A case of anterior open bite with severely narrowed maxillary dental arch and hypertrophic palatine tonsils

This case report describes an adolescent patient with an open bite and severely narrowed maxillary dentition and hypertrophic palatine tonsils, treated efficiently with rapid maxillary expansion (RME) and subsequent orthodontic tooth alignment using fixed appliances. The treatment demonstrates that RME can be effective for the correction of a severely narrowed maxillary arch, as well as, in this case, the correction of an anterior open bite in an adolescent patient where no substantial vertical skeletal discrepancy existed.     

An adult case of skeletal open bite with a severely narrowed maxillary dental arch

Surgically assisted rapid maxillary expansion is proposed as an efficient approach for adult patients with transverse maxillary deficiency. This article reports the treatment of an 18-year, seven-month old male patient with an anterior open bite and a severely narrowed upper dental arch. A posterior crossbite was present on both sides. For the correction of the posterior crossbite, a lateral maxillary expansion of more than 8 mm was required. A surgically assisted rapid maxillary expansion with Le Fort I corticotomy and mandibular setback with a sagittal splitting ramus osteotomy were determined as the treatment plan. The total treatment time was 24 months including five months of post-surgical observation. After the treatment, an acceptable occlusion was achieved with a Class I molar relationship. The amount of actual maxillary expansion was 6.3 mm at the canines and 9.7 mm at the first molars. The relapse of the expansion was 0.9 mm and 0.1 mm at the corresponding regions two years after the surgically assisted maxillary expansion. It is emphasized that surgically assisted rapid maxillary expansion is a secure and efficient approach for achieving a desirable lateral maxillary expansion with stability in adult patients demonstrating transverse maxillary deficiency. Furthermore, it is suggested that longterm observation of the maxillary arch width after retention is of a great importance for the maintenance of the acceptable treatment outcome.     

恒牙期前牙开正畸治疗时机和疗效的研究

目的　通过对恒牙初期和恒牙晚期正畸治疗成功的病例进行分析 ,探讨恒牙期前牙开患者正畸治疗的时机及引起颅面形态的变化。方法　选择 13名恒牙初期和 12名恒牙期前牙开患者 ,利用计算机X线头影测量分析治疗前后的软硬组织变化 ,并进行统计学处理。结果　正畸的治疗变化以牙齿倾斜度的变化为主 ,前牙有一定的伸长 ,垂直高度有所增加 ,软组织面型有一定程度的改善。恒牙初期与恒牙期正畸治疗相比 ,除了上下前牙倾斜度的变化以外 ,还存在一定的下颌逆时针旋转趋势 ,而恒牙期者下颌平面角有顺时针旋转倾向。结论　提倡在恒牙初期即开始正畸治疗。     

前牙开畸形颅面形态的分类研究

目的　对前牙开畸形进行分类研究 ,为临床诊断和治疗提供参考。方法　随机选取116例恒牙期前牙开患者 ,借助计算机X线头影测量技术对其颅面软硬组织及气道结构进行测量 ,综合运用多种现代多元统计方法 ,对开畸形的颅面形态进行分类。结果　对年龄、性别、颅面特征等 15 6项指标经聚类和主成分分析精简为 30个变量 ,再通过因子分析提取出 4个因子 (下颌旋转因子、面高因子、牙骨矢状因子和上颌旋转因子 )。采用逐步聚类法对 116例患者的 4个因子得分进行聚类分析 ,将前牙开畸形这一群体分为牙齿槽型开、下颌顺时针旋转型开、长面型开、上颌逆时针旋转型开和骨性Ⅲ类开 5类并归纳出可供临床使用的简单分类方法。结论　对前牙开畸形进行分类在诊断和矫治设计中起着重要作用。     

应用"摇椅形"弓丝矫治前牙开牙合的临床研究

目的　研究“摇椅形”弓丝对前牙开牙合畸形的矫治效果。方法　对 14例前牙开牙合的患者应用“摇椅形”弓丝同时配合前牙区垂直牵引进行矫治 ,通过分析矫治前后X线头颅定位侧位片 ,评价其矫治效果。结果　矫治后上下颌切牙伸长、内收 ,下颌磨牙直立 ,牙合平面改建 ;同时控制了开牙合患者垂直方向的生长。结论　应用“摇椅形”弓丝同时配合前牙区垂直牵引矫治开牙合畸形符合利用固定矫治器治疗开牙合的机理 ,能获得良好的矫治效果。     

A ten-year follow-up case report following surgical correction of anterior open bite

A case is reported whereby an anterior open-bite was treated with the Köle osteotomy in an adult Chinese girl. This study documents cephalometrically the post-treatment changes occurring in the dento-alveolar complex over a ten year follow-up period and describes the possible mechanisms contributing to the remarkable stability of the open-bite correction.     

