Orthodontic Treatment Of A Skeletal Class ? Malocclusion Adolescent Patient With Maxillary Impacted Canine

Objective: The purpose of this study was to investigate the clinical treatment effect of extraction in Skeletal Class ?malocclusion adolescent patient with maxillary impacted canine.Method: An adolescent patient treated at Dental Clinic in February 2013 was recruited into the study.The patient was a eleven years and two months old female with Angle,s Class ?,Skeletal Class ?.Positive view,On the bottom of the high basic coordination.Face basic symmetry,upper and lower jaw center line and the midline consistent.When close the chin,the chin muscle tension and mentolabial sulcus was small.Side view,convex profile,retruded mandible.Oral general examination,patients in the mixed dentition period,the right side of the canine and both side molar occlusal were class I relationship,maxillary midline in the middle,midline shift was 1.5 mm towards right on lower arch when comparing with facial midline,65 was Stranded.According to the measurement results of model checks,The lower incisors were proclined lead to the overbite and overjet were shallow.The curve of Spee was 1 mm on both sides.1mm space between 11 and 12,2mm space between 21 and 22.The mandibular teeth were slightly crowded and the lower incisors were inclined.The x-ray shows 23,25 not erupted.Treatment plan was drawn according to clinical examination and analysis results: we decide to remove stranded deciduous teeth and four first premolars followed by placement of Straight Wire Appliances.Before the bilateralmaxillary canine eruption,we use nickel titanium extended and maintain the space between the lateral incisor and first premolar.Surgery guide 23 eruption.Orthodontic traction was used to align and level the dentition.Extraction space was closed by sliding mechanics.Wire bending for finishing adjustment when the space had been closed and Hawley retainers for upper and lower.According to the pre and post treatment cephalometric radiograph was done to judge the changes of soft and hard tissue before and after treatments.Result: The active treatment lasted for 36 months.Extraction could provide space to traction impacted canine to normal dentition.Dentition was well aligned and extraction spaces were closed.Canine relationship and molar relationship were both Class ?.A good antero-posterior relationship was achieved with normal overbite and overjet.upper and lower jaw center line consistent.Comparison of the lateral radiographs before and after treatment : Bilateral condyles in good position,no significant change,Maxillary left canine and bone near the cacine were normal.X-ray shows periodontal ligament continuous.(1)SNA,SNB,ANB angle appraisal changed after treatment,which indicated the skeletal pattern to Class ?.NA-PA from the original 14 ° to 10 °,indicating the upper arch protrusion deformity has been significantly improved.FMA decreased by 2°,indicating a good vertical control,the mandible rotate anticlockwise.(2)The maxillary left side of the impacted fangs traction into the dentition,the tooth position,tooth axis have reached the normal range.The U1-SN ° decreased 5.5 °,the U1-NA ° decreased 4°,U1-NA decreased by 1.4 mm,L1-NB °decreased by 13.4 °,L1-NB distance is reduced by 7.5 mm,upper and lower anterior teeth axis are adjusted,the lower incisors were retrieved and erect.(3)The gingival margin were in good shap,periodontal attachment tissue health.The Z angle increases from 55 ° to 78.3 °,ULEP was 1.9,a decrease of 1.1,LLEP was 3.8,a decrease of 4.2,indicating that the upper and lower lip protrusion and the relationship has improved,soft tissue profile more coordinated nature.Conclusion: For young patients with skeletal Class II malocclusion and associated with impacted canine impacted patients,use straight wire appliance technology,subtracting four first premolars,can maximize the recovery of upper and lower anterior teeth,improve the type ? bone surface;the adolescent with maxillary impacted teeth,treatment should be to preserve the treatment of canine-based.According to the test results to determine the natural eruption of the need to open up the gap preferred to help eruption method,often can receive better treatment effect.If not self-eruption,need to use surgical help canine eruption.