Herbst双期拔牙矫治对颞下颌关节位置影响的CBCT研究

目的:探讨Herbst双期拔牙矫治对颞下颌关节位置关系的影响.方法:纳入15例恒牙列早期安氏Ⅱ类错(牙合)下颌后缩患者,一期矫治采用Herbst矫治器,然后拔除每位患者的4个前磨牙;二期矫治采用edgewise固定矫治器.在Herbst矫治器矫治前两周(T1期)、Herbst矫治器初戴入矫治时(T2期)、Herbst矫治器拆除时(T3期)及二期固定矫治器拆除时(T4期)分别拍摄锥形束CT(cone beam computed tomography,CBCT).应用InvivoDental软件对CBCT图像进行三维重建,再对颞下颌关节间隙进行测量,并进行统计分析.结果:T1-T2-T3期,关节前间隙先减小后增大,关节上间隙、关节后间隙先增大后减小;T3-T4期,关节上、后间隙进一步减小,关节前间隙无明显变化;与T1期比,T4各关节间隙的变化均无明显差异.结论:髁突在关节窝中的位置在Herbst矫治开始时向前下移位,一期功能矫治结束时尤其双期矫治结束时几乎回到了治疗前的位置.     

Herbst矫治器治疗与颞下颌关节改建

本文综述了使用Herbst矫治器对颞下颌关节（TMJ）的髁突、关节窝和关节盘的影响，并探讨了使用Herbst矫治器是否会导致颞下颌关节紊乱（TMD）的问题。这有利于正畸医生正确理解功能性矫治器与TMJ的关系，以指导选择矫治时机的适应性。     

Herbst矫治器对下颌后缩患者颞下颌关节改建的研究进展

本文综述了Herbst矫治器对安氏Ⅱ类下颌后缩患者颞下颌关节（TMJ）的改建,包括Herbst矫治器对髁突和关节窝的生长改建以及矫治后髁突在关节窝中位置的变化,并探讨了Herbst矫治器的远期疗效。有利于临床医生正确理解Herbst矫治器与TMJ改建的关系,从而更好的指导临床应用。     

采用锥形束CT分析安氏Ⅱ类1分类错牙合患者Twin-block矫治前后颞下颌关节的变化

目的 运用锥形束CT（CBCT）分析安氏Ⅱ类1分类错牙合在Twin-block矫治前后颞下颌关节位置及形态结构在三维方向上的变化。方法 选取20例处于生长发育高峰前期或高峰期的安氏Ⅱ类1分类错牙合患者,拍摄其功能矫治前后双侧颞下颌关节的CBCT片,运用InVivoDental软件对CBCT片进行三维重建并测量线距和角度,对测量结果进行统计学分析。结果 与治疗前相比,治疗后矢状向关节前间隙减小,关节上间隙和后间隙增大,冠状向关节上间隙增大（P<0.01）;髁突高度、矢状向髁突角度、横断面髁突前后径增加（P<0.01）。结论 采用Twin-block矫治器治疗安氏Ⅱ类1分类错牙合患者后,髁突在关节窝的位置和髁突部分骨性结构发生了一定程度的改变,髁突有新骨沉积,高度增加,在关节窝内的位置更向下和向前。CBCT的应用使颞下颌关节结构的变化得以量化,能对正畸治疗效果进行客观评价。     

Herbst矫治器治疗与颞下颌关节改建

本文综述了使用Herbst矫治器对颞下颌关节(TMJ)的髁突、关节窝和关节盘的影响,并探讨了使用Herbst矫治器是否会导致颞下颌关节紊乱(TMD)的问题。这有利于正畸医生正确理解功能性矫治器与TMJ的关系,以指导选择矫治时机和适应证。     

Herbst矫治器双期矫治与拔牙矫治AngleⅡ类错[牙合]的对比研究

目的 比较Herbst矫治器双期矫治和单纯拔牙矫治恒牙期Angle Ⅱ类错(牙合)的效果.方法 选择18例及16例FG-G期恒牙期Angle Ⅱ类错(牙合)患者,分别作为Herbat组和拔牙组;Herbst组经金属铸造夹板式Herbat矫治器矫治后,立即接受方丝弓矫治器完成二期矫治;拔牙组拔出4个双尖牙方丝弓技术矫治;通过X线头影测量方法评价两组疗效.结果 前牙覆盖减小及磨牙关系改善中,Herbst组骨性变化占44%及57%,而拔牙组主要为86%及78%的牙性变化;较拔牙组的变化,Herbst组下颌升支长度、下颌体长度、下颌有效长度分别多增加了1.59mm、1.26mm和2.41mm SNB多增加了2.15°,ANB多减小了1.66°(P<0.001);Herbst组软组织侧貌突度具有更加明显的减小.结论 对以下颌后缩为主要特征的恒牙期Ⅱ类错(牙合),采用Herbst矫治器双期矫治具有显著疗效,而不宜单纯采用拔牙矫治.     

