Long-term stability of the leveling of the curve of Spee.

The aim of the study was to investigate whether the orthodontic leveling of the curve of Spee is a treatment procedure with a stable result on a long-term basis. Measurements were made on the plaster casts of 149 orthodontically treated patients (57 males and 92 females). The mean age before treatment was 12.8 years (range, 8-25 years). Study casts were taken before treatment (T1), at the completion of orthodontic therapy (T2), and 6.7 years (mean) posttreatment (T3). Inclusion criteria were no extractions, all Angle classifications except Class III malocclusions, and all permanent teeth fully erupted except second and third molars. The curve of Spee and the irregularity index were measured on standardized digital photographs of the casts. Overjet and overbite were assessed with a ruler. Changes in the curve of Spee were correlated with changes in irregularity index, overjet, and overbite from T1 to T3. The following results were noted: (1) leveling of the curve of Spee is a relatively stable treatment procedure compared with a return of incisor crowding and deepening of the bite; (2) neither the initial depth of the curve of Spee nor the initial irregularity index is an indicator for the amount of relapse; (3) the amount of leveling is not correlated with the relapse of the 4 tested parameters (curve of Spee, irregularity index, overjet, and overbite); and (4) there is a mild correlation between the relapse of the curve of Spee and the relapse of the irregularity index, overjet, and overbite. According to the results of the study, leveling the curve of Spee during orthodontic treatment seems to be very stable on a long-term basis; it was weakly correlated with the other variables tested.     

The relationship between the curve of spee,relapse, and the Alexander discipline

Exaggerated curves of Spee are frequently observed in dental malocclusionsthat present with deep vertical overbites. During orthodontic treatment such excessive curves of Spee are usually leveled and, in most instances, this leveling will result in a reduction of the anterior overbite. The Alexander Discipline provides a good example of modern straight-wire orthodontic techniques that purport an ability to treat abnormal variations in the depth of the occlusal plane. The records of 31 randomly selected patients treated by nonextraction with the Alexander Discipline were studied. The results show that the Alexander Discipline levels the curve of Spee in Class II, Division I deep-bite cases and that when relapse occurs, the curve of Spee returns to a lesser extent than was present before orthodontic treatment. With the Alexander Discipline, a pretreatment curve of Spee that is not completely level posttreatment has a slightly higher incidence and magnitude of relapse than a pretreatment curve of Spee that is completely level posttreatment. This study indicated that, based on the pretreatment curve of Spee, there is no ability to predict relapse in mandibular intercanine width, overbite, overjet, mandibular incisor irregularity, and arch length in Class II, Division I deep-bite cases treated with the Alexander Discipline.     

Spee曲线深度与牙颌面形态之间关系的研究

目的：探讨Spee曲线深度与牙齿以及颌面形态之间的关系。方法：对106例15~21岁患者的头颅侧位片及牙齿模型进行测量分析。按照Spee曲线深度不同分为3组,分析组间差异以及Spee曲线深度与其他变量之间的相关性。结果：3组间覆牙合,覆盖,下切牙、下颌第二磨牙的倾斜情况,前下面高以及前下面高与前面高之比的差异具有统计学意义。且Spee曲线越深,则覆牙合越深,覆盖越大,前下面高越小,下切牙越直立,下颌第二磨牙越前倾、高度越低,以及前下面高占前面高的比值越小。结论：Spee曲线深度与牙齿以及颌面形态之间均密切相关,在正畸诊断以及矫治设计时需要综合考虑。     

Investigation of the changes in the positions of upper and lower incisors, overjet, overbite, and irregularity index in subjects with different depths of curve of Spee

The aim of this study was to investigate the relationship between the depth of the curve of Spee and positions of upper and lower incisors, overjet, overbite, and anterior lower crowding. The material consisted of lateral head films and dental casts of 137 untreated adolescent subjects, 76 girls and 61 boys, aged 13 to 16 years. The subjects were divided into three groups with normal Spee, flat Spee, and deep Spee and were compared with one another. Differences between the Spee groups and between sexes were assessed by means of analysis of variance and a post hoc multiple comparison test. In addition, correlation coefficients between the depth of curve of Spee and other variables were calculated. Finally, cephalometric measurements for all subjects were subjected to a multiple regression analysis, with the depth of curve of Spee as the dependent variable. The results showed that there were no statistically significant differences in the positions of upper and lower incisors and anterior lower crowding among the Spee groups. However, overjet and overbite demonstrated significant differences among the groups. Statistically significant correlations were found between the depth of curve of Spee and overjet and overbite. Multiple linear regression analysis revealed that chronological age and all other variables used in the study could account for only 28.7% of the total variance of the curve of Spee. The overbite alone explained 17.3% of the total variance of the curvature.     

