces based on Wolff's law and discusses theories around how various factors guide the intricate process of dental occlusion development.
The lingual arch space maintainer is a passive bilateral mandibular appliance used to control tooth movement and arch perimeter after the loss of lower primary molars. It consists of bands on the first molars connected by a stainless steel wire. The wire is positioned to contact the lower incisors and rest on the gingiva of the molared and molar bands. It maintains the arch shape and leeway space until the permanent teeth erupt. Advantages include allowing eruption of permanents without interference and maintaining oral hygiene, while disadvantages include not preventing opposing tooth extrusion and potential for distortion.
This document discusses the role of genetics in orthodontics. It begins with an introduction to genetics and molecular biology concepts like DNA, genes, and chromosomes. It then discusses several important figures in the history of genetics research. The document outlines several dentofacial disturbances that have a genetic influence, like cleft lip and palate. It also discusses Butler's field theory and methods used to study the role of genes, such as twin studies and polymerase chain reaction. The conclusion reflects on how genetics research has enhanced understanding of the dentofacial complex and hopes that future innovations can help answer remaining questions.
The document discusses retention and relapse in orthodontics, defining retention as maintaining teeth in their corrected positions and relapse as the loss of correction. It examines various causes of relapse like periodontal ligament traction, abnormal growth patterns, lack of adequate stabilization, and muscular imbalances. The document also outlines different retention methods and factors to consider for proper retention planning to prevent teeth from relapsing back to their original maloccluded positions.
This document provides an overview of rapid maxillary expansion (RME) in orthodontics. It discusses the history of RME dating back to 1860. It also covers anatomy related to RME, including the midpalatal suture. Key topics covered include indications and contraindications for RME, types of expansion screws used, jackscrew turn schedules, and different types of RME appliances such as the Haas expander and Hyrax expander. The document is an educational resource on the clinical use and mechanics of RME.
Serial extraction of class i malocclusionMaherFouda1
This document provides information on serial extraction techniques for correcting Class I malocclusions. It defines serial extraction as the planned extraction of deciduous teeth and sometimes permanent teeth to encourage spontaneous correction of irregularities. The document discusses the historical development of serial extraction, pioneers who developed the concept, and Dewel's technique in particular. It outlines the rationale, indications, contraindications, and timing of extractions in the serial extraction process. The goal is to utilize growth and tooth movement principles to align teeth and reduce malocclusion without extensive orthodontic treatment.
This document discusses the early management of crowded lower incisors. It begins by outlining mixed dentition analysis, which is used to determine the amount of crowding by comparing space available versus space required. For slight crowding up to 4mm, disking of primary teeth is recommended as a conservative treatment. This involves stripping enamel from the primary canine to allow space for the permanent incisors to erupt. Moderate crowding from 4-7mm may require other interventions like removing primary teeth. Severe crowding over 7mm often necessitates orthodontic treatment.
Crossbite in orthodontics,its types and management with two casessalman zahid
A 9-year-old boy presented with an anterior crossbite of his upper right central incisor and a unilateral posterior crossbite on the right side. A removable appliance with jackscrews was used over 4 months to tip the upper right incisor labially and expand the constricted upper right posterior segment. This successfully corrected both the anterior and posterior crossbites. A retainer was worn long-term to maintain the correction.
This document provides an overview of twin block therapy. It discusses the history, philosophy, design, construction, and stages of treatment using twin blocks. Twin blocks are functional appliances composed of separate upper and lower bite blocks. They are worn 24 hours a day to achieve rapid correction of malocclusions through forces transmitted to inclined planes covering the posterior teeth. Treatment typically involves an initial active phase followed by a support phase to stabilize results.
This document provides information on banding instruments and procedures in pediatric dentistry. It discusses the history of bands, various band materials and sizes, advantages and disadvantages of bands, ideal band material requirements, instruments used for banding, and banding techniques. The key points are:
- Bands are thin metal rings placed on teeth, typically molars, to secure orthodontic appliances. Accurate band placement is important for fitting appliances.
- Stainless steel is commonly used due to properties like resistance to tarnish and springiness. Band sizes vary based on tooth type.
- Banding provides strong attachment but risks caries if cement seals fail. Autoclaving is the most reliable steril
This document discusses various fixed appliance techniques for maxillary arch expansion. It begins by classifying expansion appliances based on whether they are fixed or removable, and whether they provide rapid/orthopedic or slow/dentoalveolar expansion. It then describes several common fixed appliances for rapid and slow maxillary expansion, including tooth-borne appliances like Hyrax and tooth/tissue-borne appliances like Haas. The document discusses the effects of rapid maxillary expansion on the maxilla and mandible, as well as indications/contraindications and clinical management of rapid maxillary expansion. It concludes by mentioning bonded rapid palatal expanders as an alternative to banded appliances.
This document discusses adult orthodontics, including biological concepts, history, comparisons between adolescents and adults, objectives, classifications, adjunctive orthodontics, and comprehensive orthodontics. It covers topics like the periodontal ligament, bone, teeth, classifications of adult orthodontic treatment, objectives of treatment for adults, and procedures for adjunctive orthodontics including uprighting teeth, forced eruption, and aligning anterior teeth.
This article reviews different methods of maxillary expansion including rapid maxillary expansion (RME), slow maxillary expansion (SME), and surgically-assisted maxillary expansion. RME uses appliances like Haas or Hyrax expanders to apply heavy forces and separate the midpalatal suture quickly in 2-3 weeks. SME uses appliances like quad helix or coils to apply lighter, continuous forces over months. Surgically-assisted expansion is used when expansion is needed in older patients after suture closure. Maxillary expansion treats transverse deficiencies, crossbites, and improves nasal breathing. Complications can include discomfort, relapse, and tooth tipping.
This document provides information about nasoalveolar molding (NAM) for treating cleft lip and palate. It defines cleft lip and cleft palate, and describes presurgical NAM which reshapes the alveolar and nasal segments before surgical repair. The key steps of NAM include taking an impression, fabricating an acrylic molding plate with a nasal stent, inserting the plate and using tape for retention, and making weekly adjustments to reshape the tissues over 3-5 months before surgery. The goals of NAM are to decrease the cleft deformity and improve symmetry, with benefits such as reducing the need for future bone grafts or surgeries.
