Comparison of the accuracy of different types of bite recordings - an in vitro study.

OBJECTIVES: Reconstruction of a three-dimensional jaw position determined by a bite recording is an important aspect of prosthetic therapy. Different materials are used for this purpose. In the dental technical workflow, recordings are used to mount a lower jaw cast in a patient-like spatial position relative to the upper jaw cast. We evaluated the accuracy of positioning under the influence of different jaw positions and materials. MATERIALS AND METHODS: In an experimental setup, comprising an articulator, a pair of metal casts, and an optoelectronic measurement system, the spatial position of the incisal point and two condylar points were measured. To evaluate the accuracy of repeated repositioning of casts in the technical workflow, 324 measurements were taken from 108 recordings, consisting of silicone bite-stops made of addition curing silicone with 95 shore hardness, acrylic wafers, and wax recordings. The recordings were obtained in four jaw relations differing in vertical and protrusive components. RESULTS: Of the three materials/material combinations examined, silicone showed the most consistent results across all measurements, followed by the acrylic wafer system, and then wax recordings. Generally, recordings with smaller gaps between the jaws and no protrusive components showed greater deviations compared to jaw positions with greater protrusion and higher vertical dimensions. CONCLUSIONS AND CLINICAL RELEVANCE: To achieve reliable model mounting with high accuracy, recordings should include the use of a frontal jig and four small recording platelets made of silicone, especially if only a slight elevation of the vertical dimension is needed.

Stability of class II correction with the Austro Repositioner associated with multi-brackets fixed appliances in dolichofacial patients.

BACKGROUND: The purposes of the present study were to evaluate the changes produced by the Austro Repositioner, and to assess the stability of Class II malocclusion treatment with the Austro Repositioner associated with fixed appliances and its capacity to control the vertical dimension in dolichofacial patients. METHODS: A group of patients with Class II malocclusion due to mandibular retrognathism and a dolichofacial growth pattern treated with the Austro Repositioner combined with fixed appliances were compared to a matched untreated control group of subjects with Class II malocclusion. Evaluations were made on the basis of lateral cephalograms taken at T1 (initial records), T2 (end of treatment), and T3 (1 year after treatment). Statistical comparisons were performed with paired- and two-sample t tests. RESULTS: The experimental (treated) group comprised 30 patients, 14 boys and 16 girls, and the control group comprised 30 subjects (15 boys and 15 girls) with similar ages at T1, T2 and T3. In the treated group, a significant decrease in the ANB angle was found (- 3.79 ± 1.46; p < 0.001). No significant differences were found in the maxillary skeletal measurements. In contrast, the SNB angle showed a significant increase of 3.77 ± 1.49 in the treated group compared with a nonsignificant increase of 0.77 ± 1.55 in the control group (p = 0.002). Vertical changes showed a significant decrease in the FMA angle (- 3.36 ± 1.62), while the lower anterior facial height distance and the overbite increased significantly in the treated group, reflecting a change in vertical dimensions after treatment. No significant changes were observed in either the treated or control group during the one-year posttreatment period; thus, the treatment results remained stable. CONCLUSIONS: The Austro Repositioner combined with fixed appliances could be considered an optimal treatment modality in Class II dolichofacial patients.

Does increasing vertical dimension of occlusion in centric relation affect muscular activity? An electromyographic study.

OBJECTIVE: In many esthetic treatments, clinicians may consider the option to modify the maxillo mandibular position. A raise of the vertical dimension of occlusion (VDO) may help restore esthetics, increase the space for dental materials, and reduce the invasiveness of dental procedures. Traditionally, VDO increases are done by using the centric relation (CR) position. Despite a long history of use, the neuromuscular effects of different maxillo mandibular relations are not fully studied. The aim of this study was to investigate the effect of alterations of maxillo-mandibular relation from maximal intercuspal position (MIP) to a raised VDO CR position on jaw-elevator muscle activity. MATERIALS AND METHODS: Fifteen healthy individuals were asked to carry out maximal voluntary clenching (MVC) in MIP and in CR on individual splints. Electromyographic (EMG) activity of the masseter and anterior temporalis muscles was assessed in µV as the root mean square of the amplitude. Specific indexes and ratios were also computed. Data analyzed in MIP and CR were compared by paired student's t-tests. RESULTS: MVC levels were not negatively affected by a VDO increase in CR position. On the contrary masseter muscles showed a statistically significant increase (p < 0.005). No significant effect on the anterior temporalis was observed. CONCLUSION: These results suggest that no immediate negative effect on maximum voluntary clenching was induced by a VDO increase in CR position. A slight increase observed in EMG clenching levels could be explained by the increase in VDO when clenching on the splint. CLINICAL IMPLICATIONS: The results of this study support the use of CR position as a pragmatic reference position due to the absence of relevant or negative changes in neuromuscular function.

