Evaluation of relapse after orthodontic therapy combined with orthognathic surgery in the treatment of skeletal class III

Introduction

Multidisciplinary treatment of skeletal malocclusion by orthognathic surgery in addition to orthodontics is a routine strategy believed to offer good functional and esthetic outcomes. Postoperative relapse is, however, a problem. The present study was conducted to analyze the stability of outcomes achieved by surgical treatment of skeletal class III patients in terms of the rate and extent of relapses.

Patients and methods

A total of 30 patients who had undergone orthodontic treatment combined with orthognathic surgery were included. The primary inclusion criterion was a skeletal class III treated by mandibular setback (Obwegeser/Dal Pont) surgery alone or combined with maxillary advancement (Le Fort I) surgery. Analysis was based on one preoperative and two postoperative cephalograms per patient.

Results

We observed relapse (defined, in accordance with Proffit, as changes >2 mm or 2°) at a rate of 24% after bimaxillary procedures, compared to a lower rate of 21% after mandibular setback procedures only. The relapse rate was 21% among patients who had undergone upper-jaw surgery versus 27% among those who had undergone lower-jaw surgery, which was statistically significant.

Conclusion

The majority of patients exhibited stable treatment outcomes. Maxillary advancement procedures were found to be less susceptible to relapse—resulting in more stable outcomes—and mandibular setback distances correlated positively with the degree of the relapse. No statistically significant differences were observed between the procedures conducted in both jaws versus in the lower jaw only, or in the extent of upper-jaw repositioning.     

A case of supernumerary tooth in the mandibular anterior region – Report on a rare case of five mandibular incisors

Occurrence of a supernumerary tooth in the mandibular anterior region is uncommon. We report the case of a 7-year-old male patient with five incisors including one impacted tooth in the mandibular anterior region. We extracted one of the four erupted teeth to assure the eruption of the impacted tooth within the dentition. Eleven months after tooth extraction, the incisor erupted within the dentition and the incisors exhibited close to normal arrangement. This case indicates that favorable outcomes can be achieved for cases of supernumerary teeth in the mandibular anterior region by treating in the early mixed dentition period.     

What is the accuracy of the surgical guide in the planning of orthognathic surgeries? A systematic review

Background To investigate the true accuracy of the surgical guide in the planning of orthognathic surgeries, which are performed worldwide.Material and Methods A systematic search was conducted in the PubMed database, Web of science, Scopus and Embase, covering August 2020 to January 2021. Studies that included patients with dentofacial deformity including anteroposterior, vertical and asymmetry problems who were undergoing an orthognathic surgery procedure were included; QUADAS-2 was used to determine the risk of bias by analyzing the quality of the studies. A PRISMA (flowchart) was created to show the study selection, keywords, nomination processes, and inclusion and exclusion criteria.Results Eleven studies were selected for qualitative and quantitative synthesis. All studies evaluated described high precision of the surgical guide, where the lowest error values were represented by the CAD/CAM technique.Conclusions The planning and printing errors related to the guide were all less than 2 mm, and the absolute averages of the errors related to virtual planning in the analysis of the different plans were less than 1 mm. Finally, the measurement of the ANB angle obtained equivalent results between the virtual planning and the traditional. Key words:Orthognathic surgery, splints, data accuracy, 3-D printing.     

Soft and hard tissue changes in skeletal Class III patients treated with double-jaw orthognathic surgery—maxillary advancement and mandibular setback

The soft tissues of the facial profile may change after skeletal movement in orthognathic surgery. The aim of this study was to evaluate and compare the differences and correlation between hard and soft tissues after double-jaw surgery in skeletal Class III subjects. Radiographs from the following time points were assessed using Dolphin Imaging software: preoperative (T0), 2–4 months postoperative (T1), and 6–12 months postoperative (T2). Eleven hard and soft tissue points of the facial profile were evaluated. The Student's t-test was used to assess the significance of differences between the time intervals; Pearson's correlation coefficient was used to assess the significance of correlation existing between these points; significance was set at P < 0.05. In the sample of 58 subjects, the correlation between hard and soft tissues in the mandible was greater than in the maxilla. Similarly, the correlations only between hard tissues and only between soft tissues presented a greater correlation in the mandible. The results are similar to those found in studies on single-jaw surgery for both the maxilla and the mandible. The influence of movements in hard tissues was restricted to the soft tissues of the same jaw, although there were exceptions.     

Invisalign? treatment in the anterior region

OBJECTIVE: Based on our previous pilot study, the objective of this extended study was to compare (a) casts to their corresponding digital ClinCheck? models at baseline and (b) the tooth movement achieved at the end of aligner therapy (Invisalign?) to the predicted movement in the anterior region. MATERIALS AND METHODS: Pre- and post-treatment casts as well as initial and final ClinChecks? models of 50?patients (15-63?years of age) were analyzed. All patients were treated with Invisalign? (Align Technology, Santa Clara, CA, USA). Evaluated parameters were: upper/lower anterior arch length and intercanine distance, overjet, overbite, dental midline shift, and the irregularity index according to Little. The comparison achieved/predicted tooth movement was tested for equivalence [adjusted 98.57% confidence interval (-?1.00; +?1.00)]. RESULTS: Before treatment the anterior crowding, according to Little, was on average 5.39?mm (minimum 1.50?mm, maximum 14.50?mm) in the upper dentition and 5.96?mm (minimum 2.00?mm, maximum 11.50?mm) in the lower dentition. After treatment the values were reduced to 1.57 mm (minimum 0?mm, maximum 4.5?mm) in the maxilla and 0.82?mm (minimum 0?mm, maximum 2.50?mm) in the mandible. We found slight deviations between pretreatment casts and initialClinCheck? ranging on average from -0.08?mm (SD ±?0.29) for the overjet and up to -0.28?mm (SD ±?0.46) for the upper anterior arch length. The difference between achieved/predicted tooth movements ranged on average from 0.01?mm (SD ±?0.48) for the lower anterior arch length, up to 0.7?mm (SD ±?0.87) for the overbite. All parameters were significantly equivalent except for the overbite (-1.02; -?0.39). CONCLUSION: Performed with aligners (Invisalign?), the resolvement of the partly severe anterior crowding was successfully accomplished. Resolving lower anterior crowding by protrusion of the anterior teeth (i.e., enlargement of the anterior arch length) seems well predictable. The initial ClinCheck? models provided high accuracy compared to the initial casts. The achieved tooth movement was in concordance with the predicted movement for all parameters, except for the overbite.     