This document discusses the management of cross bites in dentistry. It defines cross bites as abnormal occlusions where one or more teeth are positioned lingually or labially in relation to opposing teeth. Cross bites can be classified as anterior, posterior, skeletal, dental or functional. Management depends on the dentition stage and includes techniques like occlusal grinding, arch expansion appliances, and orthodontic tools like elastics or springs. Expansion appliances discussed include quad helix, rapid palatal expander, and hybrid designs. Surgical correction may be used for severe cross bites. The goal is to properly diagnose the cross bite type and address it at early detection for best treatment outcomes.
The document discusses the Pendulum appliance, which is used for distalization of maxillary molars. It has a light construction and produces forces in an arc-like motion. The appliance consists of an acrylic button anchored in the palate and titanium springs extending to bands on the first molars. It can distalize molars by 5mm in 3-4 months with minimal anchorage loss. Modifications include versions that allow expansion or removable springs for extraoral activation to better control distalization.
Dr. Viken Sassouni developed a cephalometric analysis method based on craniofacial x-rays of 100 children. He identified planes, arcs, and points to analyze facial proportions and classify facial patterns. A well-proportioned face has four planes intersecting at point O and equal upper/lower anterior and posterior facial heights. Sassouni found most faces were Type II patterns. His analysis considered vertical and horizontal relationships and classified occlusions, palates, profiles, and dental axes. He concluded that "normal" is relative and proportions are more important than absolute measurements.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
This document discusses various methods and appliances for distalizing maxillary molars, including removable and fixed options. Removable appliances discussed include extraoral traction using headgear as well as removable appliances with finger springs or sliding jigs. Fixed appliances discussed include intramaxillary devices like Wilson's 3D appliance as well as intermaxillary appliances like Herbst or Jasper Jumper. Factors like the presence of second molars, skeletal pattern, and growth prognosis must be considered when determining whether molar distalization is indicated.
This document discusses the management of open bite malocclusions. It begins by defining open bite and classifying it as either skeletal or dental in nature. Skeletal open bite is caused by excessive vertical growth of the jaws while dental open bite is due to reduced incisor height. Common etiologies of open bite include thumb sucking habits, tongue thrusting, and abnormal skeletal growth patterns. The document outlines various treatment approaches for different open bite classifications and etiologies.
Functional development of dental arches and occlusion /certified fixed orth...Indian dental academy
The document discusses the development of dental occlusion from birth to adulthood. It summarizes that the process involves complex interactions between tooth morphology, muscle functions, bone growth, and forces. It then outlines the key factors that influence occlusion development in more detail, including: bone and tooth relationships, functional eruption, intraoral forces like from muscles and occlusal forces from opposing teeth. It notes that bone adapts to functional forces based on Wolff's law and discusses theories around how various factors guide the intricate process of dental occlusion development.
The lingual arch space maintainer is a passive bilateral mandibular appliance used to control tooth movement and arch perimeter after the loss of lower primary molars. It consists of bands on the first molars connected by a stainless steel wire. The wire is positioned to contact the lower incisors and rest on the gingiva of the molared and molar bands. It maintains the arch shape and leeway space until the permanent teeth erupt. Advantages include allowing eruption of permanents without interference and maintaining oral hygiene, while disadvantages include not preventing opposing tooth extrusion and potential for distortion.
This document discusses the role of genetics in orthodontics. It begins with an introduction to genetics and molecular biology concepts like DNA, genes, and chromosomes. It then discusses several important figures in the history of genetics research. The document outlines several dentofacial disturbances that have a genetic influence, like cleft lip and palate. It also discusses Butler's field theory and methods used to study the role of genes, such as twin studies and polymerase chain reaction. The conclusion reflects on how genetics research has enhanced understanding of the dentofacial complex and hopes that future innovations can help answer remaining questions.
The document discusses retention and relapse in orthodontics, defining retention as maintaining teeth in their corrected positions and relapse as the loss of correction. It examines various causes of relapse like periodontal ligament traction, abnormal growth patterns, lack of adequate stabilization, and muscular imbalances. The document also outlines different retention methods and factors to consider for proper retention planning to prevent teeth from relapsing back to their original maloccluded positions.
This document provides an overview of rapid maxillary expansion (RME) in orthodontics. It discusses the history of RME dating back to 1860. It also covers anatomy related to RME, including the midpalatal suture. Key topics covered include indications and contraindications for RME, types of expansion screws used, jackscrew turn schedules, and different types of RME appliances such as the Haas expander and Hyrax expander. The document is an educational resource on the clinical use and mechanics of RME.
Serial extraction of class i malocclusionMaherFouda1
This document provides information on serial extraction techniques for correcting Class I malocclusions. It defines serial extraction as the planned extraction of deciduous teeth and sometimes permanent teeth to encourage spontaneous correction of irregularities. The document discusses the historical development of serial extraction, pioneers who developed the concept, and Dewel's technique in particular. It outlines the rationale, indications, contraindications, and timing of extractions in the serial extraction process. The goal is to utilize growth and tooth movement principles to align teeth and reduce malocclusion without extensive orthodontic treatment.
This document discusses the early management of crowded lower incisors. It begins by outlining mixed dentition analysis, which is used to determine the amount of crowding by comparing space available versus space required. For slight crowding up to 4mm, disking of primary teeth is recommended as a conservative treatment. This involves stripping enamel from the primary canine to allow space for the permanent incisors to erupt. Moderate crowding from 4-7mm may require other interventions like removing primary teeth. Severe crowding over 7mm often necessitates orthodontic treatment.
This document discusses crowding in mixed dentition and various treatment options. It begins by explaining that crowding is a primary reason parents bring children to the dentist. For mild crowding under 4mm, a lower lingual arch or palatal holding arch can be used to prevent need for future orthodontics. Patients predicted to have over 5mm of crowding should be referred to an orthodontist. Space loss can be addressed through observation, disking primary teeth, extractions, or corrective orthodontics. The document discusses various space maintainers and appliances that can be used for different clinical scenarios to address crowding and space management in mixed dentition.