Hard and soft tissue shape variation and changes in Class II division 1 malocclusion during orthodontic treatment: a geometric morphometric analysis.

BACKGROUND: This study aims to determine the hard and soft tissue shape variation and its changes in Class II division 1 malocclusion before and after orthodontic treatment using Geometric Morphometric Analysis. METHODS: This retrospective study included 141 pre-treatment and near-end treatment lateral cephalometric radiographs of Class II division 1 malocclusion patients aged 16-40 years with a skeletal II pattern (ANB > 4o). 32 landmarks in Cartesian coordinates were created and identified using MorphoJ software to establish a shape analysis. RESULTS: The vertical dimensions (hypodivergent to hyperdivergent facial profiles) showed the largest variation in the general shape of hard and soft tissue, followed by the anteroposterior dimensions (mild to severe skeletal II patterns). Variations of lip shape (long to short), lip protuberance (everted to inverted), and nasolabial angle (obtuse to acute) were present. Orthodontic treatment affected the shape of the hard and soft tissue significantly (p < 0.0001). T2 showed significant uprighting of upper incisors (17.5o) and lower incisors (3.7o), improved NLA (8o), an increase in upper lip thickness (1.5 mm), and a reduction in lower lip thickness (0.7 mm) (p < 0.05). CONCLUSION: Vertical and anteroposterior shape variations were found. Orthodontic treatment had an impact on both hard and soft tissue shapes. Hence, understanding both the hard and soft tissue shape variations and the orthodontic treatment changes is crucial for an accurate diagnosis and treatment plan to achieve a successful outcome and excellent patient satisfaction.

The combination of the horizontal and vertical dimensions in mental time representation: the existence of a spatial mental map of time.

Horizontal and vertical representations of time (past-left or down and future-right or top) have been demonstrated. However, only a few studies have investigated the existence of a spatial map of time, considering it as the interaction of different spatial dimensions in space. The aim of this study was to investigate the existence of a mental time representation along the diagonal axes, intended as the combination of the horizontal and the vertical dimensions. Seventy-nine Italian participants (85% females; mean age = 25.11 ± 4.86 years; 77 right-handed) performed an online temporal judgment task using 20 Italian temporal expressions presented either always in the center (Experiment 1) or in the four corners of the screen (Experiment 2) and two pairs of response keys ("C" and "U" for the positive diagonal; "R" and "N" for the negative diagonal). Results showed spatial-temporal associations in positive (i.e., time was represented from left-bottom to right-top) and negative (i.e., time was represented from left-top to right-bottom) diagonals, although in Experiment 2 these associations were weak for the negative diagonal. These spatial-temporal associations along both diagonals were confirmed even when participants were free to place different temporal stimuli along a diagonally drawn line, in a Time-to-Position task, indicating that the temporal expressions could be ordered linearly along the diagonal spaces. Finally, these data indicated that the horizontal information was mainly used for determining the spatial-temporal associations along both diagonals, whereas the vertical information was flexible with a bottom-to-top (for positive diagonal) and top-to-bottom (for negative diagonal) temporal representation.

