Curve Of Spee Research Articles

Predictors of Curve of Spee Leveling in Class II Division 1 Malocclusion Treated With Reverse Curve of Spee Archwires: An Observational Study.

Introduction Aligning and leveling is the initial stage of comprehensive fixed orthodontic treatment aimed at minimizing the depth of the curve of Spee (COS). Various techniques exist to decrease the magnitude of the curve. This study investigates the skeletal and dental factors that reduce COS in individuals with minor class II malocclusions receiving nitinol (NiTi) wires with a reverse curve of Spee (RCS). Materials and methods The data for this observational study was collected from a sample of 84 patients who had class II molar relations and were sequentially treated with RCS NiTi wires throughout the initial leveling and aligning phase. All patients with class II molar relationships underwent non-extraction procedures during the leveling phase. The COS was determined using digitalized dental models. Skeletal and dental characteristics that could impact COS were identified and quantified using digital lateral cephalograms and orthopantomograms recorded during the pre-treatment (T1) and post-leveling (T2) stages. After calibrating the radiographs and models, we acquired angular and linear data. The data was categorized based on gender, growth pattern, and initial alignment of the teeth. We analyzed the differences between the groups using an independent t-test and an ANOVA. A paired t-test was used to compare the difference in the dimensional values between (T1) and (T2) points. Following the correlation coefficient tests, the study used stepwise multiple linear regression analysis to assess the predictive value of independent factors on the COS. The results were considered statistically significant at p < 0.05. Results The COS decreased by -1.43 ± 0.68 mm, which is statistically significant (<0.001*). There is no significant difference in COS reduction between the categorical variables. Despite statistically significant differences in the parameters between pre- and post-treatment, the linear correlation between most of the variables and COS reduction ranged from very weak (<0.20) to weak (0.20-0.39). Conclusions The vertical extrusion of lower premolars and molars combined with the intrusion of lower incisors contributed to the reduction of the COS by RCS wires. There is a change in the orientation of the occlusal plane with the flattening of the COS.

Dental Prediction Factors of Schizophrenia: A Pilot Case-Control Study in Morocco

&amp;lt;i&amp;gt;Introduction: &amp;lt;/i&amp;gt;Schizophrenia is a severe mental illness associated with significant morbidity and mortality. This study suggests that some dental or skeletal characteristics may be potentially associated with schizophrenia. &amp;lt;i&amp;gt;Method: &amp;lt;/i&amp;gt;A case control study was conducted from 2020 to 2022 among 30 schizophrenia patients and 30 control patients. Data was collected through a clinical exam and radiographs for each patient. Different variables were assessed including teeth dimensions, maxillary and mandibular width, occlusal characteristics and cephalometric values: SNB, IMPA, and FMA. Proportions and mean with standard deviations were used as descriptive measures. Only variables with p-values &amp;lt; 0,05 were considered as statistically significant and associated with schizophrenia. &amp;lt;i&amp;gt;Results:&amp;lt;/i&amp;gt; The mean ages of schizophrenia patients and controls were 34.0 +/- 9,12 and 17,3 +/- 2.0 years respectively. The results reported a statistically significant difference, between the two groups, at maxillar and mandibular arch depth [p &amp;lt; 0,001 and p=0,036 respectively], SNB [p = 0,013], overbite [p &amp;lt; 0,001], overjet [p = 0,002] and spee curve [p = 0,006]. &amp;lt;i&amp;gt;Conclusion: &amp;lt;/i&amp;gt;According to these study findings, some dental, skeletal and occlusal characteristics may be related to schizophrenia. However, further studies with larger sample sized and long-term follow-up may be needed to confirm these findings.

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study

Introduction Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual’s dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. Objectives To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Methodology Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. Expected Result It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Conclusion Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren’t many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

Relationship between the mandibular curve of Spee and the maxillary compensating curve with dentoskeletal morphology : Across-sectional study in Chinese young adults with normal occlusion.