This document discusses types and treatment of deep bites. It describes skeletal vs dentoalveolar deep bites and factors that can cause acquired deep bites. The main treatment strategies discussed are extruding posterior teeth, flaring anterior teeth, and intruding incisors. Soft tissue considerations and their impact on treatment plan selection are also covered. Risks like apical root resorption from incisor intrusion are addressed.
This document summarizes guidelines for managing different types of space issues in children's dentition. It addresses transient crowding in the mixed dentition, localized space loss after tooth loss, and more severe crowding. Options discussed include space maintenance with removable appliances, gaining space through tooth tipping or expansion, and more complex treatment involving tooth movement or extractions. Ectopic eruption is also covered, outlining treatment approaches based on the degree of resorption and space availability.
Interceptive guidance of occlusion with emphasis on diagnosisNC Kolyaei
Serial extraction is an interceptive procedure used to correct hereditary tooth and jaw size discrepancies by extracting primary teeth. It is most effective for Class I malocclusions where the permanent teeth are in a favorable relationship. Careful monitoring of the eruption sequence is important during mixed dentition to identify issues and reduce future crowding through early intervention.
- The intra-oral examination assesses oral health, individual tooth positions, and inter-occlusal relationships. This, along with the extra-oral examination, allows for formulation of a treatment plan.
- Careful examination of the lower arch first is important, followed by the upper arch, as the lower arch often determines treatment for the upper. Tooth positions, crowding, rotations, and occlusal relationships are evaluated.
- Dental health is the most important factor, as active dental disease precludes orthodontic treatment due to risks of decalcification and accelerated bone loss during tooth movement. Treatment options depend on the degree of occlusal discrepancy and patient motivation/dental health.
This document compares and contrasts different approaches for treating congenitally missing lateral incisors: restorative, implant, and orthodontic. It outlines the orthodontic approach of canine substitution, noting the ideal malocclusion and canine traits. Extensive planning is advised to predict esthetic and functional outcomes and additional needed treatments. The implant approach uses a single tooth implant for a conservative option when adjacent teeth have no issues. While osseointegration and function are excellent, esthetics can be challenging. An interdisciplinary plan is usually needed to determine the best individualized approach.
This document discusses various methods for analyzing arch length and space in children during the transition from primary to permanent dentition. It describes common problems that can occur like premature loss of primary teeth leading to crowding or spacing issues. Five specific analysis methods are explained in detail: Nance analysis, Tanaka and Johnston analysis, Hixon and Oldfather method, Kaplan, Smith and Kenarkf method, and Moyer mixed-dentition analysis. Each method involves measuring tooth sizes on models and x-rays to determine predicted space needed and compare to actual available arch length.
Study models are essential records in orthodontics that provide a 3D representation of the teeth and occlusion. A study model has two parts - the anatomic portion showing the teeth and soft tissues, and the artistic portion which is the stone base. Models need to be trimmed accurately to reproduce the dental anatomy and occlusion. Various analyses like Carey's, Ashley Howe's and Bolton's can be done on study models to assess discrepancies and plan treatment. Mixed dentition analysis using Moyer's or Tanaka-Johnston method helps predict the size of unerupted teeth.
This document discusses incisor crowding in the mixed dentition. It provides background on normal spacing between primary teeth and how a lack of spacing can indicate crowding later on. It then discusses several solutions for replacing primary incisors, including normal spacing related to development, increased arch width, and distal repositioning of the mandibular canine. The document also discusses prevalence, etiology, methods for predicting crowding, and various treatment suggestions for managing crowding such as using a lingual arch or disking primary canines.
This document discusses serial extraction, which is an interceptive orthodontic procedure used to correct hereditary tooth-size discrepancies. It describes when serial extraction should be considered, between ages 6-12, and the criteria for determining if a patient is a suitable candidate. Ideal candidates have a Class I malocclusion with a true tooth-size discrepancy of 10mm or more. Contraindications include Class III maloccusions. A thorough examination and diagnostic records including radiographs and models are required to properly diagnose if serial extraction is appropriate.
This case report discusses the treatment of a patient with congenitally missing upper lateral incisors. There were two treatment options considered: opening the spaces for prosthetic replacement or closing the spaces via canine substitution. The parents chose to close the spaces orthodontically. Fixed appliances were used to retract the canines into the lateral incisor spaces and extract mandibular premolars to relieve crowding. After treatment, the canines were reshaped to resemble lateral incisors. The final result had a Class I occlusion and improved esthetics. The report evaluates considerations for treating missing lateral incisors cases.
Planning orthodontic treatment in the mixed dentition requires special considerations. Limited early treatment often requires a second phase, and anchorage control and retention are more difficult. Space management aims to prevent molar mesial drift and use leeway space, while molar correction may require headgear or distalization appliances. Severe localized space loss over 3mm or generalized deficiency over 4mm require complex appliances or extractions. Excess space like diastemas over 2mm are unlikely to close spontaneously. Eruption problems involving supernumeraries or delayed teeth may require exposure and traction to align properly.
The uses of orthodontic study models in DIAGNOSIS AND TREATMENT PLANNINGMaher Fouda
This document discusses various uses of orthodontic study models in diagnosis and treatment planning. It describes how study models can be used to assess tooth number, shape, size, position and space relationships. Specific analyses described include tooth size analysis, space analysis in mixed and permanent dentition, dental arch form, curve of Spee, and diagnostic setups. The document also discusses Howes' analysis and the Royal London space planning process for treatment planning.
CLASS 12th CHEMISTRY SOLID STATE ppt (Animated)eitps1506
Description:
Dive into the fascinating realm of solid-state physics with our meticulously crafted online PowerPoint presentation. This immersive educational resource offers a comprehensive exploration of the fundamental concepts, theories, and applications within the realm of solid-state physics.
From crystalline structures to semiconductor devices, this presentation delves into the intricate principles governing the behavior of solids, providing clear explanations and illustrative examples to enhance understanding. Whether you're a student delving into the subject for the first time or a seasoned researcher seeking to deepen your knowledge, our presentation offers valuable insights and in-depth analyses to cater to various levels of expertise.
Key topics covered include:
Crystal Structures: Unravel the mysteries of crystalline arrangements and their significance in determining material properties.
Band Theory: Explore the electronic band structure of solids and understand how it influences their conductive properties.
Semiconductor Physics: Delve into the behavior of semiconductors, including doping, carrier transport, and device applications.