Reabilitação oral com próteses parciais removíveis após restabelecimento de dimensão vertical de oclusão e tratamento multidisciplinar: relato de caso / Oral rehabilitation with removable partial dentures after restoration of the vertical dimension of occlusion and multidisciplinary treatment: case report

As próteses parciais removíveis (PPRs) são uma alternativa de tratamento viável na prática clínica para reabilitar arcos parcialmente desdentados. Entretanto, o planejamento dessas próteses e preparo bucal prévio são frequentemente negligenciados. O presente artigo tem como objetivo relatar o caso clínico de uma reabilitação oral com PPRs superior e inferior após abordagem multidisciplinar, de modo a enfatizar as fases de um planejamento criterioso e de preparo prévio dos dentes pilares, visando o sucesso e a longevidade da reabilitação. Paciente do sexo masculino de 57 anos de idade compareceu à clínica da Faculdade de Odontologia de Bauru, Universidade de São Paulo, queixando-se da estética de seu sorriso e de algumas ausências dentárias. O indivíduo utilizava uma PPR provisória inferior insatisfatória e apresentava perda de dimensão vertical de oclusão (DVO). Após o exame clínico, radiográfico e estudo do caso em articulador semi-ajustável, realizou-se o planejamento com abordagens restauradoras, endodônticas, periodontais e protéticas. Após tratamento periodontal, foi realizada endodontia dos elementos 12, 15 e 47, confecção de núcleos e coroas nos dentes 12 e 15, restauração a nível gengival para apoio residual no dente 47, restaurações nos dentes 11, 13, 22, 24 e 44 e, por fim, a confecção das PPRs superior e inferior. A abordagem multidisciplinar utilizada neste caso clínico viabilizou o restabelecimento da DVO e possibilitou o sucesso da reabilitação protética(AU)

Removable partial dentures (RPDs) are a viable treatment alternative in clinical practice to rehabilitate partially edentulous arches. However, the planning of these dentures and prior oral preparation are often neglected. This article aims to report the clinical case of an oral rehabilitation with upper and lower RPDs after a multidisciplinary approach, to emphasize the phases of careful planning and prior preparation of the abutment teeth, aiming at the success and longevity of the rehabilitation. A 57-year-old male patient came to the clinic of the Bauru School of Dentistry, University of São Paulo, complaining about the esthetics of his smile and some missing teeth. The subject was using an unsatisfactory lower provisional prosthesis and had a loss of vertical dimension of occlusion (OVD). After the clinical and radiographic examination and the case study in a semi-adjustable articulator, planning was carried out with restorative, endodontic, periodontal and prosthetic approaches. After periodontal treatment, endodontics were performed on elements 12, 15 and 47, creation of cores and crowns on teeth 12 and 15, restoration at the gingival level for residual support on tooth 47, restorations on teeth 11, 13, 22, 24 and 44 and, finally, the making of the upper and lower PPRs. The multidisciplinary approach used in this clinical case enabled the restoration of the OVD and enabled the success of the oral rehabilitation(AU)

Envelhecimento bucal precoce e suas consequências para a cavidade oral com foco em reabilitação com resina composta: relato de caso / Early oral aging and its consequences for the oral cavity focusing on rehabilitation with composite resin: case report

O envelhecimento bucal precoce apresenta cada vez uma maior incidência nos consultórios odontológicos e sua degradação aos tecidos orais exige uma atenção por parte do cirurgiãodentista devido ao seu alto grau de complexidade. Esse envelhecimento precoce é causado principalmente por hábitos parafuncionais, dieta ou ambos. Suas consequências são desgastes patológicos dos tecidos dentários, extrusão passiva, perda de dimensão vertical e comprometimento estético e funcional. Por conta disso, o presente estudo teve como objetivo realizar um relato de caso clínico em um paciente jovem e com queixa estética como consequência de hábitos parafuncionais, aonde foram realizados uma reabilitação oral envolvendo aumento da dimensão vertical de oclusão através de Table Tops sem desgastes dentários e restaurações estéticas, ambas com resina composta. Essa reabilitação devolveu a DVO da paciente, trazendo conforto, contatos estáveis, guias de desoclusão e satisfação estética e funcional por parte da paciente(AU)

