Comparison of Spectral Analysis of Gamma Band Activity During Actual and Imagined Movements as a Cognitive Tool.

Background. Imagined motor movement is a cognitive process in which a subject imagines a movement without doing it, which activates similar brain regions as during actual motor movement. Brain gamma band activity (GBA) is linked to cognitive functions such as perception, attention, memory, awareness, synaptic plasticity, motor control, and Imagination. Motor imagery can be used in sports to improve performance, raising the possibility of using it as a rehabilitation method through brain plasticity through mirror neurons. Method. A comparative observational study was conducted on 56 healthy male subjects after obtaining clearance from the Ethics Committee. EEG recordings for GBA were taken for resting, real, and imaginary motor movements and compared. The power spectrum of gamma waves was analyzed using the Kruskal-Wallis test; a p-value <.05 was considered significant. Results. The brain gamma rhythm amplitude was statistically increased during both actual and imaginary motor movement compared to baseline (resting stage) in most of the regions of the brain except the occipital region. There was no significant difference in GBA between real and imaginary movements. Conclusions. Increased gamma rhythm amplitude during both actual and imaginary motor movement than baseline (resting stage) indicating raised brain cognitive activity during both types of movements. There was no potential difference between real and imaginary movements suggesting that the real movement can be replaced by the imaginary movement to enhance work performance through mirror therapy.

Immunological Responses of Arsenicum album 30CH to Combat COVID-19: Protocol for a Double-Blind, Randomized, Placebo-Controlled Clinical Trial in the Pathanamthitta District of Kerala.

BACKGROUND: COVID-19 is a recent major public health concern caused by the SARS-CoV-2 virus, with approximately 44.6 million COVID-19-positive cases and 530,000 deaths in India (as of February 1, 2023). The COVID-19 vaccination drive in India was initiated in January 2021; however, an effective preventive strategy with high efficacy and immunological safety remains elusive. OBJECTIVE: The aim of this study is to assess the immunogenic responses of Arsenicum album 30CH (AA30CH) as COVID-19 prophylaxis, including assessment of immunological markers, innate and acquired immune responses, COVID-19 symptoms, and its associated antibody responses. METHODS: This randomized controlled clinical trial (RCT) will include two parallel comparator groups of AA30CH and placebo with an allocation ratio of 1:1 conducted in the Pathanamthitta district of Kerala, India. The placebo or AA30CH will be administered in three intervention schedules and blood samples will be collected before and after each of the intervention schedules. Based on the inclusion and exclusion criteria, 112 participants per arm (with an expected dropout of 20%) will be screened. Immunogenic responses will be evaluated by determining the antigen density and modulation in immunological markers and lymphocyte subsets CD3, CD4, CD8, CD24, CD27, CD38, CD4 interferon-γ, CD4 CD17, CD4 CD25 (activated T lymphocytes), T cells, B cells, dendritic cells (mature and immature), and natural killer cells on days 1, 5, 23,27, 45, 49, and 66. The innate and acquired immune responses will also be evaluated by a real-time reverse-transcriptase polymerase chain reaction (RT-PCR) array profiler (84-gene set) before and after the study interventions. The toxicity status of AA30CH in study participants will be evaluated through hepatic, renal, and hematological parameters and peripheral smears on days 1, 5, 23, 27, 45, 49, and 66. The number of participants developing COVID-19-like symptoms per National Centre for Disease Control guidelines and the number of participants testing positive for COVID-19 in RT-PCR during follow-ups in any of the three intervention schedules will be identified. Moreover, a subgroup analysis will be used to assess the COVID-19 antibody responses between vaccinated and unvaccinated participants. RESULTS: This RCT protocol has been approved by various committees and funded by the Central Council for Research in Homoeopathy, Ministry of Ayush, Government of India. The project has been implemented in collaboration with the Department of Homoeopathy, Government of Kerala. The RCT was rolled out on January 25, 2023, and enrollment was completed April 3, 2023. The immunological assays will be conducted at the Department of Biotechnology-Translational Health Science and Technology Institute, Faridabad, India. CONCLUSIONS: This study will represent the first evaluation of the immunological efficacy and safety of AA30CH in an RCT, which may significantly impact the use of homeopathy as an evidence-based medicine approach. TRIAL REGISTRATION: Clinical Trials Registry-India CTRI/2022/08/045089; https://tinyurl.com/mryrpkvk. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48479.

Gold Nanorod-Induced Effects in a Mesogenic Compound 4-(trans-4-n-Hexylcyclohexyl) isothiocyanatobenzene.