Magnetic Properties: Investigate the magnetic behavior of solids, including ferromagnetism, antiferromagnetism, and ferrimagnetism.
Optical Properties: Examine the interaction of light with solids, including absorption, reflection, and transmission phenomena.
With visually engaging slides, informative content, and interactive elements, our online PowerPoint presentation serves as a valuable resource for students, educators, and enthusiasts alike, facilitating a deeper understanding of the captivating world of solid-state physics. Explore the intricacies of solid-state materials and unlock the secrets behind their remarkable properties with our comprehensive presentation.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
Mechanisms and Applications of Antiviral Neutralizing Antibodies - Creative B...Creative-Biolabs
Neutralizing antibodies, pivotal in immune defense, specifically bind and inhibit viral pathogens, thereby playing a crucial role in protecting against and mitigating infectious diseases. In this slide, we will introduce what antibodies and neutralizing antibodies are, the production and regulation of neutralizing antibodies, their mechanisms of action, classification and applications, as well as the challenges they face.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
SDSS1335+0728: The awakening of a ∼ 106M⊙ black hole⋆Sérgio Sacani
Context. The early-type galaxy SDSS J133519.91+072807.4 (hereafter SDSS1335+0728), which had exhibited no prior optical variations during the preceding two decades, began showing significant nuclear variability in the Zwicky Transient Facility (ZTF) alert stream from December 2019 (as ZTF19acnskyy). This variability behaviour, coupled with the host-galaxy properties, suggests that SDSS1335+0728 hosts a ∼ 106M⊙ black hole (BH) that is currently in the process of ‘turning on’. Aims. We present a multi-wavelength photometric analysis and spectroscopic follow-up performed with the aim of better understanding the origin of the nuclear variations detected in SDSS1335+0728. Methods. We used archival photometry (from WISE, 2MASS, SDSS, GALEX, eROSITA) and spectroscopic data (from SDSS and LAMOST) to study the state of SDSS1335+0728 prior to December 2019, and new observations from Swift, SOAR/Goodman, VLT/X-shooter, and Keck/LRIS taken after its turn-on to characterise its current state. We analysed the variability of SDSS1335+0728 in the X-ray/UV/optical/mid-infrared range, modelled its spectral energy distribution prior to and after December 2019, and studied the evolution of its UV/optical spectra. Results. From our multi-wavelength photometric analysis, we find that: (a) since 2021, the UV flux (from Swift/UVOT observations) is four times brighter than the flux reported by GALEX in 2004; (b) since June 2022, the mid-infrared flux has risen more than two times, and the W1−W2 WISE colour has become redder; and (c) since February 2024, the source has begun showing X-ray emission. From our spectroscopic follow-up, we see that (i) the narrow emission line ratios are now consistent with a more energetic ionising continuum; (ii) broad emission lines are not detected; and (iii) the [OIII] line increased its flux ∼ 3.6 years after the first ZTF alert, which implies a relatively compact narrow-line-emitting region. Conclusions. We conclude that the variations observed in SDSS1335+0728 could be either explained by a ∼ 106M⊙ AGN that is just turning on or by an exotic tidal disruption event (TDE). If the former is true, SDSS1335+0728 is one of the strongest cases of an AGNobserved in the process of activating. If the latter were found to be the case, it would correspond to the longest and faintest TDE ever observed (or another class of still unknown nuclear transient). Future observations of SDSS1335+0728 are crucial to further understand its behaviour. Key words. galaxies: active– accretion, accretion discs– galaxies: individual: SDSS J133519.91+072807.4
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
Microbial interaction
Microorganisms interacts with each other and can be physically associated with another organisms in a variety of ways.
One organism can be located on the surface of another organism as an ectobiont or located within another organism as endobiont.
Microbial interaction may be positive such as mutualism, proto-cooperation, commensalism or may be negative such as parasitism, predation or competition
Types of microbial interaction
Positive interaction: mutualism, proto-cooperation, commensalism
Negative interaction: Ammensalism (antagonism), parasitism, predation, competition
I. Mutualism:
It is defined as the relationship in which each organism in interaction gets benefits from association. It is an obligatory relationship in which mutualist and host are metabolically dependent on each other.
Mutualistic relationship is very specific where one member of association cannot be replaced by another species.
Mutualism require close physical contact between interacting organisms.
Relationship of mutualism allows organisms to exist in habitat that could not occupied by either species alone.
Mutualistic relationship between organisms allows them to act as a single organism.
Examples of mutualism:
i. Lichens:
Lichens are excellent example of mutualism.
They are the association of specific fungi and certain genus of algae. In lichen, fungal partner is called mycobiont and algal partner is called
II. Syntrophism:
It is an association in which the growth of one organism either depends on or improved by the substrate provided by another organism.
In syntrophism both organism in association gets benefits.
Compound A
Utilized by population 1
Compound B
Utilized by population 2
Compound C
utilized by both Population 1+2
Products
In this theoretical example of syntrophism, population 1 is able to utilize and metabolize compound A, forming compound B but cannot metabolize beyond compound B without co-operation of population 2. Population 2is unable to utilize compound A but it can metabolize compound B forming compound C. Then both population 1 and 2 are able to carry out metabolic reaction which leads to formation of end product that neither population could produce alone.
Examples of syntrophism:
i. Methanogenic ecosystem in sludge digester
Methane produced by methanogenic bacteria depends upon interspecies hydrogen transfer by other fermentative bacteria.
Anaerobic fermentative bacteria generate CO2 and H2 utilizing carbohydrates which is then utilized by methanogenic bacteria (Methanobacter) to produce methane.
ii. Lactobacillus arobinosus and Enterococcus faecalis:
In the minimal media, Lactobacillus arobinosus and Enterococcus faecalis are able to grow together but not alone.
The synergistic relationship between E. faecalis and L. arobinosus occurs in which E. faecalis require folic acid
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...Advanced-Concepts-Team
Presentation in the Science Coffee of the Advanced Concepts Team of the European Space Agency on the 07.06.2024.
Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
Abstract:
In this talk I will describe some recent ideas to find gravitational waves from supermassive black holes or of primordial origin by studying their secular effect on the orbital motion of the Moon or satellites that are laser ranged.