Forsus矫治器治疗安氏Ⅱ类下颌后缩患者颞下颌关节变化的CBCT分析

目的 通过CBCT研究Forsus矫治器对生长发育期患者颞下颌关节的影响。方法 选取28例（男性14例,女性14例）生长发育期的安氏Ⅱ类错(牙合)患者,采用直丝弓矫治配合Forsus矫治器导下颌向前。每位患者在治疗前后均行CBCT扫描,使用Invivo 5软件对患者治疗前后的颞下颌关节有关数据进行测量。结果 治疗后SNB增加,ANB减小;关节窝宽度增加,关节结节倾斜角减小;髁突顶部矢状面面积、髁突顶部冠状面面积增加,差异有统计学意义（P<0.05）;男性患者髁突体积、髁突顶部高度增加,髁突前后径减小,差异有统计学意义（P<0.05）。颞下颌关节窝面积、关节窝矢状总间隙面积、关节间隙、髁突内外径、髁突最大轴面面积不变（P>0.05）。结论 Forsus矫治器治疗后,髁突与关节窝相对位置关系不变,关节窝形态及髁突顶部形态改建,男性较女性髁突改建更明显。     

Herbst矫治器治疗前后髁突位置变化的分析

目的：探讨Herbst矫治器治疗对髁突位置的影响。方法：采用国产Herbst矫治器对17例生长发育期安氏Ⅱ^1下颌后缩儿童进行临床矫治，分别于戴矫治器前(T1)，戴矫治器后1周(T2)，矫治器拆除后1周(T3)拍摄关节中位断层片进行测量分析。结果：在治疗前，髁突居关节窝中央。当戴用Herbst矫治器1周后，髁突处于显著前移位，关节上、后间隙距离增大，前间隙距离减少，前后间隙面积比(X／Y)显著减少，积极治疗(7个月)结束后，髁突在TMJ中的位置又回到治疗前水平，处于关节窝中央。结论：Herbst矫治器治疗前后髁突位置未发生明显改变，其远期疗效尚有待进一步研究。     

Herbst矫治器对颞下颌关节生长的影响

目的研究Herbst矫治器对安氏Ⅱ类1分类错耠患者颞下颌关节产生的影响。方法用Herbst矫治器治疗18例安氏Ⅱ类1分类患者，以X线头影测量方法分析髁突的生长，关节窝移位及TMJ改变。结果Herbst矫治期间，矫治组髁突向后生长量为对照组的两倍，关节窝前下移位，TMJ改变与髁突生长相似，且更加明显。矫治结束后10个月，所有TMJ改变复原，表现为关节窝后移位，髁突生长量和TMJ改变减小，且方向向前。矫治结束后2．5年，所有TMJ改变为生理性的改变。结论Herbst矫治器仅暂时影响TMJ改变量及方向。     

功能性矫治器治疗安氏Ⅱ1患者颞下颌关节MRI研究

目的:研究Herbst矫治器治疗安氏Ⅱ1错牙合后颞下颌关节的改建情况。方法:18例安氏Ⅱ1错牙合病例,治疗前后摄双侧颞下颌关节磁共振(MRI)片,在MRI片上测量髁状突表面软骨增生的量,并用Kurita法分析治疗前后髁状突、关节盘及关节窝之间位置关系的改变情况。结果:①髁状突后上方表面软骨有明显增生迹象:增生量最大1.3mm ,最小0 .6mm ,平均0 .93mm。②髁状突与关节窝,关节盘与关节窝位置关系治疗前后有显著性差异(P <0 .0 5 ) ,髁状突与关节盘位置关系治疗前后无显著性差异(P >0 .0 5 )。结论:Herbst矫治器可刺激髁状突、关节盘及关节窝产生适应性改建。     

Cone beam computed tomography study of apical root resorption induced by Herbst appliance

Objective

This study evaluated the frequency of root resorption during the orthodontic treatment with Herbst appliance by Cone Beam Computed Tomography (CBCT).

