Surgical orthodontics. /certified fixed orthodontic courses by Indian dental academy

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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,
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Surgical orthodontics. /certified fixed orthodontic courses by Indian dental academy

  1. 1. Tuesday, March 4, 2014 www.indiandentalacademy.com
  2. 2. Tuesday, March 4, 2014 ENT OF TM DEPAR ONTICS ORTHOD AND FACIAL www.indiandentalacademy.com DENTO PEDICS
  3. 3. Tuesday, March 4, 2014 www.indiandentalacademy.com Dr. Syed Zameer
  4. 4. HISTORY AND BACKGROUND PSYCHOLOGICAL IMPLICATIONS PATIENT SELECTION ETIOLOGIC FACTORS ENVELOPE OF DISCREPANCY DIAGNOSIS VARIOUS SURGICAL OPTIONS BIOMECHANICAL FACTORS Tuesday, March 4, 2014 www.indiandentalacademy.com
  5. 5. INTRODUCTION The concept of beauty is central to all human cultures regardless of race ,age and sex and it is deeply rooted in the nature of man . In various ways ,human esthetics has been woven into the tradition of human civilization. Physical appearance has always played a significant role in the development of self-conceptualization and self esteem, in the establishment of inter personal relationship, in employment opportunities and in quality of life. Tuesday, March 4, 2014 www.indiandentalacademy.com
  6. 6. What is orthodontic surgery ? Tuesday, March 4, 2014 www.indiandentalacademy.com
  7. 7. A procedure by which dento-facial deformities and malocclusions are corrected with orthodontics combined with the surgical modification of the facial morphology and various soft tissue structures . The term orthognathic originates from the Greek words “Orthos”, meaning straight, and” Gnathos”, meaning jaw. Tuesday, March 4, 2014 www.indiandentalacademy.com
  8. 8. HISTORICAL BACKGROUND First mandibular osteotomy : HULLIHEN (1849) done to correct a protrusive malposition of a mandibular alveolar segment caused by a burn Mandibular body osteotomy: VILRAY BLAIR (1897) done to correct mandibular prognathism (St. Louis Operation) The beginning of the early orthognathic surgery was in St.Louis where the orthodontist Edward Angle and the surgeon Blair worked together. Tuesday, March 4, 2014 www.indiandentalacademy.com
  9. 9. PSYCHOLOGICAL IMPLICATIONS The area of the body which maximally determines physical attractiveness is the face. It is a primary means of identification , expression and non-verbal communication. There is a high value of cosmetic characteristics in the current society and severe cranio-facial deformity may cause significant psychosocial problems. Facial deformity is defined as “ a physiognomic form that is sufficiently negatively marked so as to set the individual apart from the general population”. A dentofacial anomaly may have an adverse effect on an individuals self esteem and self confidence as well as evoke an undesirable social response . Tuesday, March 4, 2014 www.indiandentalacademy.com
  10. 10. PSYCHOLOGICAL IMPLICATIONS Tuesday, March 4, 2014 www.indiandentalacademy.com
  11. 11. PSYCHOLOGICAL IMPLICATIONS Concept of “Body image” ( Schilder and Schonfeld ) 2 components of body image are 1. Body sense 2. Body concept Body sense The actual appearance the person sees when viewing himself in a mirror or photograph. Body concept The internal process of how the patient feels about his appearance. Generally those patients with a good body image in spite of having a deformity are better candidates for surgery Tuesday, March 4, 2014 www.indiandentalacademy.com
  12. 12. PSYCHOLOGICAL IMPLICATIONS EXTERNAL & INTERNAL MOTIVATION Edgerton & knorr pointed out the importance of external versus internal motivation. ‘Internal pressure’ would be that originating within the patient and usually involves depression and a sense of inadequacy. ‘External pressure’ would include the need to please others and a desire to overcome career or social problems through a change in appearance Tuesday, March 4, 2014 www.indiandentalacademy.com
  13. 13. PATIENT SELECTION An orthodontist must determine at an early stage why the patient is seeking treatment and what the patient hopes to achieve .The surgeon must then decide whether this demand can be met surgically. LAVEL emphasized that satisfaction begins with selection of appropriate patients. The selection can be represented by the acronym SAFE. S- Self assessment of attractiveness A- Anxiety F- Fear E- Expectation Tuesday, March 4, 2014 www.indiandentalacademy.com
