一种新型Ⅲ类磁力矫治器在骨性Ⅲ类患者早期治疗中的作用评价

目的:本研究自主开发了一种新型Ⅲ类磁力Twin-block功能矫形装置（MOA-Ⅲ）,通过对青春前期安氏Ⅲ类错的临床治疗,分析其对青春前期安氏Ⅲ类错患者颅面复合体的作用,探讨其临床矫治机制。方法:应用MOA-Ⅲ矫治器对30例（男12例,女18例）青春前期轻度骨性Ⅲ类错患者进行治疗。另外选取18例（男7例,女11例）未立刻进行治疗并随访半年的患者作为对照组。患者平均初始年龄为9岁3个月,平均治疗时间为6.6个月。利用SPSS15.0软件包,应用t检验对40项相关头颅测量数据进行分析。结果:MOA-Ⅲ可对上、下颌骨间关系的调整起到非常有效的作用。上颌骨发生前移并伴随一定的顺时针旋转,下颌骨则发生轻度的后下旋转。下颌骨体及下颌支长度无显著变化。治疗后上颌前牙发生一定程度唇倾,而下前牙发生一定程度的舌倾。软组织测量显示,上唇前移而下唇发生一定程度的后移。对照组除一些下颌骨及软组织的测量项目发生变化外,其他项目均无显著差异。结论:通过与未进行治疗的对照组进行比较,应用MOA-Ⅲ矫治器对青春前期轻度骨性Ⅲ类错进行治疗是有效的。其矫治结果主要来自上颌骨及上颌牙列的前移及下颌骨的顺时针方向旋转。     

Orthopedic cervical headgear with an expanded inner bow in class II correction

Forty consecutively referred children, 20 boys and 20 girls, with a Class II division I malocclusion and protrusive maxilla were treated with orthopedic cervical headgear with a 10 mm expanded inner bow and a long outer bow bent 15 degrees upwards. The mean age of the children at the beginning of treatment was 9.3 years (SD 1.3, range 6.6 to 12.4 years), and the average treatment time was 1.8 years (SD 0.6, range 0.8 to 3.1 years). In all patients Class II molar relationships were successfully corrected to Class I molar relationships. This was accompanied by a marked widening of both maxillary and mandibular dental arches. The cephalometric analysis suggested that the observed improvement of the occlusion was due to an inhibition of forward growth of the maxilla and anterior downward rotation of the palate.     

Dentoskeletal effects and facial profile changes during activator therapy

The aim of this retrospective study was to investigate cephalometrically the skeletal, dental, and soft tissue modifications induced by activator treatment in patients with Class II malocclusions caused by mandibular retrognathism. The subjects, all in the mixed dentition, were selected from a single centre and were divided into two groups: 40 patients treated with an incisor double capping activator (20 girls, 20 boys with a mean age of 10 years) and a control group of 30 subjects (15 girls, 15 boys with a mean age of 10 years). The dentoskeletal and aesthetic changes that occurred were compared on lateral cephalograms taken before treatment (T0) and after 18-24 months, when the activator was removed (T1). In the control group the radiographs were obtained before (T0) and after (T1) 21 months (standard deviation +/- 3 months). Activator treatment in these growing patients resulted in a correction of the Class II relationship (ANB -2.14 degrees), a restriction of maxillary growth (SNA -0.5 degrees), an advancement of the mandibular structures (SNB +1.64 degrees, FH--NPg +3.39 degrees; OLp-B +5.17 mm, OLp-Pg +5.14 mm, OLp-Go +2.44 mm), a correction of the overjet (-5.03 mm), an improvement in overbite (-1.17 mm) and uprighting of the maxillary incisors (1--FH -5.64 degrees). The activator appliance was effective in treating growing patients with mandibular deficiency: activator therapy corrected Class II malocclusions by a combination of skeletal and dental changes and improved the soft tissue facial profile.     

Skeletal and dento-alveolar changes as a result of headgear activator therapy related to different vertical growth patterns.

