This document discusses six characteristics observed in 120 casts of patients with normal occlusion:
1. The upper first molar's distal cusp occludes with the lower second molar's mesial cusp.
2. Crown angulation varies by tooth type but the gingival portion is consistently distal to the incisal portion.
3. Crown inclination varies predictably by tooth group and position, affecting overbite and posterior occlusion.
4. There are no tooth rotations.
5. There are no spaces between teeth.
6. The occlusal plane varies within a limited range.
These "six keys" were consistently present in untreated cases and correlate with successful orthodontic outcomes.
The six keys to normal occlusion are:
1. Proper molar relationship with the upper first molar contacting the lower second molar.
2. Consistent crown angulation with the gingival portion of each crown more distal than the incisal portion.
3. Specific crown inclinations for the anterior and posterior teeth that contribute to proper overbite and occlusion.
Seis llaves de la oclusión normal - Artículo original..pdfMyndryDeynyMP
The six keys to normal occlusion are:
1. Proper molar relationship with the upper first molar contacting the lower second molar.
2. Consistent crown angulation with the gingival portion of each crown more distal than the incisal portion.
3. Specific crown inclinations for the anterior and posterior teeth that contribute to proper overbite and occlusion.
This presentation will discuss six significant characteristics observed in a study of 120 casts of nonorthodontic patients with normal occlusion by Lawrence F. Andrews, D.D.S. (1972)
These constants will be referred to as the “six keys to normal occlusion.” The article will also discuss the importance of the six keys, individually and collectively, in successful orthodontic treatment.
Prevalence of Malocclusion and Impacted Canine in Arab Israelian Population (...Abu-Hussein Muhamad
This document discusses the prevalence of malocclusion and impacted canines in the Arab Israeli population. It conducted a study of patients aged 10-39.5 years old who presented to an orthodontic clinic in Israel. The study found that Angle's Class II malocclusion was most prevalent at 61.36%, followed by Angle's Class I at 21.09%, with Angle's Class III being the least prevalent at 17.55%. The prevalence of impacted maxillary canines was found to be 3.7%. The study found no significant relationship between type of malocclusion and canine impaction.
orthodontic epidemiological indices
Occlusal Feature Index (Poulton & Aaronson, 1961)
Index of Tooth Position (Massler & Frankel, 1951)
Malalignment Index (Van Kirk & Pennel, 1959)
The Bjork Method (1964)
Summers’ Occlusal Index (1971)
The FDI method (Baume et al, 1973)
Little’s Irregularity Index (1975)
Handicapping Labio-lingual Deviation index (HLD) (Draker, 1960, 1967)
Swedish Medical Board Index (SMHB 1966; Linder Aronson, 1974, 1976)
Dental Aesthetic Index (DAI) (Cons et al, 1986)
Index of Orthodontic treatment Need (IOTN) (Brook & Shaw, 1989)
Index of Complexity, Outcome & Need (ICON) (Daniel & Richmond, 2000)
Peer Assessment Rating Index (PAR) (Richmond et al, 1992)
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
Esthetics in complete denture/certified fixed orthodontic courses by Indian d...Indian dental academy
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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Andrews 6 keys of normal occlusion /certified fixed orthodontic courses by In...Indian dental academy
Welcome to Indian Dental Academy
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.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
The six keys to normal occlusion are:
1. Proper molar relationship with the upper first molar contacting the lower second molar.
2. Consistent crown angulation with the gingival portion of each crown more distal than the incisal portion.
3. Specific crown inclinations for the anterior and posterior teeth that contribute to proper overbite and occlusion.
Seis llaves de la oclusión normal - Artículo original..pdfMyndryDeynyMP
The six keys to normal occlusion are:
1. Proper molar relationship with the upper first molar contacting the lower second molar.
2. Consistent crown angulation with the gingival portion of each crown more distal than the incisal portion.
3. Specific crown inclinations for the anterior and posterior teeth that contribute to proper overbite and occlusion.
This presentation will discuss six significant characteristics observed in a study of 120 casts of nonorthodontic patients with normal occlusion by Lawrence F. Andrews, D.D.S. (1972)
These constants will be referred to as the “six keys to normal occlusion.” The article will also discuss the importance of the six keys, individually and collectively, in successful orthodontic treatment.
Prevalence of Malocclusion and Impacted Canine in Arab Israelian Population (...Abu-Hussein Muhamad
This document discusses the prevalence of malocclusion and impacted canines in the Arab Israeli population. It conducted a study of patients aged 10-39.5 years old who presented to an orthodontic clinic in Israel. The study found that Angle's Class II malocclusion was most prevalent at 61.36%, followed by Angle's Class I at 21.09%, with Angle's Class III being the least prevalent at 17.55%. The prevalence of impacted maxillary canines was found to be 3.7%. The study found no significant relationship between type of malocclusion and canine impaction.
orthodontic epidemiological indices
Occlusal Feature Index (Poulton & Aaronson, 1961)
Index of Tooth Position (Massler & Frankel, 1951)
Malalignment Index (Van Kirk & Pennel, 1959)
The Bjork Method (1964)
Summers’ Occlusal Index (1971)
The FDI method (Baume et al, 1973)
Little’s Irregularity Index (1975)
Handicapping Labio-lingual Deviation index (HLD) (Draker, 1960, 1967)
Swedish Medical Board Index (SMHB 1966; Linder Aronson, 1974, 1976)
Dental Aesthetic Index (DAI) (Cons et al, 1986)
Index of Orthodontic treatment Need (IOTN) (Brook & Shaw, 1989)
Index of Complexity, Outcome & Need (ICON) (Daniel & Richmond, 2000)
Peer Assessment Rating Index (PAR) (Richmond et al, 1992)
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
Esthetics in complete denture/certified fixed orthodontic courses by Indian d...Indian dental academy
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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
Andrews 6 keys of normal occlusion /certified fixed orthodontic courses by In...Indian dental academy
Welcome to Indian Dental Academy
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.
