Effect Evaluation And Investigation On Orthodontic Treatment With Maxillary-mandibular Expansion

Patients ask for orthodontic treatment mostly because of crowding, protrusion, deep overbite and other issues affecting the appearance or functional requirements Orthodontists often find the space of requirement to solve these problems. With the current development of technology in orthodontics, requirement spaces can be found in non-extraction treatment by pushing the molar farther or by using expansion instead of extraction. The mastery of different treatment technologies leads to different choices for orthodontists.RPE technology improves the growth of the arch and changes its form by intraoral orthopedic force which is one of the approaches to correct borderline. Early maxillary arch expansion techniques were used to solve such problems as narrow maxillary arch and hypoplasia in young patients. Maxillary palatal raphe was considered integrated in adolescence, and mandibular joints made ossification between 1 to 1.5 years. Due to the difference between maxillary and mandibular development, the treatment mechanisms were not alike. With tongue blocking, use of mandibular arch expansion was limited. Part of the mandibular arch expansion was combined with the method of surgery by splitting the middle of the jaw joint, which was not accepted for domestic patients. In short, there are mainly two clinical reasons for the limitations of the mandibular arch expansion applications: ① jaw anatomy characteristics; ② long-term stability of the controversy after expansion. In this study, the mandibular arch expansion was clinically improved, to solve congestion problems that exist in the mandibular dentition, to level the deep curve of spee and to match with the maxillary arch after expansion. Usually the quality of the treatment was evaluated based on doctors’ orthodontic experiences. With the development of Evidence-Based Medicine and the national standard, it becomes necessary and possible to develop an objective grading system for the classification of treatment outcomes. ABO recently published a new index, called the objective grading system(OGS), to evaluate post-treatment dental casts and panoramic radiographs. It is a self-evaluation method and orthodontists are encouraged to score their own dental casts. ICON is another index developed to evaluate the issues of treatment need complexity, treatment improvement and outcome. It can used easily to make comparisons between before- and after–treatment results.This article aims at examining the effectiveness and advantages of maxillary-mandibular expansion technique. Previous correction cases were analyzed by using ABO-OGS and ICON indexes as quantitative evaluation of the dental state. A three-dimensional digital model was developed and arch width and soft tissue were measured. Post-treatment-visit records confirm the stability of the technique. This work provides solid reference for future clinic of maxillary-mandibular expansion. Thesis has three main parts, as follows:Part One: Assessment treatment outcome of maxillary-mandibular expansion by model analysis using American Board Orthodontic Objective Grading System(ABO-OGS)31 cases of non-extraction patients(class Ⅰ14, class Ⅱ 12, class Ⅲ 4) treated with fixed rapid expander were taken before(T1) and after treatment(T2). All the cases were measured by ABO measuring gauge and ordinary ruler. The differences of arch width between T1 and T2 were recorded and analyzed with SPSS13.0 statistical software packages. Results show that the width of dental arch before and after treatment significantly increased(P < 0.05). The pass rate was 64.5% and the potential pass rate was 32.3% based on the ABO-OGS scores of the post-treatment study models. The average score was 19.03 ± 6.897. Compared with results from other medical institutions, the passing rate is the highest. The patients with correction or covered in more than 8 mm, and overjet more than 10 mm were in potential rate and non-pass rate, and there is no difference to achieve good treatment effect among cases of different genders or different classifications. The maxillary-mandibular expansion cases could be used for treating orthodontic with satisfactory results after firmly grasping conformation cases, careful clinical operation and anchorage design.Part Two: Effects of orthodontic treatment with expander for Angel Ⅰcasesby ICONDental Angel Ⅰcases of 14 non-extraction patients treated with fixed rapid expander were taken before(T1) and after treatment(T2). All the cases were laser-scanned. The differences of arch width and length between T1 and T2 were recorded and analyzed. The ICON was used to assess the pre-treatment and post-treatment study models. Results were imported to SPSS for statistical analysis. Before and after the treatment, the dental arch width difference was statistically significant(P < 0.05). The width of the premolar changed significantly, 6.94 ± 2.518 mm and 5.99 ± 1.990 mm growth in maxillary and mandibular. Good occlusal relationships and soft tissue profiles were achieved in all cases. All cases were evaluated as greatly improved by ICON. Results show that the accurate application of maxillary-mandibular expansion can solve the problem of malocclusion crowding and at the same time protect the surface, avoiding thrust forward.Part Three: Record analysis on postretention patients with maxillary-mandibular expansionIn clinic, we make a return visit to patients. Clinical data of 12 cases was collected. All the cases were measured by both ABO measuring gauge and ordinary ruler. The differences of arch width between post-treatment and post-retention were recorded and analyzed. Results show no significant change in the width of dental arch(P < 0.05). The difference about scores of ABO-OGS index was 0.43 ± 1.512,P=0.482 > 0.05. This preliminarily verified the stability of maxillary-mandibular expansion.In summary, the maxillary-mandibular expansion treatment method has advantages in the application of the appropriate age for dental correction, not only to stimulate Mandible development, surface type of protection has significant meaning, but also to avoid the critical case patient health teeth removal, which can increase the area of health benefits of chewing. The maxillary-mandibular arch expansion method at the same time help build a better bite match, a good bite to establish stability in maintaining dental. Through the application of objective evaluation indicators for treatment efficacy RPE made unified objective and quantitative evaluation of cases to facilitate the exchange of learning among physicians, clinical orthodontic work suggestive.