Immersive Learning That Works: Research Grounding and Paths ForwardLeonel Morgado
We will metaverse into the essence of immersive learning, into its three dimensions and conceptual models. This approach encompasses elements from teaching methodologies to social involvement, through organizational concerns and technologies. Challenging the perception of learning as knowledge transfer, we introduce a 'Uses, Practices & Strategies' model operationalized by the 'Immersive Learning Brain' and ‘Immersion Cube’ frameworks. This approach offers a comprehensive guide through the intricacies of immersive educational experiences and spotlighting research frontiers, along the immersion dimensions of system, narrative, and agency. Our discourse extends to stakeholders beyond the academic sphere, addressing the interests of technologists, instructional designers, and policymakers. We span various contexts, from formal education to organizational transformation to the new horizon of an AI-pervasive society. This keynote aims to unite the iLRN community in a collaborative journey towards a future where immersive learning research and practice coalesce, paving the way for innovative educational research and practice landscapes.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
2. Crowding can be classified into:
Simple crowding
Complex crowding
3. Simple Crowding
Definition: Simple crowding is defined as
disharmony between the size of the teeth and the
space available for them.
It is crowding uncomplicated by skeletal,
muscular, or occlusal functional features.
Simple crowding is most frequently associated
with a class I molar relationship, although it may
be found with class II horizontal type (maxillary
dental protraction and normal facial skeleton).
4. Complex Crowding
Definition: Complex crowding is crowding caused
and complicated by skeletal imbalance, abnormal
lip and tongue functioning, and/or occlusal
dysfunction as well as disharmony between the
sized of the teeth and the available space.
5. Signs of Arch Length
Deficiency
Children exhibit arch length deficiencies for two
general reasons:
(1) the arch length of some children is too small
to accommodate the size of the teeth; and
(2) a child may start with an adequate arch
length but may develop a deficient arch length
from a variety of environmental factors that affect
the dentition (e.g., caries or loss of teeth)
6. MEASUREMENT OF THE AVAILABLE
ARCH LENGTH IN THE MIXED DENTITION
Measure arch length segments from the buccal
and labial sides of the arch at the contact points
between the teeth
10. The main purpose of the mixed
dentition space analysis is to
differentiate patients with severely
crowded arches from those who have
up to as much as 4 mm of incisor
crowding but who still have enough
room in the entire arch, as a result of
leeway space, for successful eruption
of the permanent premolars and
canines and proper alignment of the
incisors.
11. These patients are excellent candidates for a
lower lingual arch or palatal holding arch.
Treatment of these patients with a lingual or
palatal arch provides them with an important
and beneficial service.
Intervention with these two preventive appliances
can eliminate the need for future orthodontic
treatment or simplify future orthodontic treatment.
12. Patients predicted to have crowding of 5 or more
mm in an arch should be referred to the
orthodontist.
This is also an important service to patients and
their parents.
Arch length deficiencies occur in the mixed
dentition for two reasons: (1) the arch length is
too small to accommodate the size of the teeth
and (2) arch length is lost because of local
causes.
13. When the deficiency results from an
imbalance between the size of the teeth
and the arch, primary canines are
prematurely exfoliated by the erupting
incisors and the distances between the
distal surfaces of the permanent lateral
incisors and mesial surfaces of the
primary first molars are small or
nonexistent.
15. In the early mixed dentition, the permanent
incisors and first molars are erupted.
16. The permanent canines and premolars
have not erupted.
Their mesial-distal widths can be
measured on periapical radiographs, but
the images are enlarged in comparison to
the true widths of the teeth.
17. Orthodontists have devised several methods of
predicting the size of the nonerupted canines and
premolars.
The prediction methods use three basic predictor
variables: (1) only erupted teeth, (2) only
measurements from radiographs, and (3) a
combination of variables 1 and 2.
All methods of prediction involve error. The error
of a prediction method is called its standard
error of estimate.
18.
19. Proportional Equation
Prediction Method
The late mixed dentition starts with the eruption
of one of the permanent canines or premolars.
If most of the canines and premolars are erupted
and if the nonerupted tooth or teeth are easily
measured on a periapical radiograph, an
alternative prediction method can be used.
The method corrects the radiographic
enlargement of a nonerupted tooth.
20. The mesial-distal widths of the nonerupted
tooth and an erupted tooth are measured on
the same periapical radiograph.
The mesial-distal width of the erupted tooth is
measured on a plaster cast.
These three measurements provide the elements
of a proportion that can be solved to obtain the
width of the non-erupted tooth on the cast.
21. A simple proportional relationship can be setup:
True width of primary molar
Apparent width of primary molar
True width of unerupted premolar
Apparent width of unerupted premolar
True width of primary molar
Apparent width of primary molar
True width of unerupted premolar
App width of
unerupted premolar
X
24. Tanaka and Johnston (1974) and Moyers
(1988) created non-radiographic
prediction methods by correlating the sum
of the widths of the lower permanent
incisors with the sum of the widths of the
lower premolars and canine on one side
of the arch.
25. There is a reasonably good correlation between
the size of the erupted permanent incisors and
the unerupted canines and premolars.
These data have been tabulated for white
American children by Moyers.
26. To utilize the Moyers prediction tables, the
mesiodistal width of the lower incisors is
measured and this number is used to predict the
size of both the lower and upper unerupted
canines and premolars.
The size of the lower incisors correlates better
with the size of the upper canines and premolars
than does the size of the upper incisors, because
upper lateral incisors are extremely variable
teeth.
28. Despite a tendency to overestimate the size of
unerupted teeth, accuracy with this method is
fairly good for the northern European white
children on whose data it is based.
No radiographs are required, and it can be used
for the upper or lower arch.
Tanaka and Johnston
Prediction Method
29. Tanaka and Johnston developed another way to
use the width of the lower incisors to predict the
size of unerupted canines and premolars.
For children from a European population group,
the method has a good accuracy despite a small
bias toward overestimating the unerupted tooth
sizes.
30. TANAKA JOHNSTON
PREDICTION VALUES
TANAKA AND JOHNSTON PREDICTION VALUES
One half of the
mesiodistal width of
the four lower
incisors
+10.5 mm =
+11.0 mm=
Estimated width of mandibular
canine and premolars in one
quadrant
Estimated width of maxillary
canine and premolars in one
quadrant
32. If the analysis predicts borderline crowding of
+2mm to −4mm in both arches of a Class I
patient, consider holding arch length with a
palatal (Nance) arch and a lower lingual
holding arch.
