Orthopedic coordination of dentofacial development in skeletal Class II malocclusion in conjunction with edgewise therapy. Part II

This second of two articles describes the effects of mandibular growth enhancement in a comprehensive orthopedic approach to the correction of skeletal Class II malocclusion. Clinical and experimental evidence gives support to the concept, and case histories show the clinical mode of use of the appliance system. An initial 10- to 12-month orthopedic phase is followed by a second phase of similar duration in which full edgewise therapy is used to establish a gnathologically ideal occlusion. As the essential corrections are achieved in the orthopedic phase, the second phase is much reduced in complexity and is generally confined to alignment and final detailing. This combined approach to skeletal Class II treatment offers the possibility of better harmony of dental and facial features, with continued stability through the period of facial growth.     

Orthopedic activators for growth and treatment of Class II malocclusion

Activators are functional jaw orthopedic appliances which provide various mandibular position, but always different from habitual positions. Mechanisms and modus operandi of activators explain therapeutic objectives of clinicians. When we analyse different determinants of modus operandi of activators (skeletal, muscular and articular), it is possible to classify these appliances in rigid monobloc appliances, composite or elastic activators and thrusting activators. Many prospective or retrospective clinical studies analyse dentoalveolar or skeletal effects of the activators.     

Class I malocclusion with severe open bite skeletal pattern treatment

A case report of a Class I malocclusion with a severe skeletal open bite, excessive overjet, a high mandibular plane angle, and a forward maxillary rotation is presented. Treatment has eliminated the causative factors (i.e., mouth breathing, enamel hypoplasia of the first molars, and abnormal tongue posture and function). A normal growth pattern has been restored, ensuring a good and stable orthodontic result.     

Orthopedic/orthodontic treatment of a Class I malocclusion with a Class III skeletal pattern and maxillary deficiency. An American Board of Orthodontics case report

A case report of a Class I dental malocclusion superimposed on a Class III skeletal pattern with normal mandible and underdeveloped maxilla is presented. The patient was a 15-year-old girl whose statural growth was complete. The maxilla was deficient in anteroposterior and transverse dimensions, causing a slightly concave profile, a crossbite relationship of most of the anterior and posterior teeth, and upper anterior crowding. Sutural expansion and orthopedic advancement of the maxilla was used to reduce the maxillary deficiency. A complete 0.018-inch slot straight-wire appliance was used to align the teeth, close lower spaces, and detail the occlusion.     

Camouflage treatment of skeletal Class III malocclusion with multiloop edgewise arch wire and modified Class III elastics by maxillary mini-implant anchorage

Objective:To evaluate the effect of the multiloop edgewise arch wire (MEAW) technique with maxillary mini-implants in the camouflage treatment of skeletal Class III malocclusion.Materials and Methods:Twenty patients were treated with the MEAW technique and modified Class III elastics from the maxillary mini-implants. Twenty-four patients were treated with MEAW and long Class III elastics from the upper second molars as control. Lateral cephalometric radiographs were obtained and analyzed before and after treatment, and 1 year after retention.Results:Satisfactory occlusion was established in both groups. Through principal component analysis, it could be concluded the anterior-posterior dental position, skeletal sagittal and vertical position, and upper molar vertical position changed within groups and between groups; vertical lower teeth position and Wits distance changed in the experimental group and between groups. In the experimental group, the lower incisors tipped lingually 2.7 mm and extruded 2.4 mm. The lingual inclination of the lower incisors increased 3.5°. The mandibular first molars tipped distally 9.1° and intruded 0.4 mm. Their cusps moved 3.4 mm distally. In the control group, the upper incisors proclined 3°, and the upper first molar extruded 2 mm. SN-MP increased 1.6° and S-Go/N-ME decreased 1.Conclusions:The MEAW technique combined with modified Class III elastics by maxillary mini-implants can effectively tip the mandibular molars distally without any extrusion and tip the lower incisors lingually with extrusion to camouflage skeletal Class III malocclusions. Clockwise rotation of the mandible and further proclination of upper incisors can be avoided. The MEAW technique and modified Class III elastics provided an appropriate treatment strategy especially for patients with high angle and open bite tendency.     