Early oral aging has an increasing incidence in dental offices and its degradation to oral tissues requires attention from the dentist due to its high degree of complexity. This premature aging is mainly caused by parafunctional habits, diet, or both. Its consequences are pathological wear of dental tissues, passive extrusion, loss of vertical dimension and aesthetic and functional impairment. Because of this, the present study aims to carry out a clinical case report in a young patient with an aesthetic complaint as a result of parafunctional habits, where an oral rehabilitation was carried out involving an increase in the vertical dimension of occlusion through Table Tops without dental wear and aesthetic restorations, both with composite resin. This rehabilitation returned the patient's OVD, bringing comfort, stable contacts, disocclusion guides and aesthetic and functional satisfaction on the part of the patient(AU)

[Restorative treatment of generalized tooth wear]. / Restauratieve behandeling van gegeneraliseerde gebitsslijtage.

A 24-year-old patient with generalized tooth wear was referred to the Radboud Tooth Wear Project. The tooth wear had a chemical aetiology, caused by gastro-oesophageal reflux and resulting in functional problems of the masticatory system and a reduced quality of life. The treatment of the patient was minimally invasive, with directly applied composite restorations on all teeth, by means of which an increase of vertical dimension of occlusion was introduced. The restorative treatment was not preceded by testing of the new vertical dimension of occlusion. The patient was able to function well again after restorative treatment.

Increased vertical dimension of occlusion for varying periods differentially impairs learning and memory in guinea pigs.

There is an increasing number of studies showing that occlusal dysfunction impairs learning and memory. We previously demonstrated that the brain has a mechanism to calibrate between the activities of spindle afferents and periodontal-mechanoreceptor afferents for controlling the chewing movement, and the accurate calibration can be done only at the proper vertical dimension of occlusion (VDO). Then, the chewing at an inappropriate VDO may induce a severe mental stress due to a mal-calibration. However, it is not clear how the impairment of learning/memory progresses over the period of stress induced by occlusal dysfunction. We investigated by passive avoidance test how the behavior and learning/memory are altered in guinea pigs in which the VDO was raised by 2-3 mm over the period up to 8 weeks. We found that the guinea pigs reared under the raised occlusal-condition (ROC) for 1 week showed a very high sensitivity to electrical stimulation whereas this did not cause the memory consolidation in the 1st-day retention trial, suggesting that such hypersensitivity rather hampered the fear learning. In the guinea pigs reared under the ROC for 2 and 8 weeks, the learning ability was not largely affected and memory consolidation occurred similarly whereas the memory retention deteriorated more severely in the latter guinea pigs than in the former ones. In the guinea pigs reared under the ROC for 3 and 4 weeks, learning was severely impaired, and memory consolidation did not occur. These results suggest that the occlusal dysfunction for varying periods differentially impairs learning and memory.

A fully digital workflow to register maxillomandibular relation using a jaw motion tracer for fixed prosthetic rehabilitation: A technical report.

OBJECTIVE: This technique aimed to describe a fully digital workflow to register maxillomandibular relation for fixed prosthetic rehabilitation. CLINICAL CONSIDERATIONS: Mandibular kinematics could be reproduced in a four-dimensional (4D) virtual patient based on the intraoral scan, facial scan, cone beam computed tomography, and jaw motion trajectory, which helped record centric relation and determine a proper occlusal vertical dimension in a virtual environment. The therapeutic position could be exported directly to the dental computer-aided design software for digital waxing design with a facial scan. The 4D virtual patient was also used to verify the functional and esthetic outcomes of provisional restorations. CONCLUSIONS: This novel approach digitized the process of determination, delivery, and double-check of maxillomandibular relation, thus contributing to the establishment of a completely digital workflow for fixed prosthetic rehabilitation. CLINICAL SIGNIFICANCE: Registration of maxillomandibular relation, including centric relation and occlusal vertical dimension is critical to the success of prosthetic rehabilitation. Traditional procedures are complex and time-consuming, and heavily rely on the clinical experience of dentists. A fully digital approach to creating a 4D virtual patient and registering the maxillomandibular relation is established, which guides to determine a proper occlusal vertical dimension in centric relation. Digital delivery and double-check can simplify the conventional procedure and ensure that the determined maxillomandibular relation is reliable.

Correlation of index finger length to vertical dimensions of occlusion for edentulous patients and their satisfaction: a randomized controlled trial.