  14. 14. ETIOLOGIC FACTORS Dentofacial deformity Developmental problem. Occasionally the deformity is due to a single specific cause, much more frequently they result from a complex interaction among multiple factors that influence growth and development. ETIOLOGY KNOWN SPECIFIC CAUSE Tuesday, March 4, 2014 HEREDITARY FACTORS www.indiandentalacademy.com ENVIRONMENTAL INFLUENCES
  15. 15. SPECIFIC CAUSES FACIAL SYNDROMES AND CONGENITAL DEFECTS, WHOSE ETIOLOGY IS PRE-NATAL FAS AND RELATED PROBLEMS ANORMALITIES OF NEURAL REST CELL ORIGIN AND MIGRATION : Hemifacial microsomia Mandibulofacial dysostosis FACIAL CLEFTING SYNDROME ACHONDROPLASIA PREMATURE FUSION OF CRANIAL AND FACIAL SUTURES: POST NATAL GROWTH DISTURBANCES OF KNOWN ORIGIN, INCLUDING THE EFFECT OF TRAUMA TRAUMA: Maxillary trauma Mandibular trauma(functional ankylosis) MUSCLE DISTURBENCES(TORTICOLLIS) CONDYLAR HYPERPLASIA Plagiocephaly Crouzon’s syndrome Apert’s syndrome Tuesday, March 4, 2014 www.indiandentalacademy.com
  16. 16. HEREDITARY FACTORS Malocclusion is much more common now than it was in primitive human populations. It seems logical that one effect of increased intermarriage among previously isolated population subgroups would be an increased number of individuals requiring orthodontic –surgical treatment. The influence of inherited tendencies seems to be particularly strong for mandibular prognathism. CRANIOFACIAL anomalies often have a genetic background.Reccnt advances in molecular genetics have revealed a genetic explanation for conditions that do not even appear to be genetic in origin . Tuesday, March 4, 2014 www.indiandentalacademy.com
  17. 17. Craniosynostosis ……………………..….. MSX-2 Tricho-dento-osseous syndrome…………..DLX-3 and DLX-7 Cleidocranial dysplasia………………..…..CDFA1 Treacher Collins syndrome ……………....Long arm of ch. 5 Holoprosencephaly…………………….….HPE3 Cleft lip and palate ………………….……MSX1 and TGFB3 Crouzon syndrome………………….…….FGFR2 Tuesday, March 4, 2014 www.indiandentalacademy.com
  18. 18. ENVIRONMENTAL INFLUENCES Environmental influences on dento facial development includes obvious external influences such as trauma ,but more importantly , this category includes the group of etiologic factors related to function. The importance of posture in controlling soft-tissue pressure Form Function The form function interaction includes both the effects of active movement and the subtle but long lasting effect of the soft tissue on the developing skeletal and dental structures. Tuesday, March 4, 2014 www.indiandentalacademy.com
  19. 19. Tongue habits ,particularly tongue thrust swallowing ,have been blamed for many instances of protrusion of incisors and anterior open bite . Soft tissues of the lips , cheeks and the tongue exert pressure against the teeth and alveolar process while the tissues are at rest as well as when they are moving in function. Although these resting pressures are small in the range of 5 to 15 grams , they are large enough to cause tooth movement and remodeling of the alveolar process. BITING FORCE AND JAW MORPHOLOGY One characteristic of patients with the long-face condition is that the posterior teeth erupt further than normal. Conversly ,in short face patients , the teeth are infra-erupted. Tuesday, March 4, 2014 It seems obvious that biting force , which opposes eruption , should be involved in its control. www.indiandentalacademy.com
  20. 20. It is possible that difference in biting strength and therefore in biting force ,is involved in the etiology of long- and short-face problems. The relationship between facial morphology and occlusal forces does not prove a cause and effect relationship. There are three possibilities Muscle weakness and thus low occlusal force may allow the teeth to erupt too much and cause the mandible to rotate down and back Excessive eruption of teeth may cause the mandible to rotate down and back, putting muscles at a mechanical disadvantage that reduces occlusal force . The long face pattern and the decrease in occlusal force are both caused by something else and are not necessarily related. Tuesday, March 4, 2014 www.indiandentalacademy.com
