Early vertical correction of the deep curve of Spee

ABSTRACT Even though few technological advancements have occurred in Orthodontics recently, the search for more efficient treatments continues. This paper analyses how to accelerate and improve one of the most arduous phases of orthodontic treatment, i.e., correction of the curve of Spee. The leveling of a deep curve of Spee can happen simultaneously with the alignment phase through a method called Early Vertical Correction (EVC). This technique uses two cantilevers affixed to the initial flexible archwire. This paper describes the force system produced by EVC and how to control its side effects. The EVC can reduce treatment time in malocclusions with deep curves of Spee, by combining two phases of the therapy, which clinicians ordinarily pursue sequentially.

RESUMO Apesar de haver poucos desenvolvimentos tecnológicos nos últimos anos dentro da Ortodontia, a busca por tratamentos mais eficientes não cessou. Assim, o presente artigo visa analisar, de maneira lógica, como otimizar uma das fases do tratamento ortodôntico que mais demandam tempo: a correção da sobremordida exagerada. Pretende-se demonstrar como realizá-la concomitantemente ao alinhamento inicial, por meio de uma técnica denominada correção vertical precoce (CVP). Essa técnica utiliza dois cantilevers associados ao primeiro fio de alinhamento ortodôntico, mas não restritos a ele, a fim de iniciar a planificação da curva de Spee o mais cedo possível. Assim, o tempo de tratamento pode ser diminuído, já que duas fases do tratamento, normalmente realizadas de forma independente, podem ser realizadas ao mesmo tempo. Além disso, tanto o sistema de forças quanto os efeitos colaterais e os passos da execução da técnica serão devidamente apresentados e discutidos.

Correlação da curva de spee com overbite, overjet e padrão facial / Spee curve correlation with overbite, overjet and facial pattern

Objetivou-se com o presente estudo verificar a relação entre a profundidade da curva de Spee superior e inferior com o overjet, overbite e o padrão facial. Quarenta e três modelos e radiografias cefalométricas laterais iniciais foram selecionados de pacientes do arquivo do Curso de Especialização de Ortodontia da Faculdade de Odontologia da UERJ, pós-surto de crescimento, com dentição permanente completa e apresentando overjet de 1 a 3 mm. Os modelos foram digitalizados e a profundidade máxima da curva de Spee superior e inferior, o overjet e o overbite foram calculados, utilizando-se o programa 3Shape Ortho Analyser. O padrão facial foi determinado a partir do ângulo SN.GoGn. As associações da curva de Spee superior e inferior com overbite, overjet e padrão facial foram avaliadas através do teste de correlação de Pearson. Encontrou-se associação da profundidade da curva de Spee inferior com o overjet e com a curva de Spee superior. Não houve significância estatística na correlação da curva de Spee inferior com o overbite e padrão facial, nem da curva de Spee superior com o overbite, com o overjet ou com o ângulo do plano mandibular, sugerindo que a curva de Spee inferior acentuada está mais frequentemente associada ao overjet aumentado.(AU)

The aim of this study was to verify the relationship between the depth of the lower and upper curves of Spee with overjet, overbite and facial pattern. Forty-three initial casts and lateral cephalometric radiographs were selected from the archives of the Graduate Program in Orthodontics of Rio de Janeiro State University. All patients were postpubertal, with permanent dentition and presenting an overjet varying from 1 to 3 mm. The cast models were scanned and the maximum depth of the upper and lower curve of Spee, the overjet and the overbite were calculated using the 3Shape Ortho Analyzer software. The facial pattern was determined from the SN.GoGn angle. The associations of the upper and lower curve of Spee with overbite, overjet and facial pattern were assessed using the Pearson correlation test. An association was found between the depth of the lower curve of Spee with the overjet and with the upper curve of Spee. There was no correlation of the lower curve of Spee with the overbite and facial pattern, neither between the upper curve of Spee with the overbite, overjet or the mandibular plane angle, suggesting that a marked lower curve of Spee is more frequently associated with increased overjet. (AU)