Gold nanorods (GNRs) have a capsule-like structure with different optical properties than spherical gold nanoparticles due to surface plasmon resonance. Liquid crystals (LCs) are mesogenic compounds having crystal-like orientation and liquid-like fluidity. They are important materials from a technological point of view. Both GNRs and LC compounds are anisotropic in shape and properties. Different nano entities show interesting results when dispersed in different liquid crystalline materials which are instrumental from the application point of view. In the present work, GNRs have been dispersed in nematic liquid crystalline materials, namely 4-(trans-4-n-hexylcyclohexyl) isothiocyanatobenzene (6CHBT). Calorimetric, texture, spectroscopic, and dielectric studies were carried out for a pure 6CHBT and its composites with GNRs. Different calorimetric and dielectric parameters such as transition temperature, enthalpy, heat flow, permittivity, dielectric strength, dielectric anisotropy, and relaxation frequency have been determined, and the effect of GNRs has been explored. This article gives an insight into the influence of GNRs on the morphology and anisotropic physical properties of the nematic liquid crystalline material.

CHSI costing study-Challenges and solutions for cost data collection in private hospitals in India.

INTRODUCTION: Ayushman Bharat Pradhan Mantri Jan Aarogya Yojana (AB PM-JAY) has enabled the Government of India to become a strategic purchaser of health care services from private providers. To generate base cost evidence for evidence-based policymaking the Costing of Health Services in India (CHSI) study was commissioned in 2018 for the price setting of health benefit packages. This paper reports the findings of a process evaluation of the cost data collection in the private hospitals. METHODS: The process evaluation of health system costing in private hospitals was an exploratory survey with mixed methods (quantitative and qualitative). We used three approaches-an online survey using a semi-structured questionnaire, in-depth interviews, and a review of monitoring data. The process of data collection was assessed in terms of time taken for different aspects, resources used, level and nature of difficulty encountered, challenges and solutions. RESULTS: The mean time taken for data collection in a private hospital was 9.31 (± 1.0) person months including time for obtaining permissions, actual data collection and entry, and addressing queries for data completeness and quality. The longest time was taken to collect data on human resources (30%), while it took the least time for collecting information on building and space (5%). On a scale of 1 (lowest) to 10 (highest) difficulty levels, the data on human resources was the most difficult to collect. This included data on salaries (8), time allocation (5.5) and leaves (5). DISCUSSION: Cost data from private hospitals is crucial for mixed health systems. Developing formal mechanisms of cost accounting data and data sharing as pre-requisites for empanelment under a national insurance scheme can significantly ease the process of cost data collection.

Cost of Surgical Care at Public Sector District Hospitals in India: Implications for Universal Health Coverage and Publicly Financed Health Insurance Schemes.

BACKGROUND: In low- and middle-income countries (LMICs), provisioning for surgical care is a public health priority. Ayushman Bharat Pradhan Mantri-Jan Aarogya Yojana (AB PM-JAY) is India's largest national insurance scheme providing free surgical and medical care. In this paper, we present the costs of surgical health benefit packages (HBPs) for secondary care in public district hospitals. METHODS: The costs were estimated using mixed (top-down and bottom-up) micro-costing methods. In phase II of the Costing of Health Services in India (CHSI) study, data were collected from a sample of 27 district hospitals from nine states of India. The district hospitals were selected using stratified random sampling based on the district's composite development score. We estimated unit costs for individual services-outpatient (OP) visit, per bed-day in inpatient (IP) and intensive care unit (ICU) stays, and surgical procedures. Together, this was used to estimate the cost of 250 AB PM-JAY HBPs. RESULTS: At the current level of utilization, the mean cost per OP consultation varied from US$4.10 to US$2.60 among different surgical specialities. The mean unit cost per IP bed-day ranged from US$13.40 to US$35.60. For the ICU, the mean unit cost per bed-day was US$74. Further, the unit cost of HBPs varied from US$564 for bone tumour excision to US$49 for lid tear repair. CONCLUSIONS: Data on the cost of delivering surgical care at the level of district hospitals is of critical value for evidence-based policymaking, price-setting for surgical care and planning to strengthen the availability of high quality and cost-effective surgical care in district hospitals.

Baseline Assessment of Evidence-Based Intrapartum Care Practices in Medical Schools in 3 States in India: A Mixed-Methods Study.