  21. 21. Respiratory influence Mouth breathing has been blamed for altered dentofacial development Harvold etal showed that total blocking the nares led to Various moderate to severe malocclusions . (AJODO, 79. 1981).Because the lower jaw was positioned forward , the deformity always included a component of mandibular prognathism along with various displacements of teeth Total nasal obstruction Downward backward rotation Long face deformity Tuesday, March 4, 2014 www.indiandentalacademy.com
  22. 22. Envelope of discrepancy There are limits to how far a tooth can be moved, and these limits become important when bite relationships must be changed to correct crossbite ,deepbite , open bite or incisor protrusion. Tuesday, March 4, 2014 www.indiandentalacademy.com
  23. 23. DIAGNOSIS ………the search for truth Tuesday, March 4, 2014 www.indiandentalacademy.com
  24. 24. Tuesday, March 4, 2014 www.indiandentalacademy.com
  25. 25. Facial proportions and esthetics A precise and detailed soft tissue evaluation is always essential to derive proper diagnosis and accurate treatment plan which maximizes the patient’s benefit. The most important point in proper analysis of facial esthetics is the use of a clinical format. Examination should not be based on static laboratory x-ray film and photographic representation of the patient alone. Tuesday, March 4, 2014 www.indiandentalacademy.com
  26. 26. Three important parameters which are to be checked before proceeding with clinical examination are:- Natural head position Centric relation Relaxed lip posture Tuesday, March 4, 2014 www.indiandentalacademy.com
  27. 27. Once after these 3 things are established one can go ahead with facial examination. Two views of the patient are used for identification of problems in 3 planes of space. Frontal view Profile view Frontal view 1. Outline form & symmetry 2. Facial level 3. Midline alignments 4. Facial one thirds 5. Lower one-third evaluation 6. Upper & lower lip lengths 1. Soft tissue profile angle 2. Nasolabial angle 3. Maxillary sulcus contour 4. Mandibular sulcus contour 5. Orbital rim 6. Cheekbone contour 7. Nasal base-lip contour 7. Upper tooth to lip relationship 8. Nasal projection 9. Throat length and contour 8. Interlabial gap Tuesday, March 4, 2014 www.indiandentalacademy.com Subnasale-pogonion line ( sn-pg’) 10.
  28. 28. Outline form & symmetry General outline form & symmetry are noted. The widest dimension of the face is the zygomatic width .According to the normal values established by Farkas with Anthropometric studies the bigonial width is approximately 30% less than the bizygomatic dimension Short, square facial outlines are indicative of deep bite class II malocclusion, vertical maxillary deficiency, and in some cases masseteric hyperplasia. Long, narrow faces are associated with vertical maxillary excess, or mandibular protrusion with dental interferences leading to open bite. Tuesday, March 4, 2014 www.indiandentalacademy.com
  29. 29. Facial level To examine facial levels a reliable horizontal landmark is necessary. With the patient in natural head posture, the pupils are assessed for level with the horizon. If pupils are level, they are used as the horizontal reference line and adjacent structures are measured relative to this line. Structures compared with the pupil line are:- Upper canine level Lower canine level Chin & jaw level Tuesday, March 4, 2014 www.indiandentalacademy.com
  30. 30. Midline alignments Midlines are assessed with upper most condyle position and first tooth contact. If occlusal slides alter joint position, no reliable midline assessment can be made. The relative positions of soft tissue landmarks (nasal bridge, nasal tip, philtrum, and chin point) and dental midline landmarks (upper incisor midline, lower incisor midline) are noted. Needed changes are incorporated into the surgical-orthodontic treatment plan to position these structures on the vertical midline of the face. Philtrum is usually a reliable midline structure and can be used as the basis for midline assessment most often. Tuesday, March 4, 2014 www.indiandentalacademy.com