Relationship between depth of the curve of Spee and dentalfacial morphology in Angle Class Ⅱ maloclusion patients / 口腔疾病防治

Objective @#To compare the depth of the curve of Spee in Angle classⅡ malocclusion patients with different vertical skeletal patterns and to investigate the relationship between the depth of the curve of Spee and dentofacial morphology. @*Methods @#101 Angle classⅡ malocclusion patients were selected and randomly divided into 3 groups based on their GoGn-SN angles-high angle, average angle and low angle. Lateral cephalograms and dental models of all patients were evaluated to analyze Spee curve depth difference among different groups, Correlation analysis and a multiple linear regression analysis were performed to determine the relationship between the depth of the curve of Spee and all selected cephalometric variables.@*Results@# There was statistical difference in depth of the curve of Spee among different groups P < 0.05. The depth of the curve of Spee was least in the high angle group and greatest in the low angle group. GoGn-SN angle had statistically significant negative correlation with the depth of the curve of Spee, r = 0.428, P = 0.000, ODI, S-Go/N-Me、L7-GoGn angle had statistically significant positive correlation with the depth of the curve of Spee, r = 0.381, 0.357, 0.333, P = 0.000, 0.000, 0.001. The multiple linear regression analysis with stepwise method showed GoGn-SN angle had significant contribution to the depth of the curve of Spee. In Angle classⅡ malocclusion patients, there was statistical difference in depth of the curve of Spee among different vertical skeletal patterns@*Conclusion @#The depth of the curve of Spee is correlated with dentofacial morphology, GoGn-SN angle had significant contribution to the depth of the curve of Spee, which should be taken into consideration during orthodontic diagnosis and treatment.

Curve of spee: a literature review / Curva de spee: uma revisão de literatura

The curve of Spee (COS) is an important characteristic of the dental arch that was described as an occlusal curvature seen in the sagittal plane. This natural phenomenon has clinical importance in orthodontics and restorative dentistry. This study aim to gather the current knowledge of COS in order to become a guide for a construction of an optimal occlusion. The methodology utilized was a review and compilation of the most pertinent literature articles. The following were deliberated in this review: development, measurement, evolutive similarities, gender, side, properties, the purpose of levelling, the sorts of levelling and the long-term stability of the COS. In conclusion, although a large amount of research on COS already exists, there is no standard methodology to define an ideal model of treatment and/or prevention. Nevertheless, its results give dentists a complete overview to establish their approach towards a successful long-term stability treatment

A Curva de Spee é uma característica importante da arcada dentária e foi descrita como uma curvatura oclusal vista a partir do plano sagital. Esse fenômeno natural é de grande importância clínica especialmente em ortodontia e em dentística. Este estudo tem como objetivo compilar o atual conhecimento sobre a Curva de Spee com intenção de se tornar um guia para o desenvolvimento de uma oclusão eficiente. A metodologia utilizada foi revisão de literatura sobre a Curva de Spee e os tópicos discutidos são: desenvolvimento, mensuração, similaridades evolutivas, gênero, comparação entre lados, propriedades, o propósito do nivelamento, as maneiras de se nivelar e a estabilidade a longo prazo. Apesar do grande número de pesquisa sobre a Curva de Spee, não existiu um padrão de metodologia ou mensuramento para definir um modelo ideal para tratamento e/ou prevenção. Como conclusão, este artigo fornece uma ampla visão para capacitar o cirurgião-dentista em direção a um tratamento de sucesso e de estabilidade

Measurement of Spee curve in individuals with temporomandibular disorders: a cross-sectional study