磨牙前倾弯治疗前牙开(牙合)畸形的临床效果评价

目的 开拾畸形在临床治疗上难度较大，治疗方法较单一、局限、疗程长、矫治效果不确定，本文目的在于了解应用前倾弯矫治前牙开He时的矫治效果。方法 对5例前牙开He的患者应用前倾弯进行矫治，通过分析矫治前后X线头颅定位侧住片，评价前倾弯在矫治前牙开He畸形的效果。结果 发现矫治过程中，第一磨牙明显近中倾斜；矫治前后全面高、前后面高有显著性变化；上颌切牙至腭平面、下颌切牙至下颌平面的垂直距离明显增加；下颌第一磨牙至下颌平面的角度明显变大，说明在矫治后上下切牙伸长并向舌侧移动。结论 前倾弯治疗开He主要是通过前牙的伸长和舌侧移动来达到建立覆He的目的，而后牙不仅不能直立，而且会更加近中倾斜，从而使He平面不能改变，而使开He的矫治效果不稳定。     

Prediction of mandibular movement and its center of rotation for nonsurgical correction of anterior open bite via maxillary molar intrusion

Objectives:To evaluate quantitatively the relationship between molar intrusion (change [Δ] maxillary first molar [U6]–palatal plane [PP]) and changes in vertical and sagittal cephalometric parameters and to determine the center of mandibular autorotation.Materials and Methods:Twenty-one patients diagnosed with anterior open bite and successfully treated with molar intrusion (overbite [OB] > 0 mm) were retrospectively enrolled. Lateral cephalograms taken before and after molar intrusion were used to measure changes in vertical and sagittal cephalometric parameters. The center of mandibular autorotation was calculated by measuring displacement of gonion (Go) and pogonion (Pog). Paired t-tests were used to compare variables, and linear regression analysis was used to examine the relationship between ΔU6-PP and other variables.Results:The mandible exhibited counterclockwise rotation after maxillary molar intrusion, which led to closure of anterior open bite. Strong linear relationships, in descending order, between ΔU6-PP and ΔOB, Δanterior facial height (AFH), Δvertical reference plane (Pog), and Δsella-nasion to Go-menton (SN-GoMe), were observed. When the maxillary molar was intruded 1 mm, OB increased by 2.6 mm, AFH decreased by 1.7 mm, Pog moved forward by 2.3 mm, and SN-GoMe decreased by 2°. The center of mandibular autorotation was located 7.4 mm behind and 16.9 mm below condylion after molar intrusion.Conclusions:The mandible exhibited counterclockwise rotation after maxillary molar intrusion; the center of mandibular autorotation was located behind and below condylion with individual variations.     

Relapse of skeletal class III with anterior open bite after bimaxillary orthognathic surgery depending on maxillary posterior impaction and mandibular counterclockwise rotation

The goal of this study is to evaluate relapse after orthognathic surgery of skeletal class III with anterior open bite depending on the posterior impaction and mandibular counterclockwise rotation. Patients (n = 29) were divided into two groups according to the change of mandibular occlusal plane angle (MnOP): Group A had a clockwise change of MnOP > 0° (n = 11) and Group B had a counterclockwise change of MnOP < −2° (n = 18). Lateral cephalograms were analyzed preoperatively, and at immediate stage, six weeks, six months, and one year after surgery. One year after surgery, the stability of the maxilla was good in both groups. Upward movement of the mandible was observed six weeks after surgery due to mandibular autorotation. The amount of mean relapse was small, although a significant difference was observed horizontally between groups. Group B demonstrated more forward movement of B point, pogonion, and menton than Group A (p < 0.05). SNB angle increased in both groups (p < 0.05). At one year follow up, good occlusal stability was observed in both groups with positive overbite. Our study suggested that bimaxillary procedures with clockwise and counterclockwise rotation of mandibular occlusal planes for correction of mandibular prognathism with anterior open bite appeared to be relatively stable procedures.     