  31. 31. Transverse Facial Proportions: Rule of fifths Tuesday, March 4, 2014 www.indiandentalacademy.com Facial one thirds
  32. 32. The Central Fifth: - Delineated by the inner canthus of the eyes Inner canthal distance= alar base of nose The Medial Fifth: - Width of mouth= interpupillary distance Line from the outer canthus should coincide with the gonial angles Tuesday, March 4, 2014 www.indiandentalacademy.com
  33. 33. Lower one-third evaluation This area of facial analysis is extremely important in surgical orthodontic diagnosis and treatment planning. The importance of relaxed lip position for these measurements cannot be overemphasized. Upper & lower lip lengths The lips are measured independently in a relaxed position. The normal length from subnasale to upper lip inferior is 19 to 22mm. The lower lip is measured from lower lip superior to soft tissue menton and normally measure in a range of 38 to 44mm. The closed lip length is misleading and should not be used Tuesday, March 4, 2014 treatment planning www.indiandentalacademy.com for
  34. 34. Upper tooth to lip relationship Conditions of disharmony are produced by 4 variables :Increased or decreased anatomic upper lip length Increased or decreased maxillary skeletal length Thick upper lip expose less incisor than thin upper lips, all other factors being equal. The angle of view changes the amount of incisor visible to the viewer. The distance from upper lip inferior to maxillary incisal edge is measured. The normal range is 1 to 5 mm. Women show more within this range. Surgical and orthodontic vertical changes are based primarily on this measurement Over impaction of upper incisor teeth leads to the appearance of premature ageing, especially in conjunction with maxillary retraction. This type of surgical movement Tuesday, March 4, is rarely indicated. 2014 www.indiandentalacademy.com
  35. 35. Interlabial gap With the lips relaxed, a space of 1 to 5mm between upper lip inferior and lower lip superior is present. Females show a larger gap within the normal range. This measurement is also dependent on lip lengths and vertical dentoskeletal height.Increase in inter labial gap are seen with anatomic short upper lip, vertical maxillary excess, and mandibular protrusion with open bite secondary to cuspal interferences. Decreased interlabial gap is found with vertical maxillary deficiency, anatomically long upper lip (natural change with ageing, esp. in males) and mandibular retrusion with deep bite. An anatomically short upper lip should be recognized as a soft tissue problem and should not Tuesday, March 4, 2014 www.indiandentalacademy.com be treated by excessively shortening the maxilla. This can lead to a short, round facial outline
  36. 36. Closed lip position Even though an understanding of relaxed lip position is essential, an understanding of closed lip position adds support to diagnostic patterns. The closed lip position also reveals disharmony between skeletal and soft tissue lengths. Increased mentalis contraction, lip strain, and alar base narrowing are observed in vertical skeletal excess, anatomic short upper lip and in some cases of mandibular protrusion with open bite. Tuesday, March 4, 2014 www.indiandentalacademy.com
  37. 37. Smile position lip level Ideal exposure with smile is three-quarters of the crown height to 2mm of gingiva. Females show more gingival exposure than males. Excess gingival exposure may be caused by:a short upper lip, vertical maxillary excess, short clinical crown, and /or large lip elevation Because of etiological variability surgical shortening of the maxilla is indicated only when excess gingival exposure is found in combination with increased interlabial gap, increased incisor exposure, increased lower facial height. Tuesday, March 4, 2014 www.indiandentalacademy.com
  38. 38. Particular care should be taken with short clinical crowns. A 3 to 4mm repose incisor exposure may expose unacceptable amounts of gingiva when smiling The gingival smile is never treated to ideal at the expense of underexposing the incisors in the relaxed lip position. Tuesday, March 4, 2014 www.indiandentalacademy.com