Indian dental academy has a unique training program & curriculum that provides students with exceptional clinical skills and enabling them to return to their office with high level confidence and start treating patients
State of the art comprehensive training-Faculty of world wide repute &Very affordable.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Esthetics in prosthodontics/certified fixed orthodontic courses by Indian den...Indian dental academy
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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
1) The document argues against routinely mounting dental casts on articulators for orthodontic treatment, as there is no convincing evidence that it improves outcomes.
2) While articulators may help elucidate jaw relationships, using them routinely appears perfunctory given that factors like occlusion and condyle position are no longer considered primary causes of temporomandibular disorders.
3) The paradigm around temporomandibular disorders has shifted from a dental model to a biopsychosocial one, and orthodontics is now considered temporomandibular disorders neutral.
Esthetics in complete denture/cosmetic dentistry course by Indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Dr. Rahul VC Tiwari - Fellowship In Orthognathic Surgery - Jubilee Mission Medical College Hospital and Research Center, Thrissur, Kerala - 19TH PUBLICATION - IJOHMR
This document discusses the history and considerations around extraction versus non-extraction orthodontic treatment. It notes that views on extractions have changed over time, from rarely being done to becoming common in the 1960s and then declining since the 1990s. Key factors in the extraction decision are stability of results and esthetics. Extraction may allow for better alignment but can result in narrower dental arches and smiles. Non-extraction through arch expansion risks instability but can provide better esthetics with wider smiles. The optimal choice depends on the individual case and a balance of these prioritizing stability and esthetics.
Andrews six keys of occlusion / certified fixed orthodontics courses in indiaIndian dental academy
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
Mandibular arch form the relationship between dental and basal anatomyEdwardHAngle
We investigated mandibular dental arch form at the levels of both the clinically relevant application points of the orthodontic bracket and the underlying anatomic structure of the apical base. The correlation of both forms was evaluated and examined to determine whether the basal arch could be used to derive a standardized clinical arch form.
ANDREWS STRAIGHT WIRE APPLIANCE 1 and 2.pptxSadhuAbhijeet
The document discusses the history and development of the Andrews Straight Wire appliance. It describes Dr. Lawrence Andrews' research over 10 years collecting over 120 casts of individuals with optimal untreated occlusion. From this research, Andrews identified six consistent characteristics, called the "Six Keys to Optimal Occlusion". Extensive measurements were then taken of the casts to determine tooth positions and relationships. This led to the design of the fully programmed Andrews Straight Wire appliance, which is designed to guide teeth into positions matching the six keys without requiring as many archwire bends as non-programmed appliances. The keys and measurements aimed to eliminate the need for first order bends in treatment with the Straight Wire appliance.
Description :
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 normal occlusion, providing definitions and terminology. It covers the concept of occlusion from the fictional period before 1900, through the hypothetical period from 1900-1930, to the current factual period. Key factors discussed include the line and plane of occlusion, Andrews' six keys to optimal occlusion, and factors determining tooth position. The document emphasizes that occlusion is a dynamic process influenced by factors like tooth morphology, habits, restorations, and the temporomandibular joint.
This document provides an introduction to orthodontics. It begins by defining orthodontics as the branch of dentistry concerned with preventing, intercepting, and correcting malocclusions and other dentofacial deformities. Ideal occlusion and Andrews' six keys of occlusion are described. The document outlines the different branches of orthodontics including preventive, interceptive, and corrective orthodontics. The aims of orthodontic treatment are discussed as achieving aesthetic harmony, functional efficiency, and structural balance. Finally, the 4th year orthodontic syllabus is summarized.
This document discusses the development of the concept of occlusion from early fictional and hypothetical periods to the current factual period. It outlines key figures and their contributions, such as Angle establishing occlusion as the basis of orthodontics. It describes Andrews' six keys to optimal occlusion and three occlusion philosophies, with gnathology focusing on occlusion as part of the functional masticatory system rather than just teeth. Determinants of occlusion include fixed, variable, vertical and horizontal factors.
This document discusses diagnostic records for orthodontic treatment planning. It emphasizes the importance of thorough evaluation of dental casts, facial and intraoral photographs, and radiographs to identify all dental, skeletal, and soft tissue problems. Cephalometric analysis and 3D imaging such as CBCT are described as useful tools to further characterize dentofacial proportions and anomalies. The goal of comprehensive diagnostic records is to complete the diagnostic phase of treatment planning by identifying all significant orthodontic problems to inform development of an appropriate treatment plan.
This document discusses the concepts of occlusion from its early fictional and hypothetical development to becoming an established fact. It traces how occlusion was initially described as antagonism or meeting of teeth. Angle standardized the definition as the relation of inclined tooth planes in occlusion and cited examples like "Old Glory" skull. Factors determining tooth position include forces from lips, cheeks, tongue and occlusal contacts. Occlusion involves dynamic tooth contact positions as well as static postural resting positions and relationships with the temporomandibular joint. Terminologies like normal, ideal and traumatic occlusion are defined.
This document discusses factors that affect normal occlusion. It begins by outlining the learning objectives and contents of the seminar. The key factors discussed include:
1) Bone relation - The position and size of the jaws, which are influenced by heredity, congenital conditions, and trauma.
2) Tooth relation - The developmental position of teeth, which can be modified by the presence of other tooth germs if space is limited.
3) Eruption - The path teeth follow to erupt through the gums and be guided into place by intraoral forces.
