Crossbite in orthodontics,its types and management with two cases
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A 9-year-old boy presented with an anterior crossbite of his upper right central incisor and a unilateral posterior crossbite on the right side. A removable appliance with jackscrews was used over 4 months to tip the upper right incisor labially and expand the constricted upper right posterior segment. This successfully corrected both the anterior and posterior crossbites. A retainer was worn long-term to maintain the correction.
Crossbite in orthodontics,its types and management with two cases
- 2. 4th Year Prof. B.D.S. Department of Orthodontics, Salman Zahid
- 3. Cross bite is a discrepancy in the buccolingual relationship of the upper and lower teeth
- 4. CLASSIFICATION (1)BASED IN THE LOCATION
- 6. When the lower incisors come in front of the upper incisors, this condition is called as anterior crossbite or reverse over jet.
- 7. Etiology of the anterior crossbite is based on: 1. Dental factor. 2. Skeletal factor. 3. Soft tissue factor. 4. Functional factor
- 8. Anomalies of tooth sizes. Anomalies of tooth shape. Faulty eruption pattern where the tooth erupts out of the normal position. Retained deciduous teeth. Ectopic eruption. Tooth ankylosis. Supernumerary teeth.
- 9. Asymmetric growth of maxilla or mandible due to: Inherited growth pattern. Trauma during growth or at birth. Long standing functional problem.
- 10. Digit sucking. Habit of biting upper lip.
- 11. Habitual forward positioning of the mandible for maximum intercuspation. This may lead to anterior crossbite.
- 12. It occurs when single tooth is involved.
- 13. It occurs when a single arch segment is involve.
- 14. Deviation from the ideal occlusion in the transverse plane is called as posterior crossbite.
- 15. Etiological factors are also based on: 1. Dental factor. 2. Skeletal factor. 3. Functional factor. 4. Soft tissue factor.
- 16. Prolonged retention of the primary teeth. Ectopic eruption of the permanent first molar Cleft palate cases.
- 17. Inheritance. Deficient lateral growth of maxilla. Abnormal mandibular growth laterally.
- 18. Deviation of mandible during jaw closure because of the occlussal interference. This results in unilateral posterior croossbite.
- 19. It occurs when single posterior tooth is involved.
- 20. when a single arch segment is involve.
- 21. When one side of arch is involved
- 22. When both the arches are involved.
- 23. When the buccal cusp of the maxillary posterior tooth(teeth) occlude lingual to the buccal cusp of the mandibular molar teeth. Most commonly seen in clinical practice.
- 24. When the maxillary posterior teeth occludes completely on the buccal aspect of the mandibular posterior teeth. Also called as scissor bite
- 25. It occurs when the maxillary upper molars occlude on the lingual aspect of the mandibular lower molars.
- 26. Skeletal crossbite occurs because of : 1. Discrepancy in the size of mandible/maxilla. 2. Due to inheritance. 3. Defective embryological development.
- 27. Dental crossbite occurs b/c of: 1. Supernumerary teeth. 2. Retained deciduous teeth. 3. Deciduous tooth results in the displacement of the permanent tooth germ. 4. Lingual eruption of the anterior teeths.
- 28. Forward positioning of the mandible due to habit. Results in pseudo Class III.
- 30. Elimination of the factors that may lead to the anterior cross bite Removal of occlusal prematurities Extraction of supernumerary tooth before they cause displacement of other tooth. Habit breaking appliance.
- 31. Equilibration to eliminate mandibular shift Expansion of constricted maxillary arch Unilateral repositioning of teeth
- 32. Mostly observed in primary or early mixed dentition, a shift into posterior cross will be solely due to occlusal interferences caused by primary canine or molar Child requires only limited equilibration of primary teeth to eliminate interference and lateral shift
- 33. W Arch: -Fixed appliance constructed of 36 mil steel wire soldered to the molar bands. -Activated simply by opening apices of W. -Delivers proper force levels when opened 4-6mm wider than passive width.
- 34. Quad helix Appliance: -Efficient fixed slow expansion appliance. -Expansion continued at a rate of 2mm per month(1mm on each side) until cross bite is slightly overcorrected. -Most posterior crossbites require 2-3 months of active treatment and 3 months of retention (during which lingual arch left passively in place).
- 35. -The force from elastic is directed vertically as well as faciolingually which will extrude posterior teeth and reduce overbite - Cross-elastics, typically run from the lingual of the upper molar to the buccal of the lower molar.
- 36. Tongue Blade: Used when a cross bite is seen at the time the permanent teeth are making an appearance in the oral cavity. This is continued for 1-2 hours for about 2 weeks.
- 37. Used only in those cases where the cross bite is due to a palataly placed max incisors. (Constructed at 450 angulations on the lower anterior teeth by acrylic or cast metal).
- 38. Used when anterior cross bite involving 1 or 2 max. anterior teeth. Effective only when there is enough space for aligning the teeth.
- 39. Rapid Maxillary Expansion (Hyrax Screw): Patients for opening the midpalatal suture may have such severe crowding that even with this arch expansion, premolar extraction will be required. Opening the midpalatal suture should be used primarily as a means of correcting a skeletal crossbite.