INTRODUCTION: Implementation research with pre- and post-comparison was planned to improve the quality of evidence-based intrapartum care services in Indian medical schools. We present the baseline study results to assess the status of adherence to intrapartum evidence-based practices (IP-EBP) in study schools in 3 states in India and the perception of the faculty. METHODS: A concurrent mixed-methods approach was used to conduct the baseline assessment in 9 medical schools in Rajasthan, Gujarat, and Union Territory from October 2018 to June 2019. IP-EBP among pregnant women in uncomplicated first (n=135), second (n=120), and third stage (n=120) of labor were observed using a predesigned, pretested checklist quantitatively. We conducted in-depth interviews with 33 obstetrics and gynecology faculty to understand their perceptions of intrapartum practices. Quantitative data were analyzed using SPSS (version 22). COM-B (Capability, Opportunity, and Motivation Behavior) model was used to understand the behaviors, and thematic analysis was done for the qualitative data. FINDINGS: Unindicated augmentation of labor was done in 64.4%, fundal pressure applied in 50.8%, episiotomy done in 58.3%, and delivery in lithotomy position was performed in 86.7% of women in labor. CONCLUSIONS: Intrapartum practices that are not recommended were routinely practiced in the study medical schools due to a lack of staff awareness of evidence-based practices and incorrect beliefs about their impact.

RAPIDIRON: Reducing Anaemia in Pregnancy in India-a 3-arm, randomized-controlled trial comparing the effectiveness of oral iron with single-dose intravenous iron in the treatment of iron deficiency anaemia in pregnant women and reducing low birth weight deliveries.

BACKGROUND: Anaemia is a worldwide problem and iron deficiency is the most common cause. In pregnancy, anaemia increases the risk of adverse maternal, foetal and neonatal outcomes. India's anaemia rate is among the highest in the world with India's National Family Health Survey indicating over 50% of pregnant women were affected by anaemia. India's Anaemia Mukt Bharat-Intensified National Iron Plus Initiative aims to reduce the prevalence of anaemia among reproductive-age women, adolescents and children by 3% per year and facilitate the achievement of a Global World Health Assembly 2025 objective to achieve a 50% reduction of anaemia among women of reproductive age. However, preliminary results of the NFHS-5 survey completed in 2020 indicate that anaemia rates are increasing in some states and these targets are unlikely to be achieved. With oral iron being the first-line treatment for iron deficiency anaemia (IDA) in pregnancy, these results are likely to be impacted by the side effects, poor adherence to tablet ingestion and low therapeutic impact of oral iron. These reports suggest a new approach to treating IDA, specifically the importance of single-dose intravenous iron infusions, may be the key to India effectively reaching its targets for anaemia reduction. METHODS: This 3-arm, randomized controlled trial is powered to report two primary outcomes. The first is to assess whether a single dose of two different intravenous formulations administered early in the second trimester of pregnancy to women with moderate IDA will result in a higher percentage of participants achieving a normal for pregnancy Hb concentration at 30-34 weeks' gestation or just prior to delivery when compared to participants taking standard doses of oral iron. The second is a clinical outcome of low birth weight (LBW) (< 2500 g), with a hypothesis that the risk of LBW delivery will be lower in the intravenous iron arms when compared to the oral iron arm. DISCUSSION: The RAPIDIRON trial will provide evidence to determine if a single-dose intravenous iron infusion is more effective and economically feasible in reducing IDA in pregnancy than the current standard of care. TRIAL REGISTRATION: Clinical Trials Registry - India CTRI/2020/09/027730. Registered on 10 September 2020, http://ctri.nic.in/Clinicaltrials/showallp.php?mid1=46801&EncHid=&userName=anemia%20in%20pregnancy.

Study of internet addiction and its association with depression and insomnia in university students.

INTRODUCTION: Use of internet has increased exponentially worldwide with prevalence of internet addiction ranging from 1.6% to 18 % or even higher. Depression and insomnia has been linked with internet addiction and overuse in several studies. AIMS AND OBJECTIVES: Present study has looked in to pattern and prevalence of internet addiction in university students. This study has also explored the association of internet addiction with depression and insomnia. MATERIAL AND METHODS: In this cross sectional study 954 subjects were enrolled who had been using internet for past 6 months. Information regarding pattern of use and socio demographic characteristics were recorded. Internet addiction Test (IAT), PHQ-9,and insomnia Severity Index (ISI) were applied to measure internet addiction, depression and insomnia respectively. RESULTS: Among 954 subjects, 518 (60.59%) were male and 376 (39.41%) were female with mean age of 23.81 (SD ± 3.72). 15.51% study subjects were internet addicts and 49.19% were over users. Several parameters including graduation level, time spent per day on line, place of internet use, smoking and alcohol had significant association with internet addiction. Internet addiction was predominantly associated with depression and insomnia. CONCLUSION: Internet addiction is a rising concern among youth. Several parameters including gender, time spent on line, alcohol, smoking predicts higher risk of internet addiction. Depression and insomnia are more common in internet addicts and overusers.