This intervention may prevent the need for future
orthodontic treatment, or at least reduce the
severity of the malocclusion.
33. If the analysis predicts severe crowding in excess of
−6 mm in one or both arches of a Class I patient,
holding arches are not needed.
In patients with crowding, primary canines may be
extracted in both upper and lower arches to allow the
permanent lateral incisors to erupt and to prevent the
erupting incisors from shifting to the right or left of the
facial midline.
The crowded malocclusion will require
comprehensive orthodontic treatment. These patients
may benefit from serial extraction treatment.
34. If the analysis predicts borderline crowding
between +2mm and −5mm in the lower arch of a
Class II patient, it is important to place a lower
lingual holding arch to preserve arch length.
If the lower holding arch allows the permanent teeth
mesial to the first molars to erupt, the eventual
treatment of a nonsurgical Class II malocclusion will
be simplified.
It should be clear that holding lower arch length per
se with an appliance will not correct the Class II
malocclusion.
35. If the analysis predicts severe crowding in
excess of −5mm in the lower arch of a Class II
patient, a lingual holding arch may still be
appropriate for the nonsurgical malocclusion.
These patients have a malocclusion that is very
difficult to treat, and they should be referred for
comprehensive orthodontic treatment.
36. If the analysis predicts borderline crowding of
+2mm to −5mm in the upper arch of a Class III
patient, it is important to place a palatal holding
arch to preserve arch length.
In these patients, extraction of premolars to
relieve upper arch crowding complicates
orthodontic treatment. Holding upper arch length
will not correct the Class III malocclusion but can
assist in the eventual treatment of a nonsurgical
malocclusion.
37. If the analysis predicts severe crowding in
excess of −6mm in the lower arch of a Class III
patient, a holding arch may be appropriate.
The arch length preserved by the holding arch
could enable an orthodontist to retract lower
anterior teeth in a nonsurgical Class III
malocclusion.
These patients should be referred for
comprehensive orthodontic treatment.
38. Crowding can be classified
as
Mild crowding – upto 1.5mm
Moderate crowding – 1.5 to 5mm
Severe crowding – 6 to 8 mm
39. Mild crowding can be treated by several
methods. Cases that require only a simple
tipping movement may often be treated with a
removable appliance such as a spring retainer
Moderate crowding may be treated with either
extraction or nonextraction of permanent teeth.
Severe crowding teeth would need to be
extracted to create adequate space.
40. Serial Extraction in Severely Crowded
Cases in the Mixed Dentition
When a patient is diagnosed with a Class I
malocclusion and a severe TSALD of 8 to 10 mm
or greater during the early mixed dentition, a
decision may be made by the orthodontist that
the patient would ultimately require extraction of
four premolars to allow space for the proper
alignment of the remaining teeth.
41. Crowding
The stepwise management of crowding involves the
following steps :
1.Observation
2.Disking of primary teeth
3.Extractions of overretained teeth/ rootpieces
etc.Serial extractions if crowding is severe.
4.Corrective orthodontic referral.
42. Observation
Clinical observation reveals that if the physiologic spaces
are between 2 -6mm there is a fifty percent chance that
the crowding will self resolve.
If the physiologic spaces are more than 6 mm then there will
be no crowding.
43. Transient Incisor liability occurs because the
mesiodistal dimentions of the permanent incisors
is much larger than the deciduous teeth.
45. CAUSES OF CROWDING IN MODERN DENTITIONS :
1.Inherited discrepancy between tooth size and jaw size
2.Increase in cross racial marriages
3.Change in dietary habits
4.Early loss of primary teeth
5.Over retained deciduous teeth.
46. Classification of Crowding
1.Premature tooth loss but no space loss
2.Localised crowding : less than 3 mm
3.Localised crowding : more than 3 mm
4.Moderate generalized crowding : less than 4 mm
5.Severe generalised crowding : 4 to 9 mm
6.Very severe generalised crowding : more than 10mm
47. Premature Tooth Loss With Adequate
Space: Space Maintenance
Early loss of a primary tooth presents a potential
alignment problem because drift of permanent or
other primary teeth is likely unless it is prevented.
Space maintenance is appropriate only when
adequate space is available and all unerupted
teeth are present and at the proper stage of
development.
If there is not enough space or if succedaneous
teeth are missing, space maintenance alone is
inadequate.
48. PREMATURE TOOTH LOSS BUT
ADEQUATE SPACE
1. Band & loop space maintainer
2. Partial denture space maintainer
3. Distal shoe space maintainer
4. Lingual arch space maintainer
5. Mild to moderate crowding of incisors with
adequate space.
49. Band and Loop Space
Maintainers
The band and loop is a unilateral fixed appliance
indicated for space maintenance in the posterior
segments
The simple cantilever design makes it ideal for
isolated unilateral space maintenance.
50.
51. Because the loop has limited strength, this appliance
must be restricted to holding the space of one tooth
and is not expected to accept functional forces of
chewing.
Although bonding a rigid or flexible wire across the
edentulous space has been advocated as an
alternative, this has not proved satisfactory clinically.
It also is no longer considered advisable to solder the
loop portion to a stainless steel crown because this
precludes simple appliance removal and
replacement.
Teeth with stainless steel crowns should be banded
like natural teeth
52. If a primary second molar has been lost, the band
can be placed on either the primary first molar or the
erupted permanent first molar.
Some clinicians prefer to band the primary tooth in
this situation because of the risk of decalcification
around any band, but primary first molars are
challenging to band because of their morphology,
which converges occlusally and makes band
retention difficult.
A more important consideration is the eruption
sequence of the succedaneous teeth.
53. The primary first molar should not be banded if
the first premolar is developing more rapidly than
the second premolar, because loss of the banded
abutment tooth would require replacement of the
appliance
54. Before eruption of the permanent incisors, if a
single primary molar has been lost bilaterally, a
pair of band and loop maintainers are
recommended instead of the lingual arch that
would be used if the patient were older.
This is advisable because the permanent incisor
tooth buds are lingual to the primary incisors and
often erupt lingually.