Aging in the craniofacial complex

OBJECTIVE: To describe the dental arch changes occurring after adolescence through the sixth decade of life. MATERIALS AND METHODS: Longitudinal dental casts from 40 patients (20 male and 20 female) were digitized and analyzed. Measurements were recorded after the presumed cessation of circumpubertal growth (T1), at approximately 47 years of age (T2), and at least one decade later (T3) were compared. RESULTS: The majority of the measurements were found to have a significant time effect, demonstrating at least some level of change throughout the aging process (T1-T3). Exceptions to this observation were the posterior maxillary arch width measurements, mandibular intermolar and interpremolar (as measured at the second premolars) widths, the maxillary incisor irregularity index, overjet, overbite, and curve of Spee. The T1-T3 changes reflected for the most part the T1- T2 changes, while the T2-T3 changes affected overall modifications only for the mandibular intercanine width and maxillary depth, as measured at the second premolars. All changes reflected a decrease in arch width, depth, and perimeter, with a significant increase in the mandibular incisor irregularity index. CONCLUSIONS: The dental arches continue to change and adapt throughout life and into the sixth decade, though the degree of change decreases with time.     

Stability of transverse expansion in the mandibular arch.

This was a retrospective, longitudinal cephalometric and cast study of 29 white patients at pretreatment, posttreatment, and an average of 6 years 3 months postretention. The goal was to assess changes with treatment and retention with the expanding mandibular lingual arch appliance in conjunction with fixed edgewise treatment. Seven mandibular cast measurements were assessed, including arch crowding, arch perimeter, arch length, and arch width at the permanent canines, first premolars, second premolars, and first molars. Cephalometric radiographs were digitized, and 16 cephalometric measurements were made. Repeated-measures analysis of variance and 2-sample t tests were used to determine statistically significant changes. It was found that the expanding lingual arch used for less than 6 months with the mandibular fixed edgewise appliance caused an increase in both the transverse and sagittal dimensions of the mandibular dental arch. Transverse expansion was more stable in the posterior region of the mandibular dental arch than in the anterior region. Mandibular intercanine width increase could be maintained only by fixed retention. Although the maxillary and mandibular incisors were advanced and proclined, lip protrusion did not occur.     

Spee曲线深度与牙弓形态之间的关系研究

目的 研究Spee曲线深度与牙弓形态之间的关系。 方法 将150例18-25岁的维吾尔族人分为男女两组,其中男62人,女88人,利用计算机软件测量Spee曲线深度,尖牙间宽度,磨牙间宽度,牙弓长度。结果 Spee曲线深度与性别因素无关,左右侧Spee曲线深度存在统计学意义,牙弓形态受性别因素影响,却与Spee曲线深度不存在关联。结论 临床上,Spee曲线深度可当一个参考平面辅助咬合重建以及正畸治疗。     

An evaluation of the curve of Spee in the maxilla and mandible of human permanent healthy dentitions

STATEMENT OF PROBLEM: The characteristics of the curve of Spee in the mandibular arch have been extensively investigated. However, few studies have examined the characteristics of the curve of Spee in the maxillary arch. PURPOSE: The purpose of this study was to examine the differences in the curve of Spee between the maxillary and mandibular arches. The effects of gender on the curve of Spee were also investigated. Material and methods Fifty Japanese adults (25 men and 25 women) with permanent healthy dentitions participated. Standardized digital pictures of the right side of maxillary and mandibular dental casts were made with a digital camera. The cusp tips of the molars, premolars, and canines of the maxilla and mandible were identified. The radius and the depth of the curve of Spee were measured on the dental casts by means of computer software (Occlcircle). The Mann-Whitney test and the Wilcoxon signed rank test were used to test the statistical significance (alpha=.05). RESULTS: The curve of Spee showed a mean radius of approximately 106.4 mm in the maxillary arch and 83.4 mm in the mandibular arch. Radii of the curves of Spee in the maxillary arch were significantly larger than those in the mandibular arch (P <.0001) and had a depth of approximately 1.6 mm in the maxillary arch and 1.9 mm in the mandibular arch. The depth of the curve of Spee in the mandibular arch was significantly deeper than that in the maxillary arch (P =.0326). CONCLUSIONS: The curve of Spee was not influenced by the gender of the subjects investigated. The shape of the curve of Spee in the maxillary arch was significantly flatter than that in the mandibular arch.     

