Book Reviews

Abstract

This paper describes the orthodontic treatment of two cases that were presented by the winner of the William Houston Medal at the Membership in Orthodontics examination of the Royal College of Surgeons Edinburgh in 2005. The first case presentation is a Class II division 1 malocclusion treated by a combination of functional appliance and fixed appliance treatment and the second case presentation is a Class III malocclusion treated by a combination of fixed appliance treatment and orthognathic surgery.     

Comparison of oropharyngeal airway dimensional changes in patients with skeletal Class II and Class III malocclusions after orthognathic surgery and functional appliance treatment: A systematic review

ObjectiveTo compare the dimensional changes in the oropharyngeal airway in patients with skeletal Class II and Class III malocclusion before and after orthognathic surgery and treatment with a functional appliance.MethodsThe protocol was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and was registered to the International Prospective Register of Systematic Reviews (PROSPERO) under the registration number CRD42020170901. Furthermore, the reporting of the present SR was performed based on the PRISMA checklist.ResultsThe use of removable functional appliances increased the volume of the oropharyngeal airway in patients with skeletal Class II malocclusion. Furthermore, the increase in the volume of the oropharyngeal airway following the removable functional appliance treatment was more than that observed after fixed functional appliance treatment in growing patients. For patients with skeletal Class III malocclusion, who underwent the bimaxillary orthognathic surgery, resulted in no change in the dimensions of the oropharyngeal airway.ConclusionGrowing patients who receive removable functional appliance treatment have a more favorable long-term prognosis with regard to the oropharyngeal airway when compared with those who receive fixed functional appliance. Alternatively, in patients aged from (18–22) years with skeletal class III malocclusion Bimaxillary orthognathic surgery was found to be the recomended and superior method of treatment.     

Outcome of combined orthodontic-surgical treatment in a United Kingdom university dental institute

Introduction: This retrospective observational cohort study evaluated effectiveness of combined orthodontic–orthognathic surgical treatment in a UK University Dental Institute. Methods: Patients were identified from a database maintained prospectively throughout a 5-year period of observation. Demographic and clinical data included age, malocclusion, Index of Treatment Need, Index of Orthognathic Functional Treatment Need, orthodontist, surgeon, surgical procedure and treatment-time. Peer Assessment Rating (PAR) scores were generated from pre- and post-treatment dental study casts by a single calibrated examiner. Results: One hundred and sixty two subjects began treatment during the period of observation, 92 completed, 14 elected to discontinue before surgery and 56 remained in treatment. Outcome data were available for 73, 16 males and 57 females (mean age 23.28 [SD, 7.92] years). Within this sample, 33 (45.2%) presented with class II division 1, 6 (8.2%) with class II division 2 and 34 (46.6%) with class III malocclusion. Isolated maxillary and mandibular surgery was carried out in 3 (4.1%) and 24 cases (32.8%), respectively; bimaxillary surgery was performed in 46 (63.1%). Mean total treatment time in fixed appliances was 920.28 days (30.7 months). Mean pre-treatment PAR score was 39.09 [SD, 9.42] and post-treatment 5.86 [SD, 4.25] with a mean 83.7% PAR score reduction, representing a greatly improved occlusal result. Kruskal–Wallis testing found no evidence of any relationship between independent variables and percentage PAR reduction; however, surgeon identity did significantly influence treatment length (P?=?0.007). Conclusions: This investigation demonstrates that in terms of static occlusion combined orthodontic–orthognathic surgery is effective in correcting severe malocclusion.     

Lip Morphology Changes Following Orthognathic Surgery for Class III Malocclusion

Objectives:To test the hypothesis that there is no difference in the morphology of the lips and to determine the degree of improvement in the smile after orthognathic surgery for Class III malocclusion.Materials and Methods:The sample subjects included 30 adult female patients with dento-skeletal Class III malocclusion and 28 adult female volunteers with normal occlusion. Frontal facial photographs were taken before and after treatment, and 35 landmarks were placed on each tracing made from the frontal facial photograph. Thereafter, the landmarks were digitized into an x and y coordinate system with the subnasal point as the origin. The pretreatment rest and smile conditions were compared with the posttreatment conditions, respectively, using paired t-tests. In addition, two sample t-tests were used to test for differences between groups.Results:Both the upper and lower lips in the smiles of the Class III pretreatment group were positioned downward, and the upward movement of the upper lip and commissure points were smaller compared with the control group. When smiling, the horizontal direction of the mouth corners was statistically significantly different between the pretreatment and posttreatment conditions, whereas these were wider in the posttreatment than in the pretreatment conditions. These characteristics of the Class III smile improved after orthognathic treatment, but the differences with the control group remained unchanged immediately after treatment.Conclusion:The hypothesis is rejected. The soft tissue morphology of patients with dento-skeletal Class III malocclusion shows a significant improvement after orthognathic surgery.     