Histopathological and Immunohistochemical Findings in Congenital Pouch Colon: A Prospective Study.

BACKGROUND: There is a paucity of literature on the histopathological aspects of congenital pouch colon (CPC) and immunohistochemical (IHC) assessment has not been reported. So we planned to study the histopathological and IHC findings within the spectrum of CPC and compare the findings with the normal colon. METHODS: This is a descriptive prospective study on CPC patients. There were 49 cases of CPC (42 males and 7 females) and 13 controls. Histological examination was done using hematoxylin and eosin and Masson trichrome stain. IHC analysis was done with actin, myosin, and desmin antibodies, and neuron-specific enolase and S100 markers for counting ganglionic cells. RESULTS: Histologically, congestion, edema and hemorrhage were seen in mucosa, submucosa, and serosa. Muscle layers were disrupted and divided into bands. An additional muscle coat inside of the muscularis propria was seen in CPC types 1 and 2. Mature ganglionic cells were reduced and muscle layers showed reduced and patchy positivity for smooth muscle actin, myosin, and desmin compared to a normal colon. CONCLUSIONS: Histopathological and IHC findings suggest that CPC has distinct defects in the neuromusculature.

Haemostatic Disorder in Women with Unexplained Menorrhagia: A Tertiary Care Centre Experience from Northern India.

INTRODUCTION: Menorrhagia is a common gynaecological problem and its cause remains unexplained in a significant proportion of females. AIM: The present study was done to diagnose a wide range of haemostatic disorders which can give rise to menorrhagia in women of adolescent, postadolescent and perimenopausal age group. MATERIALS AND METHODS: A total of 1100 women presenting to gynaecological emergency with complaints of menorrhagia underwent comprehensive evaluation. After excluding local pelvic pathology and hormonal disorders as a cause of menorrhagia 104 women were included in this study. Screening investigations including bleeding time, prothrombin time, activated partial thromboplastin time, platelet count and morphology were done. The following diagnostic investigations were carried out as and when required. Platelet aggregation tests using adenosine diphosphate and ristocetin, platelets function tests, specific factor analysis as and when required. RESULTS: Age of patients ranged from 13 years to 46 years. Eighteen patients had menorrhagia since menarche. Seven patients had family history of abnormal bleeding. Twenty three patients were found to have systemic haemostatic disorder (10 patients of Von Willebrand Disease (vWD), seven of Glanzmann-Thrombasthenia, one of Bernard- Soulier syndrome and five of immune thrombocytopenic purpura). CONCLUSION: From this study it is concluded that systemic haemostatic disorders are found in substantial number of women presenting with menorrhagia. Hence, after excluding organic/hormonal cause, haemostatic disorders should be considered before taking patient for invasive surgical procedures.

Revisiting profile of deliberate self-harm at a tertiary care hospital after an interval of 10 years.

CONTEXT: Sociocultural factors complement psychopathological factors that result in deliberate self-harm (DSH). A study of change in these factors over time is essential for preventive action. AIMS: To identify factors influencing DSH, which have shown significant variation over a period of 10 years. SETTINGS AND DESIGN: Two hospital-based cross-sectional analytic types of observational studies were performed at two different times at an interval of 10 years. MATERIALS AND METHODS: Sociodemographic profile, factors related to DSH, stressful life events, and psychiatric disorders were assessed in two groups of patients drawn from the same tertiary care hospital, 100 consecutive patients in 2002 and 117 in 2012. The observations were compared to identify factors that have undergone significant change. STATISTICAL ANALYSIS: Descriptive statistics along with Chi-square test was used in this study. RESULTS: A significant decrease in the overall number of married subjects (60% vs. 43%) and an increase in the number of unmarried females (34% vs. 61%) were seen. A significant increase in the overall number of rural subjects (17% vs. 34%) and especially in a number of rural females (7% vs. 23%) was also seen. An increase in subjects from middle socioeconomic class (15% vs. 29%) and education up to secondary school (9% vs. 25%) was also seen. A significantly higher number of subjects had a psychiatric disorder (50% vs. 81%) with a significant increase in diagnoses of depression (36% vs. 67%). Family and social issues remain the most common antecedent stressful events. Chemical methods are still the most preferred means, but a higher number (8% vs. 18%) report a history of self-harm. CONCLUSION: Variations in factors responsible for DSH identified in this comparative study have preventive implications.