Spee曲线深度与颅颌面形态之间关系研究

目的    研究Spee曲线深度与颅颌面形态之间的关系 。方法    对2013—2014年在大连医科大学附属第二医院口腔科就诊的88例14～32岁错牙合畸形患者的头颅侧位片及记存模型进行测量分析。将选取的13项头影测量指标与Spee曲线深度进行相关以及回归分析。结果    Spee曲线深度与性别因素无关。不同安氏分类间Spee曲线深度差异具有统计学意义,安氏Ⅱ类明显高于安氏Ⅲ类。SNA、ANB、AO-BO、后前面高比、ODI、上下唇长比与Spee曲线深度呈正相关关系,APDI、IMPA、颏唇角与Spee曲线深度呈负相关关系。结论    颅颌面形态与Spee曲线深度之间存在相关性,在正畸诊疗过程中应加以考虑。     

The effectiveness and long-term stability of overbite correction with incisor intrusion mechanics.

BACKGROUND: Correction of deep overbite with subsequent achievement of long-term stability is difficult. The purpose of this study was to investigate the effectiveness and long-term stability of overbite correction with incisor intrusion mechanics. METHODS: The treated group consisted of 25 subjects (13 female, 12 male) with deep overbite of at least 4 mm (mean overbite, 5.9 mm). The orthodontic treatment was initiated in the late mixed or early permanent dentition, and all patients were treated nonextraction. All patients had lateral cephalometric radiographs taken at pretreatment (T1), posttreatment (T2), and postretention (T3). The treatment included cervical headgear and lever arches to intrude mainly the maxillary incisors and occasionally the mandibular incisors. Premolars were not included in the fixed appliances during the treatment. The untreated group consisted of 25 age- and sex-matched subjects from the Bolton Growth Study. RESULTS: The mechanics used were effective in overbite correction. During the posttreatment period, overbite increased by 0.7 mm. CONCLUSIONS: Although this change was statistically significant, the amount was small and is considered clinically insignificant, given the severity of the overbite pretreatment. Furthermore, a net overbite correction (T3-T1) of 3.3 mm and postretention overbite on 2.6 mm is an excellent clinical outcome.     

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??Objective    To explore the relationship between curve of Spee and craniofacial morphology.  Methods    Lateral cephalograms and dental models of 88 patients between the age of 14 and 32 were evaluated. Correlation analysis and a multiple linear regression analysis were performed to determine the relationship between the curve of Spee and 13 selected cephalometric variables. Results    The curve of Spee was not affected by sex. The depth of the curve of Spee significantly differed among different Angle classifications in which class ?? was obviously higher than class ??. SNA?? ANB?? AO-BO?? post. facial height/ant. facial height?? ODI and upper lip length/lower lip length had statistically significant positive correlation with the depth of the curve of Spee. APDI ?? IMPA and mentolabial angle had negative correlation with the depth of the curve of Spee. Conclusion    The depth of the curve of Spee is correlated with craniofacial morphology?? which should be taken into consideration during orthodontic diagnosis and treatment.     

安氏Ⅱ类错(牙合)患者Spee曲线深度与牙颌面形态间的关系

目的 探讨安氏Ⅱ类错(牙合)不同垂直骨面型患者间Spee曲线深度的差异以及Spee曲线深度与牙颌面形态间的关系.方法 随机选取101名安氏Ⅱ类错(牙合)患者,按照GoGnSN角的大小将所有患者分为高角、均角、低角3组.对所有患者的模型和头颅侧位片进行测量,分析不同组间、Spee曲线深度的差异,并将头影测量项目与Spee曲线深度进行相关与回归分析.结果 不同垂直骨面间Spee曲线深度差异有统计学意义(P<0.05),高角组最小,低角组最大;GoGn-SN角与Spee曲线深度呈负相关,r=-0.428,P=0.000;ODI、S-Go/N-Me、L7-GoGn角与Spee曲线深度呈正相关,r值分别为=0.381、0.357、0.333,P值分别为:0.000、0.000、0.001.逐步多元线性回归分析显示GoGn-SN角对Spee曲线深度产生显著影响.结论 安氏Ⅱ类错(牙合)不同垂直骨面型间Spee曲线深度存在差异,Spee曲线深度与牙颌面形态间存在相关性,GoGn-SN角对Spee曲线深度产生显著影响.     