Three-part bi-maxillary osteotomy: a case report involving resorbable plates

Abstract

This case report describes a patient who presented with a severe class 2 skeletal discrepancy together with a Class II malocclusion and a large anterior open bite. The malocclusion and skeletal discrepancy were managed with a combination of orthodontic and orthognathic treatment.

The orthognathic surgery was undertaken following orthodontic decompensation using sectional mechanics to allow a segmental bimaxillary osteotomy and genioplasty to be performed. Although the discrepancy was severe using this combination of treatment, a successful outcome, both facially and occlusally, was achieved.     

骨性开畸形正颌外科手术前后的正畸治疗

目的：通过分析总结骨正开He畸形手术前后正畸治疗的原则和方法,以指导临床。方法：前牙开He畸形32例,男性9例,女性23例,开He度1－8．5mm,平均4mm31例伴下颌前突,1例伴下颌后。单纯术前正8 ,纯术后正3 ,余21例在手术前后均行正畸治疗。结果：术产术畸疗程为4－33个月,平均12个月;术后正畸疗程为3－17个月,平均8．5个月。开He畸形的术前治疗的;排齐上下牙列,解除牙列拥挤;去代偿治疗,避免上下切牙He向伸长移;支上下牙列列的唇颊向倾斜度。上下颌骨垂直牵引,防止开He复发,上下颌间Ⅱ类或Ⅲ类牵引,调整磨牙关系,结论通过系统的术前术后正畸治疗及正颌外科手术,可矫正前牙开He畸形,并取得良好的矫治效果。     

Surgical treatment of a skeletal Class III patient using customized brackets based on the CAD/CAM virtual orthodontic system

The computer-aided design/computer-aided manufacturing (CAD/CAM) virtual orthodontic system produces customized brackets, indirect bonding jigs, and archwires based on a three-dimensional virtual setup. In surgical cases, this system helps to visualize the final occlusion during diagnosis and to efficiently plan individualized presurgical orthodontic treatments. A 20-year-old female patient with a skeletal Class III malocclusion, maxillary protrusion, and lip protrusion was successfully treated with orthognathic surgery and orthodontic treatment with maxillary first premolar extractions. The CAD/CAM system was applied for efficient treatment, with a total active treatment time of 16 months. In this case report, the applicability of the CAD/CAM virtual orthodontic system for orthognathic surgery cases is demonstrated. Suggestions are also made to overcome the limitations and to maximize the advantages of this system during orthodontic treatment of patients undergoing orthognathic surgery.     

Clinical predictive factors for temporomandibular disorders following combined orthodontic and orthognathic surgical treatment in patients with Class III malocclusion

Objective: The aim of this study was to identify clinical factors predisposing to the development or worsening of temporomandibular disorders (TMDs) following orthodontic surgical treatment for Class III malocclusion.

Methods: A retrospective cohort study was performed on 88 patients with Class III malocclusion having undergone a combined orthodontic and orthognathic surgical treatment. Temporomandibular joint and masticatory muscle examinations were available prior to treatment and one year post-operatively. Multivariate logistic regression was used to predict the development of post-operative TMDs, and linear regression was used to predict the worsening of TMDs using Helkimo indices.

Results: Patients with Class III malocclusion presenting with pre-treatment anamnestic TMJ clicking (OR = 5.8; p = 0.03) and undergoing bimaxillary osteotomy procedures (OR = 18.6; p = 0.04) were more at risk for the development of TMDs.

Discussion: TMDs must be evaluated, monitored, and managed with caution in patients with Class III malocclusion presenting with pre-treatment joint clicking and who are planned for bimaxillary osteotomies.     

Characterization of phenotypes of skeletal Class III malocclusion in Korean adult patients treated with orthognathic surgery using cluster analysis