The purpose of this cross-sectional study was to use multiple regression analysis to evaluate the relationship between the mandibular curve of Spee (COS) and the maxillary compensating curve with dentoskeletal morphology in young Chinese adults with normal occlusion. This study comprised 62young adults (31males, mean age: 24.1 ± 2.2years; 31females, mean age: 23.3 ± 3.3years) with Angle classI normal occlusion. For every subject, intraoral scan models of the maxillary and mandibular arches and lateral cephalograms were acquired. The depth of the COS and compensating curve were assessed on the intraoral scan models. Multiple dental arch dimensional and cephalometric variables were screened by univariate analysis. Subsequently, amultiple linear regression model (forward stepwise selection) was constructed to determine which variables were significantly correlated with the two curve depths. In the mandible, the COS depth was deepest at the mesiobuccal cusp of the first molar. Overjet, mandibular arch width and mandibular-occlusal plane angle significantly correlated with the COS depth (P < 0.05), accounting for 33.1% of the variation in the mandibular COS. In the maxilla, the deepest point of the compensating curve was at the distobuccal cusp of the first molar. Mandibular arch perimeter and overbite significantly correlated with the maxillary compensating curve (P < 0.05), explaining 23.3% of the variation. Overjet, overbite, mandibular-occlusal plane angle, mandibular arch width and perimeter should be considered when reconstructing occlusal curves in clinical orthodontic treatment and in prosthetic restoration.

Does curve of Spee affect the precision of 3D-printed curvature-adaptive splints?

ObjectivesThis study aimed to propose a standardized protocol for the fabrication of three-dimensionally (3D)-printed curvature-adaptive splints (CASs) and assess the precision of CASs on dentitions with different depths of the curve of Spee (COS). Methods76 lower dental resin models, each exhibiting one of the four types of COS (0-, 2-, 4-, and 6-mm deep), were selected and digitally scanned. CASs were designed, 3D printed, and grouped into C0, C2, C4, and C6, corresponding to the four types of COS depths. To assess precision, the CASs occluded with the resin model were scanned as a whole and compared with the originally designed ones. ResultsIn terms of translational deviations observed in the CASs, the mean value of absolute sagittal deviation (0.136 mm) was significantly higher than those of vertical (0.091 mm) and transversal deviations (0.045 mm) (P < 0.01). Regarding rotational deviations of the CASs, the mean deviation in pitch (0.323°) was significantly higher than those in yaw (0.083°) and roll (0.110°) (P < 0.01). However, when comparing the accuracy of CASs across C0, C2, C4, and C6 groups, no statistically significant difference was found. Additionally, the translational deviations, rotational deviations, and RMSE of all groups were significantly lower than the clinically acceptable limits of 0.5 mm, 1°, and 0.25 mm, respectively (P < 0.01). ConclusionsThe depth of the COS has no significant impact on the precision of CASs, as evidenced by the absence of statistically significant differences in translational, rotational deviations, and RMSE among all groups (C0, C2, C4, and C6). Moreover, despite relatively high deviations in the sagittal dimension and pitch, all dimensional deviations and RMSE remained statistically significantly lower than the corresponding clinically acceptable limits (CALs) in all groups. Clinical SignificanceThis standardized protocol incorporating “curvature-adaptation” represents an optimized approach to fabricating diverse 3D-printed splints tailored to dentitions with different anatomical features in contemporary digital dentistry.

LOW-QUALITY EVIDENCE SUGGESTS A STRONG ASSOCIATION BETWEEN DEPTH OF CURVE OF SPEE AND DENTOSKELETAL CHARACTERISTICS

Is there variation in the depth of the curve of Spee in individuals with different dentoskeletal patterns? A systematic review with meta-analysis. Paes-Souza Sde, Marañón-Vásquez GA, Galisteu-Luiz K et al. Europ J Orthodont. 2022;44(5):491-502. This study was supported in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brasil (CAPES), Finance code DS 001, and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ - APQ1, number E-26/210.435/2019). Systematic review.

Correlation between Depth of the Curve of Spee and Some Specific Malocclusion Characteristics in a Population from Sibiu County, Romania-A Cross-Sectional Study.