The prevalence of edentulism is pandemic and people resort to complete dentures for the restoration of missing teeth and esthetics. However, the determination of the correct occlusal vertical dimensions (OVD) constitutes to play an important role in overall patient satisfaction. The objective of this study was to apply anthropometric methods to correlate the length of index finger (2D) to measure the OVD from base of the nose to the base of the chin (Sn-Me) and to assess satisfaction by comparing both the methods. A total of 80 edentulous patients were randomized and controlled for this trial into experimental and control groups. A correlation was found between Sn-Me and finger measurements, dentures' satisfaction was assessed after a 1-week follow-up and marked according to the Visual Analog Scale. Our findings established that finger measurements are greater among males, and in both genders, positive, and statistically significant correlations exist between the facial and finger length measurements. Moreover, 97.0% patients from experimental group were satisfied with the use of complete dentures through the new anthropometric method. Hence measuring the length of index finger can be an adjunct method for the restoration of OVD and is a relatively time-effective and simple method with a satisfactory follow-up.Trial registration: ID: NCT05153213 ( https://clinicaltrials.gov/ct2/show/NCT05153213 ).

Cephalometric evaluation of deep overbite correction using anterior bite turbos.

OBJECTIVES: To evaluate the outcome of treating deep overbite (OB) using anterior bite elevators concurrently with a pre-adjusted edgewise appliance. MATERIALS AND METHODS: The Case Western Reserve University (CWRU) cephalometric analysis was used to isolate tipping movement of upper (TUI) and lower incisors (TLI), bodily tooth movement of upper (BUI), and lower incisors (BLI), as well as vertical skeletal changes in the anterior region of the maxilla (MXSK) and mandible (MNSK). Thirty treated subjects were examined at pretreatment (T1) and posttreatment (T2) and compared to an untreated control group matched on age, sex, and Angle malocclusion from the Bolton Brush Growth Study Collection (CWRU, Cleveland, Ohio). RESULTS: Overbite (OB) in the treated group was decreased significantly (P < .001) (-5.6 mm) compared to controls. Statistically significant (P < .001) changes were found for BUI (-0.7 mm), TUI (0.9 mm), TLI (-1.4 mm), BLI (-1.1 mm), and MNSK (-1.6 mm). Most of the overbite correction was in the lower arch and included tipping and intrusion of the lower incisors along with an increase in lower vertical facial height. CONCLUSIONS: Deep OB correction was achieved efficiently using anterior bite elevators with pre-adjusted edgewise appliance. Correction using bite turbos would be a treatment option for individuals presenting with decreased lower facial height and deep bite.

Elderly-friendly indoor vertical dimensional layout method based on joint mobility.

INTRODUCTION: The vertical dimensional arrangement of space is primarily influenced by the reachable range of human fingertips. Currently, this dimensional layout analysis concentrates solely on static body dimensions based on Farley's principle. However, the joint mobility of the elderly population has diminished, necessitating the identification of the factors influencing the age-friendly spatial vertical dimension layout through experimentation. METHODS: A random sample of 62 adults and 62 elderly individuals were selected to measure the joint mobility of 8 groups with varying comfort levels. The measurement results were analyzed using an independent sample t-test with SPSS software. RESULTS: The joint mobility of the elderly group exhibited a notable difference from that of the adult group across distinct comfort gradients. A significant reduction in the range of motion of all joints in the elderly was observed. The findings suggest that the reachable range of the upper limbs of the elderly should be considered in conjunction with joint mobility. We propose a vertical dimensional layout method for residential spaces that accommodates the joint mobility of elderly users. CONCLUSION: The joint mobility of the elderly is significantly deteriorating, and the traditional vertical spatial layout method cannot adequately support the daily life of the elderly. It is essential to integrate the joint mobility factor into the vertical dimensional layout design process. In this paper, we propose an elderly-friendly vertical spatial dimension layout method. It offers a reference for subsequent planning of elderly-friendly vertical dimension layout.

Stability of vertical dimension following total arch intrusion.