Treatment results and long-term stability of anterior open bite malocclusion

OBJECTIVES: To evaluate treatment results and long-term stability of anterior open bite malocclusion and to identify predictive factors for both treatment results and their stability. DESIGN: Retrospective study. SETTING AND SAMPLE POPULATION: The Department of Orthodontics and Oral Biology at the Radboud University Nijmegen Medical Centre, The Netherlands. Fifty-two patients with an anterior open bite. METHODS: Lateral cephalograms and dental casts were analysed at: start of treatment (Ts), end of treatment (T0), 2 and at least 5 years after the end of treatment (T2 and T5, respectively). A standard cephalometric analysis was performed, while the Peer Assessment Rating (PAR) index was used to evaluate the occlusion. RESULTS: The mean PAR reduction at T0 was 74%, but decreased to 56% at T5. The mean overbite (OB) increased from -3.2 mm (+/- 1.9) at Ts to 0.4 mm (+/- 1.1) at T0, 0.1 mm (+/- 1.6) at T2 and 0.2 mm (+/- 1.8) at T5. Thirty-seven patients (71%) had a positive OB at T0, but the bite opened again in 10 of these patients (27%) from T0 to T5. Forty-four per cent of our patients had an open bite at T5. No pre-treatment variables could predict these changes. CONCLUSION: Treatment response and long-term stability of the anterior open bite was found to be rather poor. This has to be taken into consideration when planning treatment of open bite patients. Prediction of open bite closure at the end of active treatment or at the follow-up was not possible.     

Long-term evaluation of rapid maxillary expansion and bite-block therapy in open bite growing subjects: A controlled clinical study

Objective:To evaluate the long-term effects of rapid maxillary expansion (RME) and posterior bite block (BB) in prepubertal subjects with dentoskeletal open bite.Materials and Methods:The treatment group (TG) comprised 16 subjects (14 girls, 2 boys) with dentoskeletal open bite with a mean age of 8.1 ± 1.1 years treated with RME and BB. Three consecutive lateral cephalograms were available before treatment (T1), at the end of the active treatment with the RME and BB (T2), and at a follow-up observation at least 4 years after the completion of treatment (T3). The TG was compared with a control group (CG) of 16 subjects (14 girls, 2 boys) matched for sex, age, and vertical skeletal pattern. An independent sample t-test was used to compare the T1 to T3, T1 to T2, and T2 to T3 cephalometric changes between the TG and the CG.Results:In the long term, the TG showed a significantly greater increase in overbite (+1.8 mm), reduced extrusion of maxillary and mandibular molars (−3.3 mm), and, consequently, a significant decrease in facial divergence (−2.8°) when compared with untreated subjects.Conclusions:The RME and BB protocol led to successful and stable recovery of positive overbite in 100% of the patients considered. Correction of open bite was associated with reduced extrusion of maxillary and mandibular molars with a significant improvement in vertical skeletal relationships when compared with the CG.     

����ҡ�ι���ǰ������ֱǣ������ǰ��������18����Ч����

目的    探讨镍钛（NiTi）摇椅弓附加前牙区垂直牵引对前牙开牙合畸形的治疗效果。 方法    利用NiTi摇椅弓加前牙区垂直牵引对2007—2009年在厦门市第一医院思明分院口腔科就诊的18例前牙开牙合畸形患者进行矫治,并对矫治前后的头颅侧位片进行测量分析。结果    X线头影测量显示治疗后骨骼无显著变化,下切牙伸长,下磨牙压低,上切牙及上下后牙竖直,上颌牙合平面有顺时针旋转的趋势,下颌牙合平面有逆时针旋转的趋势。开牙合间隙关闭,前后牙建立良好的咬合关系,所有病例治疗后均取得满意疗效。结论    NiTi摇椅弓加前牙区垂直牵引是治疗前牙开牙合的有效方法。     

薄型牙槽骨的重度前牙开病例治疗1例

本文报告1例25岁女性重度开牙合患者的治疗。患者Ⅲ度开牙合,全口牙槽骨极薄,唇舌侧根型明显,采用固定矫治并配合肌功能训练,在治疗过程中上颌尖牙穿出唇侧骨皮质,将上颌双侧尖牙托槽换成HX托槽并进行龈牙合向反向粘接,同时减少唇肌训练的强度和时间后,尖牙牙根重新位于骨松质中,矫治后建立了正常的覆牙合覆盖,尖牙、磨牙达到Ⅰ类关系,咬合功能良好,面形得到改善。本病例表明非骨性重度开牙合病例通过固定矫治配合有效的肌功能训练可以得到很好的治疗效果。     

Long-term stability of soft tissue changes in anterior open bite adults treated with zygomatic miniplate-anchored maxillary posterior intrusion

Objectives:To evaluate soft tissue changes and their long-term stability in skeletal anterior open bite adults treated by maxillary posterior teeth intrusion using zygomatic miniplates and premolar extractions.Materials and Methods:Lateral cephalograms of 26 patients were taken at pretreatment (T1), posttreatment (T2), 1 year posttreatment (T3), and 4 years posttreatment (T4).Results:At the end of treatment, the soft tissue facial height and profile convexity were reduced. The lips increased in length and thickness, with backward movement of the upper lip and forward movement of the lower lip. The total relapse rate ranged from 20.2% to 31.1%. At 4 years posttreatment, 68.9% to 79.8% of the soft tissue treatment effects were stable. The changes in the first year posttreatment accounted for approximately 70% of the total relapse.Conclusions:Soft tissue changes following maxillary posterior teeth intrusion with zygomatic miniplates and premolar extractions appear to be stable 4 years after treatment.     