Background: This study aimed to investigate the relationship between the Curve of Spee (COS) depth and malocclusion characteristics in a population from Sibiu County, Romania. The research sought to understand how the COS's anatomical dimensions correlate with different classes of malocclusion and the position of the frontal teeth. Methods: A total of 265 participants from the Dentistry Ambulatory of the Military Hospital of Sibiu were included in this study. It employed digital intraoral scanning technology to measure the COS, overjet, and overbite, with malocclusion classification. Statistical analyses, including correlation and regression, were conducted to examine the relationships between COS depth, frontal teeth position, and malocclusion characteristics. Results: The average COS depth measured was 1.0564 mm, presenting variability when compared to existing literature. Most of the study participants had Class I malocclusion. A significant positive correlation between COS depth and overjet was identified, with no notable gender-based differences in these occlusal parameters. Conclusions: The findings affirm the integral role of COS in occlusal dynamics and malocclusion diagnosis. The COS measurement of a mean of 1.0564 mm, when compared to other results emphasizes the differences in occlusal curvature among various populations. The results contribute to a refined understanding of occlusal relationships, supporting the need for personalized orthodontic and prosthetic treatments based on precise anatomical measurements.

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study.

Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual's dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren't many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

Association of Mandibular Incisor Proclination and Mandibular Arch Widths with The Levelling of Curve of Spee

Background: In this study, we aimed to determine the changes in mandibular incisor proclination and mandibular arch widths after leveling the curve of Spee (COS). Methods: Patients included in this quasi-experimental study were scheduled for fixed orthodontic treatment with a non-extraction therapy in the mandibular arch, no posterior crowding, eruption of all mandibular teeth except third molars, no spacing and Little’s irregularity index greater than 2. The COS depth and mandibular arch widths (inter-canine and inter-molar widths) were measured on plaster casts and recorded in millimeters. Mandibular incisors inclinations were measured on a cephalometric radiograph according to the incisor mandibular plane angel (IMPA) and lower incisor to NB (L1) angle. The pre-treatment and post-treatment values were compared using paired sample T-test. Pearson correlation was used to analyze the association between COS changes and other variables. P-value &lt;0.05 was considered statistically significant. Results: A total of 58 subjects with an average age of 25.10±6.81 years participated in this study. COS depth values significantly reduced after treatment (2.34±0.78mm vs 1.75±0.56mm), (P&lt;0.001). Average IMPA and L1-NB values significantly increased following COS flattening (P&lt;0.001). Mandibular inter-canine and inter-molar widths also showed significant increase after treatment (P&lt;0.001). Pearson’s correlation revealed a significant and inverse correlation between COS changes and mandibular arch width and mandibular incisor proclination values (P&lt;0.001 for both). Patient’s age and gender did not have a significant effect on COS depth. Conclusion: Flattening of COS leads to an increase in lower incisor proclination and mandibular arch width.

Unveiling the Influence of the Curve of Spee on Bite Force and Chewing Ability: A Comparative Study.

To investigate the impact of the curve of Spee (CS) accentuation on bite force, chewing ability, and additionally, other factors that influence chewing ability and bite force such as restorations, caries, gender, habits, and TMJ problems. 231 participants (118 male and 113 female, mean age = ±27.96 years) were recruited for this cross-section study. Participants completed a data collection sheet in which age, gender, Angle's classification of malocclusion, overjet, overbite, TMJ problems, habits, restorations, and caries experience were recorded. Two examiners made a lower impression, chewing ability test and measured the bite force for each participant. Measurement of the CS was obtained digitally from the poured dental cast, and the categorization was as follows: flat (<1 mm), normal (1-2 mm), or deep (>2 mm). The mean maximum bite force (MBF) was 468.722 N for participants with flat CS, 389.822 N for normal CS, 647.08 N for deep CS, and 384.667 N for reverse CS. The average MBF was higher for participants with deep CS (p < 0.05). MBF force was higher in males. However, BMI was not significantly related to MBF values. Participants with normal and flat CS have comparable chewing capacity (p > 0.05). Also, a significant difference in bite force and chewing ability was found between the three categories of CS (p < 0.05). Bite force variations across various CS types were linked to gender and habits. Chewing ability showed no differences concerning gender, habits, TMJ problems, caries, or restorations, emphasizing CS's significant impact on bite force while showcasing the unchanged nature of chewing ability amidst diverse factors.

