Class I Malocclusion_ Dr. Nabil Al-Zubair

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Class I Malocclusion_ Dr. Nabil Al-Zubair

  1. 1. Class I Malocclusion Dr. Nabil Al-Zubair
  2. 2. or incorrect relation between the teeth of the two dental arches. The term was coined by Edward Angle, the "father of modern orthodontics", as a derivative of occlusion, which refers to the manner in which opposing teeth meet. Malocclusion is a misalignment of teeth
  3. 3. Presence of alignment or Occlusal Features Outside the Normal when the anteroposterior incisor relationship is Class I. • Definition **Note: always when making Dx we look at the incisors relationship.
  4. 4. 1) Class I malocclusion. 2) Bimaxillary protrusion Most common forms are:
  5. 5. Class I malocclusions 60% Class II malocclusions 32 % PREVALENCE This is the most common of all the malocclusions.
  6. 6. Extra-oral Features: Intra-oral features • Straight profile • Harmonious face • Average Vertical Proportions • Class I incisor relation • Canine and molar relationships are usually class I • overjet is usually within average • overBITE: normal, deep, reduced or open bite • Normal Bite, Crossbite or Scissor Bite
  7. 7. • Harmonious face • Straight profile • Nothing really abnormal Extra-oral Features of : ‫الوجه‬‫المتناسق‬ ‫الجانبي‬ ‫التشكيل‬ ‫مستقيم‬
  8. 8. There is a harmonious growth between the upper and lower jaw, which accounts for the skeletal and facial balance Growth:
  9. 9. when the maxillary growth exceeds the mandibular growth that will result in class II skeletal relationship. On the other hand if the mandibular growth exceeds the maxillary growth that will result in class III. Harmonious Growth
  10. 10.  Average Vertical Proportions
  11. 11. **But some vertical and transverse anomalies may be found.  Vertical and transverse: **Within normal range - LFH - Frankfort mandibular angle
  12. 12.  The soft tissue form and activity are usually within normal range  Soft tissues (lips) :  Favorable ‫إيجابي‬ is not aetiological factor. This is a major factor in determining tooth position.  Competent lips
  13. 13. The exception is (Bimaxillary proclination) where the upper & lower incisors are proclined. the lips are full and everted.
  14. 14. (Bimaxillary proclination) the lips are full and everted. This may be duo to: 1- Racial in origin 2- Lack of lip tonicity results in the incisors being moulded forwards under tongue pressure.
  15. 15. DIAGNOSIS:
  16. 16. History Clinical examination Study models Radiography I. OPG II. Periapical III. Lateral ceph DIAGNOSIS:
  17. 17. Intra-oral features
  18. 18. Intra-oral features • Class I incisor relation • Canine and molar relationships are usually class I • The overjet is usually within average • Can be associated with normal overbite, deep, reduced or open bite • Can be associated with normal bite, crossbite or scissor bite.