BACKGROUND: The purpose of this study is to evaluate stability of vertical dimension following total arch intrusion using miniscrews by measuring the change during treatment and relapse amount after more than one year of retention. METHODS: Thirty patients (6 men, 24 women) were included in this study. Lateral cephalographs were taken with conventional radiography at the start of treatment (T0), after treatment (T1), and at least one year after treatment (T2). The evaluation was performed by measuring changes of selected parameters during treatment and the extent of relapse after more than one year. RESULTS: During total arch intrusion treatment (T1-T0), anterior and posterior teeth intruded significantly. The mean vertical distance between the maxillary posterior teeth and palatal plane was reduced by 2.30 mm (P < 0.001). The mean vertical distance between the maxillary anterior teeth and palatal plane was reduced by 2.04 mm (P < 0.001). The anterior facial height was also reduced by 2.70 mm (P < 0.001). During retention period (T2-T1), the vertical distance between the maxillary anterior teeth and the palatal plane significantly increased by 0.92 mm (P < 0.001). The anterior facial height increased by 0.81 mm (P < 0.01). CONCLUSIONS: Anterior facial height significantly decreases after treatment. During retention period, relapse of AFH and maxillary anterior teeth observed. There was no correlation between initial amount of AFH, mandibular plane angle, or SNPog and posttreatment AFH relapse. However, there was a significant correlation between the amount of intrusion of anterior and posterior teeth achieved by the treatment and the extent of relapse.

Aesthetic and functional rehabilitation of collapsed occlusal vertical dimension using an advanced digital workflow.

This report presents a clinical case that follows a comprehensive digital workflow to increase occlusal vertical dimension of a patient presenting with occlusal wear. A 56-year-old patient with aesthetic and functional problems presented to the authors' clinic. An intraoral scanner was used to obtain digital models of the patient's existing maxillary and mandibular arches. Advanced sculpting software and digital tooth libraries were used to design the patient's ideal smile. A three-dimensional (3D) printer was used to fabricate temporary restorations and resin casts. Full-mouth restoration was successfully completed with zirconia crowns using an advanced digital workflow.

Digital jaw relation recording to evaluate a new vertical dimension of occlusion using CAD/CAM-fabricated tooth-colored splints: a case report.

Pronounced defects of the dental hard tissue can be caused by different etiologic factors. Most frequently, they are associated with changes in the vertical dimension of occlusion (VDO), which may also influence the condylar positions. These defects can lead to irreversible loss of tooth structure and have dramatic functional and esthetic consequences, often requiring complex rehabilitation. In this situation, CAD/CAM-fabricated occlusal splints made of tooth-colored polycarbonate are a proven and safe pretreatment approach in terms of esthetics and function. Rebuilding lost dental hard tissue to restore the occlusion and VDO to an adequate condylar position is a prerequisite for any sustainable and functional rehabilitation. In the future, digital systems will support this complex process, customizing it and making it simpler and more precise. The DMD-System (Ignident) provides patient-specific jaw movement data to optimize the CAD/CAM workflow. This system allows real movement patterns to be digitized and analyzed for functional and potential therapeutic purposes, integrating them into the dental and laboratory workflow. In the present case, the familiar tooth-colored CAD/CAM-fabricated occlusal splint is supplemented by digital centric jaw relation recording and individual movement data.

Short-term effect of orthodontic clear aligners on muscular activity and occlusal contacts: A cohort study.

INTRODUCTION: The simultaneous presence of maxillary and mandibular clear aligners alters the vertical dimension and the quantity and quality of occlusal contacts. Few data in the literature explain how this occurs and the effects on neuromuscular coordination. This study aimed to evaluate occlusal contacts and muscular balance during treatment with clear aligners over a short follow-up time. METHODS: Twenty-six female adult patients were enrolled in this study. The center of occlusal force (COF) was evaluated using a T-Scan II device, whereas muscular symmetry and balance were determined through surface electromyography using a standardized protocol that reduces anthropometric and electrode variations. Both evaluations were performed in centric occlusion and with aligners worn before treatment, after 3 months, and after 6 months. RESULTS: A statistically significant variation in COF position was reported in the sagittal plane but not in the transverse plane. The shift in the COF position was followed by a change in muscular balance evaluated through surface electromyography. CONCLUSIONS: Treatment with clear aligners resulted in an anterior shift of the COF when biting in centric occlusion and a posterior shift when the aligners were worn in healthy female patients after 6 months of observation. This change in occlusal contact was followed by an improvement in muscular function symmetry in the short term when aligners were worn, compared with the centric occlusion during treatment.