Influence of the Curve of Spee on Tooth Displacement Patterns: A Finite Element Analysis at Varying Implant Heights.

Background Monocortical mini-screw-type temporary anchorage devices (TADs), or mini-screws, have significantly impacted orthodontic treatment strategies, especially in severe crowding and protrusion cases. These devices offer flexibility in placement sites, but the chosen location can considerably influence tooth displacement patterns. Key factors include the 'line of force' and the biomechanical properties of orthodontic tools. By analyzing tension distribution and three-dimensional displacements, the finite element method (FEM) provides a thorough means to comprehend these patterns. The Curve of Spee (COS) is a crucial factor potentially affecting displacement. Objective This study aimed to leverage finite element analysis (FEA) to understand the impact of varying mini-implant heights (10 mm, 13 mm, and 16 mm) on the displacements of different tooth types under a consistent force of 150 gm and compare these displacements both in the presence and absence of the COS. Materials and methods A CAD model of the jaw and teeth was developed using CT scan data and a Rexcan III 3D White Light Scanner. This model was meshed in Altair HyperMesh using tetrahedral elements, resulting in a Finite Element Model. The model incorporated various components, including teeth, the periodontal ligament (PDL), alveolar bone, brackets, a titanium mini-screw, and an archwire measuring 0.019 x 0.025 inches. Unique material properties were assigned to the PDL, and the assembly accurately replicated the clinical alignment of the archwire and brackets. Subsequently, stress and strain analyses were conducted on the model using the FEM. Results The displacement patterns of various teeth at implant heights of 10 mm, 13 mm, and 16 mm under a 150-gm force were analyzed in relation to the COS. Notably, for the central incisor, the COS significantly affected displacements in the Y and Z directions. Similarly, the Lateral Incisor and Canine exhibited marked changes in the Z direction with the presence of the COS. The Second Premolar's apex displacement showed significant variation due to the COS, while the First Molar displayed notable changes in the X direction. Generally, the presence of the COS either maintained or slightly increased Z-directional displacements across teeth, particularly at the apices. Conclusion The presence of COS significantly influences tooth displacement patterns when using mini-screws at different implant heights. Central incisors, lateral incisors, and canines are particularly sensitive to changes in the Z direction with the COS. The biomechanical analysis emphasizes the importance of considering COS in treatment planning for optimal results with mini-implants in orthodontics.

Curve of Spee modification in different vertical skeletal patterns after clear aligner therapy: a 3D set-up retrospective study

ObjectiveThe purpose of the present study was to evaluate: (1) changes in the curve of Spee (COS) after clear aligner therapy and (2) whether such changes correlated with the patient’s skeletal patterns.Materials and methodsThree-dimensional mandibular models of 106 patients (47 males and 59 females; mean age 22.3 SD ± 3.4 years) treated with clear aligners were retrospectively analysed. The perpendicular distance between the occlusal reference plane and the buccal cusp tip of each lateral tooth was measured. Five angular cephalometric measurements (PP-MP, PP-OP, OP-MP, AFH, and PFH) were performed and correlated with the T1–T0 difference in linear distances. The patients were divided into three groups according to facial divergence. Variance analysis with Tukey post hoc correction was performed to evaluate the differences among groups.ResultsThe one-way ANOVA test showed a statistically significant difference for all analysed variables, except for the change in the distance of the second molar from the occlusal reference plane. Tukey’s HSD test showed the following differences: In normodivergents, the T1–T0 difference in the distance of the first molar from the occlusal plane was 1 mm greater than that observed in the hyperdivergent group (p < 0.05); in the normodivergent group, the T1–T0 difference in the distance of the second premolar from the occlusal plane was 1.23 mm greater than that observed in the hyperdivergent group (p < 0.05), while in the hypodivergent group, it was 1.08 mm greater than in the hyperdivergent group (p < 0.05); finally, in normodivergents, the T1–T0 difference in the distance of the first premolar from the occlusal plane was 0.97 mm greater than that observed in the hyperdivergent group (p < 0.05).ConclusionTreatment with aligners did not lead to a clinically significant change in COS depth. However, when dividing the sample into groups based on craniofacial divergence, COS depth change differed significantly between the three groups.