The bilateral band and loops enable the
permanent incisors to erupt without interference
from a lingual archwire
At a later time the two band-and-loop appliances
can be replaced with a single lingual arch if
necessary.
55. The partial denture is most useful for bilateral
posterior space maintenance when more than
one tooth has been lost per segment and the
permanent incisors have not yet erupted.
In these cases because of the length of the
edentulous pace band and loop space
maintainers are contraindicated and the lingual
position of the unerupted permanent incisors and
their likely lingual position at initial eruption make
the lingual arch a poor choice.
The partial denture also has the advantage of
replacing occlusal function.
56. Another indication for this appliance is
posterior space maintenance in
conjunction with replacement of missing
primary or delayed permanent incisors,
for esthetics.
Anterior space maintenance is
unnecessary because arch circumference
generally is not lost even if the teeth drift
and redistribute the space, so
replacement of missing anterior teeth is
done solely to improve appearance.
This has social advantages even for
young children.
57.
58.
59. Distal Shoe Space
Maintainers
The distal shoe is the appliance of choice
when a primary second molar is lost
before eruption of the permanent first
molar.
This appliance consists of a metal or
plastic guide plane along which the
permanent molar erupts.
The guide plane is attached to a fixed or
removable retaining device.
60.
61. When fixed, the distal shoe is usually retained
with a band instead of a stainless steel crown so
that it can be replaced by another type of space
maintainer after the permanent first molar erupts.
Unfortunately, this design limits the strength of
the appliance and provides no functional
replacement for the missing tooth.
If primary first and second molars are missing,
the appliance must be removable and the guide
plane is incorporated into a partial denture
because of the length of the edentulous span.
This type of appliance can provide some occlusal
function.
62. To be effective, the guide plane must
extend into the alveolar process so that it
contacts the permanent first molar
approximately l mm below the mesial
marginal ridge, at or before its emergence
from the bone.
An appliance of this type is tolerated well
by most children, but is contraindicated in
patients who are at risk for subacute
bacterial endocarditis or are immuno-
compromised, because complete
epithelialization around the intra-alveolar
portion has not been demonstrated.
63. Careful measurement and positioning are
necessary to ensure that the blade will
ultimately guide the permanent molar.
Faulty positioning is the most common
problem with this appliance
66. Measurement on the radiograph: The outline
of the distal shoe is designed on radiograph. The
mesio-distal length of the horizontal position of
the distal shoe should be as long as the
maximum width of the second primary molar and
vertical height should be about 1 mm under the
mesial contour of the unerupted first permanent
molar
67. Distal Shoe Space Maintainer
Intra alveolar appliance
Molar guidance
appliance.
Indication:
Loss of ‘E; before
eruption of ‘6’
68.
69. Lingual Arch Space
Maintainers
A lingual arch is indicated for space maintenance
when multiple primary posterior teeth are missing
and the permanent incisors have erupted.
70.
71. A conventional lingual arch, attached to bands on
the primary second or permanent first molars and
contacting the maxillary or mandibular incisors,
prevents anterior movement of the posterior
teeth and posterior movement of the anterior
teeth.
72. A lingual arch space maintainer is usually
soldered to the molar bands but can be
removable, depending on the number of
adjustments anticipated and the care of the
appliance expected from the patient.
Removable lingual arches (e.g.,those that fit into
attachments welded onto the bands) are more
prone to breakage and loss.
73. Regardless of whether it is removable, the
lingual arch should be positioned to rest
on the cingula of the incisors,
approximately 1 to l.5 mm off the soft
tissue, and should be stepped to the
lingual in the canine region to remain
away from the primary molars and
unerupted premolars.
The most common problems with lingual
arches are distortion, breakage and loss.
Careful instructions to parents and
patients can reduce these problems.
74.
75. Maxillary lingual arches as space
maintainers are not familiar to many
clinicians but are contraindicated only in
patients whose bite depth causes the lower
incisors to contact the archwire on the
lingual of the maxillary incisors.
When bite depth does not allow use of a
conventional design, either the Nance
lingual arch or a transpalatal arch can be
used.
76. The Nance arch is an effective space maintainer,
but soft tissue irritation can be a problem.
The best indication for a transpalatal arch is
when one side of the arch is intact and several
primary teeth are missing on the other side.
In this situation, the rigid attachment to the intact
side usually provides adequate stability for space
maintenance.
When primary molars have been lost bilaterally
however, both permanent molars may tip
mesially despite the transpalatal arch, and a
conventional lingual arch or Nance arch is
preferred.
79. Localized Space Loss (3mm or less):
Space Regaining
After premature loss of a primary tooth, space
may be lost from drift of other teeth before a
dentist is consulted.
Repositioning the teeth to regain space rather
than just space maintenance is required.
Up to 3 mm of space can be reestablished in a
localized area with relatively simple appliances
and a good prognosis
80. Maxillary Space Regaining
Generally, space is easier to regain in the
maxillary than in the mandibular arch, because of
the increased anchorage for removable
appliances afforded by the palatal vault and the
possibility for use of extraoral force (headgear).
Permanent maxillary first molars can be tipped
distally to regain space with either a fixed or
removable appliance, but bodily movement
requires a fixed appliance.
81. Because the molars tend to tip forward and
rotate mesiolingually, distal tipping to regain 2-
3mm often is satisfactory.
A removable appliance retained with Adams'
clasps and incorporating a helical fingerspring
adjacent to the tooth to be moved is very
effective. This appliance is the ideal design for
tipping one molar.
82.
83. One posterior tooth can be moved
up to 3 mm distally during 3 to 4
months of full-time appliance wear.
The spring is activated
approximately 2 mm to produce 1
mm of movement per month.
The molar generally will derotate
spontaneously as it is tipped distally.
84. For unilateral bodily space regaining, a
fixed intra-arch appliance is preferred.
The excellent anchorage provided by the
remaining teeth and palate can support
the forces generated by a coil spring on a
segmental archwire to produce distal
movement of the molar on only one side,
with good success.
85.
86. If bodily movement of both permanent maxillary
first molars is necessary in regaining space, this
can be accomplished by using a banded and
bonded fixed appliance or headgear.
Sometimes both molars need to be moved
distally but one requires substantially more
movement than the other.
