in the name of god dr:nahvi force eruption. unerupted tooth fractured tooth
TRANSCRIPT
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
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
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
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 elasticityMaintains force over a range of tooth movement
Direction of force
parallel to the long axis
avoid torquing forces
Oral Maxillofacial Surg Clin N Am 16 (2004) 75-89
• Fixed appliancesDo not require special patient cooperation precise coronal and root movements
• Removable appliancesless chairtimebetter oral hygieneMore 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,not to exceed five hours per day.
• wear the appliance 24 hours 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
• 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 resorption2) External cervical resorption3) Dentoalveolar ankylosis4) Calcific metamorphosis of the pulp and aseptic pulp necrosis.
Dental Press J Orthod. 2010 Nov-Dec;15(6):18-24