ObjectivesTo characterize the phenotypes of skeletal Class III malocclusion in adult patients who underwent orthognathic surgery (OGS).Materials and MethodsThe sample consisted of 326 patients with Class III malocclusion treated with OGS (170 men and 156 women; mean age, 22.2 years). Using lateral cephalograms taken at initial visits, 13 angular variables and one ratio cephalometric variable were measured. Using three representative variables obtained from principal components analysis (SNA, SNB, and Björk sum), K-means cluster analysis was performed to classify the phenotypes. Statistical analysis was conducted to characterize the differences in the cephalometric variables among the clusters.ResultsClass III phenotypes were classified into nine clusters from the following four major groups: (1) retrusive maxilla group, clusters 7 and 9 (7.1% and 5.5%; severely retrusive maxilla, normal mandible, severe and moderate hyperdivergent, respectively) and cluster 6 (9.2%; retrusive maxilla, normal mandible, normodivergent); (2) relatively protrusive mandible group, cluster 2 (20.9%; normal maxilla, normal mandible, hyperdivergent); (3) protrusive mandible group, clusters 3 and 1 (11.7% and 15.3%; normal maxilla, protrusive mandible, normodivergent and hyperdivergent, respectively) and clusters 8 and 4 (15.3% and 3.7%; normal maxilla, severe protrusive mandible, normodivergent and hypodivergent, respectively); and (4) protrusive maxilla and protrusive mandible group, cluster 5 (11.4%; protrusive maxilla, severely protrusive mandible, normodivergent). Considerations for presurgical orthodontic treatment and OGS planning were proposed based on the Class III phenotypes.ConclusionsBecause the anteroposterior position of the maxilla and rotation of the mandible by a patient''s vertical pattern determine Class III phenotypes, these variables should be considered in diagnosis and treatment planning for patients who have skeletal Class III malocclusion.     

边缘骨性Ⅲ类错[牙合]手术与非手术效果的对比分析

目的：比较边缘骨性Ⅲ类错[牙合]正颌手术与正畸掩饰治疗（拔牙）后的效果差异。方法：对两组骨性Ⅲ类手术边缘病例治疗前后的X线头颅侧位片进行对比分析,其中手术治疗组12例,单纯正畸组13例,所有病例治疗前ANB角都〉-5°。结果：手术组治疗的主要变化是下颌骨前齿槽区的后移及下切牙的直立,正畸组的主要变化是下切牙的后倾及后移。两组治疗后的X线头影测量值经Mann-Whitney U检验显示ANB角,上下颌骨长度比（M/M ratio）,NAPog角,下切牙倾斜角（∠L1/ML）,上下切牙交角（∠U1/L1）有显著性差异,而标志软组织凹陷度的Holdaway角和Z角没有差异。结论：对于骨性Ⅲ类手术边缘错而言,选择合适的病例,手术与正畸掩饰治疗都可以获得可接受的咬合和美观效果。     

Orthodontic-surgical treatment: neuromuscular evaluation in skeletal Class II and Class III patients

ObjectivesThe aim of this study was the evaluation of the neuromuscular response to treatment according to diagnostic phases, as a follow-up of patients under surgical orthodontic treatment. The patient sample was subdivided into sub-samples, according to clinical characteristics.Materials and methodsAll of the patients who underwent orthognathic surgery in the Department of Orthodontics (University of Milan) were subjected to periodic electromyographic evaluation of the masticatory muscles (masseter and anterior temporal muscles), and to electrokinesiographic evaluation of the mandibular movements. The patient sample comprised 80 patients (37 males; and 43 females) at the end of growth. The electromyographic instruments used in the study included a Freely and a K6-I electromyography. Statistical evaluation was carried out with the Student's t-tests for independent samples.ResultsThere are many differences between the skeletal Class II and skeletal Class III patients that are shown through the analysis of these data obtained. In the beginning phases of the treatment the muscular activities were higher in the Class II patients than in the Class III patients. Nevertheless this difference was reversed at the end of the treatment. A similar difference could be found in the mandibular kinesiology, in fact the maximum mandibular opening movement was greater in the skeletal Class II patients than in the skeletal Class III patients at the beginning of the treatment. At the end of the treatment this difference was lost. At the beginning of the treatment the Class II patients showed a greater protrusive movement of the mandibular than the Class III patients. At the end the treatment however this gap was reduced without being reversed.ConclusionsFunctional evaluation in patients in surgical orthodontic therapy is an important element in the diagnostic–therapeutic recordings, so as to reduce as much as possible any incorrect neuromuscular activity that can result in relapse.     