It provides details on each of these factors and how they influence the development of normal occlusion. The document also reviews the historical development
1. A study compared long-term stability of adolescent versus adult surgery for treatment of mandibular deficiency, finding that beyond 1 year post-surgery, younger patients showed significantly greater changes in horizontal and vertical positions of mandibular landmarks and angles.
2. Early mandibular advancement surgery may be less stable long-term than performing the same surgery on older, growth-completed patients.
3. Younger patients undergoing two-jaw surgery experienced even greater long-term changes than those receiving isolated mandibular advancement.
1. Andrews analyzed 120 non-orthodontically treated models and 1150 treated cases to identify six keys of optimal occlusion. This revealed inconsistencies in treated results compared to the natural optimal occlusion.
2. Shortcomings of traditional edgewise appliances include perpendicular bracket bases, flat bases, non-angled slots, equal stem prominence, lack of built-in molar offset, and unsatisfactory landmarks. This requires extensive wire bending to achieve optimal occlusion.
3. Andrews developed a preadjusted edgewise appliance to address these issues. The brackets are designed based on measurements of natural tooth morphology and positioning to guide teeth into optimal occlusion with minimal wire bending.
Principles and concept of andrew’s preadjusted edgewise appliance /certified ...Indian dental academy
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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
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 the biomechanics of space closure during orthodontic treatment. It covers topics such as determinants of space closure including axial inclination and midline discrepancies. It also discusses fundamentals of anchorage control including extraoral forces, intermaxillary elastics, and tipping movements. Additionally, it describes strategies for differential space closure such as applying different moment-to-force ratios to anterior vs. posterior teeth. The center of resistance during anterior retraction is also examined.
The document discusses occlusion and temporomandibular disorders. It begins with an introduction to the temporomandibular joint (TMJ) and its classification as a compound joint. The presentation then covers the anatomy of the TMJ including ligaments, muscles, the articular disc, movements, and examination. Common TMJ disorders are outlined such as hyperplasia and hypoplasia of the condyle. Treatment options for different disorders are mentioned. The document provides an overview of the structure, function and clinical aspects of the temporomandibular joint and disorders.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Esthetics in prosthodontics/certified fixed orthodontic courses by Indian den...Indian dental academy
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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
1) The document argues against routinely mounting dental casts on articulators for orthodontic treatment, as there is no convincing evidence that it improves outcomes.
2) While articulators may help elucidate jaw relationships, using them routinely appears perfunctory given that factors like occlusion and condyle position are no longer considered primary causes of temporomandibular disorders.
3) The paradigm around temporomandibular disorders has shifted from a dental model to a biopsychosocial one, and orthodontics is now considered temporomandibular disorders neutral.
Esthetics in complete denture/cosmetic dentistry course by Indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Dr. Rahul VC Tiwari - Fellowship In Orthognathic Surgery - Jubilee Mission Medical College Hospital and Research Center, Thrissur, Kerala - 19TH PUBLICATION - IJOHMR
This document discusses the history and considerations around extraction versus non-extraction orthodontic treatment. It notes that views on extractions have changed over time, from rarely being done to becoming common in the 1960s and then declining since the 1990s. Key factors in the extraction decision are stability of results and esthetics. Extraction may allow for better alignment but can result in narrower dental arches and smiles. Non-extraction through arch expansion risks instability but can provide better esthetics with wider smiles. The optimal choice depends on the individual case and a balance of these prioritizing stability and esthetics.
Andrews six keys of occlusion / certified fixed orthodontics courses in indiaIndian dental academy
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
Mandibular arch form the relationship between dental and basal anatomyEdwardHAngle
We investigated mandibular dental arch form at the levels of both the clinically relevant application points of the orthodontic bracket and the underlying anatomic structure of the apical base. The correlation of both forms was evaluated and examined to determine whether the basal arch could be used to derive a standardized clinical arch form.
ANDREWS STRAIGHT WIRE APPLIANCE 1 and 2.pptxSadhuAbhijeet
The document discusses the history and development of the Andrews Straight Wire appliance. It describes Dr. Lawrence Andrews' research over 10 years collecting over 120 casts of individuals with optimal untreated occlusion. From this research, Andrews identified six consistent characteristics, called the "Six Keys to Optimal Occlusion". Extensive measurements were then taken of the casts to determine tooth positions and relationships. This led to the design of the fully programmed Andrews Straight Wire appliance, which is designed to guide teeth into positions matching the six keys without requiring as many archwire bends as non-programmed appliances. The keys and measurements aimed to eliminate the need for first order bends in treatment with the Straight Wire appliance.
Description :
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 normal occlusion, providing definitions and terminology. It covers the concept of occlusion from the fictional period before 1900, through the hypothetical period from 1900-1930, to the current factual period. Key factors discussed include the line and plane of occlusion, Andrews' six keys to optimal occlusion, and factors determining tooth position. The document emphasizes that occlusion is a dynamic process influenced by factors like tooth morphology, habits, restorations, and the temporomandibular joint.
This document provides an introduction to orthodontics. It begins by defining orthodontics as the branch of dentistry concerned with preventing, intercepting, and correcting malocclusions and other dentofacial deformities. Ideal occlusion and Andrews' six keys of occlusion are described. The document outlines the different branches of orthodontics including preventive, interceptive, and corrective orthodontics. The aims of orthodontic treatment are discussed as achieving aesthetic harmony, functional efficiency, and structural balance. Finally, the 4th year orthodontic syllabus is summarized.
This document discusses the development of the concept of occlusion from early fictional and hypothetical periods to the current factual period. It outlines key figures and their contributions, such as Angle establishing occlusion as the basis of orthodontics. It describes Andrews' six keys to optimal occlusion and three occlusion philosophies, with gnathology focusing on occlusion as part of the functional masticatory system rather than just teeth. Determinants of occlusion include fixed, variable, vertical and horizontal factors.