  39. 39. Profile view Soft tissue profile angle This angle is formed by connecting soft tissue glabella, subnasale, and soft tissue pogonion. Tuesday, March 4, 2014 Class I occlusion presents a total facial angle range of 165 to 175 degrees. Surgical procedures should generally address the cosmetic imbalance established with this angle. The profile angle is the most important key to the need for anteroposterior surgical correction. When values are less than 1650 or greater than 1750, skeletal www.indiandentalacademy.com malocclusion needing surgery are probably the cause
  40. 40. Nasolabial angle This angle is formed by the intersection of the upper lip anterior and columella at subnasale. This angle can change noticeably with orthodontic and surgical procedures that alter the antero-posterior position or inclination of the maxillary anterior teeth. Desirable range of 85 to 105 degrees As a general rule, the maxilla should not be moved posteriorly in treating dento-facial deformities, especially in combination with superior repositioning.This creates nasal elongation, alar base depression, and opening of the nasolabial angle, all of which creates facial premature ageing. Tuesday, March 4, 2014 www.indiandentalacademy.com
  41. 41. Maxillary sulcus contour Normally this sulcus is gently curved and gives information regarding upper lip tension Maxilla should not be retracted significantly when a deeply curved thick lip is present since this produces poor lip support. If possible maxilla should be moved forward into a thick, curved lip to improve lip support. Tuesday, March 4, 2014 www.indiandentalacademy.com
  42. 42. Orbital rim The orbital rim is an antero-posterior indicator of maxillary position. Deficient orbital rims may correlate positionally with a retruded maxillary position because the osseous structures are often deficient as groups ,rather than in isolation.The globe normally is positioned 2-4mm anterior to the orbital rim. The surgical maxillary versus mandibular decision is influenced by the orbital rim position. Deficient orbital rims dictates maxillary advancement, all other factors being equal. Tuesday, March 4, 2014 www.indiandentalacademy.com
  43. 43. Cheekbone contour Cheekbone assessment requires frontal and profile examination simultaneously. Cheekbone contour (CC) correlates with maxillary antero-posterior position, frequently the cheek bone contour is deficient in combination with maxillary retrusion. This area should have an apex at the cheekbone point (CP) and not appear flat. The CP is located 20 to 25mm inferior and 5 to 10 mm lateral to the OC. Tuesday, March 4, 2014 www.indiandentalacademy.com
  44. 44. Throat length and contour The distance from the neck-throat junction to the soft tissue menton should be noted .No millimeter measurement is necessary ,but a planned mandibular setback will change this length. The predicted esthetic result should produce a normal appearing length without sagging. A patient with a short, sagging throat length is not a good candidate for mandibular setback. Often a mandibular setback is necessary with chin augme-ntation to balance lips with chin and maintain throat length. Suction lipectomy is a useful adjunct for controlling submental sag with setbacks or when isolated fat accumulation is present. Tuesday, March 4, 2014 www.indiandentalacademy.com
  45. 45. Chin-neck angle: Also termed cervicomental angle Varies between 105-120º Tuesday, March 4, 2014 www.indiandentalacademy.com
  46. 46. Nasal projection The nasal projection measured horizontally from subnasale to nasal tip is normally 16 to20mm ,nasal projection is an indicator of maxillary antero-posterior position. This length becomes particularly important when contemplating anterior movement of maxilla. Decreased nasal projection contraindicates Maxillary advancement. With a class III malocclusion, short nose, and all Tuesday, March 4,other parts equal, mandibular setback is indicated. 2014 www.indiandentalacademy.com
  47. 47. Subnasale - pogonion line ( sn-pg’) The relationship of lips to the sn-pg’ line is an important aid in orthodontic soft tissue analysis and treatment. Tooth movement changes the relationship of the lips to the sn-pg’ line and therefore the esthetic result. Burrstone reported that the upper lip is in front of the sn-pg’ line by 3.5mm±1.4mm, and lower lip in front of the line by 2.2mm±1.6mm. All tooth movements should be assessed in regard to the anticipated Tuesday, March 4, 2014 change to the sn-pg’ line. www.indiandentalacademy.com lip