Introduction: Several factors are cited as capable to influence the development of Temporomandibular Disorders (TMD), among them, the psychological, systemic, genetic, and occlusal factors. The curve of Spee is the factor directly related to the TMJ. However, the combination of variations in amplitude, and the presence of signs and symptoms of TMD have not been investigated. Objective: The aim of this study was to measure the curve of Spee in patients with TMD, through the use of study models, comparing these values with the different clinical and symptomatic presentations of such individuals. We evaluated 198 models of patients treated at the care service for patients with TMD at UFJF. The maximum depth of the curve was determined by the sum of the distances between the lowest part of the buccal cusp of the posterior teeth of each hemiarch to a reference plane, using a caliper to measure. The following factors were considered: gender, presence of myalgia (temporal, masseter, medial pterygoid, lateral and sternocleidomastoid muscles) and TMJ arthralgia, and the presence of occlusal interferences and parafunctional habit of bruxism. For statistical analysis, we used T-test and ANOVA test with a significance level of 5%. Conclusion: There was a statistically significant association between the presence of occlusal interferences and changes in the curve (p = 0.01). There was no association between the following factors: the presence of myalgia and/or arthralgia, gender, achievement of bruxism, and the type of TMD presented with changes in the Spee curve.

Reference points suitable for evaluation of the additional arch length required for leveling the curve of Spee / 대한치과교정학회지

OBJECTIVE: The additional arch length required for leveling (AALL) the curve of Spee (COS) can be estimated by subtracting the two-dimensional (2D) arch circumference, which is the projection of the three-dimensional (3D) arch circumference onto the occlusal plane, from the 3D arch circumference, which represents the arch length after leveling the COS. The purpose of this study was to determine whether the cusp tips or proximal maximum convexities are more appropriate reference points for estimating the AALL. METHODS: Sixteen model setups of the mandibular arch with COS depths ranging from 0 mm to 4.7 mm were constructed using digital simulation. Arch circumferences in 2D and 3D were measured from the cusp tips and proximal maximum convexities and used to calculate the AALL. The values obtained using the two reference points were compared with the paired t-test. RESULTS: Although the 3D arch circumference should be constant regardless of the COS depth, it decreased by 3.8 mm in cusp tip measurements and by 0.4 mm in proximal maximum convexity measurements as the COS deepened to 4.7 mm. AALL values calculated using the cusp tips as reference points were significantly smaller than those calculated using the proximal maximum convexities (p = 0.002). CONCLUSIONS: The AALL is underestimated when the cusp tips are used as measurement reference points; the AALL can be measured more accurately using the proximal maximum convexities.

Advance research on space analysis related factors / 医学研究生学报

Orthodontics is the procedure of managing the space .Space analysis is a comprehensive quantitative analysis that can analyze the factors that influence the arch space .It also helps to judge if the treatment goals can be reached , thus helping the treat-ment plan making and guiding clinical orthodontics .And space analysis related factors include crowding , curve of Spee, arch width, arch growth, arch protrusion, mesiodistal angulation, an so on.In this review, we summarizes the above-mentioned factors.

Applicatioin of micro-screw for mandibular incisors intrusion: a clinical and cephalometric study / 中华医学美学美容杂志

Objective To evaluate the effects of micro-screw on the intrusion of lower incisors and the leveling of curve of Spee in the process of orthotherapy.Methods Fifteen patients (5 males,10 females) with deep-bite were selected,aged from 11.3 to 28.8 years,with average of 17.2 years.All of them were Angle Class Ⅱ Classification 1 malocclusion and had a curve of Spee larger than 3 mm.Orthotherapy of extraction was adopted for the first premolars of two upper mandible and second premolars of two lower mandible.All these patients had micro-screws implanted at root apex area between lower lateral incisor and canine bilaterally,and when the 0.457 mm× 0.635 mm (0.018 in ×0.025 in) Ni-Tisquare wire was internalized,the strength of intrusion from micro-screws was used.Lateral cephalometric radiographs were taken before loading the micro-screw and immediately when the curve of Spee was leveled.Two linear and two angular measurements were selected for cephalometric analysis.Results The following results were noted: the lower incisors were significantly intruded for a mean of (4.10±0.98) mm; the mandibular molars were not significantly extruded for a mean of (0.91±0.69) mm; some lower incisors proclined and some lower incisors retroclined for a mean of (-0.09±4.12)°.After bite opening,the mandibular plane angle was minimally altered for a mean of (0.25±0.70)°; the ratio of lower incisor intrusioin to lower molar extrusion was 4.5: 1.0.Conclusions The combined use of micro screw with Ni-Ti wire is capable of enhancing the intrusion of lower incisors and leveling the curve of Spee,and it has minimal side effects on the posterior teeth.