Material and Methods

The sample comprised 23 patients (11 men, 12 women; mean ages 15.76±1.75 years) with Class II division 1 malocclusion, treated with Herbst appliance. CBCT was obtained before treatment (T0) and after Herbst treatment (T1). All the dental roots, except third molars, were evaluated, and apical root resorption was determined using the axial guided navigation method. Paired t-tests and Wilcoxon T Test were used to compare the dependent samples in parametric and nonparametric cases, respectively. Chi-Square Test with Yates’ correction was used to evaluate the relationship between apical root resorption and gender. Results were considered at a significance level of 5%.

Results

Apical resorption was detected by CBCT in 57.96% of 980 roots that underwent Herbst appliance treatment. All patients had minimal resorption and there was no statistical significance between the genders.

Conclusion

CBCT three-dimensional evaluation showed association between Herbst appliance and minimal apical root resorption, mostly in the anchoring teeth, without clinical significance.     

The incisor-lip relationship in Herbst/multibracket appliance treatment of Class II, Division 2 malocclusions

The purpose of this investigation was to examine the effect of Herbst/multibracket appliance treatment on the upper incisor-lower lip relationship in the management of Class II, division 2 malocclusions. The study evaluated 19 successfully treated subjects using lateral head films analyzed at 3 occasions: before (T1) and after (T2) Herbst/multibracket appliance treatment and 1-year posttreatment (T3). The average treatment (T1-T2) changes showed (1) the lower lip overlap on the upper incisors was reduced from 6.0 mm to 4.2 mm (P < .001), (2) the upper incisors were proclined 15.3 degrees (P < .001) and the lower incisors were proclined 9.6 degrees (P < .001), (3) the overbite was reduced from 7.3 mm to 1.7 mm (P < .001), and (4) the sagittal jaw base relationship (Wits) improved from +3.5 to +0.5 mm (P < .001). The average posttreatment (T2-T3) changes showed (1) the upper incisor-lower lip relationship remained stable, (2) the upper (0.6 degrees; P < .001) and lower (2.3 degrees; P < .001) incisors retroclined, (3) the overbite increased (1.2 mm; P < .001), and (4) the sagittal jaw base relationship remained unchanged. In conclusion, it was found that the upper incisor-lower lip relationship was improved by Herbst/multibracket appliance treatment and remained stable during a 1-year posttreatment period in spite of minor relapses of incisor tooth positions and relationships.     

Temporomandibular joint remodeling in adolescents and young adults during Herbst treatment: A prospective longitudinal magnetic resonance imaging and cephalometric radiographic investigation

The aim of this prospective study was to analyze and compare the temporomandibular joint adaptive mechanisms in 25 adolescent and 14 young adult Class II malocclusions treated with the Herbst appliance. Temporomandibular joint remodeling was analyzed by magnetic resonance imaging. In each subject, 4 magnetic resonance images of both temporomandibular joints were available: before treatment, at the start of treatment (when the Herbst appliance was placed), during treatment (6 to 12 weeks after appliance placement), and after treatment (when the appliance was removed). Furthermore, effective temporomandibular joint changes (the sum of condylar remodeling, fossa remodeling, and condyle-fossa relationship changes) were analyzed with the aid of lateral cephalometric radiographs from before and after treatment. All subjects were treated to Class I or overcorrected Class I dental arch relationships, and their mandibles became significantly (P <.001) more prognathic. After 6 to 12 weeks of Herbst treatment, signs of condylar remodeling were seen at the posterosuperior border in 48 of the 50 adolescent condyles and in 26 of the 28 young adult condyles. Bilateral remodeling of the mandibular ramus could be detected in 1 adolescent and 2 young adult patients. Signs of glenoid fossa remodeling at the anterior surface of the postglenoid spine were noted in 36 adolescent and 22 young adult temporomandibular joints. Effective temporomandibular joint changes during treatment were more horizontally directed and larger in both adolescents and young adult patients treated with the Herbst appliance than in an untreated group of subjects with ideal occlusion (Bolton standards). The increase in mandibular prognathism accomplished by Herbst therapy in both adolescents and young adults seems, in particular, to be a result of condylar and glenoid fossa remodeling. Because the Herbst appliance is most successful in Class II patients also at the end of the growth period, the treatment method could be an alternative to orthognathic surgery in borderline skeletal Class II cases. Magnetic resonance imaging renders an excellent opportunity to visualize the temporomandibular joint remodeling growth processes.     