87. To accomplish this, an asymmetric facebow with
a neckstrap attachment can be used.
’This will result in more movement on the side
with the longer outer bow but will also move that
tooth toward lingual crossbite.
Asymmetric cervical headgear is neither as easyt
o adjust nor as comfortable to wear as symmetric
headgear, and it requires excellent patient
compliance.
For space regaining, it should be used only to
deal with bilateral but asymmetric space loss-not
true unilateral space loss, which is treated best
with a removable or fixed appliances
88.
89. Regardless o f the method used to regain these
limited amounts of space a, space maintainer is
required when adequate space has been
restored.
A fixed space maintainer is recommended rather
than trying to maintain the space with the
removable appliance that was used for space
regaining.
90. Moderate and Severe
Generalized Crowding
For children with amoderate space deficiency,
usually there is generalized but not severe
crowding of the incisors.
Other times the primary canines are lost to
ectopic eruption of thelateral incisors and more
severe crowding goes largely unrecognized.
Usually when the permanent canines are
erupting the real extent of the problem is noted.
91. Children with moderate crowding and inadequate space in
the early mixed dentition face one of two choices.
Either the arch will need to be expanded to accommodate
the permanent teeth or some permanent teeth will need to
be extracted.
Generally, if the lower incisor position is normal or
somewhat retrusive, lips are normal or retrusive, the
overjet is adequate, the overbite is not excessive, and
there is good keratinized tissue facial to the lower incisors,
some facial movement of the incisors and expansion can
be accommodated.
If facial movement is anticipated and the amount and
quality of tissue is questionable, a periodontal consultation
about a gingival graft is appropriate.
92. Surgical or nonsurgical management of the tissue
may be required prior to beginning the tooth
movement.
A conservative approach to this dilemma is to place a
Iingual arch after the extraction of the primary canines
and allow the incisors to align themselves.
Ultimately the lingual arch or another appliance can
be used to increase the arch length.
A word of caution is necessary here.
Clinical experi-ence indicates that a considerable
degree of faciolingual irregularity will resolve if space
is available, but rotational irregularity will not.
If the incisors are rotated, severely irregular or spaced
and early correction is felt to be important, a multiply
bonded and banded appliance is indicated
93.
94. Lower incisor teeth usually can be tipped 1 to
2mm facially without much difficulty, which create
sup to 4mm of additional arch length.
If the overbite is excessive and the upper and
lower incisors are in contact, however, facial
movement of the lower incisors will not be
possible unless the upper incisors also are
proclined.
When expansion by tipping the incisors facially is
indicated, two methods should be considered.
96. The other method is to band the permanent
molars, bond brackets on the incisors, and use a
compressed coil spring on a labial archwire to
gain the additional space.
97. Early Treatment of Severe
Crowding
A key question, which remains unanswered, is
whether early expansion of the arches (before all
permanent teeth erupt) gives more stable results
than later expansion (in the early permanent
dentition).
Partly in response to the realization that recurrent
crowding occurs in many patients who were
treated with premolar extractions a number of
approaches to early arch expansion recently
have regained some popularity in spite of a lack
of data to document their effectiveness.
98. Expansion can involve any combination of
several possibilities: maxillary dental or skeletal
expansion, moving the teeth facially or opening
the midpalatal suture; mandibular buccal
segment expansion by facial movement of the
teeth; or advancement of the incisors and distal
movement of the molars in either arch.
99. A less aggressive approach is to expand the
upper arch in the early mixed dentition, using a
lingual arch (or perhaps a jack screw expander
but this must be done carefully and slowly in the
early mixed dentition) to produce dental and
skeletal change
100.
101. Late Mixed Dentition Treatment for
Severe Crowding
One alternative is a functional appliance that
incorporates lip and buccal shields or a lip
bumper to reduce the resting pressure of the lips
and cheeks and produce dental expansion
Lip pads and buccal shields will lead to anterior
movement of the incisors and buccal movement
of the primary molars or premolars, which allows
the teeth to align themselves along a larger arch
circumference
102.
103. Last, several approaches can be used for either
severe crowding or severe localized space loss
that focus on increasing arch circumference by
repositioning molars distally and often moving
incisor forward sometimes with the same
appliance and its side effects
104. There are three major limitations to this
approach:
the long duration of treatment from the primary or
early mixed dentition through the eruption of the
permanet teeth;
the possibility of creating unesthetic dentoalveolar
protrusion;
and the uncertain stability of the long-term result.
105. Distal Molar Movement
If bodily distal movement of one or both
permanent maxillary first molars is necessary to
adjust molar relationships and gain space, if
there are adequate anterior teeth for anchorage,
and if some anterior incisor movement can be
tolerated, several appliances can be considered.
All are built around the use of a heavy lingual
arch, usually with an acrylic pad against the
anterior palate to provide anchorage.
106.
107. Extraoral Appliances
To tip or bodily move molars distally, extraoral force via a
facebow to the molars is the most effective and straightfor-
ward methods
The force is directed specifically to the teeth that need to
be moved, and reciprocal forces are not distributed on the
other teeth that are in the correct positions.
The force should be as nearly constant as possible to
provide effective tooth movement and should be light
because it is concentrated against only two teeth.
The more the child wears the headgear,the better; 14 to 16
hours per day is minimal.
Approximately100gm of force per side is appropriate.
126. LOCALISED SPACE LOSS : LESS THAN 3
MM
SPACE REGAINING :
In the mandibular Arch
With Fixed appliances
Lip Bumper
Active lingual Arch
In the Maxillary Arch
Pendulum appliance
134. DENHOLTZ APPLIANCE
It is a maxillary active semifixed lip bumper
which incorporates open coil springs to induce
a distalizing force on the maxillary first
permanent molars
136. LIP BUMPERS
Lip bumpers are capable of the following:-
Correct lip biting habit
Upright lingually tipped lower incisors
Correct mild crowding of anterior teeth
Distalize the molar teeth
Act as space regainer
Help to re-inforce anchorage
137. LIP BUMPERS
They are screen like devices, which shield the dentition
from perioral musculature.
They are also referred to as Lip plumpers.
They may be made for the maxillary or mandibular
arch.
The type of anchorage used is Intra-
oral,Intramaxillary,Re-Inforced Muscular.