  48. 48. Relationship of the lips to the nose and chin: In a chin deficient patient, lower lip may appear full or procumbent Tuesday, March 4, 2014 www.indiandentalacademy.com
  49. 49. CEPHALOMTRIC DIAGNOSIS Tuesday, March 4, 2014 www.indiandentalacademy.com
  50. 50. Soft tissue Cephalometric analysis Arnett and Bregman presented the Facial Keys to Orthodontic Diagnosis and treatment planning as a three-dimensional clinical blueprint for soft tissue analysis and treatment planning. Cephalometrics for orthognathic surgery This cephalometric analysis was specially designed for the patient who requires maxillofacial surgery And uses those landmarks and measurements which can be altered by common surgical procedures . PA view cephalograms Rickets analysis (rocky mountain) Grummens analysis Tuesday, March 4, 2014 www.indiandentalacademy.com
  51. 51. BIOMECHANICAL FACTORS IN SURGICAL ORTHODONTICS Tuesday, March 4, 2014 www.indiandentalacademy.com
  52. 52. It was not untill mid of 20th century ,that refinements in Surgical technique , Biological understanding and Antibiotic made surgery a practical option Appropriate diagnosis Treatment planning Biomechanical principles Tuesday, March 4, 2014 www.indiandentalacademy.com
  53. 53. Maxillary orthognathic surgery MAXILLARY SURGERY IMPACTION ADVANCEMANT INFERIOR POSITIONING SET BACK SEGMENTATION OF MAXILLA The level of the osteotomy must also be considered. The options range from leFort I to LeFort III , with several variations Tuesday, March 4, 2014 www.indiandentalacademy.com
  54. 54. IMPACTION The most common indication for maxillary surgery is vertical skeletal dysplasia The maxilla can be moved upwards by 10 – 15 mm with excellent stability Alar cinch Collins and Epker identified patients who may develop undesirable nasal aesthetic changes as those who have normal or wide frontonasal aesthetics before surgery. These observations led to the development of techniques to ensure an esthetic reconstruction of alar Tuesday, March 4, 2014 www.indiandentalacademy.com
  55. 55. The suture is passed from transverse nasalis muscle on one side of The alar base to the other side and tied to a pre determined width V-Y Closure The upper lip when closed in a V-Y fashion , follows the hard tissue at nearly 1:1 ratio, with prevention of loss of vermilion. Tuesday, March 4, 2014 www.indiandentalacademy.com
  56. 56. COGS analysis indications include:Increased upper and lower facial height (N-ANS & ANS-Gn) Increased mandibular plane angle (MP-HP) Increased posterior facial height (N-PNS ) Increased gonial angle (Ar-Go-Gn) Increased facial height ratio (N-ANS/ANS-Gn) Divergent occlusal planes Clinical presentation:Increased lip to tooth relation Increased gingival display Increased inter labial gap relation Relative mandibular deficiency Anterior open bite (may be compensated by hyper eruption of teeth) Tuesday, March 4, 2014 www.indiandentalacademy.com
  57. 57. Biomechanical factors Minimize orthodontic extrusion –occurs rapidly with mechanics such as the placement of low modulus continuous archwires Segmented arch mechanics are an excellent way to predictably control the point of force application and the magnitude of force applied When divergent occ. planes exist the treatment occ. plane must be selected first , then appropriate force system designed .(typically a functional occlusal plane is drawn) Tuesday, March 4, 2014 www.indiandentalacademy.com
  58. 58. If maxillary ant. teeth have erupted significantly beyond the treatment occ. plane , an extremely efficient orthodontic mechanism for leveling the arch is the intrusive base arch. NOTE :Many surgeons perform intermaxillary fixation, orienting the maxilla to mandible and autorotating the entire maxillomandibular complex to the desired vertical position , and then using rigid fixation .This will cause a slight maxillary advancement in addition to impaction. Tuesday, March 4, 2014 www.indiandentalacademy.com