Comparison of pharyngeal airway dimension, tongue and hyoid bone position based on ANB angle.

OBJECTIVE: This study was undertaken to cephalometrically evaluate the pharyngeal airway dimension, tongue and hyoid position in subjects with normal nasorespiratory functions having different dentofacial patterns (A-point-nasion-B-point [ANB] >40 and ANB <40) and to find if a correlation existed. MATERIALS AND METHODS: Class I and Class II Division I patients were selected randomly. Lateral head cephalograms were taken in normal head position within a lead foil attached to the tongue tip and a barium coating on the dorsal surface of tongue. The lateral cephalograms obtained were traced using lead acetate paper and measurements were taken. Different analyses were done for the pharyngeal airways, hyoid bone, and tongue. RESULTS: The ANB angle is a significant predictor for Class I and Class II Division I malocclusion, and the mean ANB angle of Class II Division I was different and higher. The overall mean pharynx and hyoid parameters were different and lower in Class II Division I patients than in Class I patients. The mean tongue parameter almost remained the same except for the tongue position (TT-LOP), which was higher in Class II Division I. CONCLUSION: In general, there was no difference either in the pharyngeal airway anterioposterior dimension or in the position and relationship of the hyoid bone and tongue, between Class I and Class II Division I patients. These findings are consistent with the findings in studies. Anterioposterior dimension of the upper airway is usually maintained by adaptation of both the tongue and the hyoid bone. The result should be viewed in the light of the fact that only anterioposterior dimensions were taken into consideration; the vertical and transverse dimensions of these complex anatomical structures need to have newer three-dimensional (3-D) imaging technique to find if a correlation existed between them, making future studies more comprehensive.

Association of ABO blood group and breast cancer in Jodhpur.

There is a large amount of evidence that the ABO blood group system may play a role in disease etiology. However, in relation to breast cancer, these findings are inconsistent and contradictory. Present study was conducted for analysis to access ABO blood groups potential role of in breast carcinoma. The study was conducted on 206 clinically diagnosed breast cancer patients from Radiotherapy Department of Mathura Das Mathur Hospital in Jodhpur, from September 2006 to December 2007. The standard agglutination test was used to determine the blood groups. Association of ABO blood groups and risk of breast cancers was found out with Odd Ratios (ORs) with 95% Confidence Interval (CI). In reference of proportion of breast cancer in blood group AB [OR 1 with 95% CI 0.476 to 2.103), the breast carcinoma in blood group A [OR 7.444 with 95% CI 4.098 to 13.5222) was found at 7.4 times at higher risk than in blood group 'AB'. Breast cancer was found minimum in blood group 'AB' and maximum in blood group 'A'.

Controlling molecular tautomerism through supramolecular selectivity.

We have isolated the stable as well as the metastable tautomers of 1-deazapurine in the solid state by exploiting principles of supramolecular selectivity in the context of cocrystal design.

An easy entry into 2-halo-3-aryl-4(3H)-quinazoliniminium halides from heteroenyne-allenes.

An efficient three-step synthesis of 2-halo-3-aryl-4(3H)-quinazoliniminium halides from commercially available materials is described. Upon reaction with hydrogen halides, generated in situ from a Lewis acid (MX) and trace water, a variety of easily accessible heteroenyne-allenes underwent facile intramolecular cyclization to afford the title compounds in good yields. The method is highly versatile and provides a general way to construct quinazoliniminium ring systems with a variety of different substitutions.

Synthesis and antiproliferative evaluation of 5-oxo and 5-thio derivatives of 1,4-diaryl tetrazoles.