Comparative evaluation of the curve of Spee in two age groups and its relation to posterior teeth disclusion.

Objectives: This study aims to compare the curve of Spee in human permanent healthy dentitions in two age groups to the disclusion in the premolar and molar region during protrusion. Materials and Methods: Sixty subjects were chosen and equally divided into two age groups of 18-25 years and 35-44 years. The left side of the mandibular dental casts was photographed using a digital camera to measure the curve of Spee. The canine cusp, mesiobuccal cusp of the first molar and the distal cusp of the second molar were marked and joined to form an arc. Using AUTOCAD software, the radius for this arc was obtained. A protrusive interocclusal record was made using rigid bite registration material to measure the amount of posterior disclusion during edge to edge protrusion. A dial gauge with an accuracy of 1/100 of a millimeter was used to measure the distance between the cusp tip indentations at the region of the buccal cusp of the mandibular 2nd premolar and distobuccal cusp of mandibular 1st molar. The results obtained were statistically analyzed. Results: The radius of curve of Spee increased nonsignificantly with age. The mean disclusion values measured in premolar and molar region showed a nonsignificant decrease with age. Conclusion: As age advances, there is a flattening of the curve of Spee and a concurrent reduction in the disclusion values during protrusion.

Avaliação do espaço adicional requerido no perímetro do arco inferior para o nivelamento da curva de Spee / Assessment of the additional lower arch perimeter needed for leveling the curve of Spee

OBJETIVO: determinar o perímetro de arco adicional necessário para o nivelamento da curva de Spee através de uma técnica laboratorial em modelos de estudo. MÉTODOS: foram utilizados 70 modelos inferiores nos quais se mediu a profundidade da curva de Spee e o perímetro do arco (de segundo molar a segundo molar). Nos mesmos modelos, após a simulação do nivelamento da curva de Spee, o perímetro de arco foi novamente avaliado, mantendo sua forma e comprimento. RESULTADOS: foi confirmada a correlação entre a profundidade da curva de Spee e o perímetro de arco adicional, sendo deduzida a fórmula [Paa = 0,21 CSmax - 0,04]. CONCLUSÃO: a técnica proposta permitiu, através da avaliação do perímetro de arco com curva de Spee nivelada, a determinação do espaço disponível para o alinhamento dentário.

AIM: To determine the additional arch perimeter needed for leveling the curve of Spee by means of a laboratory technique using dental casts. METHODS: Seventy lower dental models were used for measuring the depth of the curve of Spee and assessing the arch perimeter from second molar to second molar. In these dental casts, after simulation of leveling the curve of Spee, arch perimeter was reevaluated, after maintaining its form and length. RESULTS: The correlation between the depth of the curve of Spee and the additional arch perimeter was ratified, as can be shown by the formula [Paa = 0,21 CSmax - 0,04]. CONCLUSION: The proposed technique allowed, through the assessment of the arch perimeter with the leveled curve of Spee, the determination of the space available for tooth alignment.

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° for interincisal angle. A statistically significant correlation was found between overjet and overbite.