  19. 19. Problems associated with Class I: • Crowding • Spacing • Deep Bite • Open Bite • Cross Bite • Localized Teeth Problems (impaction)
  20. 20. Crowding
  21. 21. Crowding: space deficiency The most common problem. or labial segment buccal segment both It can be in or if there is a crowded dental arch, the last tooth within the arch to erupt will often be impacted or crowded out of the line of the dental arch. ‫تزاحم‬
  22. 22. 1. difficulty cleaning all tooth surfaces, leading to more dental decay 2. an improper bite pattern 3. incorrect functioning of the teeth 4. an increased chance of developing periodontal disease 5. an unattractive smile, leading to lower self-esteem Problems associated with crowding include:
  23. 23. •‫السليمة‬ ‫المضغ‬ ‫عملية‬ ‫إعاقة‬. •‫خطورة‬ ‫يزيد‬ ‫مما‬ ‫األسنان‬ ‫نظافة‬ ‫على‬ ‫المحافظة‬ ‫صعوبة‬ ‫اللثة‬ ‫أمراض‬ ‫أو‬ ‫والتهابات‬ ، ‫األسنان‬ ‫بتسوس‬ ‫اإلصابة‬. •‫األحيان‬ ‫بعض‬ ‫في‬ ‫الفم‬ ‫وعضالت‬ ‫الفك‬ ‫و‬ ‫األسنان‬ ‫إجهاد‬ ‫تحطم‬ ‫أو‬ ‫كسر‬ ‫خطورة‬ ‫من‬ ‫يزيد‬ ‫مما‬ ‫كبيرة‬ ‫بدرحة‬ ‫األسنان‬. •‫سلبية‬ ‫آثار‬ ‫من‬ ‫الشعور‬ ‫لهذا‬ ‫ما‬ ‫و‬ ‫باإلبتسامة‬ ‫الرضا‬ ‫عدم‬ ‫بنفسه‬ ‫الشخص‬ ‫ثقة‬ ‫على‬. ‫األسنان؟‬ ‫تزاحم‬ ‫عواقب‬
  24. 24. Crowding is a condition where there is Malalignment of teeth caused by inadequate space Definition ‫كافية‬ ‫غير‬ ‫مساحة‬ ‫وجود‬ ‫عدم‬ ‫بسبب‬‫االزدحام‬ ‫ارتصاف‬ ‫سوء‬ ‫عن‬ ‫عبارة‬ ‫وهو‬‫لألسنان‬‫نقص‬ ‫عن‬ ‫ناجم‬ ‫أو‬ ‫الفك‬ ‫حجم‬ ‫في‬ ‫صغر‬ ‫بسبب‬ ‫السنية‬ ‫القوس‬ ‫على‬ ‫المسافة‬/‫و‬ ‫األسنان‬ ‫حجم‬ ‫في‬ ‫كبر‬,‫المخصصة‬ ‫المسافة‬ ‫ضياع‬ ‫بسبب‬ ‫أو‬ ‫والوحشي‬ ‫األنسي‬ ‫األسنان‬ ‫انسالل‬ ‫نتيجة‬ ‫الدائمة‬ ‫لألسنان‬ ‫شكل‬ ‫تغير‬ ‫بسبب‬ ‫أو‬ ‫اللبنية‬ ‫لألسنان‬ ‫المبكر‬ ‫القلع‬ ‫عن‬ ‫الناجم‬ ‫الزائد‬ ‫والخدود‬ ‫الشفاه‬ ‫ضغط‬ ‫عن‬ ‫الناجم‬ ‫السنية‬ ‫القوس‬,‫كما‬ ‫أدناه‬ ‫الصورة‬ ‫في‬  Environmental Crowding Hereditary Crowding 1. Classification Classification of Crowding There are different methods of Classification of Crowding
  25. 25. Also called late incisor crowding is due to late mandibular growth Classification of Crowding Determined Genetically & is caused by disproportion between jaw size and teeth size Primary crowding Secondary crowding Tertiary crowding Acquired crowding is caused by loss of arch length due to Environmental cause
  26. 26. Crowding Aetiology Primary / hereditary crowding:- (Determined genetically) - discrepancy between the size of the teeth & the size of the arches. - Normal teeth & small dental arch - Large teeth & normal dental arch Secondary crowding: (An acquired anomaly) After - Premature loss of deciduous (1) mesial drifting of the posterior teeth (in the lateral segment) 2) lingual or distal displacement of the anterior teeth Tertiary crowding: The etiopathogensis is under debates Occur mainly in the mandibular anterior teeth during & after adolescence - Forward growth of mandible in conjunction with soft tissue pressures - Mesial migration of the posterior teeth. - Erupting third molars
  27. 27. Tertiary crowding: (late incisor crowding is due to late mandibular growth)
  28. 28. This is caused & associated with skeletal, muscular or functional occlusal problems This is due to disharmony b/w the size of teeth & the space available for them without skeletal, muscular or functional occlusal problems Simple crowding Complex crowding Classification of Crowding
  29. 29. Severe malalignment of all four incisor, supporting zone restricted Crowding in mixed dentition: Slight malalignment of anterior teeth, No abnormality in supporting zone First degree crowding Second degree crowding Third degree crowding Pronounced malalignment of anterior teeth, No abnormality in supporting zone
  30. 30. 1. Premature loss of primary tooth 2. Proximal caries leading to arch length discrepancy 3. Prolonged retention of primary tooth 4. Altered eruption sequence 5. Discrepancy in individual tooth size 6. Rotation of tooth 7. Ankylosed primary tooth 8. Trauma 9. Iatrogenic treatment 10. Abnormal shape of the tooth 11. Abnormal eruption path 12. Transposition of tooth Aetiology of crowding 1. Tooth size – jaw size discrepancy Hereditary crowding:Environmental Crowding