Correlation of intercondylar distance and occlusal vertical dimension in dentate individuals: A clinical study.

STATEMENT OF PROBLEM: Determining the vertical dimension of occlusion for an edentulous patient depends on clinical judgment and the skill and experience of the dentist. Though many methods have been advocated, a universally accepted method of determining the vertical dimension of occlusion in edentulous patients is lacking. PURPOSE: This clinical study aimed to find a correlation between the intercondylar distance and occlusal vertical dimension in dentate individuals. MATERIAL AND METHODS: This study was conducted on 258 dentate individuals aged 18 to 30 years. The Denar posterior reference point was used to determine the center of the condyle. The posterior reference point was marked on either side of the face with this scale, and the intercondylar width between these 2 posterior reference points was measured with custom digital vernier calipers. A modified Willis gauge was used to measure the occlusal vertical dimension from the base of the nose to the lower border of the chin when the teeth were in maximum intercuspation. The relationship between the ICD and OVD was analyzed with the Pearson correlation test. Simple regression analysis was used to formulate a regression equation. RESULTS: The mean intercondylar distance was 133.5 mm, and the mean occlusal vertical dimension was 55.4 mm. A statistically significant correlation (R=0.619) was found between the intercondylar distance and occlusal vertical dimension in the study population (P<.001). CONCLUSIONS: A significant correlation was found between the intercondylar distance and occlusal vertical dimension of the participants. Occlusal vertical dimension may be predicted from the intercondylar distance by using a regression model.

Comparison of cephalometric changes in Class II growing patients with increased vertical dimension after high-pull and cervical headgear treatment.

AIM: The aim of the present study was to evaluate the cephalometric changes in growing Class II patients with increased vertical dimension treated with cervical or high-pull headgear, by using an untreated control group with similar skeletal characteristics. MATERIALS: From the initial sample, 56 patients satisfied the inclusion and exclusion criteria; 20 patients were treated with cervical headgear (CHG), 15 with high-pull headgear (HHG), and 21 were not treated (CG). Cephalograms were available for each subject at baseline (T1) and after treatment/observation time (T2) for the three groups. A total of 17 measurements were taken on the lateral head films. Group comparison among CHG, HHG and CG was done using ANOVA test. CONCLUSION: In Class II high-angle growing patients, cervical headgear seems to be preferred in the correction of maxillary protrusion, molar relationship and increased anterior facial height. Extrusion of the upper molar may favour forward repositioning of the mandible and clockwise rotation in Class II patients with increased vertical dimension.

Ecological patterns and processes in the vertical dimension of terrestrial ecosystems.

Climatic gradients such as latitude and elevation are considered primary drivers of global biogeography. Yet, alongside these macro-gradients, the vertical space and structure generated by terrestrial plants form comparable climatic gradients but at a fraction of the distance. These vertical gradients provide a spectrum of ecological space for species to occur and coexist, increasing biodiversity. Furthermore, vertical gradients can serve as pathways for evolutionary adaptation of species traits, leading to a range of ecological specialisations. In this review, we explore the ecological evidence supporting the proposition that the vertical gradient serves as an engine driving the ecology and evolution of species and shaping larger biogeographical patterns in space and time akin to elevation and latitude. Focusing on vertebrate and invertebrate taxa, we synthesised how ecological patterns within the vertical dimension shape species composition, distribution and biotic interactions. We identify three key ecological mechanisms associated with species traits that facilitate persistence within the vertical environment and draw on empirical examples from the literature to explore these processes. Looking forward, we propose that the vertical dimension provides an excellent study template to explore timely ecological and evolutionary questions. We encourage future research to also consider how the vertical dimension will influence the resilience and response of animal taxa to global change.