The purpose of this study is to evaluate the dental and skeletal effect of the headgear activator according to Van Beek (1981). Special emphasis is put on the changes in vertical position of the incisors after treatment. The material for this study consists of pre- and post-treatment cephalograms of 43 girls and 35 boys with severe Class II malocclusions. Changes due to treatment were compared with two control groups: the series of Riolo et al. (1984), and 50 Austrian children with Class II malocclusions who did not receive treatment during the observation period. The headgear activator was found to be an effective treatment tool in the correction of Class II division 1 malocclusions. The observed skeletal changes were limited to minor growth stimulation of the mandible, while an orthopaedic effect on the maxilla could not be established. The dento-alveolar changes due to headgear activator treatment were most obvious in the upper incisor area resulting in an intrusion and a retroclination of these teeth. Moreover, vertical control of the lower anterior facial height in open bite growth patterns was observed in the sample investigated.     

Effects of orthodontic treatment on mandibular rotation and displacement in Angle Class II division 1 malocclusions

The aim of this retrospective cephalometric study was to investigate the effects of orthodontic treatment on rotation and displacement of the mandible in Angle Class II, division 1 malocclusions. Thirty patients in the treated group (15 boys and 15 girls; mean age at pretreatment, 12.27 +/- 1.36 years) were compared with 28 subjects who had untreated Class II, division 1 malocclusions (15 boys and 13 girls; mean age at T1, 12.01 +/- 0.07 years). The patients in the first group were treated nonsurgically, without extraction, and without the use of functional appliances. Cephalometric data were obtained from three lateral cephalograms per case representing pretreatment (T1), posttreatment (T2), and at least 2-years postretention (T3). Thirty-seven variables were measured representing craniofacial morphology, tooth measurements, and mandibular displacement. Some variables were obtained from cranial base, maxillary, or mandibular superimposition. Statistical significance was established at P < .05, P < .01, and P < .001. The findings indicated that orthodontic treatment of Class II, division 1 malocclusions induced a more vertical mandibular growth direction associated with an increased vertical displacement of pogonion. Occlusal or vertical movement of maxillary and mandibular molars was not correlated to mandibular rotation or horizontal displacement of pogonion. When compared with controls, the treated group did not exhibit a significant difference in mandibular rotation or occlusal movement of maxillary molars; however, it did show a greater occlusal movement of mandibular molars during treatment.     

Comparison of the effects of Twin Block and activator treatment on the soft tissue profile

The aim of this study was to evaluate and compare the effects of activator and Twin Block (TB) appliances on the soft tissue profile. The study included 50 skeletal Class II patients (25 girls and 25 boys, mean age: 11.9 +/- 0.16 years) who were randomly allocated to one of two functional appliance treatment groups. The control group included 25 untreated skeletal Class II patients (13 boys and 12 girls, mean age: 10.11 +/- 0.91 years). Data were obtained from standardized lateral cephalograms taken at the beginning (T0) and end (T1) of appliance wear. The mean treatment time was 9 months for the activator group and 8 months for the TB group. The observation period of the control group was 8 months. Soft tissue profile changes were evaluated by means of 12 linear and five angular measurements. The groups were compared at T0 and T1 using analysis of variance, and treatment/observation differences (T1-T0) were evaluated with the Kruskal-Wallis test. Treatment changes in both appliance groups differed significantly (P < or = 0.001) from those in the control group, except for Ss-y, Ls-y, Li-E, and A-y measurements in the TB group and Ls-y, Li-E, nasolabial angle, and A-y measurements in the activator group. When the effects of the two appliances were compared, significant differences were observed only for SS-y (P < or = 0.05), Ss-E (P < or = 0.05), Si-E (P < or = 0.05), and nasolabial angle (P < or = 0.01). The effects of the activator and TB appliances on the soft tissue profile were similar; both significantly changed the soft tissue profile.     

Effects of cervical headgear and fixed appliances on the space available for maxillary second molars.

INTRODUCTION: This study examined the effects of cervical headgear and fixed appliances on the space available for the eruption of the maxillary second molars. Cervical headgear was the only intervention until a Class I molar relationship was achieved. METHODS: Thirty-four patients (18 girls, 16 boys) with Class II molar occlusions, treated without extractions, were included in this study. Five linear and 4 angular cephalometric measurements were made from pretreatment and posttreatment radiographs. RESULTS: Treatment prevented the mesial drift of the maxillary first permanent molars and the forward displacement of the maxilla, displaced the pterygomaxillary fissure posteriorly, and uprighted the first permanent molars. In the male group, the only significant changes were molar uprighting and clockwise rotation of the maxilla. CONCLUSIONS: These results suggest that posterior displacement of the pterygomaxillary fissure by treatment and growth at the maxillary tuberosity compensated for the restricted anterior movement of the maxillary first molars, allowing the second molars to erupt.     