A series of 1,4-diaryl tetrazol-5-ones were synthesized by copper mediated N-arylation of 1-phenyl-1H-tetrazol-5(4H)-one with aryl boronic acids, o-R(1)C(6)H(4)B(OH)(2) where R(1)=H, OMe, Cl, CF(3), Br, CCH. The 1,4-diaryl tetrazol-5-ones substituted with OMe, Cl, CF(3), Br underwent thionation with Lawesson's reagent to yield the corresponding 5-thio derivatives. The 1-(2-bromophenyl)-4-phenyl-1H-tetrazole-5(4H)-thione so obtained was subjected to lithiation/protonation and Sonogashira coupling to produce 1,4-diphenyl-1H-tetrazole-5(4H)-thione and 1-(2-ethynylphenyl)-4-phenyl tetrazole-5-thione, respectively. The title compounds were found to be stable to strong Lewis acid conditions. Three of these novel compounds were found to inhibit L1210 leukemia cell proliferation and SK-BR-3 breast cancer cell growth over several days in culture in vitro. Shorter tetrazole derivative treatments also reduced the expression of the Ki-67 marker of cell proliferation in SK-BR-3 cells and the rate of DNA synthesis in L1210 cells.

Estimation of nickel and chromium in saliva of patients with fixed orthodontic appliances.

AIM: To examine whether orthodontic treatment induces an increase in salivary nickel and chromium concentration. METHODS: Ten new patients (7 females and 3 males) beginning fixed orthodontic treatment were included in the study. The mean age of the sample was 17.5 years (range 14 to 24 years). Three samples of stimulated saliva were collected from each orthodontic patient, 1 at each of the following times: before insertion of the fixed appliance (which served as a baseline/reference level for salivary nickel and chromium content), 1 week after insertion of the appliance, and 3 weeks after insertion of the appliance. These samples were analyzed for nickel and chromium content using the atomic absorption spectrometer and their values recorded in ng/mL. The Friedman test was used to test the statistical significance of differences in concentrations of each metal before and after insertion of orthodontic appliances. Post-hoc comparisons were performed using the Wilcoxon signed rank test and Mann-Whitney U test. RESULTS: This study showed that there was a statistically significant difference in salivary nickel and chromium concentrations before and 1 week and 3 weeks after insertion of fixed orthodontic appliances. The highest concentrations of nickel and chromium were found after 1 week. The salivary nickel and chromium concentrations tapered off 3 weeks after insertion but were significantly higher than baseline levels. CONCLUSION: The salivary nickel and chromium concentrations significantly increased after insertion of fixed orthodontic appliances as compared to baseline levels, with the maximum concentration seen in the first week after placement of fixed orthodontic appliances.

An experience of single centre at C S M Medical University, Lucknow, for the prevalence of hemophilia in Uttar Pradesh.

OBJECTIVE: To evaluate the incidence of hereditary bleeding disorders, registered at our centre from all over Uttar Pradesh over an extended period of 10 years. MATERIAL AND METHODS: A complete coagulation profile of 240 cases conducted, followed by clinical history of the patient. The frequency and type of bleeding, age of onset, treatment taken, consanguinity and the blood transfusion if any, are little information collected from the patient. RESULTS: The complete scenario of bleeders indicated maximum number (92%) of hemophilia 'A' from northern UP as compared from other zones (76.5% ± 3). Contrarily, hemophilia 'B' registered maximum from eastern zone (26%) and minimum from the northern zone (8%). The age diversity at diagnosis ranged between 1-32 years. The reasons for difference are all speculative. Definite cause needs extensive research. CONCLUSIONS: The study showed that elderly patients with hemophilia had significantly more impairments in physical functioning and depression than younger ones.

Biometric study of tooth size in normal, crowded, and spaced permanent dentitions.

INTRODUCTION: At present, there is a void in the orthodontist's armamentarium with regard to the assessment of malocclusion due, in part, to tooth size. A biometric study of tooth size was carried out to examine the extent to which tooth size contributes to dental crowding or spacing. METHODS: A sample of 240 orthodontic study casts was selected from a larger sample. These casts met the selection criteria. The sample was divided into crowded, spaced, and normal dentition groups with 80 casts in each group. The criterion of grouping was based on the tooth size-arch length discrepancy in the arch. Each group comprised 40 maxillary and 40 mandibular casts that were further divided equally by sex. The data were statistically analyzed. RESULTS: Mesiodistal crown dimensions of individual teeth, the sum of the incisors, and the sum of the canines and the premolars were uniformly larger in crowded arches than in normal and spaced dentition groups. Mesiodistal crown dimensions of individual teeth were smaller in the spaced arches compared with normal dental arches, but the difference was significant only in the combined mesiodistal crown dimensions of the mandibular incisors. Correlations of the combined mesiodistal crown dimensions of the incisors with the combined mesiodistal crown dimensions of the canines and the premolars were positive in all 3 groups. CONCLUSIONS: Mesiodistal tooth size is an important factor in the assessment of crowding or spacing and in orthodontic treatment planning.