Comparative assessment of growth performance, heat resistance and carcass traits in four poultry genotypes reared in hot-humid tropical environment.

This study investigated the impact of heat stress on growth and carcass traits in four poultry genotypes-Giriraja, Country chicken, Naked Neck and Kadaknath reared in a hot and humid tropical environment. Birds from all genotypes had ad libitum access to feed and water while being challenged with consistently high environmental temperatures in the experimental shed. Daily diurnal meteorological data were recorded inside and outside the shed. The study specifically examined growth variables and carcass characteristics. Significant differences (p < 0.01) were observed in body weight and average daily gain at various intervals. Notably, feed intake showed significant differences (p < 0.01) across weeks, indicating interactions between genotypes and time intervals. The feed conversion ratio (FCR) varied significantly (p < 0.01), with the highest FCR recorded in the Kadaknath breed. Livability percentages were similar across groups, except for Giriraja, which had significantly lower livability (p < 0.01). Carcass traits, including dressing, wings, feathers and giblet percentages, showed significant differences among genotypes (p < 0.01). Hepatic mRNA expression of growth-related genes revealed numerical variations, with Naked Neck displaying the highest (p < 0.05) fold change in IGF-1 expression compared to other genotypes. The study recognized in the Naked Neck genotype to possess higher resilience in maintaining homoeostasis and uncompromised growth under heat stress, providing valuable insights for sustainable poultry farming in challenging environmental conditions.

Comparative evaluation of frictional characteristics between nano coated and non coated orthodontic brackets and arch wire configuration-An experimental in vitro study.

OBJECTIVE: To compare and assess the coefficient of frictional resistance between nano-coated orthodontic brackets and orthodontic archwires with conventional orthodontic brackets and archwires. METHODOLOGY: In this experimental study, 128 samples were divided into 4 groups consisting of 32 orthodontic wires and brackets in each group. The samples were randomly allocated into GROUP A- ZNO nanoparticle coated archwires and brackets, GROUP B ZNO nanoparticle coated bracket and conventional archwire, GROUP C-ZNO nanoparticle coated archwire and conventional bracket, and GROUP D- conventional archwire and bracket after positioning them on special jigs frictional resistance was studied and evaluated. Bon - Ferroni test was used for inter group comparison and one way ANOVA was used for intr-group comparison. RESULTS: The lowest mean frictional resistance is seen with Group A (nanocoated archwire with nanocoated bracket) N = 0.3401 ± 0.420; and highest with Group D (conventional brackets with conventional archwires) N = 0.8413 ± 0.60. a significant difference in mean frictional resistance was observed between the groups (P ≤ 0.01). The frictional resistance for the groups was in the following order from lowest to highest: group A < B < C < D. CONCLUSION: The study showed decreased friction in ZNO nanoparticle coated archwires and brackets than conventional archwires and brackets.

An Analysis of the Stress induced in the Periodontal Ligament during Extrusion and Rotation Movements- Part II: A Comparison of Linear vs Nonlinear FEM Study.

BACKGROUND: Optimal orthodontic forces are those which stimulate tooth movement with minimal biological trauma to the tooth, periodontal ligament (PDL) during and alveolar bone. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. The mechanical behavior of the PDL is known to be nonlinear elastic and thus a nonlinear simulation of the PDL provides precision to the calculated stress values. Therefore in this study, the stress patterns in the PDL were evaluated with extrusion and rotational movements using the nonlinear finite element method (FEM). MATERIALS AND METHODS: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modelling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with nonlinear material properties. RESULTS: It was observed that with the application of extrusive load, the tensile stresses were seen at the apex whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. CONCLUSION: For rotational and extrusion movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using nonlinear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement.

An Analysis of the Stress Induced in the Periodontal Ligament during Extrusion and Rotation Movements: A Finite Element Method Linear Study Part I.