- 40. RPE: Recommended for more mature patients. Two turns initially and two turns per day until the suture opens Forces transmitted on suture SPE: Younger patients because it is more physiologic and equally effective. Slow expansion, with one turn(1/4 mm) of the screw every other day in these Less pressure to teeth and suture
- 41. Three approaches to correction of less severe dental cross bites are feasible: -a heavy labial expansion arch -an expansion lingual arch -cross-elastics
- 42. Cross bite due to skeletal asymmetry Correction require orthognathic surgery once growth has slowed to adult levels
- 43. A 12.8 year-old Caucasian girl presented for treatment complaining of an unpleasant smile. Oral breathing, lip incompetence, and atypical swallowing. An increased facial lower third and a convex profile. Intraoral evaluation showed a Class II, division 1 malocclusion, and bilateral posterior crossbite
- 46. Treatment Plan Palatal expansion, by a modified Haas-type expander, Increasing the maxillary transversal dimension to correct the bilateral posterior crossbite. A comprehensive orthodontic treatment initiated in order to improve the results obtained after expansion .
- 48. TREATMENT PROGRESS Activation of the screw initiated immediately after appliance insertion with a complete turn. After that, the patient was instructed to keep the activation with 2/4 turns in the morning and 2/4 turns in the afternoon, during eight days. The expander passively maintained for a period of three months, followed by a removable retainer, which was used for another six months. The whole treatment lasted about 1 year and 3 months.
- 49. Corticotomy was performed on the buccal and palatal side of the right maxillary segment Expansion started 10 days after corticotomy and was performed using fixed orthodontic appliance and a heavy labial arch wire (0.040-in Stainless Steel wire). Cross bite correction was achieved in 10 weeks. The lower left third molar was uprighted using a miniscrew. Leveling, aligning, arch coordination, and finishing were continued using the fixed orthodontic appliance and intermaxillary elastics.
- 51. Based on this case report, a rapid maxillary expansion protocol carried out at mixed dentition was effective and stable 21 years post treatment.
- 53. A 9-year-old boy was referred by his pediatric dentist for an orthodontic consultation regarding his anterior bite.
- 54. Extra Oral Examination: Balanced face with a pleasant profile maxillary dental midline coincide with the facial midline. The chin was deviated to the right side by 3 mm from the facial midline, and the entire Intra Oral Examination: Mixed dentition stage with Class I left and half-cusp Class II right molar relationships. The overbite was deep (100% on the left maxillary central incisor) Anterior crossbite of 11 Unilateral (right) posterior crossbite were evident. Both crossbites were being expressed as a result of functional shifts in the sagittal (i.e., forward) and transverse dimensions (to the right side).
- 57. Based on the above findings,two treatment approaches were considered: Quad-helix expansion combined with bite opening and bracket-bonding only the four maxillary incisors would permit simultaneous correction of both anterior and posterior crossbites. However, expansion with the quad- helix would not control the palatal tipping of the right posterior segment mesial to the first molar (especially the primary maxillary right canine). Removable appliance was chosen to better control the canine and the adjacent palatal
- 58. The removable appliance option included the use of two upper removable appliances. The first incorporated a jackscrew set to act in an anteroposterior direction to tip the maxillary right permanent central incisor labially and bilateral posterior bite planes (about 4 mm thick) to disengage the bite and facilitate tooth movement. Another removable appliance with a midpalatal jackscrew and bilateral posterior bite planes (of minimal thickness) to further expand the right maxilla (differential expansion). Two Adams clasps and two ball clasps were incorporated in both appliances to aid retention.
- 60. The first appliance was used for 7 weeks to achieve a positive overjet of the maxillary right central incisor. After anterior crossbite correction, a bilateral, posterior open bite resulted from use of the posterior bite planes that caused intrusion of mostly the mandibular posterior segments.
- 61. Use of the second appliance was followed for 8½ weeks Expansion was continued until the desired transverse correction of the maxillary right posterior segment was achieved. The total active treatment period was about 4 months. For both appliances, the patient was seen during the first week after appliance insertion to ensure comfort and monitor cooperation. Thereafter, follow-up appointments were scheduled every 3–4 weeks.
- 63. Upon completion of treatment,the right molar relationship was restored to Class I. the left molar relationship had a tendency to Class III and chin asymmetry was reduced. The upper Hawley was then used full-time (day and night) for 6 months. The patient was then asked to wear the retainer only at night for another 4 months. The case was followed up out of retention for an additional 4 months. Use of the Hawley retainer promotes retention and resolution of any residual lateral posterior open bite. Stable anterior and posterior relationships were evident, and continued spontaneous alignment of the mandibular incisors was noticed. Furthermore, there was a spontaneous decrease in the maxillary diastema
Editor's Notes
- #37: It is placed inside the mouth contacting the palatal aspect of the maxillary teeth. Upon slight closure of jaw the opposing side of the stick come in contact with the labial aspect of the opposing mandibular tooth acts as a fulcrum.