This document discusses diagnostic records for orthodontic treatment planning. It emphasizes the importance of thorough evaluation of dental casts, facial and intraoral photographs, and radiographs to identify all dental, skeletal, and soft tissue problems. Cephalometric analysis and 3D imaging such as CBCT are described as useful tools to further characterize dentofacial proportions and anomalies. The goal of comprehensive diagnostic records is to complete the diagnostic phase of treatment planning by identifying all significant orthodontic problems to inform development of an appropriate treatment plan.
This document discusses the concepts of occlusion from its early fictional and hypothetical development to becoming an established fact. It traces how occlusion was initially described as antagonism or meeting of teeth. Angle standardized the definition as the relation of inclined tooth planes in occlusion and cited examples like "Old Glory" skull. Factors determining tooth position include forces from lips, cheeks, tongue and occlusal contacts. Occlusion involves dynamic tooth contact positions as well as static postural resting positions and relationships with the temporomandibular joint. Terminologies like normal, ideal and traumatic occlusion are defined.
This document discusses factors that affect normal occlusion. It begins by outlining the learning objectives and contents of the seminar. The key factors discussed include:
1) Bone relation - The position and size of the jaws, which are influenced by heredity, congenital conditions, and trauma.
2) Tooth relation - The developmental position of teeth, which can be modified by the presence of other tooth germs if space is limited.
3) Eruption - The path teeth follow to erupt through the gums and be guided into place by intraoral forces.
It provides details on each of these factors and how they influence the development of normal occlusion. The document also reviews the historical development
1. A study compared long-term stability of adolescent versus adult surgery for treatment of mandibular deficiency, finding that beyond 1 year post-surgery, younger patients showed significantly greater changes in horizontal and vertical positions of mandibular landmarks and angles.
2. Early mandibular advancement surgery may be less stable long-term than performing the same surgery on older, growth-completed patients.
3. Younger patients undergoing two-jaw surgery experienced even greater long-term changes than those receiving isolated mandibular advancement.
1. Andrews analyzed 120 non-orthodontically treated models and 1150 treated cases to identify six keys of optimal occlusion. This revealed inconsistencies in treated results compared to the natural optimal occlusion.
2. Shortcomings of traditional edgewise appliances include perpendicular bracket bases, flat bases, non-angled slots, equal stem prominence, lack of built-in molar offset, and unsatisfactory landmarks. This requires extensive wire bending to achieve optimal occlusion.
3. Andrews developed a preadjusted edgewise appliance to address these issues. The brackets are designed based on measurements of natural tooth morphology and positioning to guide teeth into optimal occlusion with minimal wire bending.
Principles and concept of andrew’s preadjusted edgewise appliance /certified ...Indian dental academy
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.
Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078
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 the biomechanics of space closure during orthodontic treatment. It covers topics such as determinants of space closure including axial inclination and midline discrepancies. It also discusses fundamentals of anchorage control including extraoral forces, intermaxillary elastics, and tipping movements. Additionally, it describes strategies for differential space closure such as applying different moment-to-force ratios to anterior vs. posterior teeth. The center of resistance during anterior retraction is also examined.
The document discusses occlusion and temporomandibular disorders. It begins with an introduction to the temporomandibular joint (TMJ) and its classification as a compound joint. The presentation then covers the anatomy of the TMJ including ligaments, muscles, the articular disc, movements, and examination. Common TMJ disorders are outlined such as hyperplasia and hypoplasia of the condyle. Treatment options for different disorders are mentioned. The document provides an overview of the structure, function and clinical aspects of the temporomandibular joint and disorders.
role of harmones and vitamins in craniofacial growth and developmentDeeksha Bhanotia
Growth and development of the craniofacial structures is influenced by hormones and vitamins. The pituitary gland secretes growth hormone which acts directly and indirectly to stimulate growth of the maxilla, mandible, and other bones. Studies have shown increased craniofacial growth in patients receiving long-term growth hormone therapy. Deficiencies or excess of growth hormone can result in conditions like dwarfism or gigantism with characteristic dental and skeletal features.
Removable appliances have several advantages including improved oral hygiene, less chair time, ability to do tipping movements and bite reduction, less strain on teeth. They require patient cooperation and have a greater risk of being misplaced. They work by applying single forces to tip teeth around their center of resistance. Key components are retentive elements like clasps to aid retention, active elements like springs and elastics to induce tooth movement, and a base plate for support. Patients must be instructed to wear appliances full-time and maintain oral hygiene.
This document discusses the management of open bite and crossbite under the guidance of Dr. Mridula Trehan. It defines open bite and classifies it based on location and tissues involved. Anterior open bite can be skeletal or dental in nature. Crossbite is classified based on location as anterior or posterior, and based on nature as skeletal, dental, or functional. Treatment depends on the type and includes appliances, elastics, expansion, and in severe skeletal cases, surgery. The goal is to address the underlying cause and intrude or prevent eruption of posterior teeth to correct the bite.
This document discusses the management of deep bites. It defines deep bite, classifies it as skeletal or dental, and outlines factors to consider in treatment. Skeletal deep bites are due to genetic or growth factors, while dental deep bites result from overerupted incisors or infraoccluded molars. Diagnosis involves clinical exams, models, and lateral cephs. Treatment may involve bite planes, myofunctional appliances, or fixed appliances to intrude incisors or extrude molars depending on the individual case. The goal is to achieve functional and aesthetic occlusion.