Psychologic implications of orthognathic surgery in patients with skeletal Class II or Class ill malocclusion

The psychologic profile of 100 consecutive patients undergoing orthognathic surgery for correction of Class II or Class III malocclusion was monitored in a prospective observational study. Patients and their relatives or friends completed questionnaires about their self-image before surgery, 6 weeks postoperatively, and 6 months postoperatively. Preoperatively, patients with Class III malocclusion felt significantly less attractive (P = .03), had slightly higher attention to physical appearance, and had slightly stronger feelings of insecurity regarding their facial appearance compared with Class II patients. Grading of attractiveness/self-confidence improved significantly in Class III patients at 6 weeks postoperatively (P = .006), while in Class II patients the improvement was less pronounced and only significant at 6 months postoperatively (P = .002). Grading of attractiveness/self-confidence by relatives/friends of patients with Class II and Class III was similar preoperatively, but was significantly higher for Class III patients 6 weeks postoperatively in comparison with Class II patients (P = .048). These data indicate that the psychologic profiles are significantly different between Class II and Class III patients preoperatively and show different dynamics postoperatively.     

Stability after surgical-orthodontic correction of skeletal Class III malocclusion. I. Mandibular setback

Postsurgical stability of mandibular setback to correct mandibular prognathism was compared for three approaches: transoral vertical ramus osteotomy, bilateral sagittal split osteotomy with wire osteosynthesis and maxillomandibular fixation, and bilateral sagittal split osteotomy with rigid internal fixation via bone screws. In the transoral vertical ramus osteotomy group, the mean postsurgical change in chin position was almost zero, but nearly 50% of the patients did have clinically significant changes in chin position; two thirds of these movements were posterior and one third anterior. In the bilateral sagittal split osteotomy groups, the chin either stayed in its immediately postsurgical position or moved anteriorly. In one fourth of the patients who received maxillomandibular fixation and in nearly half of the patients who received rigid internal fixation, the chin moved forward more than 4 mm.     

Orthopedic treatment outcomes in Class III malocclusion. A systematic review

OBJECTIVE: To assess the scientific evidence on the effectiveness of early orthopedic treatment in Class III subjects. MATERIALS AND METHODS: A literature survey was performed by applying the Medline database (Entrez PubMed). The survey covered the period from January 1966 to December 2005 and used the Medical Subject Headings (MeSH). The following study types that reported data on the effects of Class III treatment with orthopedic appliances (facial mask, chincup, FR-3) on intermaxillary sagittal and vertical relationships were included: randomized clinical trials (RCTs), and prospective and retrospective longitudinal controlled clinical trials (CCTs) with untreated Class III controls. RESULTS: The search strategy resulted in 536 articles. After selection according to criteria for inclusion and exclusion, 19 articles qualified for the final review analysis. One RCT and 18 CCTs were retrieved. CONCLUSION: The quality standard of the retrieved investigations ranged from low (four studies) to medium/high (five studies). Data derived from medium/high quality research described over 75% of success of orthopedic treatment of Class III malocclusion (RME and facial mask therapy) at a follow-up observation 5 years after the end of orthopedic treatment.     

Category 7: Class II skeletal malocclusion with transverse maxillary constriction in an adult patient.

This case report was submitted to the American Board of Orthodontics as part of the board-certification process. The summary of treatment and records are reprinted here much as they were submitted to the board.     

骨性Ⅲ类错牙合患者牙弓形态特征分析

目的探讨骨性Ⅲ类错患者的牙弓形态特征,为临床诊断和治疗提供理论依据。方法选择骨性Ⅲ类错患者47例为实验组,个别正常50例为对照组,在石膏模型上测量与牙弓形态特征相关的7个项目,计算上下颌相应测量项目之差,采用SPSS 17.0软件对数据进行独立样本t检验。结果实验组的上颌牙弓前段长度小于对照组,上颌尖牙角大于对照组（P<0.05）;男性实验组的上下颌第一前磨牙间宽度之差大于对照组,牙弓前段长度之差小于对照组（P<0.05）。结论骨性Ⅲ类错患者的牙弓宽度基本正常,但牙弓前段长度不足,且前段弓形较为平直。