Postretention assessment of deep overbite correction in Class II Division 2 malocclusion

The purposes of this study were to evaluate the long-term stability of deep overbite correction in Class II Division 2 malocclusion and to search for predictors of postretention overbite. The sample of 62 (31 males, 31 females) was limited to Class II Division 2 patients with initial deep overbite and successful orthodontic treatment as judged clinically at the end of treatment. Study models and cephalograms were analyzed before treatment, after treatment, and out of retention (average 15 years). The sample was divided into two groups according to the degree of postretention overbite: Group 1 (N=33; overbite > or = 4.0 mm at T3, mean = 5.17 +/- 0.87) and group 2 (N=29; overbite <4.0 mm at T3, mean = 2.95 +/- 0.87). The results showed that patients with very upright pretreatment maxillary and mandibular incisors tended to have deeper initial overbite and a tendency to return to their original relationship by the postretention stage. Posttreatment vertical growth contributed to maintenance of overbite correction. By stepwise multiple regression analysis, initial overbite was selected as the most important predictor of postretention overbite. Initial overbite was positively related with postretention overbite.     

Orthodontic relapse in subjects with varying degrees of anteroposterior and vertical dysplasia.

Fifty seemingly well-treated orthodontic cases were studied by means of pretreatment, posttreatment, and postretention dental casts, lateral cephalograms, and other orthodontic records. The sample was restricted to cases exhibiting anteroposterior and/or vertical dysplasia as revealed by pretreatment dental casts. The sample was divided into a stable group and a relapse group. Each group contained twenty-five cases. A double-blind design was used. The raw data were analyzed by the stepwise discriminant analysis and by the multivariate analysis of variance. On the basis of the results obtained from this study, the following conclusions can be drawn: 1. In seemingly well-treated orthodontic cases, relapse or stability can neither be predicted nor judged from one set of records alone. 2. Relapse or stability of an orthodontic case can be predicted by comparing the posttreatment variables with the pretreatment variables. 3. Relapse or stability of an orthodontic case can be judged by comparing the postretention variables to the posttreatment variables. 4. The PP-GoGn angle and the mandibular intercanine width are the two most important variables associated with orthodontic relapse. 5. Changing the PP-GoGn angle, either by treatment or by growth, was associated with relapse. In other words, changes in the PP-GoGn angle tended to be unstable. This suggests that decreasing the PP-GoGn angle should be avoided. 6. In both the stable and the relapse groups, the mandibular intercanine width decreased postretention. This decrease was associated more with the relapse group than with the stable group. 7. The mandibular intercanine width tended to relapse toward its original pretreatment value. This suggests that, at the end of active treatment, the mandibular intercanine width should be maintained as originally presented. 8. There was no significant interaction between orthodontic relapse (or stability) and Angle Class I and II cases. 9. There was no significant interaction between relapse (or stability), of an orthodontic case, and the sex of the patient. 10. There was no significant interaction between orthodontic relapse (or stability) and whether or not extraction was included as a part of the mechanotherapy. Thus, the pretreatment deep overbite is not necessarily a contraindication to extraction.     

Spee曲线口腔正畸学应用研究进展

错牙合畸形伴深覆牙合病例中经常伴随Spee曲线异常。深Spee曲线会造成咀嚼肌失衡,严重可导致咬合功能障碍。正确理解Spee曲线概念以及整平Spee曲线的方法对于每位正畸医生均相当重要,且临床治疗中存在一定难度。本文对Spee曲线的发生发展、整平Spee曲线的方法以及影响因素做一系统性梳理,以助于正畸临床的诊断与治疗。     

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错牙合畸形伴深覆牙合病例中经常伴随Spee曲线异常。深Spee曲线会造成咀嚼肌失衡,严重可导致咬合功能障碍。正确理解Spee曲线概念以及整平Spee曲线的方法对于每位正畸医生均相当重要,且临床治疗中存在一定难度。本文对Spee曲线的发生发展、整平Spee曲线的方法以及影响因素做一系统性梳理,以助于正畸临床的诊断与治疗。     

