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IN THE NAME OF GOD. Force eruption. Dr:Nahvi. Force eruption. Unerupted tooth Fractured tooth. Tooth eruption . A permanent tooth should erupt: 6 months after natural exfoliation of its predecessor Eruption delayed : if the interval extends to more than 1 year. .
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IN THE NAME OF GOD Force eruption Dr:Nahvi
Force eruption • Unerupted tooth • Fractured tooth
Tooth eruption A permanent tooth should erupt: 6 months after natural exfoliation of its predecessor Eruption delayed : if the interval extends to more than 1 year.
Eruption of a tooth is considered to be delayed : • The normal time for eruption has been exceeded. • The tooth is not present in the dental arch and shows no potential for eruption. • The root of the unerupted tooth is completely formed. • The homologous tooth has been erupted for at least 6 months. J Can Dent Assoc 2010
Most commonly become impacted • third molars • maxillary canines • maxillary central incisors • mandibular second premolars
Causes of Delayed Eruption • Localized • Generalized
Localized • the presence of supernumerary teeth(most common ) • Odontoma • dilaceration • malpositioning of the tooth germ • Crowding • calcifying odontogenic cyst • trauma to the corresponding deciduous tooth
systemic conditions • cleidocranialdysostosis • hypothyroidism • Gardner syndrome • Down syndrome
Criteria for Treatment • chief complaint • At least 3 mm of bone • The tooth is mature J Can Dent Assoc 2010;76:a147
Alignment of an impacted tooth • position and direction • degree of root completion • degree of dilacerations • presence of space
Treatment planning: 1-surgical exposure 2-Attachment to the tooth 3-Orthodontic mechanics
surgical exposure • (1) exposure of the entire labial aspect (the window approach) • (2) a technique which exposes only 4–5 mm of the labial aspect
Attachment • Gold chain • Band • Cast gold crown,onlay • Threated pin • Wire loop • Direct bond attachment(the best)
General characteristics of orthodontic Forces • Optimal:light,continuous -Ideal material Maintains elasticity Maintains force over a range of tooth movement
Force • Continuous • Interrupted • Intermittent • Extrusion 35-60gr
Direction of forceparallel to the long axisavoid torquingforces Oral Maxillofacial Surg Clin N Am 16 (2004) 75-89
Force eruption Fixed appliances Removable appliances
Fixed appliances • Do not require special patient cooperation • precise coronal and root movements • Removable appliances • less chairtime • better oral hygiene • More esthetic
Removable appliances • retention clasps • labial bow • Hook(for attachment of elastics) • Finger spring,Zspring,Canine retractor
Removable appliances • at least 10 hours per day. • Rest intervals,notto exceed five hours per day. • wear the appliance 24hours a day, removing it only for meals
the elastics should be changed every two or three days. • Lingual tipping will be minimized when the labial bow is used for the extrusive force JCO/JULY 2002
Fixed appliances coil : • maintains the space • anchorage and balancing resistance J Can Dent Assoc 2010
Anchorage support for the extrusion—a minimum of one tooth on either side of a single-rooted tooth (2 anchors) or two teeth on either side of a multi-rooted tooth (4 anchors) Use a heavy square or rectangular NiTi wire to minimize tipping
Magnetic force • For a patient with other missing teeth Contemporary orthodontics
Elastics -light -medium(1/8 =3.18mm 127.58gr) -heavy Orthodontic Elastics (3/8", 5/16", 1/4", 3/16", 1/8") Shiraz Univ Dent J 2009; 10(1):7-15
clinical problems (canine) 1) Lateral root resorption 2) External cervical resorption 3) Dentoalveolarankylosis 4) Calcific metamorphosis of the pulp and aseptic pulp necrosis. Dental Press J Orthod. 2010 Nov-Dec;15(6):18-24