The second molar dilemma in orthodontics: to bond or not to bond?

To compare orthodontic treatment (OT) outcome in adolescents undergoing nonextraction fixed OT with or without bonding of second molars using the score of the American Board of Orthodontics Cast Radiograph Evaluation (C-R-Eval). This study included healthy adolescents with skeletal Class I or mild Class II/Class III malocclusion, normal or deep overbite (OB), and mild-to-moderate dental crowding (<5 mm) who underwent nonextraction fixed OT with ("bonded" group) or without ("not-bonded" group) bonding of second molars. Patient treatment records, pre- and posttreatment digital models, lateral cephalograms, and orthopantomograms were assessed. The evaluated outcomes included leveling of the curve of Spee (COS), OB, control of incisor mandibular plane angle (IMPA), number of emergency visits (related to poking wires and/or bracket failure of the terminal molar tubes), treatment duration, and C-R-Eval. Treatment variables were compared across time points and among groups. The sample included 30 patients (mean age 16.07 ± 1.80 years) in the bonded group and 32 patients (mean age 15.69 ± 1.86 years) in the not-bonded group. The mean overall C-R-Eval score was significantly higher (P < .001) in the not-bonded group (25.25 ± 3.98) than in the bonded group (17.70 ± 2.97). There were no significant differences in mean changes of COS, OB, IMPA, or treatment duration among groups. The mean number of emergency visits was significantly higher in the bonded (3.3 ± 0.6) than the not-bonded group (1.9 ± 0.4) (P < .001). Bonding of second molars enhances the outcome of nonextraction fixed OT as demonstrated by the C-R-Eval without increasing treatment duration, irrespective of more emergency visits.

An Evaluation of the Curve of Spee in the Maxilla and Mandible of Human Permanent Healthy Dentitions: A Cross Sectional Analytical Study in a Group of Nepalese Population

Introduction: Familiarity with the typical measurements of the maxillary and mandibular curves of Spee can assist clinicians in formulating sagittal plane occlusion and proves beneficial in delivering prosthetic rehabilitation for patients with occlusal derangement. The objective of this study is to evaluate and compare the radius and depth of the Spee curve in the maxillary and mandibular arches among both male and female individuals within young Nepalese population. Materials and Methods: The study comprised 21 men and 21 women aged between 18 and 30 years. Alginate impressions were made for both the maxillary and mandibular arches and dental stone casts were subsequently created. Digital images of the right side of maxillary and mandibular dental casts were captured using a digital camera and subsequently transferred to a computer. The tips of the distal cusps of molars, premolars, and canines in both the maxillary and mandibular arches were identified. Utilizing the computer software (Corel DRAW), the radius and depth of the Spee curve were measured based on the digital photographs of the dental casts. Results: The results indicated a substantial difference in the depth of the Spee curve between the mandibular and maxillary arches (p&lt;0.001), with the mandibular arch displaying a significantly greater depth. Furthermore, the Spee curve was notably deeper in females (p=0.045) compared to males. However, there was no statistically significant difference in the depth of the Spee curve in the mandible between genders (p=0.171). Conclusions: The radius of the Spee curve was unaffected by the gender or arch of the subjects under investigation. Nevertheless, the Spee curve was observed to be significantly flatter in the maxillary arch when contrasted with the mandibular arch. Additionally, a notable difference in the depth of the Spee curve was identified between females and males, with females displaying a greater depth.

The predictability of maxillary curve of Spee leveling with the Invisalign appliance.