Clinical crown length and reduction in overjet, overbite, and dental height with orthodontic treatment

To evaluate the clinical crown length relative to fixed-appliance orthodontic treatment of excessive overjet and deep overbite and to correlate such changes to the vertical dental height, the following measurements were undertaken for 12 females and 8 males, between the ages of 16 and 20 years, on three separate occasions--2 days before banding, 2 days after debanding, and 12 months after debanding: (1) overjet, overbite and dental height measured from right lateral cephalometric x-ray films; (2) clinical crown length, measured from study models, of 400 teeth divided into four groups--maxillary incisors and canines (120 teeth), maxillary second premolars and first molars (80 teeth), mandibular incisors and canines (120 teeth) and mandibular second premolars and first molars (80 teeth); and (3) gingival condition by means of the gingival index of L?e and Silness. Fixed edgewise orthodontic appliances were used and the four first premolars were extracted. From the results of the investigation, the following conclusions were evident: after a 12-month follow-up observation period, the achieved reduction in overjet, overbite, and dental height showed relapses of 9%, 11%, and 29%, successively; only 7% of the 400 teeth examined showed reductions in clinical crown length. This change was probably the result of gingival hyperplasia. The gingival condition greatly improved by approximately 64% after 12 months of debanding, accompanied by 25% to 50% relapse in the amount of change in clinical crown length (noted 2 days after debanding); and the intrusive tooth movement during orthodontic correction of deep overbite was the result of vertical movement of the tooth, with its investing tissues and soft-tissue attachment, into the jaws.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cephalometric evaluation of open bite treatment with NiTi arch wires and anterior elastics.

The aim of this study was to evaluate cephalometrically the effects of open bite treatment with NiTi arch wires and anterior elastics. The study group comprised of 17 patients who displayed a high angle skeletal pattern, along with an anterior open bite. After initial leveling, 0.016 x 0.022 inch upper accentuated-curve and lower reverse-curve arch wires were placed, with anterior elastics applied in the canine regions. Cephalometric assessment was carried out on lateral head films taken at the beginning of treatment and on average 2.8 months after open bite closure was obtained. The results of this study indicated that open bite closure had been achieved mainly by extrusion of the lower incisors and uprighting of the upper incisors. The functional occlusal plane was leveled by extrusion of lower premolars and uprighting of lower molars. Lateral cephalograms obtained from 10 patients who had been available after 1 year postretention were used to evaluate relapse changes. During the follow-up period, position of the upper and lower incisors and the inclination of the occlusal plane were maintained. However, extrusion of upper and lower molar teeth resulted in a reduction in overbite.     

平导和反SPEE曲弓丝治疗前牙深覆[牙合]的效果比较

目的比较平导、弓丝上加反SPEE曲治疗深覆[牙合]的效果。方法选择深覆[牙合]均在Ⅱ度以上患者27名，平导组14名，反SPEE曲组13名，年龄11—28岁，咬合打开前后拍头颅侧位片进行X线头影测量分析。结果戴用平导可以使下颌骨向下旋转，下面高及全面高增加，打开咬合主要靠磨牙的增高；反SPEE曲可以使下面高及全面高增加，但增加的效果不如平导作用大，差别有显著性，打开咬合主要靠切牙的压低和磨牙的少量增高，磨牙增高的量较平导组的小，差别有显著性。结论两种方法打开咬合的机制不同，临床适应征不同。     

Relationship between dental size and normal occlusion in Brazilian patients

The present study was performed on dental casts and lateral cephalometric films of 30 Caucasian Brazilian individuals (15 males and 15 females) aged 18 to 27 years and 4 months, all presenting normal occlusion and satisfactory facial profile. The aims were to investigate the existence of dental discrepancies according to Bolton's criteria, to obtain mean values for overbite, overjet, curve of Spee and interincisal angle, and to demonstrate any correlation among these parameters. A single calibrated operator measured each variable characteristics and the process was recorded twice with an accurate modified digital caliper. It was observed that the sample of normal occlusion did not present any dental discrepancy among the 12 teeth of opposite arches. The overall ratio (91.46) and anterior ratio (77.83) were in accordance with those proposed by Bolton. The mean values for normal occlusion in this Brazilian sample were defined as: 2.45 mm for overbite; 1.92 mm for overjet; 1.01 mm for curve of Spee and 129.57 degrees for interincisal angle. A statistically significant correlation was found between overjet and overbite.