Treatment effects of the mandibular anterior repositioning appliance on patients with Class II malocclusion.

The mandibular anterior repositioning appliance (MARA) is a tooth-borne functional appliance for use in patients with Class II malocclusions; it positions the mandible forward into a Class I occlusion. The aim of this study was to investigate the MARA's dental and skeletal effects on anterior, posterior, and vertical changes in 30 Class II patients. The treatment group consisted of 12 boys with an average age of 11.2 years and 18 girls with an average age of 11.3 years. A pretreatment cephalometric radiograph was taken 2 weeks before treatment, and a posttreatment cephalometric radiograph was taken 6 weeks after removal of the MARA, with an average treatment time of 10.7 months. The mean and standard deviation were calculated for each cephalometric variable, and Student t tests were performed to determine the statistical significance of the changes. The results of the study showed that the MARA produced measurable treatment effects on the skeletal and dental elements of the craniofacial complex. These effects included a considerable distalization of the maxillary molar, a measurable forward movement of the mandibular molar and incisor, a significant increase in mandibular length, and an increase in posterior face height. The effects of the MARA treatment were then compared with those of the Herbst and Fr?nkel appliances. The treatment results of the MARA were very similar to those produced by the Herbst appliance but with less headgear effect on the maxilla and less mandibular incisor proclination than observed in the Herbst treatment group.     

Craniofacial morphology in Chinese and Swedish children with Angle Class I and Class II occlusal relations

The purpose of this study was to compare the craniofacial morphology of a group of Chinese children from northern China with a group of Swedish children. Each ethnic group comprised 20 boys and 20 girls with Class I occlusion, and 20 boys and 20 girls with Class II occlusion. The ages of the children ranged from eight to ten years. Lateral cephalometric radiographs were used for the recording of a number of skeletal, dental, nasopharyngeal airway, and hyoid bone variables. The results of the comparisons of the two ethnic groups showed that the antero-posterior dimensions of the anterior cranial base and the maxilla in the Chinese children were significantly smaller than the corresponding dimensions in the Swedish children. The mean values of anterior and posterior face heights, inclination of the upper incisors, and protrusion of the lower incisors, were significantly greater in the Chinese than in the Swedish samples. In the median plane, the size of the nasopharyngeal airway was significantly greater in the Chinese than in the Swedes. This difference was due to the fact that the soft tissues covering the posterior nasopharyngeal wall were thinner in the Chinese children than in the Swedish children. In general, the ethnic differences were the same in the Class I and the Class II groups. The differences in some of the dental and skeletal characteristics found between northern Chinese and Caucasian-children are similar to previously described differences between southern Chinese and Caucasian children.     

An orthopaedic approach to the treatment of Class III malocclusions in the early mixed dentition

The aim of this investigation was to study cephalometrically the skeletal, dental and soft tissue modifications induced by a Delaire facemask and Bionator III appliance in a sample of 30 patients (17 boys and 13 girls), aged 4.1-9 years [mean 5.85 years, confidence interval (CI) 5.41-6.29], in the early mixed dentition with a skeletal Class III malocclusion caused by maxillary retrognathism (group 1) and compared with a control sample of 24 subjects (14 boys and 10 girls), aged 4-9 years (mean 5.97 years, CI 5.35-6.58) with untreated Class III malocclusions (group 2). For each patient a lateral cephalogram was taken before treatment (T0), after facemask removal (T1), and at the end of the retention period with a Bionator III (T2). Cephalometric analysis was carried out. The post-treatment cephalometric values in the treated group showed a forward displacement of the maxilla resulting in a statistically significant increase (P < 0.001) in the SNA angle, A-NPg (mm) and PNS-A (mm) linear values. There was a clockwise rotation of the mandible, with a decrease in the SNB angle and a satisfactory correction of the Class III relationship. The beneficial effects on the facial profile were confirmed by an increase in UL-EL distance and in NB--HL and NsPgs--HL angles, and by a decrease in the facial convexity angle. These findings indicate that the Delaire facemask and Bionator III treatment is effective for correcting skeletal Class III malocclusions caused by maxillary retrognathism in the early mixed dentition.     