To evaluate the predictability of the Invisalign appliance (Align Technology, Santa Clara, Calif) in leveling the maxillary curve of Spee (COS). A retrospective sample of adult subjects treated with the Invisalign appliance between 2013 and 2019 were selected. Patients were treated nonextraction in the maxillary arch and had either Angle Class I or II malocclusions with a minimum of 14 aligners with no bite ramps. Initial, predicted, and actual outcomes were analyzed with Geomagic Control X software (version 2017.0.3; 3D Systems, Cary, NC). A sample of 53 cases satisfied inclusion/exclusion criteria. Paired t-tests demonstrated a significant difference between mean predicted and actual maxillary COS leveling with a shortfall of 0.11 mm (SD = 0.37; P = .033). Planned intrusion tended to be more accurate posteriorly with an overexpression of 117% for the first molars. Planned extrusion was the least accurate, with the mid-arch demonstrating expressions of -14% to -48%. These teeth intruded despite a prescribed extrusive movement. The Invisalign appliance did not accurately predict maxillary COS leveling. Planned intrusive movements were overcorrected, and planned extrusive movements were either undercorrected or resulted in intrusion. This effect was most apparent for the upper first molar, which expressed 117% and -48% of planned intrusion and extrusion, respectively.

DEEP BITE MALOCCLUSION: EXPLORATION OF THE SKELETAL AND DENTAL FACTORS

Background and objective: A deep bite malocclusion may be due to skeletal and dental factors. The analysis of the etiological factors may have an influence on the treatment plan. The aim of this study was to exploration the most common dental and skeletal factors that contribute to deep bite malocclusion in Yemeni individuals, as well as the correlations between them. Material and methods: a cross-sectional prospective study was conducted to evaluate 136 individuals with deep bites using study casts and lateral cephalometrics (62 males and 74 females), with ages ranging from 18 to 28 years, with the Onyx program used for analysis. The recorded data was collected, tabulated, and statistically analyzed by SPSS. Results: The Gonial angle and Jarabak index form the highest contribution to skeletal deep bite (59.3%), and the least contributing factors were the decreased saddle angle (3%), followed by decreases in the inclination angle) Pn line- PP) (11.1%). On the other hand, the most contributing dental factor to the deep bite was an exaggerated curve of spee (63.5%), followed by a decreased clinical crown length of the Lower first molar (52.6%), and the least contributing dental factor was an increased clinical crown length of the maxillary incisors. There was more correlation between skeletal factors than dental factors. Conclusion: Deep bite malocclusion was characterized mostly by counterclockwise rotation of the mandible and increased spee curve. Understanding the most common dental and skeletal contributors will help clinicians treat patients with deep malocclusions more successfully. Peer Review History: Received: 4 February 2023; Revised: 11 March; Accepted: 28 April 2023, Available online: 15 May 2023 Academic Editor: Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, amaka_mgbahurike@yahoo.com Received file: Reviewer's Comments: Average Peer review marks at initial stage: 5.5/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Rola Jadallah, Arab American University, Palestine, rola@aauj.edu Dr. Khaled A AL-Haddad,Orthodontics, Pedodontics and Prevention Department Faculty of Dentistry, Sana'a University, Yemen, ya_haddadi@yahoo.com

Comparative evaluation and co-relation in variation of curve of Spee and curve of Wilson in Class II div. 1, Class II div. 2, and Class III as against Class I malocclusion in central India population- an in vitro study

Introduction- Getting acceptable cosmetic results in the soft tissues of the face serves as the foundation for orthodontic treatment planning. Also, in order to achieve healthy static and dynamic occlusal interactions, the teeth must be positioned within the basal bone at the correct position, angle, and inclination. To avoid periodontal issues, provide stability, and achieve a functional occlusion, it is essential to ascertain the individual's dental arch form before starting of treatment and thus to utilise the mechanics that follow throughout the treatment. Objectives- To evaluate and compare variation in Curve of Spee and Curve of Wilson in Class II Div.-1, Class II-Div-2 and Class-III as against Class I malocclusion in central India population. Methodology- Irreversible hydrocolloid impression will be taken with perforated metal stock trays and stone cast will be poured. This will be scanned using CAD CAM machine and curve of Spee and Wilson will be measured using reverse engineering. Expected Result- It will assist us in treatment planning for preventing periodontal issues, assuring stability, and achieving functional occlusion by evaluating and comparing the Spee and Wilson curves in Class II Divison-1, Class II Divison-2, and Class-III malocclusion with Class-I malocclusion. Conclusion- Every single patient receiving orthodontic treatment has the COS, which is crucial to achieving a stable occlusion. Almost every patient who receives orthodontic treatment eventually experiences the Spee Curve. Since there aren't many studies examining the relationship between the Curves of Spee and Wilson, their impact on dentoskeletal morphology, and their role in occlusal stability.