O presente estudo foi realizado em modelos de gesso e radiografias cefalométricas laterais de 30 indivíduos brasileiros, leucodermas, sendo 15 do sexo feminino e 15 do sexo masculino, com idades variando de 18 anos a 27 anos e 4 meses, todos portadores de oclusão excelente e bom perfil facial. Os objetivos foram verificar a existência de discrepância dentária de Bolton, obter valores médios para a sobremordida (overbite), sobressaliência (overjet), curva de Spee e ângulo interincisivo e verificar a existência de correlação entre essas variáveis. As medições foram realizadas por um único avaliador e o procedimento realizado duas vezes com auxílio de um paquímetro digital modificado de alta precisão. Observou-se que a amostra de oclusão normal não apresentou discrepância dentária entre os doze dentes dos arcos opostos e as razões total (91,46) e anterior (77,83) foram próximos aos dos propostos por Bolton. Os valores médios encontrados como padrão para a amostra de oclusão normal de indivíduos brasileiros foram determinados em: 2,45 mm para a sobremordida; 1,92 mm para a sobressaliência; 1,01 mm para a curva de Spee e 129,57(0) para o ângulo interincisivo, havendo apenas correlação significativa entre sobressaliência e as classes de sobremordida.

Crown angulations of posterior teeth of normal occlusion measured from marginal ridge plane / 대한치과교정학회지

In the previous studies about prescription of preadjusted appliance, occlusal plane was used as a reference plane for crwon angulation (tip) measurement But this reference plane is not parallel to the he connecting the facial axis points at which the centers of brackets are positioned (Andrews' plane), due to the curve of Spee. Therefore, we developed a new reference plane unaffected by the curve of Spee and more parallel to the Andrews' plane. It is an imaginary line connecting mesial and distal marginal ridges of each posterior tooth, and we named it 'marginal ridge plane'. In this study, crown angulations of posterior teeth of 29 normal occlusion samples were measured and measurements from both reference planes were compared. Crown angulation measurements measured from occlusal plane were different from crown angulation measurements from marginal ridge plane in the upper and lower 2nd molars (p<0.01), and 1st premolars (p<0.05). These results were analyzed as the crown angulation measurements from occlusal plane were affected by the curve of Spee. Crown angulations should be vaned according to the amount of curve of Spee to maintain- the continuity of marginal ridges. To solve this problem, determining bracket angulation as the bracket slot is parallel to the marginal ridge plane of each posterior teeth is recommended.

A photoelastic study of the effect of loops in arch wire and orthodontic elastics in relief of Curve of Spee / 대한치과교정학회지

Multiloop Edgewise Archwire(MEAW) is effective in relief the Curve of Spee in mandibular arch but up & down orthodontic elastics must be used with it. The purpose of this study was to analyse the effect of orthodontic elastics, like as up & down elastics, Class II elastics, and Class III elastics, and the effect of L loop in Multioop Edgewise Archwire. 1. Intrusive force of MEAW in anterior teeth was reduced and uprighting force in premolars was increased by up & down elastics. 2. Uprighting force was significantly increased with Class III elastics in multiple L loop arch wire. 3. The force of Class II elastics made molars tip mesially and Curve of Spee deep.

Roentgenocephalometric study on craniofacial morphology of deepbites / 대한치과교정학회지

This study was investigated to evaluate the morphologic characteristics of deepbite tendency as multiple factors. The subjects consisted of 60 control subjects(male 25, female 35) and 137 deepbite patients(68 male, 69 female). The deepbite group was composed of 4 subgroups(Class I 44, Class II div. 1 40, Class II div. 2 13, Class III 40). The mean age was 21.57 year for the control group 21 year for deepbite group lateral cephalograph in centric occlusion were taken, traced, and digitized for each subject. The statistically computerized analysis was carried out with SAS program. The results were as follows; 1. In deep bite group, saddle angle is lesser than that of normal group. 2. The vertical dysplasia is prominent on anterior lower face and is closely related with mandibular form and inclination. 3. Without consideration of sagittal relationship, the dental factors such as curve of Spee, interincisal angle, U1 to upper lip length were prominent in the deepbite group. 4. Although there were individual variances in the perioral soft tissue profile, the lip presented more protruded pattern. 5. There was no significant difference in hyoid bone position and inclination between normal and deepbite group. 6. The multivariate discriminant analysis between normal and Class I deepbite group showed that curve of Spee, AB-MP angle, interincisal angle, articular agnle were critical in the determination of deepbite as multiple factors.