  59. 59. ADVANCEMENT The maxilla can be moved forward up to 10 mm. This movement has 2 limitations:Major limitation to move the maxilla forward is the resistance of the soft tissues anterior to it (upper lip). It is particularly important in a patient with cleft lip and palate who are likely to have maxillary deficiency and are good candidate for maxillary advancement. Velopharyngeal closure during speech:Failure to achieve a seal to between soft palate and the posterior pharyngeal wall allows leakage of air through the nose and causes “cleft-palate speech” in normal patients. Tuesday, March 4, 2014 www.indiandentalacademy.com
  60. 60. COGS analysis indications include:Glabella – subnasale ( G-Sn ) Nasion –Point A (N-A) Nasion –Point B (N-B) Nasion –pogonion (N-Pg) Nasion - pogonion (N-Pg’) Clinical indications:Decreased pharyngeal airway Excessive submental adipose tissue Decreased malar convexity Increased nasolabial grooves Tuesday, March 4, 2014 www.indiandentalacademy.com
  61. 61. Along with the A-P discrepancy in many pts. varying degree of transverse discrepancy is found . Typically a cross bite exists as part of the presenting class III malocclusion CROSS BITE DENTAL SKELETAL RELATIVE ABSOLUTE DIAGNOSIS SK. CROSS BITE:- Tuesday, March 4, 2014 PA cephalogram (J point measured to MSR) Model analysis Occlusograms www.indiandentalacademy.com
  62. 62. The maxilla can be narrowed or widened perhaps 15mm ,but 10 mm of change is more reasonable expectation. Techniques for correction: Maxillary transverse distraction osteogenesis Surgically assisted RPE Segmentation of the maxilla The location of the segmental osteotomy depends on the desired arch Tuesday, March 4, 2014 www.indiandentalacademy.com expansion.
  63. 63. Development of inter dental osteotomy site Segmental root springs Bracket repositioning with continuous wire can also be used Tuesday, March 4, 2014 www.indiandentalacademy.com
  64. 64. With an open coil spring ,the roots are brought closer together rather than farther apart The most important area in interdental osteotomy is the divergence of roots not the crowns Tuesday, March 4, 2014 www.indiandentalacademy.com
  65. 65. Transverse dental constriction TPA provides an essential method of arch expansion(0.036’’ SS heat treated) First the TPA should be fitted passively, to assure no unintentional forces ,moments Or vertical couples Activation:- Expand the TPA Place buccal root torque (to prevent buccal tipping) Note :- equal amount of torque on both sides to prevent iatrogenic occ. plane cant Tuesday, March 4, 2014 www.indiandentalacademy.com
  66. 66. Inferior repositioning (down graft) Technically feasible procedure Strong tendency for relapse Inter-positional grafts are required to prevent the relapse tendency. Instability may be due to the stretch of the soft tissues created when the maxilla is moved downward. This would create a gentle and constant force to move the maxilla back. Tuesday, March 4, 2014 www.indiandentalacademy.com
  67. 67. COGS analysis indications include:Decreased lower facial height (ANS-Gn) Decreased mandibular plane angle (MP-HP) Decreased gonial angle (Ar-Go-Gn) Increase facial height ratio (N-ANS/ANS-Gn) Deep overbite Clinical presentation:Decreased lip to tooth relation Decreased gingival display No interlabial gap Relative prognathism/prominent chin button Tuesday, March 4, 2014 www.indiandentalacademy.com
  68. 68. Backward movement Very limited movement is possible (only 3-5mm) due to bony interferences. Instead the objective is to retract the protruding anterior portion by sectioning the maxilla and removing the bone across the palate Then the anterior segments can be brought back posteriorly while the posterior segments remain in position. Tuesday, March 4, 2014 www.indiandentalacademy.com
  69. 69. END OF PART - I Tuesday, March 4, 2014 www.indiandentalacademy.com
  70. 70. CONTENTS ……PART II Mandibular surgeries:- Advancement High angle Low angle Setback Chin surgery Dentoalveolar surgeries Implication of incomplete growth Soft tissue changes Appliance selection Retention and stability Conclusion and references Tuesday, March 4, 2014 www.indiandentalacademy.com
  71. 71. Tuesday, March 4, 2014 www.indiandentalacademy.com

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