A Comparative Analysis Of Depth of Curve Of Spee Between Individuals with Normal Dentition And Individuals With Occlusally Worn Out Dentition

Introduction: The curve of spee plays an important role to create Christensen’s phenomenon in natural dentition. This study was performed to assess the difference in depth of the curve of Spee between normal and attrited dentition.&#x0D; Methods: An analytical cross-sectional study was performed to measure the depth of curve speed in a total of 80 willing participants who met the inclusion criteria, of which 40 had normal dentition and 40 had attrited dentition. Measurements were done on stone casts by using a rigid metal scale and a digital vernier caliper. Analytical statistical analysis (independent t-test) was done using SPSS Statistical Software Package (version 21.0).&#x0D; Results: There was a statistically significant difference in the depth of the curve of Spee between the two groups.&#x0D; Conclusions: The depth of the curve of spee decreases with the advancing of the age of human as attrition of the teeth occurs with age. Although there is a decrease in the depth of the curve of spee it should be maintained and created while performing full mouth rehabilitation and other extensive prosthodontic treatments.

Variability in depth of curve of Spee and its associated skeletal and dental implications in population of Pakistan

Background and Aim: The curve of Spee (COS) is a physiological entity in human dentition. A functional masticatory system necessitates an appropriate occlusal curvature. The primary objective of this investigation was to assess the skeletal and dental parameters in individuals with variation in the depth of curve of Spee. Materials and Methods: A total of 276 patients with pre-treatment lateral cephalograms and dental cast models were investigated in the Orthodontics and Dentofacial Orthopedics Unit of a Tertiary Care Hospital of Mardan, Pakistan from January 2021 to December 2022. Patients with no prior history of orthopedic treatment for functional jaw, prosthodontic treatment, no prior history of cleft lip and palate and cranio-facial disorders were enrolled. Ethical approval was obtained and all the patients were categorized into three groups based on the depth of curve of Spee (COS): Group-I (flat curvature &lt; 2 mm), Group-II (normal curvature 2-3 mm), and Group-III (deep curvature &gt; 3 mm). Lateral cephalometric analysiswas done to measure the four angular and four linear parameters. Molar relation, overbite, COS depth, and overjet were measured based on the occlusal classification. SPSS version 27 was used for data analysis.

The Effect of Accentuation of Curve of Spee on Masticatory Efficiency—A Systematic Review and Meta-Analysis

The appropriate alignment of the lower teeth is indicated by the Curve of Spee (COS), which can be observed in the sagittal profile view of human skulls. Graf Von Spee made the initial observation on this occlusal curvature. Through this systematic review and meta-analysis, we evaluated studies that looked at how COS affected masticatory activities. The databases PubMed-MEDLINE, Web of Science, Cochrane, and Scopus were all searched. A total of 12 documents were ultimately picked because they met the necessary inclusion and exclusion requirements. The data was then loaded into the RevMan 5 programme for meta-analysis after being chosen for information on the sample size, variables analyzed, and various aspects of the research. The Curve of Spee was found to have a noticeable impact on both the masticatory efficiency as well as dentofacial alignment in the 12 studies that we selected for the review and meta-analysis. In addition, other occlusal curvatures such as the Curve of Monson and the Curve of Wilson were found to be of vital importance on a similar level to the COS. The meta-analysis further revealed that seven of the included clinical trials had mentioned the noticeable impact on masticatory efficiency. This study focused on the significance of the COS on force distribution in the oral cavity as well as the necessity of COS corrections after receiving full orthodontic care. Following orthodontic treatment, the COS, along with other occlusal curves such as the Curve of Wilson and the Curve of Monson, is essential in removing strains from the condyle, as well as the maxilla and mandible, which enhances masticatory effectiveness and lessens the overall strain on a patient's oral cavity.