This document discusses preventive orthodontics and space maintainers. It begins by defining preventive orthodontics and distinguishing it from interceptive orthodontics. It then lists the advantages and disadvantages of preventive orthodontics. The document goes on to describe various preventive orthodontic procedures and space maintainer types, materials, indications, and factors to consider when planning space maintainers. The overall goal is to educate students on the principles and procedures of preventive orthodontics and space maintenance.
The document discusses retention and relapse after orthodontic treatment. It defines relapse as teeth returning to their original position after treatment. Relapse can be caused by bone adaptation, ligament traction, growth changes, muscular forces, failure to address the original cause, third molars, and occlusion issues. Retention aims to hold teeth in their corrected positions and allow tissues to remodel. It discusses different retention philosophies and types of retainers including removable retainers like Hawley, Begg, and Invisalign retainers as well as fixed retainers. The goal of retention is to stabilize teeth after active treatment.
This document discusses prostaglandins and their role in orthodontic tooth movement. It begins with an introduction to orthodontic tooth movement and the various chemical mediators involved, including prostaglandins. It then discusses how drugs can alter the rate of tooth movement, with prostaglandins and other substances like vitamin D and PTH increasing the rate, while NSAIDs and bisphosphonates decrease it. The document concludes by focusing on prostaglandins and their mechanism of action in accelerating orthodontic tooth movement.
This document discusses various orthodontic appliances used under the guidance of Dr. Mridula Trehan. It provides details on commonly used appliances like headgear, face mask, and chin cup. For headgear, it describes the components of the face bow assembly and different types of headgears based on the site of anchorage. Face mask is discussed in terms of its indications, parts, biomechanics and different types. Chin cup is summarized focusing on its principle, parts, types and fabrication process. Force magnitude and duration of wear for various appliances is also highlighted.
This document provides an overview of orthodontic appliances, including their classification, advantages, and disadvantages. It discusses removable appliances, fixed appliances, and the ideal requirements of an orthodontic appliance. Removable appliances are convenient but require patient cooperation, while fixed appliances do not rely on patient compliance but are more difficult for oral hygiene. The ideal appliance should cause desired tooth movement safely, apply controlled forces, and be esthetically acceptable.
MANAGEMENT OF CLASS II & CLASS III MALOCCLUSIONSDeeksha Bhanotia
This document discusses the management of Class II and Class III malocclusions. It describes the features, etiology, treatment objectives, and treatment approaches for Class II Division 1 and 2 malocclusions, including the use of growth modification, camouflage, and surgical correction. Treatment approaches discussed include myofunctional appliances, fixed functional appliances, and extractions. The document also covers the features, etiology, diagnosis, and interceptive and definitive treatment of Class III malocclusions, including the use of FR III, reverse pull headgear, and orthognathic surgery. It distinguishes true skeletal Class III malocclusions from pseudo Class III malocclusions caused by dental or functional factors.
This document discusses the evolution of smile visualization and quantification in orthodontics. It describes how orthodontics has shifted away from solely focusing on the profile and incorporating an analysis of the smile in three dimensions and over time. Dynamic video recordings are highlighted as an important record for understanding smile types and performing measurements of smile characteristics. Direct measurements of smile features are presented as an objective, biometric tool for smile analysis and treatment planning.
This document discusses various procedures and techniques for interceptive orthodontics, which aims to recognize and address developing malocclusions and irregularities in young patients. It describes serial extraction, which involves extracting teeth in a planned sequence to address crowding. It also covers topics like developing anterior crossbites, habits like thumb sucking, space regaining when teeth are extracted, muscle exercises, and intercepting skeletal issues like Class II or III malocclusions. The goal of interceptive orthodontics is to address orthodontic issues early before they worsen.
A 9-year-old female presented with an impacted maxillary right central incisor and canine. The crowns were surgically exposed and Multi-Purpose Attachments (MPAs) with hooks were bonded to apply light eruptive forces and align the teeth over 20 months. MPAs helped avoid soft tissue laceration during incisor eruption and prevented occlusal interference during canine retraction. At the 43-month follow-up, lingual retainers bonded to MPAs had successfully aligned and retained the impacted teeth.
This document provides information on fixed orthodontic appliances. It defines fixed appliances as those that cannot be removed by the patient and discusses their advantages like better control over tooth movement and disadvantages like difficulty maintaining oral hygiene. It describes different types of attachments used in fixed appliances like bands, brackets, and wires. It also covers indications, methods of fixing appliances, components, and techniques like edgewise and Begg appliances.
This document summarizes a presentation on facial asymmetry given by Dr. Deeksha Bhanotia. It discusses the etiology, classification, diagnosis, and management of facial asymmetry. Facial asymmetry can be caused by genetic factors like clefts or environmental factors like trauma. It is classified as dental, skeletal, muscular, or functional asymmetry. Diagnosis involves medical history, dental and facial evaluation, and radiographs. Management depends on the underlying cause and may involve orthodontic treatment and/or orthognathic surgery.
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1. The six
keys to
Normal
Occlusion
Lawrence F. Andrews, D.D.S.
San Diego, California
Department of Orthodontics and Dentofacial Orthopaedics
Under the guidance of:
Dr. MridulaTrehan, Professor & Head
Presented by:
Deeksha Bhanotia, PG I year
2. This article will discuss six significant characteristics
observed in a study of 120 casts of non orthodontic
patients with normal occlusion.
These constants will be referred to as the “six keys to
normal occlusion.”
The article will also discuss the importance of the six
keys, individually and collectively, in successful
orthodontic treatment.
Orthodontists have the advantage of a classic guideline
in orthodontic diagnosis, that is, the concept given to the
specialty a half-century ago by Angle that, as a sine qua
non of proper occlusion, the cusp of the upper first
permanent molar must occlude in the groove between
the mesial and middle buccal cusps of the lower first
permanent molar.