The influence of activator treatment on skeletal growth in Angle Class II: 1 cases. A roentgenocephalometric study

The aim of this study was to evaluate possible skeletal effects of activator treatment on children with Angle Class II:1 malocclusions. The material consisted of lateral roentgenocephalograms of 31 girls and 22 boys, 8-14 years of age, who were treated with Andresen activators for an average period of 2.5 years. Growth and treatment effects were determined by comparing measurements on cephalograms of a group of untreated children with the same facial morphology and growth rate. The cephalograms were superimposed on the sella-nasion line and on the internal structures of the mandible. The activator treatment had a significant effect on the sagittal intermaxillary relationship and the anterior facial height. Among the girls the decreased ANB angle was mainly due to a retarded forward growth of the maxilla, while this decrease among the boys depended more on increased mandibular growth. Another feature was the anterior rotation of the mandible in the activator subjects although to a lesser extent than in the control groups. The total amount of condylar growth did not differ between the groups, but the direction of growth did. In the activator groups the growth was in a more superior-posterior direction than among the controls, thus contributing to the increased total length of the mandible in the activator groups.     

肌激动器和FRⅡ型功能矫治器治疗安氏Ⅱ类1分类错的对比研究

目的:比较肌激动器和Fr&ankelⅡ(FRⅡ)型功能矫治器治疗安氏Ⅱ类1分类错的效果。方法:选择处于生长发育高峰期或高峰前期的患儿34例,其中12例用肌激动器矫治,22例用FRⅡ型矫治器矫治。所有患儿均为凸面型,上颌前突和(或)下颌后缩;ANB角\5b;磨牙及尖牙为远中关系。对比每个患儿矫治前后的模型和头侧位片并作统计学分析。结果:矫治结束后所有患儿磨牙和尖牙均达到或接近中性关系,ANB角减小至正常范围。使用 FRⅡ型矫治器组的患儿牙弓宽度比肌激动器组明显增加,而两组的基骨弓宽度无显著性差异。FRⅡ型矫治器使上切牙内收更显著,而肌激动器更能有效地控制下切牙的倾斜度。结论:两种功能矫治器都能有效地改善上下颌骨及牙弓的Ⅱ类关系。     

Stability of skeletal changes after activator treatment of patients with class III malocclusions.

The aim of this study was to examine the skeletal changes produced by Class III activator during the treatment of patients with skeletal Class III malocclusions and to characterize the stability of these changes in the years after treatment. The samples consisted of 19 girls and 9 boys. Their mean age was 9.6 +/- 1.4 years at the beginning of the treatment. The average treatment time was 1 +/- 0.5 years. Measurements were obtained from cephalometric head films taken before treatment, at the end of treatment, and 6.6 +/- 2.1 years after the end of activator treatment. During the treatment, the Class III activator produced a statistically significant increase in the ANB angle, and this change remained through the postactivator period. The gonial angle exhibited a compensatory decline during the postactivator period. The skeletal profile was improved with treatment and was not lost during the posttreatment period despite significant increase in maxillomandibular differential. This study indicates that Class III activator may be a viable mode for the initial stage of skeletal Class III treatment, in conjunction with the period of postfunctional fixed or removable appliance therapy to improve the occlusion.     

A longitudinal study of the effects of surgery, radiation, growth hormone, and orthodontic therapy on the craniofacial skeleton of a patient evidencing hypopituitarism and a Class II malocclusion: Report of a case

Facial growth is an important factor for the orthodontists in the timing of treatment of the patient with a Class II malocclusion who has a potential for retarded growth. This patient had an isolated idiopathic growth hormone deficiency and hypothyroidism and was treated during a circumpubertal growth spurt in two phases. The first phase involved a functional appliance and the second was accomplished with fixed appliances. The case report affords one of the rare opportunities to document and analyze the multifactorial effects of surgery, radiation, growth and thyroid hormones, and orthodontic treatment on the craniofacial growth of a patient evidencing a Class II, Division 1 malocclusion (retrognathic mandible). Hand-wrist, panoramic, cephalometric radiographs, dental, and skeletal height and weight measurements are employed. Six-year posttreatment dental and craniofacial skeletal changes and management problems are presented as well. (AM J ORTHOD DENTOFAC ORTHOP 1994;106:571-82.)     

Dentoalveolar and skeletal changes associated with the pendulum appliance.

