Pre&After Surgical Orthodontics Treatment Of Skelital Class ?.A Case Report

Objective:discussion on therapeutic methods and effects of combined orthodontic and orthognathic treatment by adoption of combined orthodontic and orthognathic treatment on a 19-year-old male patient with skeletal class III malocclusion.Methods:a 19-year-old patient who was received and cured by outpatient service in the department of stomatology at our hospital in March,2014 and diagnosed with skeletal class III malocclusion was selected.Oral clinical examinations:the patient was of permanent dentition with loss of the lower left first molar and a large area of caries lesion on the lower right first molar.Molars and canine teeth of both sides were of full mesio-relationships,namely class III malocclusion.The maxilla midline was 1 mm shift to the left with,anterior crossbite is 7mm and first-degree open bite.The dental arch form was of a round&square.The 1/3 lower faces was long with mentalis tension.The patient's facial profile was concave and long with a shallow nasolabial groove and the 1/3 lower faces was porrect.In combination with clinical examinations,model analysis and X-ray cephalometrics,treatment difficulty was evaluated and the treatment plan was made.We determined to adopt combined orthodontic and orthognathic treatment.Before orthodontics,the residual crown of the lower right first molar was extracted.A healthy tooth was moved forward to replace the decayed tooth and realize bilateral symmetry.During the preoperative orthodontic phase,alinement and levelling of dentition were conducted and the space was closed.The tooth axis inclination and the maxilla midline were adjusted.Before surgery,the stage model was applied to adjust high occlusal points to match the dental arch.After preoperative orthodontics,Bilateral Sagittal Split Ramous Osteotomy(BSSRO)and genioplasty were conducted at the same time.After operation,the plywood was removed to start orthodontic treatment.Triangle traction and box traction were used between maxilla and mandible to subtly adjust the occlusion relationship and Class ? elastics were used to consolidate the effect and prevent recurrence until the treatment goals were finished.The fixed appliance was removed and the Hawley retainer was worn to maintain the stability of therapeutic effects.After treatment,panoramic films,lateral and anteroposterior cephalometric films were taken to be analyzed.Results:by 19-month combined orthodontic and orthognathic treatment,the patient's facial form was improved greatly.The face type was transformed from a concave type into a straight type.The midline was in line with the midline of soft tissue.Relationships of overbite and overjet were normal.Relationships of molars and canine teeth were of class ?.By analyzing patients' teeth models before and after treatment and X-ray cephalometrics,the ANB angle increased and the SNB angle decreased.Positions of maxilla and mandible changed.L1-A-Pog reduced from original 10.03mm to normal 3.07mm and Wits changed from-16.90 before treatment to-9.20 after treatment,indicating the relationship of patient's upper and lower jaws was improved.FMA reduced from 39.66° to 37.36° with reduction of nearly 3°,indicating that counterclockwise rotation of underjaw occurred after BSSRO.The height of patient's 1/3 lower faces reduced.The crossing angle of the incisal edge of upper central incisors and line NA increased by 8.81 °,showing compensatory labial inclination of upper central incisors.The overjet changed from original-7mm to present 3mm.Normal relationships of overbite and overjet of the anterior teeth of maxilla and mandible were established.LL-SnPog reduced from 5mm to 2mm,indicating retrusion of the lower lip,while the angle of mentolabial sulcus decreased from 171.74° to 157.32°,making the soft tissue profile improved.Conclusion:selection of therapeutic schedules played a guiding role in therapeutic outcomes.Adult patients with severe skeletal class III malocclusion achieved good therapeutic outcomes by combined orthodontic and orthognathic treatment.For patients with mild maxillary maldevelopment and mild compensatory labial inclination of upper anterior teeth,during combined orthodontic and orthognathic treatment,BSSRO could be operated only without a maxillary operation.In addition,patient's appearance and function were improved greatly and effects satisfying the patient were obtained.