3. But Angle, of course, had not contended that this factor
alone was enough.
Clinical experience and observations of treatment
exhibits at national meetings and elsewhere had
increasingly pointed to a corollary fact-that even with
respect to the molar relationship itself, the positioning of
that critical mesio-buccal cusp within that specified
space could be inadequate.
Too many models displaying that vital cusp-embrasure
relationship had, even after orthodontic treatment,
obvious inadequacies, despite the acceptable molar
relationship as described by Angle.
Recognizing conditions in treated cases that were
obviously less than ideal was not difficult, but neither
was it sufficient, for it was subjective, impressionistic,
and merely negative.
4. A reversal of approach seemed indicated a deliberate
seeking, first, of data about what was significantly
characteristic in models which, by professional
judgment, needed no orthodontic treatment.
Such data, if systematically reduced to ordered,
coherent paradigms, could constitute a group of
referents, that is, basic standards against which
deviations could be recognized and measured.
The concept was, in brief, that if one knew what
constituted “right,” he could then directly, consistently,
and methodically identify and quantify what was wrong.
A gathering of data was begun, and during a period of
four years (1960 to 1964), 120 non orthodontic normal
models were acquired with the cooperation.
5. Six keys to normal occlusion of local dentists,
orthodontists, and a major university.
Models selected were of teeth which (1) had’ never had
orthodontic treatment, (2) were straight and pleasing in
appearance, (3) had a bite which looked generally
correct, and (4) in my judgment would not benefit from
orthodontic treatment.
The crowns of this multisource collection were then
studied intensively to ascertain which characteristics, if
any, would be found consistently in all the models.
Some theories took form but soon had to be discarded;
others required modification and then survived.
6. Angle’s molar cusp groove concept was validated still
again. But there was growing realization that the molar
relationship in these healthy normal models exhibited
two qualities when viewed buccally, not just the classic
one, and that the second was equally important.
Other findings emerged. Angulation (mesiodist.al tip) and
inclination (labiolingual or buccolingual inclination) began
to show predictable natures as related to individual tooth
types. These 120 non-orthodontic normals had no
rotations.
There were no spaces between teeth. The occlusal
plane was not identical throughout the battery of
examples but fell neatly into so limited a range of
variation that it clearly was a differential attribute.
7. Tentative conclusions were reached, and six
characteristics were formulated in general terms.
However, a return was needed now to the complementary
bank of information made available by many of this
nation’s most skilled orthodontists-the treated cases on
display at national meetings.
Eleven hundred fifty of these cases were studied, from
1965 to 1971, for the purpose of learning to what degree
the six characteristics were present and whether the
absence of any one permitted prediction of other error
factors, such as the existence of spaces or of poor
posterior occlusal relations.
American orthodontic treatment can be considered to be
about the finest in the world.
8. Most of our leaders in this field spent 10 or 15 years in
successful practice before submitting their work at these
national meetings.
There can be no disparagement of their competency.
The fact that some range of excellence was found within
the 1,150 models implies no adverse criticism; instead,
that finding simply reflected the present state of the art.
Few would claim that orthodontics, even on the high
level seen at the meetings, has reached its ultimate
development.
Last to make such a claim would be the masters whose
work is there displayed for closest scrutiny by peers as
well as by neophytes.
9. Having long since benefited from the good examples
offered by such men, I at this point in the research
assumed that a comparison of the best in treatment
results (the 1,150 treated cases) and the best in nature
(the 120 non orthodontic normals) would reveal
differences which, once systematically identified, could
provide significant insight on how we could improve
ourselves orthodontically.
Deliberately, we sought those differences.
The six differential qualities were thus validated.
They were established as meaningful not solely because
all were present in each of the 120 non orthodontic
normals, but also because the lack of even one of the
six was a defect predictive of an incomplete end result in
treated models.
10.
11. Subsequent work elaborated and refined the
measurements involved and provided statistical
analysis of the findings. These matters will be
reported in future papers. For the present article, a
summary is offered chiefly in verbal form.
The significant characteristics shared by all of the
non orthodontic normal are as follows:
1. Molar relationship: The distal surface of the
distobuccal cusp of the upper first permanent molar
made contact and occluded with the mesial surface of
the mesio-buccal cusp of the lower second molar.
The mesiodistal cusp of the upper first permanent
molar fell within the groove between the mesial and
middle cusps of the lower first permanent molar.
12. (The canines and premolars enjoyed a cusp-embrasure
relationship buccally, and a cusp fossa relationship
lingually.)
2. Crown angulation, the mesiodistal tip (Fig. 4). In this
article, the term crown angulation refers to angulation (or
tip) of the long axis of the crown, not to angulation of the
long axis of the entire tooth.
As orthodontists, we work specifically with the crowns of
teeth and, therefore, crowns should be our
communication base or referent, just as they are our
clinical base.
The gingival portion of the long axis of each crown was
distal to the incisal portion, varying with the individual
tooth type.
13.
14. 3. Crown inclination (labiolingual or buccolingual
inclination): Crown inclination refers to the labiolingual or
buccolingual inclination of the long axis of the crown, not to
the inclination of the long axis of the entire tooth. (See Fig.
6.) The inclination of all the crowns had a consistent
scheme :
A. ANTERIOR TEETH (CENTRAL AND LATERAL
INCISORS): Upper and lower anterior crown inclination
was sufficient to resist overeruption of anterior teeth and
sufficient also to allow proper distal positioning of the
contact points of the upper teeth in their relationship to the
lower teeth, permitting proper occlusion of the posterior
crowns.
15.
16.
