| Objectives: To study the orthodontic orthognathic treatment approach of an adult patient with skeletal class Ⅲ malocclusion and to discuss the clinical outcome of this approach.Methods: A 24 year old male patient was selected in February 2015 by the second hospital of Da Lian medical university.This patient had a skeletal class Ⅲ discrepancy with an anterior crossbite.with a bilateral molar and canine class Ⅲ relationships.Little crowding was observed in both arches.Upper and lower midline were in normal coincide with the facial midline.Overjet and openbite were about 1 mm.The right 1st premolar and 1stmolar were in a buccal crossbite.Curve of spee was flat on the left side,while concave on the right side.Maxillary arch form is oval while,a square to round arch form in the mandible.Tongue size is normal with no soft tissue abnormalities.The patient showed no issues in pronunciation and swallowing.Oral hygiene was good.Chin position is in the middle of the face without any deviations.Laterally,the profile was concave,The maxilla was normal and mandibular protrusion was obvious.After cephalometric analysis and model analysis,a combined orthodontic and orthognathic approach treatment was decided for the patient.The treatment plan: A first stage of nonextraction fixed orthodontic appliance aimed to;align and level the teeth and to decompensate the teeth,by proclination of the upper incisors and retroclination of the lower incisors.Model simulation was done to make sure that a normal bite is established with an appropriate anterior overbite,and adjust occlusal relationship of the posterior teeth.Then the second stage of orthognathic surgery.The third and the last stage was a postoperative orthodontic treatment to adjust the occlusal relationship and to produce interdigitation of teeth.Final analysis was done to compare pre and post cephalometric X-rays,changes in soft tissue,and the appearance of the patients before and after treatment,the treatment effect was discussed.Result:The total treatment time was 19 months.A positive overbite and overjet was achieved.A normal molar and canine Class I relationship was achieved bilaterally.A flat curve of spee was produced in the lower arch.Mandibular arch shape is oval in shape.Frontal view of the patient showed a great improvement of the smile which isnow greatly coordinated with the lower lip line.From the lateral view of the soft tissue profile a great improvement was achieved.No tenderness in the joint area.(1)cephalometric radiographs before and after treatment were analyzed: the maxilla with minor changes,SNA increased about 1.83° from79.19° to 81.02°.there In the mandible there is a significant change after the treatment,SNB reduced about 4.16° from 84.95°to 80.79°.U1-NA angle decreased from 38.90° to 30.3°,L1-MP increased from89.66° to 97.87° which result from decompensation the lower incisor into a normal position.AO-BO increases from-16.57 mm to-5.79 mm,suggesting that the skeletal discrepancy was greatly improved.FMA treatment increased about 3.77°,CF decreased0.12 degree,suggesting that after the a clockwise rotation of the mandible with an increase of lower facial height.After the treatment we found no adverse side effects such as gingival recession,root resorption,crown elongation etc..(2)Soft tissue analysis before and after treatment: before treatment Z angle was reduced from 80° to74.75°.The proportion of soft tissue become more coordinated,the soft tissue profile of mandibular has been greatly improved by the concave profile turned into face type,with the front view of beautiful and harmonious.The patient was very satisfied with the result.Conclusion : A satisfactory results can be achieved by a combined orthodontic-,Orthognathic approach for adult patients with moderate to severe skeletal Class Ⅲdiscrepancies with an anterior crossbite.Orthodontic treatment was performed by dental decompensation with the aid of model simulation to make sure that a normal occlusal adjustment will be produced after the surgery. |
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