  31. 31.  Crowded mandibular incisor teeth Premature exfoliation of the primary canine  A midline displacement of the permanent mandibular incisors on the crowded side  Lateral incisors on the crowded side blocked out, usually lingually but occasionally labially  Crowded Maxillary incisor teeth Clinical Features of Class I Crowding  Class I molar
  32. 32.  Crowded mandibular incisor teeth Premature exfoliation of the primary canine  A midline displacement of the permanent mandibular incisors on the crowded side  Lateral incisors on the crowded side blocked out, usually lingually but occasionally labially  Crowded Maxillary incisor teeth  Bulging of canines in the unerupted position
  33. 33.  Crowded mandibular incisor teeth Premature exfoliation of the primary canine  A midline displacement of the permanent mandibular incisors on the crowded side  Lateral incisors on the crowded side blocked out, usually lingually but occasionally labially  Crowded Maxillary incisor teeth  A splaying out of the permanent maxillary or mandibular incisor teeth due to the crowded position of the unerupted canines  Bulging of canines in the unerupted position
  34. 34.  Crowded mandibular incisor teeth Premature exfoliation of the primary canine  A midline displacement of the permanent mandibular incisors on the crowded side  Lateral incisors on the crowded side blocked out, usually lingually but occasionally labially  Maxillary mandibular alveolodental PROTRUSION without interproximal spacing  Crowded Maxillary incisor teeth  A splaying out of the permanent maxillary or mandibular incisor teeth due to the crowded position of the unerupted canines  Gingival Recession on the labial surface of the prominent mandibular incisor  Bulging of canines in the unerupted position
  35. 35. Management of crowding Investigations: Mixed dentition model analysis like Moyer’s is carried out to find out the arch length discrepancy
  36. 36. uses 4 lower permanent incisors TO: Predict the amount of crowding (or spacing) when 1st , 2nd premolars and canines erupt Moyer’s analysis Step1: Determine space available - Determine teeth size (lower incisors) - Use Moyer’s chart to get the total teeth size for the unerupted mandibular 1st,2nd premolars and canine Step 3: space analysis Space available - space required = a negative # = space deficiency Space available - space required = a positive # = excess space Step2: Determine space required:
  37. 37. Age – After eruption of 21/12 Timing Treatment Slight crowding–slight changes in the position of anterior teeth Wait and watch No treatment Moderate crowding–lack of space by width of one lateral incisor Can wait till (OR) premolar eruption Expansion Guidance of eruption Pronounced crowding Immediate Treatment Serial extraction Extraction & orthodontic treatment Crowding in mixed dentition : Therapy
  38. 38. Management of crowding in young adult
  39. 39.  Arch length analysis for permanent dentition like Carey’s analysis should be carried out  Complete Kessling’s diagnostic set-up should be carried out without proclining incisors Management of crowding in young Adult Investigations:
  40. 40. Carey’s analysis Crowding is determined by: - Subtracting the total mesiodistal tooth mass present from the amount of space available:
  41. 41. Degree of crowding= the Permanent Dentition space available= A+B_C+D space required= total mesiodistal tooth mass space required - space available
  42. 42. Treatment of crowding: Stripping Distallization Expansion Extraction MILD or MODERATE moderate to severe Treatment depends on the severity Analyze space discrepancy using model analysis.