骨性安氏Ⅱ类错He的外科与正畸联合治疗

目的：探讨外科与正畸联合治疗骨性安氏Ⅱ类错Ｈｅ的方法和特点。方法：总结分析近年一经外科与正畸联合治疗的骨性安氏Ⅱ类错Ｈｅ病例２２例,介绍典型病例治疗过程,着重讨论拔牙时机,术前后正畸治疗特点及术式选择。结果：本研究２２例患者经联合治疗后,颌骨关系正常,牙弓形态衣Ｈｅ曲线正常,牙排列整齐,咬合关系好,面形及功能均获明显改善,疗效满意。     

Early orthognathic surgery with three-dimensional image simulation during presurgical orthodontics in adults

To correct dentofacial deformities, three-dimensional skeletal analysis and computerized orthognathic surgery simulation are used to facilitate accurate diagnoses and surgical plans. Computed tomography imaging of dental occlusion can inform three-dimensional facial analyses and orthognathic surgical simulations. Furthermore, three-dimensional laser scans of a cast model of the predetermined postoperative dental occlusion can be used to increase the accuracy of the preoperative surgical simulation. In this study, we prepared cast models of planned postoperative dental occlusions from 12 patients diagnosed with skeletal class III malocclusions with mandibular prognathism and facial asymmetry that had planned to undergo bimaxillary orthognathic surgery during preoperative orthodontic treatment. The data from three-dimensional laser scans of the cast models were used in three-dimensional surgical simulations. Early orthognathic surgeries were performed based on three-dimensional image simulations using the cast images in several presurgical orthodontic states in which teeth alignment, leveling, and space closure were incomplete. After postoperative orthodontic treatments, intraoral examinations revealed that no patient had a posterior open bite or space. The two-dimensional and three-dimensional skeletal analyses showed that no mandibular deviations occurred between the immediate and final postoperative states of orthodontic treatment. These results showed that early orthognathic surgery with three-dimensional computerized simulations based on cast models of predetermined postoperative dental occlusions could provide early correction of facial deformities and improved efficacy of preoperative orthodontic treatment. This approach can reduce the decompensation treatment period of the presurgical orthodontics and contribute to efficient postoperative orthodontic treatments.     

Modifications in Class I and Class II Div. 1 malocclusion during orthodontic treatment and their association with TMD problems

ABSTRACT

Objective: To observe changes in tooth movements of patients with Class I and Class II malocclusion during the first 6 months of orthodontic treatment and to investigate the relation between TMJ problems and these changes.

Methods: The sample was comprised of 63 individuals (20 control, 25 Class I malocclusion, 18 Class II Div. 1 malocclusion). Occlusion analysis was performed through T-Scan® record and chewing pattern examination before and after the 6-month period. The existence of TMD was evaluated using joint vibration analysis (JVA). Patients with malocclusion had active fixed orthodontic treatment.

Results: Disclusion time reduced in the patients group during the treatment period. No association was observed between the first 6-month period of the orthodontic treatment and TMD.

Discussion: It is suggested that occlusion analyses should be done before any orthodontic treatment, and disclusion time should be minimized as much as possible.     

Treatment planning in Class III malocclusion

In Class III malocclusion, the overjet is reduced and may be reversed, with one or more incisor teeth in lingual crossbite. In the early mixed dentition, and in older patients with mild skeletal discrepancies, orthodontic treatment usually involves proclining the maxilliary anterior teeth into positive overjet. When the permanent dentition has established, orthodontic therapy is usually aimed at compensating for the underlying mild-moderate Class III skeletal discrepancy by proclining and retroclining the maxillary and mandibular incisors, respectively. In contrast, adolescent and non-growing patients with severe Class III skeletal discrepancies require a combination of orthodontic treatment and orthognathic surgery to correct the underlying skeletal pattern. Adolescent patients with moderately severe skeletal discrepancies require careful treatment planning because they are often at the limits of orthodontic compensation, and further mandibular growth may prevent a stable Class I occlusion from being maintained with growth. In this situation, treatment should be limited to aligning the maxillary arch, accepting that orthognathic surgery will be required to correct the underlying Class III skeletal discrepancy when skeletal growth has been completed. This article will inform dental professionals about the aetiology, assessment, diagnosis and treatment of patients with Class III malocclusions. Specifically, the types of orthodontic treatment that can be completed at the various stages of dental development and skeletal growth will be discussed.     

The impact of orthognathic surgery on quality of life for class III dentofacial deformities

In this study, we aim to evaluate the quality of life in patients with Class III deformities after orthognathic surgery. A total of the 40 patients (26 female and 14 male) were included. The mean age of the patients was 24.85. Patients' ages ranged from 20 to 36 years. All patients received orthodontic treatment before surgery. Sagittal split ramus osteotomy was performed for single jaw patients. Le Fort I osteotomy and sagittal split ramus osteotomy was performed for double jaw patients. Patients completed the Oral Health Impact Profile 14 (OHIP-14) and Orthognathic Quality of Life Questionnaire (OQLQ) three times. [Preoperatively (T0), 1^st week after orthognathic surgery (T1) and in the 6^th - 12^th months after orthognathic surgery (T2)]. There was a statistically significant difference in the dimensions of OHIP-14 when the preoperative (T0) score, postoperative 1^st week (T1) score and postoperative 6^th - 12^th month (T3) score are compared among themselves except for psychological discomfort, physical disability, and handicap. OQLQ total score and preoperative (T0) score was greater than the postoperative 1^st week (T1) score and the postoperative 1^st week(T1) score was greater than the postoperative 6^th - 12^th month (T2) scores except oral function. When single jaw and double jaw surgeries were compared, no statistically significant difference was found between OHIP-14 and OQLQ total scores for preoperative, postoperative 1^st week, and postoperative 6^th - 12^th months. When both OHIP-14 and OQLQ scores were examined after orthognathic surgery, the OHRQOL of patients with Class III dentofacial deformity improved significantly.     