BACKGROUND: Orthodontic tooth movement occurs due to various biomechanical changes in the periodontium. Forces within the optimal range yield maximum tooth movement with minimum deleterious effects. Among various types of tooth movements, extrusion and rotational movements are seen to be associated with the least amount of root resorption and have not been studied in detail. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with extrusion and rotational movements using the finite element method FEM. MATERIALS AND METHODS: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with extrusive and rotational movements by a 3D FEM using ANSYS software with linear material properties. RESULTS: It was observed that with the application of extrusive load, the tensile stresses were seen at the apex, whereas the compressive stress was distributed at the cervical margin. With the application of rotational movements, maximum compressive stress was distributed at the apex and cervical third, whereas the tensile stress was distributed on cervical third of the PDL on the lingual surface. CONCLUSION: For extrusive movements, stress values over the periodontal ligament was within the range of optimal stress value as proposed by Lee, with a given force system by Profitt as optimum forces for orthodontic tooth movement using linear properties. During rotation there are stresses concentrated at the apex, hence due to the concentration of the compressive forces at the apex a clinician must avoid placing heavy stresses during tooth movement.

Stress Induced in Periodontal Ligament under Orthodontic Loading (Part II): A Comparison of Linear Versus Non-Linear Fem Study.

BACKGROUND: Simulation of periodontal ligament (PDL) using non-linear finite element method (FEM) analysis gives better insight into understanding of the biology of tooth movement. The stresses in the PDL were evaluated for intrusion and lingual root torque using non-linear properties. MATERIALS AND METHODS: A three-dimensional (3D) FEM model of the maxillary incisors was generated using Solidworks modeling software. Stresses in the PDL were evaluated for intrusive and lingual root torque movements by 3D FEM using ANSYS software. These stresses were compared with linear and non-linear analyses. RESULTS: For intrusive and lingual root torque movements, distribution of stress over the PDL was within the range of optimal stress value as proposed by Lee, but was exceeding the force system given by Proffit as optimum forces for orthodontic tooth movement with linear properties. When same force load was applied in non-linear analysis, stresses were more compared to linear analysis and were beyond the optimal stress range as proposed by Lee for both intrusive and lingual root torque. To get the same stress as linear analysis, iterations were done using non-linear properties and the force level was reduced. CONCLUSION: This shows that the force level required for non-linear analysis is lesser than that of linear analysis.

Stress Induced in the Periodontal Ligament under Orthodontic Loading (Part I): A Finite Element Method Study Using Linear Analysis.

BACKGROUND: Orthodontic tooth movement is a complex procedure that occurs due to various biomechanical changes in the periodontium. Optimal orthodontic forces yield maximum tooth movement whereas if the forces fall beyond the optimal threshold it can cause deleterious effects. Among various types of tooth movements intrusion and lingual root torque are associated with causing root resoprtion, especially with the incisors. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with intrusion and lingual root torque using finite element method (FEM). MATERIALS AND METHODS: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with intrusive and lingual root torque movements by a 3D FEM using ANSYS software using linear stress analysis. RESULTS: It was observed that with the application of intrusive load compressive stresses were distributed at the apex whereas tensile stress was seen at the cervical margin. With the application of lingual root torque maximum compressive stress was distributed at the apex and tensile stress was distributed throughout the PDL. CONCLUSION: For intrusive and lingual root torque movements stress values over the PDL was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using linear properties.

Traumatic impact loading on human maxillary incisor: A Dynamic finite element analysis.

BACKGROUND: The most vulnerable tooth is the maxillary incisor, which sustains 80% of dental injuries. Dynamic Finite element analysis is used to understand the biomechanics of fracture of maxillary incisor under traumatic impact loading. AIM: The aim was to investigate the stress patterns of an upper incisor in a three-dimensional (3D) model under traumatic impact loading in various directions. MATERIALS AND METHODS: A 3D finite element model of the upper incisor and surrounding tissues was established. A sinusoidal force of 800N was applied over a period of 4 ms. RESULTS: Software performs a series of calculations and mathematical equations and yields the simulation results. During the horizontal impact (F1), stresses were concentrated in the cervical area of the crown, reaching peak stress of 125 MPa at 2 ms. CONCLUSION: A horizontal force exerted on the labial surface of the tooth tends to cause cervical crown fractures, oblique crown root fractures, and oblique root fractures.

An experimental study of arch perimeter and arch width increase with mandibular expansion: a finite element method.