17. B. UPPER POSTERIOR TEETH (CANINES THROUGH
MOLARS): A lingual crown inclination existed in the upper
posterior crowns
. It was constant and similar from the canines through
the second premolars and was slightly more pronounced
in the molars.
The long axis of the crown for all teeth, except molars, is
judged to be the mid developmental ridge, which is the
most prominent and center most vertical portion of the
labial or buccal surface of the crown.
The long axis of the molar crown is identified by the
dominant vertical groove on the buccal surface of the
crown.
18.
19.
20. C. LOWER POSTERIOR (CANINES THROUGH MOLARS).
The lingual crown inclination in the lower posterior teeth
progressively increased from the canines through the
second molars.
4. Rotations: There were no rotations.
5. Spaces: There were no spaces; contact points were tight.
6. Occlusal plane: The plane of occlusion varied from
generally flat to a slight curve of Spee.
The six keys to normal occlusion contribute individually and
collectively to the total scheme of occlusion and, therefore,
are viewed as essential to successful orthodontic treatment.
Key I. Molar relationship. The first of the six keys is molar
relationship.
21.
22. The non orthodontic normal models consistently
demonstrated that the distal surface of the
distobuccal cusp of the upper first permanent
molar occluded with the mesial surface of the
mesiobuccal cusp of the lower second molar (Fig.
1). Therefore, one must question the sufficiency of
the traditional description of normal molar
relationship. As Fig. 2 shows, it is possible for the
mesio buccal cusp of the upper first molar to
occlude in the groove between the mesial and
middle cusps of the lower first permanent molar
(as sought by Angle) while leaving a situation
unreceptive to normal occlusion.
23. The closer the distal surface of the distobuccal cusp of
the upper first permanent molar approaches the mesial
surfaces of the mesiobuccal cusp of the lower second
molar, the better the opportunity for normal occlusion.
Fig. 1 and Fig. 2, 4 exhibit the molar relationship found,
without exception, in every one of the 120 non
orthodontic normal models; that is, the distal surface of
the upper first permanent molar contacted the mesial
surface of the lower second permanent molar.
Key II. Crown angulation (tip). The gingival portion of the
long axis of all crowns was more distal than the incisal
portion (Fig. 3).
In Fig. 4, crown tip is expressed in degrees, plus or
minus.
24.
25. The degree of crown tip is the angle between
the long axis of the crown (as viewed from
the labial or buccal surface) and a line
bearing 90 degrees from the occlusal plane.
A “plus reading” is awarded when the gingival
portion of the long axis of the crown is distal
to the incisal portion.
A “minus reading” is assigned when the
gingival portion of the long axis of the crown
is mesial to the incisal portion.
26. Each non orthodontic normal model had a distal
inclination of the gingival portion of each crown;
this was a constant. It varied with each tooth type,
but within each type the tip pattern was consistent
from individual to individual (quite as the locations
of contact points were found by Wheeler, in An
Atlas of Tooth B’oym, to be consistent for each
tooth type).
Normal occlusion is dependent upon proper distal
crown tip, especially of the upper anterior teeth
since they have the longest crowns.
27. Let us consider that a rectangle occupies a wider space
when tipped than when upright (Fig. 5). Thus, the degree
of tip of incisors, for example, determines the amount of
mesiodistal space they consume and, therefore, has a
considerable effect on posterior occlusion as well as
anterior esthetics.
Key III. Crown inclination (labiolingual or buccolingual
inclination), The third key to normal occlusion is crown
inclination (Fig. 6).
In this article, crown inclination is expressed in plus or
minus degrees, representing the angle formed by a line
which bears 90 degrees to the occlusal plane and a line
that is tangent to the bracket site (which is in the middle
of the labial or buccal long axis of the clinical crown, as
viewed from the mesial or distal).
28.
29. A plus reading is given if the gingival portion of the
tangent line (or of the crown) is lingual to the incisal
portion, as shown in Fig. 6. A minus reading is
recorded when the gingival portion of the tangent line
(or of the crown) is labial to the incisal portion, as
illustrated in Fig. 6.
A. ANTERIOR CROWN INCLINATION. Upper and
lower anterior crown inclinations are intricately
complementary and significantly affect overbite and
posterior occlusion.
Properly inclined anterior crowns contribute to normal
overbite and posterior occlusion, when too straight-up
and down they lose their functional harmony and over-
eruption results.
30. In Fig. 7, A the upper posterior crowns are forward
of their normal position when the upper anterior
crowns are insufficiently inclined. When anterior
crowns are properly inclined, as on the overlay of
Fig. 7, B, one can see how the posterior teeth are
encouraged into their normal positions. The
contact points move distally in concert with the
increase in positive (+) upper anterior crown
inclination.
31.
32. Even when the upper posterior teeth are in proper
occlusion with the lower posterior teeth, undesirable
spaces will result somewhere between the anterior
and posterior teeth, as shown in Fig. 8, if the
inclination of the anterior crowns is not sufficient. This
space, in treated cases, is often incorrectly blamed
on tooth size discrepancy.
B. POSTERIOR CROWN INCLINATION-UPPER. The
pattern of upper posterior crown inclination was
consistent in the non orthodontic normal models.
Spaces resulting from normally occluded posterior
teeth and insufficiently inclined anterior teeth are often
falsely blamed on tooth size descrepancy.
Crown inclination existed in each crown from the
upper canine through the upper second premolar. A
slightly more negative crown inclination existed in the
upper first and second permanent molar (Fig. 9).
33. C. POSTERIOR CROWN INCLINATION-LOWER. The lower
posterior crown inclination pattern also was consistent among
all the non orthodontic normal models.
A progressively greater “minus” crown inclination existed
from the lower canines through the lower second molars
(Fig. 10).