Severe skeletal Class III malocclusion treated without surgery or extraction

Among the malocclusions involving skeletal discrepancies, Class III occurs with the least frequency; however, it is also severe in the majority of cases. Compared with a Class II malocclusion, the mesial occlusion invariably manifests itself with greater deforming characteristics of facial harmony. The deficiency in the middle third of the face and/or the excessive length of the lower third of the face leads to significant loss of the profile's harmony. Good treatment strategies for this type of malocclusion could involve anything from intervening in the mixed dentition and/or permanent dentition in young adults to the combined orthodontic and surgical approach in patients without growth potential, who do not allow for compensations. This case report illustrates a Class III adolescent patient with severe facial profile deformity during the pubescent growth spurt, treated without extractions or orthognathic surgery.     

常见正颌手术后咬合关系的维护和调整

目的 探讨临床常见的正颌手术后,如何很好的维护和调整上下牙列的咬合关系,为临床提供有益的参考.方法 选择骨性Ⅰ类双颌前突行根尖下截骨后徙术、Ⅱ类下颌后缩行下颌升支矢状劈开前徙术、Ⅲ类骨性反骀行下颌升支骨切开后退及合并上颌前徙术各6例患者,共18例患者.正颌手术后依据分类分别行3种不同的牵引模式进行咬合调整.结果 18例...     

A study of adult orthodontic patients and their treatment

This retrospective epidemiological study was undertaken to assess factors related to adult orthodontic treatment and to identify any associated trends. Case records of all patients (676) aged 18 years or over at the start of active orthodontic treatment at the Eastman Dental Hospital, London were examined. Variables associated with patients and their treatment (age, sex, source of referral, malocclusion, type of appliance, and interdisciplinary treatment including orthognathic surgery) were studied and the data analysed statistically. Findings revealed that the number of adult patients undergoing orthodontic treatment has increased significantly, especially since 1985. The age of the patients treated was also found to increase in recent years. The percentage of female patients (72 per cent) Class III malocclusions (21.6 per cent) and Class III skeletal bases (26.2 per cent) was higher than found in studies on children. Most of the treatments required fixed appliances and over half involved interdisciplinary treatment, with an increase in the percentage of orthognathic surgical cases. Surgery was significantly more common in males (P less than 0.01) and highly significantly associated with Class III malocclusions and skeletal III bases (P less than 0.001). Twenty-five per cent of adult patients were found to have had a previous course of orthodontic treatment though these patients were not significantly different from adult patients presenting for the first course of treatment.     

Impact of orthognathic surgery on the prevalence of dehiscence in Class II and Class III surgical-orthodontic patients:: A cone beam computed tomographic study

ObjectivesThe objectives were to evaluate and compare the presence of bone dehiscence before and after orthognathic surgery.Materials and MethodsIn this retrospective study, 90 cone-beam computed tomography (CBCT) scans from 45 patients were evaluated. Class II (n = 23) and Class III (n = 22) orthodontic patients who were being prepared for orthognathic surgery were measured. CBCT scans were obtained about 30 days prior to (T0) and 6 months after (T1) double jaw orthognathic surgery. The distance between the cemento-enamel junction (CEJ) and the alveolar bone crest was assessed at the buccal and lingual surfaces of all teeth, on both sides and arches, except for the second premolars and the second and third molars. A total of 1332 sites were measured for Class II (644) and Class III (688) patients. The software used was OsiriX (version 3.3 32-bit). Data were compared with Wilcoxon and McNemar tests at the 5% level.ResultsBone dehiscence before surgery was present in 26% and 15% of the Class II and III groups, respectively. The presence of dehiscence increased to 31% in the Class II and 20% in the Class III patients after surgery (P < .05).ConclusionsThe prevalence of dehiscence increased slightly in Class II and Class III surgical-orthodontic patients after orthognathic surgery. Temporary vascular supply reduction and oral hygiene difficulties may explain these results; however, more studies are needed.