AIMS: The objective of this study was to estimate the increase in arch perimeter associated with mandibular lateral expansion, To estimate the increase in intermolar width with mandibular lateral expansion and to find out the changes of tooth inclination with mandibular expansion. MATERIALS AND METHODS: The mandibular bone with dentition of indian skeletal specimen was obtained. The computer tomogram (CT) slices of the mandible were taken. Finite element model (FEM): Numerical representation of the geometry was created by dividing the geometry into finite number of elements and the elements were connected together with nodes at the junction. RESULTS: The result of the study showed when 10° of lateral expansion was applied to the lower buccal segment at the center of rotation found at 4.3 mm below the root apex of first molar, a space of 1.3 mm between the canine and first premolar, and thus an increase in arch perimeter of 2.6 mm. CONCLUSION: The tip of the mesiolingual cusp of the first molar moved 4.2 mm laterally, resulting in a change in intermolar width by 8.4 mm. Three-dimensional simulation showed that 1 mm of intermolar expansion increased the arch perimeter by 0.30 mm. CLINICAL SIGNIFICANCE: As the finite element method evolves and scientists are able to more clearly define physical properties of biological tissues, more accurate information can be generated at the level that other analytical methods cannot fully provide data.This result would be of value clinically for prediction of the effects of mandibular expansion.

An esthetic treatment outcome of orthognathic surgery and dentofacial orthopedics in class II treatment: a cephalometric study.

AIM: The main objective of any orthodontic treatment is to achieve well-established stable occlusal relationship with a definite positive change in facial profile. The purpose of this study was to determine, if such a goal is achievable for patients who could be classified as borderline surgical cases without the invasive use of the actual surgery or, with the use of the recently developed and rapidly spreading fixed functional appliance system (Forsus) and a comparison of the esthetic treatment outcome with the two systems. MATERIALS AND METHODS: Twelve postadolescent borderline skeletal class II patients with a deficient mandible. All the patients used in the study were treated by a preadjusted edgewise appliance for presurgical decompensation with or without extractions and for postsurgical finishing and detailing. Out of the 12 patients six were treated with bilateral saggital split osteotomy (BSSO) and six were treated with fixed functional appliance (Forsus). RESULTS: The results suggested that although surgical patients had a better mandibular advancement, profile reduction, and marked improvements in soft tissue structures, the patients who had undergone fixed functional therapy also had comparable improvement in the above aspects. In the maxilla there was no change in cases treated with surgery but in case of Forsus some retraction of anterior dental segment was evident. CONCLUSION: In surgical group, class II malocclusion correction was more skeletal than dental, whereas in functional group class II malocclusion correction was more dental than skeletal. CLINICAL SIGNIFICANCE: Looking at the common surgical risks, cost-effective and postsurgical problems and patients with borderline class II malocclusion, fixed functional therapy is a valuable adjunct in the management of class II malocclusion.

Identification of individuals using palatal rugae: Computerized method.

UNLABELLED: Identification of individuals is a challenging task in forensic odontology. In circumstances where identification of an individual by fingerprint or dental record comparison is difficult, the palatal rugae may be considered as an alternative source. Palatal rugae have been shown to be highly individualistic and it maintains consistency in shape throughout life. AIMS AND OBJECTIVES: The present study is conducted to test the efficiency of computerized software in the identification of individuals after obtaining digital photographic images of the rugae. MATERIALS AND METHODS: The intra oral photographs of 100 individuals were taken using a SLR digital camera. The custom made external attachment was attached to the camera to standardize all the photographs. A special software was designed called the Palatal Rugae Comparison Software (PRCS Version 2.0) to match the clinical photographs. Five evaluators including 3 dentists, 1 computer professional, and 1 general surgeon were asked to match the rugae pattern using the software. The results were recorded along with time taken by each operator to match all the photos using software. RESULTS: The software recorded an accuracy of 99% in identification of individuals. CONCLUSION: The present study supports the fact of individuality of the rugae. Computerized method has given very good results to support the individualization of rugae. Through our study, we feel that palatal rugae patterns will be of great use in the future of forensic odontology.