Cross bite ppt


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Cross bite ppt

  2. 2. What is normal BITE?
  3. 3. What is CROSS BITE??
  4. 4. • It’s a condition where one or more teeth may be abnormally malposed buccally or lingually or labially with reference to the opposing tooth or teeth –Graber • Discrepancy in the buccolingual relationship of the upper and lower teeth –Laura • An abnormal buccolingual (labiolingual) relationship of the teeth –Moyer • Post X-bite: Deviation from ideal occlusion in the transverse plane of space. -Proffit
  5. 5. PREVALANCE • Gender?? • Ethnic group??
  6. 6. • • • • • • • • • • • • Buccal crossbite Lingual crossbite/complete lingual Palatal crossbite/lingual Unilateral crossbite Bilateral crossbite Functional lateral crossbite Complete mandibular Complete maxillary Complete crossbite Scissor bite Anterior crossbite Posterior crossbite
  7. 7. BUCCAL CROSSBITE • The buccal cusps of the lower teeth occlude buccal to the buccal cusps of the upper teeth
  8. 8. LINGUAL CROSSBITE • The buccal cusp of the lower teeth occlude lingual to the lingual cusps of the upper teeth
  9. 9. PALATAL CROSSBITE • Palatal displacement of the maxillary teeth as it relates to the antagonist teeth
  10. 10. FUNCTIONAL LATERAL CROSSBITE • Caused by an occlusal interference that requires the mandible to shift either anteriorly or laterally in order to achieve maximum occlusion
  11. 11. • COMPLETE MANDIBULAR CROSSBITE When all the mandibular teeth are buccally positioned to all the maxillary teeth if the mandibular arch is wide • COMPLETE MAXILLARY CROSSBITE When the maxillary dental arch is wide
  12. 12. COMPLETE CROSSBTE when all teeth in one arch are positioned either inside or outside to the all teeth in the opposing arch.
  13. 13. SCISSOR BITE is present when one or more of the adjacent posterior teeth are either positioned completely buccally or lingually to the antagonistic teeth and exhibit a vertical overlap. e.g: brodie syndrome, pierre robin syndrome---primary,mixed! Chewing,muscle,normal growth of Mn.
  14. 14. ANTERIOR CROSSBITE A malocclusion in which one or more of the upper anterior teeth occlude lingually to the mandibular incisors; the lingual malpositions of one or more maxillary anterior teeth in relation to the mandibular anterior teeth when the teeth are in centric relation occlusion
  15. 15. This is when the upper incisors are in reverse overjet and occlude lingual to the lower incisor. An example of this would be an extreme class III incisor relationship.
  16. 16. POSTERIOR CROSSBITE When one or more posterior teeth locked in an abnormal relation with the opposing teeth of the opposite arch; can be either buccal or a lingual cross-bite and may be accompanied by a shift of the mandible.
  18. 18. ETIOLOGY
  20. 20. SOFT TISSUE
  21. 21. DIAGNOSIS • • • • History Clinical examination Study models Cephalogram lateral ceph for anterior crossbite P.A view for posterior crossbite
  22. 22. TREATMENT
  23. 23. TRIAGE
  24. 24. PRE-ADOLESCENT CHILDREN 1. Equilibration to eliminate mandibular shift 2. Expansion of a constricted maxilla 3. Unilateral repositioning of teeth
  25. 25. • MOVIE
  26. 26. II- MIXED DENTITION • • • • • Rationale for Early Interceptive Treatment: Little possibility for self-correction To save permanent dentition. Postponing Rx---greater complexity Can cause growth modifications and dental compensations • Permanent deviation & craniofacial asymmetry & masticatory patterns • Condylar deviation & TMJ sounds
  27. 27. • Interference with growth of the middle third of the face • Abnormal speech patterns • Loss of arch integrity • Periodontal disease • Undesirable esthetics • Root resorption of central incisors
  28. 28. • Those that deliver rapid-heavy-intermittent forces: • Fixed inclined bite planes • Constructed of acrylic • Placed onto the mandibular incisors • Treat lingually locked maxillary incisors • Do not require patient compliance • May open the bite, create a temporary • speech defect, or traumatize the dentition • No significant long-term side effects
  29. 29. • Reversed stainless steel crowns • Anterior stainless steel crowns cemented backwards on the maxillary teeth • Stainless steel crown needs to open the bite 2 to 3 mm and establish at least a 25 percent overbite for successful treatment • If they worsen or fail to treat the crossbite, add crown
  30. 30. • Tongue Blades • Usually employed as a follow up to treatment with inclined plane • Simplest but least successful approach • Works best if the bite is normal and the involved tooth is newly erupted
  31. 31. PERMANENT DENTITION • Individual teeth displaced into anterior crossbite • Transverse maxillary expansion by opening the midpalatal suture
  32. 32. HYRAX SCREW
  33. 33. RAPID PALATAL EXPANSION -Activation is 0.5 mm per day i.e. 2 turns for the screw -force is 10-20 lbs of forces applied -Forces transmitted on suture SLOW PALATAL EXPANSION -Activation is 1mm per week -2lbs pressure applied -less pressure to teeth and sutures
  34. 34. SEQUELAE
  35. 35. • Movement of the lateral and medial poles of the working condyle during mastication in patients with unilateral posterior crossbite • condylar movements in patients with unilateral posterior crossbites might be related to the susceptibility to TMJ disc displacement
  36. 36. • Ultrasonographic Thickness of the Masseter Muscle in Growing Individuals with Unilateral Crossbite • The masseter muscle in untreated individuals with unilateral crossbite is thinner in the crossbite side when compared to the non-crossbite side possibly due to asymmetric activity of the masticatory muscles. Such an asymmetry in thickness of the masseter muscle could not be detected some years after the successful correction of the crossbite.
  37. 37. Is it important to correct cross bite in every patient?
  38. 38. F L O B R U S H I S N T SMI L E E E THANKYOU H