A cephalometric comparison of treatment with the Twin-block and stainless steel crown Herbst appliances followed by fixed appliance therapy.

This study compared the effects of 2 treatment protocols for correcting Class II disharmony. The first phase of treatment consisted of functional jaw orthopedics with either the Twin-block or the stainless-steel crown Herbst appliance; the second phase consisted of comprehensive fixed-appliance therapy in both protocols. Each of the 2 samples comprised 28 consecutively treated Class II patients. The mean age at the start of treatment was approximately 12 years, and the mean age at the end of the treatment was approximately 14.5 years in both groups. The duration of the treatment phase with the functional appliance was approximately 13 months, and the duration of fixed-appliance therapy was approximately 15 months in both groups. The sex distribution was identical in the 2 groups. Lateral cephalograms were analyzed at the start of treatment (T1) and at the end of the overall treatment protocol (T2). Nonparametric statistics were used for comparisons of starting forms and of the T1-T2 changes between the 2 treatment groups. The stainless-steel crown Herbst appliance and the Twin-block appliance produced very similar therapeutic modifications in Class II patients, although the Twin-block group exhibited almost 2 mm greater correction of the maxillomandibular differential than did the crown Herbst group. The treatment effects of both protocols led to a normalization of the dentoskeletal parameters at the end of the overall treatment period. Twin-block therapy also induced a greater increase in the height of the mandibular ramus (posterior facial height). Overall, only minor differences were detected in the treatment and posttreatment effects of a compliance-free (crown Herbst) and a noncompliance-free (Twin-block) appliance for correcting Class II disharmony.     

Maxillary molar distalization or mandibular enhancement: a cephalometric comparison of comprehensive orthodontic treatment including the pendulum and the Herbst appliances.

Several methods of Class II treatment that do not rely on significant patient compliance have become popular during the last decade, including several versions of the Herbst appliance and the pendulum or Pendex molar-distalization appliances. Yet, these 2 general approaches theoretically have opposite treatment effects, one presumably enhancing mandibular growth, and the other moving the maxillary teeth posteriorly. This study examined the treatment effects produced by 2 types of the Herbst appliance (acrylic splint and stainless-steel crown) followed by fixed appliances, and the pendulum appliance followed by fixed appliances. For each of the 3 treatment groups, lateral cephalograms were analyzed before the start of treatment (T1) and after the second phase of treatment (T2). Patients were matched according to age and sex. The comprehensive treatment time for the pendulum group was 31.6 months, and the acrylic and crowned Herbst groups were treated for 29.5 months and 28.0 months, respectively. Overall from T1 to T2, there were no statistically significant differences in mandibular growth among the 3 groups. Skeletal changes accounted for a larger portion of molar correction in the Herbst treatment groups than in the pendulum group. Patients in the pendulum group had an increase in the mandibular plane angle. Conversely, the mandibular plane angle in patients treated with either Herbst appliance closed slightly from T1 to T2. At T2, the chin points (pogonion) of patients in both Herbst groups, however, were located slightly more anteriorly than were the chin points of the pendulum patients. It is likely that the slight downward and backward rotation of the mandible occurring during treatment in the pendulum patients accounted for much of this difference. The treatment effects produced by the 2 types of Herbst appliance were similar at T2, in spite of their differences in design. It is important not to generalize the findings of this comparison beyond the appliance systems evaluated. The 2 general approaches we evaluated involved a substantial dentoalveolar component in the treatment of Class II malocclusion. A comparison of a molar-distalizing appliance such as the pendulum with other types of functional appliances might yield differing results.     

Does bite-jumping damage the TMJ? A prospective longitudinal clinical and MRI study of Herbst patients

The aim of this prospective longitudinal study of 62 consecutively treated Class II malocclusions was to determine whether bite-jumping causes temporomandibular disorders (TMD). The function of the temporomandibular joint (TMJ) was assessed anamnestically, clinically, and by means of magnetic resonance images (MRIs) taken before (T1), after (T2), and 1 year after (T3) Herbst treatment. Average treatment time with the Herbst appliance was 7.2 months. In all subjects, Herbst treatment resulted in a Class I or overcorrected Class I dental arch relationship. Thereafter, treatment was continued with a multibracket appliance. The condyle was positioned significantly forward during treatment but returned to its original position after removal of the Herbst appliance. A temporary capsulitis of the inferior stratum of the posterior attachment was induced during treatment. Over the entire observation period from before treatment to 1 year after treatment, bite-jumping with the Herbst appliance: (1) did not result in any muscular TMD; (2) reduced the prevalence of capsulitis and structural condylar bony changes; (3) did not induce disc displacement in subjects with a physiologic pretreatment disc position; (4) resulted in a stable repositioning of the disc in subjects with a pretreatment partial disc displacement with reduction; and (5) could not recapture the disc in subjects with a pretreatment total disc displacement with or without reduction. A pretreatment total disc displacement with or without reduction did not, however, seem to be a contraindication for Herbst treatment. In conclusion, bite-jumping using the Herbst appliance does not have a deleterious effect on TMJ function and does not induce TMD on a short-term basis.     