Is the benefit of early orthodontic treatment worth the burden?

In summary, early interception of Class III malocclusion is definitely warranted for many patients. A careful analysis of the patient's problem, and an analysis of the patient's airway is essential if one is to make the correct decision as to the amenability of early treatment of the patient's Class III malocclusion. The Class I patient, in most instances, especially if the crowding is severe, can be favorably impacted with guidance of occlusion. This procedure shortens treatment time and lessens the burden for both the patient and the family. Space preservation is also a viable procedure if the Class I patient has minor mandibular anterior crowding. Early Class II intervention can be attempted if all parties concerned know the literature and expectations. Of the three types of malocclusions, the Class II malocclusion presents with the most problems, and early Class II treatment must be viewed pessimistically.     

How do patients perceive the British orthodontic society online information resource about orthognathic treatment? A qualitative study

Objectives: To explore the accessibility, usability and relevance of the British Orthodontic Society (BOS) online information resource (OIR), Your Jaw Surgery.

Design: Qualitative, cross-sectional study.

Setting: 5 UK sites.

Participants: Patients before, during and after treatment for non-cleft skeletal discrepancy.

Methods: Patients were identified at joint clinics and recruited after having time to view the OIR. Semi-structured interviews were conducted with 17 patients (aged 16–46 years). The interviews were transcribed and thematic analysis was undertaken using a framework approach.

Results: The main themes identified were the overall usefulness, personal relevance and positive perceptions of the OIR. The OIR was seen to be useful for patients considering treatment, and potentially useful for patients undergoing treatment. Participants were looking for a personally relevant resource that would give them the best possible idea of how they would look and feel after surgery. The OIR was perceived as trusted, positive and reassuring.

Conclusions: Patients at different stages of treatment found the OIR helpful and reassuring. Clinicians may find it useful to direct patients to the OIR to complement a professional consultation, but should be aware that patients may perceive it as presenting a positive image of the long-term benefits of orthognathic surgery.     

Outcome of photographic evaluation of facial appearance in orthognathic surgery: how does it correlate with planning of treatment and patient-reported outcome?

The outcome of treatment in orthognathic surgery is dependent on preoperative surgical planning. The main purpose of the present study was to evaluate from photographs the improvement in facial appearance after orthognathic surgery. In addition, the outcomes of two different planning techniques, 2-dimensional and 3-dimensional, were compared and the correlation between the outcome and health-related quality of life (HRQoL) assessed.The study was a randomised controlled trial with the intervention being either 2-dimensional or 3-dimensional treatment planning. An evaluation panel compared photographs taken before and after operation on patients with severe class III malocclusion. The change in facial appearance was rated, the two planning techniques compared, and the result correlated with previously published findings on cephalometric accuracy and HRQoL in the same group.Completed 12-month follow-up resulted in the inclusion of 57 subjects aged between 18 and 28 years at the time of operation (mean 21 years). We found significant differences between the two evaluations (p = 4.4E-9) but no significant difference in facial improvement between the planning techniques (p = 0.54). However, there was a correlation between cephalometric measurement of accuracy in the anterior maxilla and evaluation of improvement of facial appearance (p = 0.024, r = 0.30), but we found no correlation +between HRQoL and the evaluation of facial appearance (p = 0.31, r = -0.14). We conclude that there was an improvement in facial aesthetics after orthognathic surgery that was independent of the planning technique used.     

Cone–beam computed tomographic analysis of maxillary and mandibular changes after high condylectomy combined with orthodontic treatment for active unilateral condylar hyperplasia

Our aim was to evaluate the efficacy of high condylectomy combined with orthodontic treatment for active unilateral condylar hyperplasia in 25 affected patients, by an analysis of the maxillary and mandibular changes on cone–beam computed tomography (CT). High condylectomy was the sole operative treatment. Variables that reflected the canting of the occlusal plane, the height of the maxillary complex, the buccolingual angulation of the maxillary first molar, the height of the ramus, the total length of the mandible, and the deviation of the chin were measured and compared between the two sides and between time intervals: preoperatively (T1) and the end of treatment (T2). The differences between time intervals in the deviation of the chin (p < 0.001) and the canting of the occlusal plane (p < 0.001) were significant, but there were no significant differences in the height of the ramus (p = 0.476) and the total length of the mandible (p = 0.838) between the affected and unaffected sides at T2. There were significant differences between time intervals in the buccolingual angulation on the unaffected side and the height of the maxillary complex on the affected side (p < 0.001). Facial asymmetry was corrected and the occlusal plane was improved. In conclusion, high condylectomy as the sole operative treatment combined with orthodontic treatment can provide an alternative method for correction of facial asymmetry associated with active unilateral condylar hyperplasia.