The purpose of the study was to examine the dentoalveolar and skeletal effects of the pendulum appliance in Class II patients at varying stages of dental development and with varying facial patterns (high, neutral, and low mandibular plane angles). Specifically, the amount and nature of the "distalization" of the maxillary first molars and the reciprocal effects on the anchoring maxillary first premolars and incisors were studied, as were skeletal changes in the sagittal and vertical dimensions of the face. Pretreatment and posttreatment cephalometric radiographs obtained from 13 practitioners were used to document the treatment of 101 patients (45 boys and 56 girls). The average maxillary first molar distalization was 5.7 mm, with a distal tipping of 10.6 degrees. The anchoring anterior teeth moved mesially, as indicated by the 1.8-mm anterior movement of the upper first premolars, with a mesial tipping of 1.5 degrees. The maxillary first molars intruded 0.7 mm, and the first premolars extruded 1.0 mm. Lower anterior facial height increased 2.2 mm; there was no significant difference in lower anterior facial height increase between patients of high, neutral, or low mandibular plane angles. In patients with erupted maxillary second molars, there was a slightly greater increase in lower anterior face height and in the mandibular plane angle and a slightly greater decrease in overbite in comparison to patients with unerupted second molars. Similar findings were observed in patients with second premolar anchorage versus those with second deciduous molar anchorage. The results of this study suggest that the pendulum appliance is effective in moving maxillary molars posteriorly during orthodontic treatment. For maximum maxillary first molar distalization with minimal increase in lower anterior facial height, this appliance is used most effectively in patients with deciduous maxillary second molars for anchorage and unerupted permanent maxillary second molars, although significant bite opening was not a concern in any patient in this study.     

The effects of early headgear treatment on dental arches and craniofacial morphology: a report of a 2 year randomized study

The aim of the present study was to determine the effects of early headgear treatment on dental arches and craniofacial morphology in children in the early mixed dentition. The total study group comprised 68 children of both sexes (40 boys and 28 girls) aged 7.6 years [standard deviation (SD) 0.3]. The children, who had a Class II tendency in occlusion and moderate crowding of the dental arches, were randomly divided into two groups of equal size, matched according to gender. In the headgear (HG) group, treatment was initiated immediately. The mean treatment time was 16 months. In the second group, which served as the control, only interceptive procedures were performed during the follow-up period. The records, which included dental casts and lateral cephalograms, were obtained after follow-up periods of 1 and 2 years. The lengths and the widths of the maxillary and mandibular dental arches were significantly increased in the HG group after the 2 year follow-up period. The mean increase in lower arch length and width was 2.4 mm (SD 1.7) and 2.2 mm (SD 1.2), respectively. On average, the space gain in the lower arch was half that of the upper arch. No significant changes were found in the arch dimensions of the control group. Maxillary growth restraint and labial tilting of the incisors were the most significant cephalometric findings in the HG group when compared with the controls. The use of headgear in the early mixed dentition is effective in the treatment of moderate crowding. It is noteworthy that significant space gain in the dimensions of the lower arch can be achieved by headgear application to the upper first molars.     

Dental Arch and Cephalometric Changes Following Treatment for Class III Malocclusion by Means of the Function Regulator (FR-3) Appliance

AIM: The aim of this retrospective clinical study was to evaluate dental arch, skeletal, dentoalveolar, and soft tissue profile changes following treatment of Class III malocclusion by means of the Function Regulator (FR-3) appliance. SUBJECTS AND METHODS: The study sample consisted of 14 growing patients (seven boys and seven girls) with a mean age of 9.7 +/- 1.1 years presenting Class III malocclusion. They were treated with an FR-3 appliance exclusively for a period of 2.4 +/- 0.6 years. Dental casts and lateral cephalometric radiographs were obtained immediately before initiation and after completion of treatment with the FR-3 appliance. Thirteen variables were used for the dental cast analysis and 61 variables for the cephalometric analysis. The paired t-test was utilized to evaluate the presence of significant changes (p < 0.05). RESULTS: The evaluation of the dental casts revealed that there was a significant increase in intermolar, interpremolar, and intercanine width of the maxilla and of palatal height after treatment. Concerning the mandible, an increase in intermolar and intercanine width and a decrease in lower arch depth were observed. Cephalometric evaluation revealed a significant decrease in SNB angle and an increase in ANB angle, overjet, facial convexity, nose prominence, and lower soft tissue face height. There was an increase in upper lip thickness and a decrease in lower lip convexity observed after treatment. CONCLUSIONS: The results of this study confirm a favorable functional and esthetic maxillary and mandibular position following treatment by means of the function regulator (FR-3) appliance.