Tip and torque: Before continuing to the fourth key to normal
occlusion, let us more thoroughly discuss a very important
factor involving the clinical applications of the second and
third keys to occlusion (angulation and inclination) and how
they collectively affect the upper anterior crowns and then
the total occlusion.
As the anterior portion of an upper rectangular arch wire is
lingually torqued, a proportional amount of mesial tip of the
anterior crowns occurs. If you ever felt you were losing
ground in tip when increasing anterior torque, you were
right.
34. To better understand the mechanics involved in tip and
torque, let us picture an unbent rectangular arch wire
with vertical wires soldered at 90 degrees, spaced to
represent the upper central and lateral incisors, as in A
and B of Fig. 11.
As the anterior portion of the arch wire is torqued
lingually, the vertical wires begin to converge until they
become the spokes of a wheel when the arch wire is
torqued 90 degrees as progressively seen in Fig. 11, C,
D, and E.
The ratio is approximately 4:1. For every 4 degrees of
lingual crown torque, there is 1 degree of mesial
convergence of the gingival portion of the Fig. Fig. 10
35.
36. Central and lateral crowns, for example, as in C, if
the arch wire is lingually torqued 20 degrees in the
area of the central incisors, then there would be a
resultant -5° mesial convergence of each central and
lateral incisor. In that the average distal tip of the
central incisors is +5°, it would then be necessary to
place -1 to 10 degrees distal tip in the arch wire to
accomplish a clinical +5 degree distal tip of the
crown. This mechanical problem can be greatly
eased if tip and torque are constructed in the
brackets rather than the arch wire.
Key IV. Rotations. The fourth key to normal occlusion is
that the teeth should be free of undesirable rotations.
An example of the problem is seen in Fig. 12, a
superimposed molar outline showing how the molar, if
rotated, would occupy more space than normal,
creating a situation unreceptive to normal occlusion.
37. Key V. Tight contacts. The fifth key is that the
contact points should be tight (no spaces).
Persons who have genuine tooth-size
discrepancies pose special problems, but in the
absence of such abnormalities tight contact should
exist. Without exception, the contact points on the
non orthodontic normal were tight. (Serious tooth-
size discrepancies should be corrected with
jackets Fig. 11. The wagon wheel. Anterior arch
wire torque negates arch wire tip in a ratio of four
to one, so the orthodontist will not have to close
spaces at the expense of good occlusion.)
38. Key VI. Occlusal plane. The planes of occlusion found on
the non orthodontic normal models ranged from flat to slight
curve of Spee. Even though not all of the non orthodontic
normals had flat planes of occlusion, I believe that a flat
plane should be a treatment goal as a form of overtreatment.
There is a natural tendency for the curve of Spee to deepen
with time, for the lower jaw’s growth downward and forward
sometimes is faster and continues longer than that of the
upper jaw, and this causes the lower anterior teeth to be
forced back and up.
Fig. 12. A rotated molar occupies more mesiodistal space,
creating a situation unreceptive to normal occlusion.
Crowded lower anterior teeth and/or a deeper overbite and
deeper curve of Spee.
39.
40. At the molar end of the lower dentition, the molars
(especially the third molars) are pushing forward,
even after growth has stopped, creating essentially
the same results.
If the lower anterior teeth can be held until after
growth has stopped and the third molar threat has
been eliminated by eruption or extraction, then all
should remain stable below, assuming that treatment
has otherwise been proper.
Lower anterior teeth need not be retained after
maturity and extraction of the third molars, except in
cases where it was not possible to honour the
musculature during treatment and those cases in
which abnormal environmental or hereditary factors
exist.
41. Intercuspation of teeth is best when the plane of
occlusion is relatively flat (Fig. 13, B). There is a
tendency for the plane of occlusion to deepen after
treatment, for the reasons mentioned. It seems only
reasonable to treat the plane of occlusion until it is
somewhat flat or reverse to allow for this tendency.
In most instances one must band the second
permanent molars to get an effective foundation for
leveling of the lower and upper planes of occlusion.
A deep curve of spee results in a more contained
area for the upper teeth, making normal occlusion
impossible. In Fig. 13, only the upper first premolar is
properly intercuspally placed.
43. The remaining upper teeth, anterior and
posterior to the first premolar, are
progressively in error.
A reverse curve of Spee is an extreme form
of overtreatment, ; excessive space for each
tooth to be intercuspally placed (Fig. 13, C).
44. Although normal persons are as one of a kind as
snowflakes, they nevertheless have much in
common (one head, two arms, two legs, etc.).
The 120 non orthodontic normal models studied in
this research differed in some respects, but all
shared the six characteristics described in this
report.
The absence of any one or more of the six results
in occlusion that is proportionally less than normal.
45. It is possible, of course, to visualize and to
find models which have deficiencies, such as
the need for caps, preventing proper contact,
but these are dental problems, not
orthodontic ones. Sometimes there are
compromises to be weighed, and these pose
the true challenge to the professional
judgment of the orthodontist.
46. As responsible specialists, we are here to attempt
to achieve the maximum possible benefit for our
patients. We have no better example for emulation
than nature’s best, and in the absence of an
abnormality outside our control, why should any
compromise be accepted?
Successful orthodontic treatment involves many
disciplines, not all of which are always within our
control. Compromise treatment is acceptable
when patient cooperation or genetics demands it.
Compromise treatment should not be acceptable
when treatment limitations do not exist.
47. In that nature’s non orthodontic normal
models provide such a beautiful and
consistent guideline, it seems that we should,
when possible, let these guidelines be our
measure of the static relationship of
successful orthodontic treatment. Achieving
the final desired occlusion is the purpose of
attending to the six keys to normal occlusion.