Hyrax versus transverse sagittal maxillary expander: An assessment of arch changes on dental casts. A retrospective study

ObjectiveThe aim of this study was to compare arch changes before and after maxillary expansion with Transverse Maxillary Sagittal Expander (TSME) and Hyrax Palatal Expander (HPE), in growing patients with diagnosis of maxillary hypoplasia.Materials and methodsThe sample consisted of 40 patients’ records (20 males 20 females mean age 9.2 ± 2.6 years) were selected from the archive of the Orthodontic Department of the University of Milan, Italy. Patients were randomly divided in two groups: patients in group 1 were treated with HPE as they presented only transverse deficiency of the maxilla and in group 2 were treated with TSME. Plaster models have been measured with a Verniere caliper to evaluate the differences in maxillary expansion of the two devices. Measurements were performed on casts poured from impressions taken before appliance bonding (T0), immediately after appliance debonding (T1) and at 6 months follow-up (T2). The variations in the following distances have been considered: inter-molar distance, inter-canine distance, palatal depth, palatal length and arch circumference. Shapiro-Wilk test was performed to assess normality distribution. ANOVA for repeated measures with multiple paired t-test for pairwise comparisons and its non-parametric equivalent Friedman’s test with multiple Wilcoxon tests for pairwise comparisons were performed to evaluate changes in time of each variable in each group. Between groups comparisons were performed for each variable at each observing time using independent t-test or Mann-Whitney test. Significance level was set at p < 0,05.ResultsBoth the Friedman test and the rm-ANOVA test and their respective post-hoc show that within both groups the respective variables have a statistically significant increase between T0 and T1 (p < 0,05) and a slight decrease between T1 and T2 (p < 0,05) that is not clinically relevant remaining always T2 greater than T0 in a statistically and clinically relevant way (p < 0,05). The analysis between the differences of the measurements at different timing measured by the Mann-Whitney test shows that for all the variables there is no statistically significant difference between the 2 devices (p < 0,05), except for the perimeter of the arch and the length of the palate; in this case it appeared that the TSME is better statistically (p < 0,05).ConclusionsThe study has shown that RPE and TSME can achieve similar results in transversal palatal expansion. Differences have been found in the palatal length and in the arch perimeter where TSME seems to be more efficient.     

Skeletal class III and anterior open bite treatment with different retention protocols: a report of three cases

Abstract

The treatment of skeletal class III and anterior open bite can be unstable and orthodontists frequently observe relapse. Here, we report on the management of three patients with skeletal class III profiles and open bites treated by orthodontic camouflage. Each received a retention protocol involving the use of two separate appliances during the night and day accompanied by myofunctional therapy. Long-term follow-up revealed a stable outcome.     

Aesthetic and functional outcomes using a multiloop edgewise archwire for camouflage orthodontic treatment of a severe Class III open bite malocclusion

Occasionally, orthodontists will be challenged to treat malocclusions and skeletal disharmonies, which by their complexity one might think that the only treatment alternative is the surgical-orthodontic approach. A male patient, aged 17 years old, was diagnosed with a skeletal Class III malocclusion, anterior open bite and negative overjet. An unpleasant profile was the patient’s ‘chief complaint’ showing interest in facial aesthetics improvement. Nevertheless, the patient and his parents strongly preferred a non-surgical treatment approach. He was treated with a multiloop edgewise archwire to facilitate uprighting and distal en-masse movement of lower teeth, correct the Class III open bite malocclusion, change the inclination of the occlusal plane and obtain the consequent morphological-functional adaptation of the mandible. The Class III malocclusion was corrected and satisfactory changes in the patient’s profile were obtained. Active treatment was completed in 2 years, and facial result remained stable at 2 years 6 months after debonding.     

Stability of anterior open bite in permanent dentition treated using extraction or non-extraction methods: A systematic review and meta-analysis of each method

Purpose

To evaluate the literature on the stability of open bite treatment using extraction or non-extraction methods.