  43. 43. - Treatment planning should be aimed at the choice of extraction - After extraction, treatment is done with preferably fixed appliance mechamotherapy Extraction Non-extraction In cases with mild discrepancy, non-extraction method of treatment is followed  Proximal reduction & treatment with either removable appliances or fixed appliance  Lip bumpers are useful in increasing the arch length  Arch expansion procedures also can be carried out to alleviate crowding  Molar distalisation is another method to gain space in minor crowding correction  Treatment can be either by non-extraction or extraction
  44. 44. Removable Appliances - Mild Crowding - Stripping then - Removable Appliances Contain: Z-spring & Labial bow Proximal reduction & treatment with either Stripping: cutting 0.5mm from the tooth mesially and distally but not more because then you’ll enter the dentine. To minimize the width of the teeth mesiodistally fixed appliance
  45. 45. Lip bumpers Relieve anterior crowding by DISTALIZATION of first permananet Molar
  46. 46. Arch expansion Mild – Moderate Crowding
  47. 47. Molar distalisation Moving the teeth posteriorly Mild – Moderate crowding
  48. 48. Extraction Usually either 1st or 2nd premolars are removed - (this is not a rule ya3ni if the premolars are sound but the 1st molar is grossly carious and decayed then we will go for extracting the molar instead of the sound premolars) Moderate – Severe crowding
  49. 49. What happen if we treat sever crowding without extraction?
  50. 50. Spacing
  51. 51. Imperfections in teeth alignment & distance, wherein there is gap b/w two teeth or many teeth Definition Types of Spacing LOCALIZED Spacing A condition in which Spacing is present in localised regions or areas (i) LOCALIZED Spacing (ii) GENERALIZED Spacing
  52. 52. Determined genetically Caused by (1) disproportionately sized teeth & jaws (2) tooth agenesis Primary / hereditary spacing An acquired anomaly Caused by drifting of teeth subsequent to loss of permanent teeth Secondary spacing  caused by bone loss due to periodontal disease Tertiary spacing: Classification of Spacing
  53. 53. Close the space / maintain Replace with an implant or bridge Aetiology of localized spacing a. Congenitally missing teeth b. Unerupted teeth: impacted/unerupted c. Premature loss of permanent teeth 1. Missing teeth This results in: (i) ectopic eruption of permanent successor & (ii) when the primary tooth is exfoliated after ectopic eruption of permanent successor space results 2. Prolonged retention of primary teeth 3. Sucking habits
  54. 54. 1. Arch length – tooth material discrepancy 2. Macroglossia 3. Sucking habits 4. Abnormal tongue posture Micodontia Macrognathia Best treated by : - jacket crowns, composite build-ups or - consolidation of spaces & placement of bridges Small teeth in normal jaws Normal teeth in large jaws a. Best method of treatment: Protract the Posterior Teeth to close anterior spaces if the profile is acceptable c. Other methods: jacket crowns, composite build-ups or consolidation of spaces & placement of bridges GENERALIZED Spacing The causes for Generalized spacing are:
  55. 55.  Conditions where spaces are to be closed by protraction of posterior teeth can be achieved only by fixed appliances mechanotherapy Orthodontic Management  Remove the cause  can be closed with removable appliances/ fixed appliance  If there is proclination associated with spacing. Hawley’s appliances are used for closing space & retraction  Retention: cases treated orthodontically usually required long-term retention LOCALIZED Spacing Generalized spacing  Prosthodontic management: some times localized spaces are best treated by: Jacket crowns or composite build-ups
  56. 56.  Generalized spacing is usually due to a jaw-size to teeth-size discrepancy. treatment of generalized spacing :- Usually with fixed appliance retain with permanent retainer bcz spacing tend to relapse you need to