Mandibular articular disk position changes during Herbst treatment: a prospective longitudinal MRI study.

The aim of this prospective longitudinal study of 15 consecutively treated Class II malocclusions was to assess any possible changes in the relative position of the articular disk to the condyle during different phases of Herbst therapy. Using a disk position index, parasagittal MRIs (central, medial and lateral slices) of the right and left TMJ were analyzed at five occasions: before Herbst treatment (T1), at start of treatment when the appliance was placed (T2), after 6 weeks of treatment (T3), after 13 weeks of treatment (T4), and after 7 months of treatment when the appliance was removed (T5). In all subjects Herbst treatment resulted in Class I or overcorrected Class I dental arch relationships. Condyle position was on average unchanged during Herbst treatment (T1 to T5). Before treatment (T1) the articular disk was in a slight protrusive position relative to the condyle. At start of treatment (T2) the mandible was advanced to an incisal edge to edge position. Because of the physiologic relative movement of disk and condyle on mandibular protrusion the disk attained a pronounced retrusive position. At the end of treatment (T5), the disk had almost returned to its original pretreatment position. In several cases, however, a slight retrusive disk position prevailed. In conclusion, Herbst treatment did not result in any adverse changes in articular disk position. On the contrary, the Herbst appliance could possibly be useful in the therapy of patients with anterior disk displacement.     

Arch width changes with a rapid maxillary expansion appliance anchored to the primary teeth

OBJECTIVE: To examine the dimensional changes after rapid maxillary expansion (RME) carried out in the transitional dentition with the primary teeth as anchorage. MATERIALS AND METHODS: Group A was composed of 31 consecutive transitional dentition patients with posterior quadrant crossbites treated with a Haas-type RME appliance anchored on the maxillary primary molars and canines. No treatment was administered after palatal expansion. Study models were made before RME (T1), at appliance removal (T2), and at least 1 year after appliance removal (T3). A control sample of 60 individuals with posterior quadrant crossbites who had had no orthodontic treatment was categorized into group B (30 individuals with an average age comparable with the treated patients at T2) and group C (30 individuals with an average age comparable with the treated patients at T3). RESULTS: Permanent molar crossbites were corrected at T2, and this correction was maintained at T3 in all patients. The mean permanent maxillary intermolar width was 42.6 +/- 2.3 mm at T1, 46.7 +/- 1.9 mm at T2 (P < .01), and 46.3 +/- 1.8 mm at T3 (P < .01) in group A; 42.9 +/- 2.7 mm (P < .01) in group B; and 44.4 +/- 3.0 (P < .01) in group C. Premolar and canine widths were slightly wider than the control at T3. CONCLUSION: To avoid undesirable treatment-induced effects on maxillary permanent molars, a stable transverse correction could be achieved with the RME appliance anchored on the primary teeth.     

Neuromuscular and skeletal adaptations following mandibular forward positioning induced by the Herbst appliance

The purpose of this study was to examine neuromuscular and skeletal adaptations to changes in sagittal jaw relationships induced by the Herbst appliance. Six patients (age, 9 years and 5 months to 11 years and 2 months) with Angle Class II, division 1 malocclusions were studied longitudinally. The structural changes were determined by analyzing serial lateral cephalograms. Electromyographic recordings of specific masticatory muscles were used to evaluate neuromuscular adaptations. Similar cephalometric changes were observed in all patients. In all patients, lateral pterygoid muscle activity increased immediately after insertion of the appliance, but the activity decreased markedly after 4 to 6 months of treatment. In 4 of the 6 patients studied, however, the condyles were located in a slightly more downward and forward position. These findings indicate that the adaptation of muscular function occurs within a relatively short period and precedes the compensatory morphological changes produced through functional appliance therapy.