  57. 57. Median diastema Is a form of localised spacing wherein there is a space present b/w two central incisors Causes of median diastema Normal/developmental 1. Physiological median diastema 2. Ethnic & familial 3. Imperfect fusion at midline of premaxilla Tooth material discrepancy 1. Micodontia 2. Macrognathia 3. Missing lateral 4. Peg lateral 5. Extracted teeth Physical impediment 1. Retained deciduous 2. Mesiodens 3. Enlarged labial frenum 4. Midline pathology Habits 1. Thumb sucking 2. Tongue thrusting Artificial causes RME
  58. 58. The possibility of space closure without treatment is inversely proportionate to diastema size. %Diastema in mm 991 mm 851.5 mm 501.85 mm 12.7 mm
  59. 59. Investigations  Examine & confirm whether median diastema is localized or part of generalized spacing  Measure the mesiodistal width of the teeth  BLANCH TEST:  Periapical radiograph: (V-shaped notching b/w the central incisors)
  60. 60.  Certain group of peoples, especially Negroid exhibit median diastema as an ethnic norm  Median diastema is seen in some families also 1. Physiological median diastema/ ugly duckling stage: 2. Ethnic & familial  Spacing b/w central incisors is part of normal growth  Self-corrected condition 3. Imperfect fusion at midline of premaxilla
  61. 61. Treatment of diastema :- if there is mesiodense or supernumerary you need to surgically extract the supernumerary tooth. { with both of these cases we need to do ortho to close the space } 1st ) We need to remove the cause >> If there is frenal attachment you need to do orthodontic & frenectomy.
  62. 62. Orthodontic Management Median diastema 1. Closure by mesial tipping movements: Appliances used are: Removable appliance with two finger springs Removable appliance with split labial bow 2. Closure by bodily movements:
  63. 63. if spacing results from proclination of incisors 3. Closure by reduction of overjet: Hawley’s appliances / Robert's retractor are used for closing space & retraction Fixed appliance
  64. 64. - Very small median diastema – composite build-ups /Crown 4. Restorative management: if you close the space then the appearance of the teeth will be odd so the more aesthetic option is to widen or enlarge them to look better.
  65. 65. Class I malocclusionwith deep Bite: Class I malocclusionwith open Bite: Class I malocclusionwith Crossbite:
  66. 66. growing patient Non-growing patient Anterior Bite Plane the overlapping of the upper anterior teeth over the lowers in the vertical plane”. Class I malocclusionwith deep Bite:
  67. 67. Class I malocclusion with Open Bite: Growing patient Non-growing patient Fixed appliance with box elastics/ Surgery - Eliminate habit: Thumb sucking/Tongue thrust/Mouth breathing - Growth modification Frankel IV or chin cap with high pull headgear
  68. 68. Class I malocclusion with Crossbite Malocclusion in which the mandibular teeth are in buccal version to the maxillary teeth Anterior Cross bite: Z-spring with posterior bite plane Expansion screw with posterior bite plane Tongue blade Single tooth: Cross-elastics Unilateral: Unilateral expansion screw Functional appliance Bilateral: Quad Helix Appliance Coffin spring/ Expansion screw Posterior Cross bite:
  69. 69.  IMPACTED or UNERUPTED TEETH.
  70. 70. Maxillary canine should be palpable in the buccal sulcus around 10 years old. If not, investigate by taken radiograph.
  71. 71. Palatal: bucal= 85% : 15% Unilateral : bilateral = 4:1 Female : Male = 70% : 30% Impacted canines Aetiology Multifactorial: - Long path eruption - Earlier development than adjacent lateral -Missing, small or anomalous adjacent lateral ( Guidance theory) -Genetic theory, inheritance Retained primary canines (Cs)
  72. 72. Auto transplantation Impacted canines: Treatment options: Pt. refuse ortho trt & no pathology Review with RGs every 6 month Pt. age= 10-13 Yrs Ext. of primary canines Pt. unwilling ortho trt & there is pathology Surgical exposure & Orthodontic alignment No treatment Interceptive treatment Surgical extraction ‫راغب‬ ‫غير‬
  73. 73. Surgical exposure & Orthodontic alignment
  74. 74. Dr. Nabil Al-Zubair

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