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Aims of the Study: The aims of the study are: (a) to compare the perceptions of dental specialists and laypeople regarding smile esthetics; (b) to compare male and female smile parameters; (c) to find influence of smile parameters on esthetics of smile. Materials and Methods: The study was conducted on 60 subjects (30 males and 30 females) of age 18 to 25 years. Frontal posed photographs of all subjects were taken using a digital camera and rated on a visual analog scale by 10 dental specialists and 10 laypersons. Measurements made on photographs were used to analyze various parameters of smile, such as buccal corridor space, smile arc, modified smile index, anterior height of smile, most posterior maxillary tooth visible, and midline relationship of central incisors to philtrum. Results: Visual analog scale values showed that 6 photographs were rated as very good (3 males, 3 females), 29 as good (11 males, 18 females), 21 as average (13 males, 8 females), and 4 photographs were rated as bad (3 males, 1 female). A high correlation was observed between ratings of dental specialists and layperson’s ratings for both male and female smiles. Most of the subjects had non-consonant smile arc, and a high correlation was found between buccal corridor space on right and left sides in both males and females. Most of the male and female smiles had an average anterior height of smile; permanent maxillary first molar was the last tooth visible during smile (73.3% females, 66.7 males); and 55% subjects had coincident midline relationship of central incisors to philtrum. Conclusion: There was no significant difference in perception of dental specialists and laypersons regarding esthetics of smile. Smile arc and anterior height of smile influenced the esthetics of smile. No significant difference was found between male and female smile parameters except modified smile index.

Over the last few decades, medical-assisted robots have been considered by many researchers, within the research domain of robotics. In this article, a 5-degrees-of-freedom spatial medical manipulator is analyzed for path planning, based on inverse kinematic solutions. Analytical methods have generally employed for finding the inverse kinematic solutions in earlier studies. However, this method is only appreciable in case of closed-form solutions. The unusual joint configurations of considered manipulator result in more complexity to attain the closed-form solutions, analytically. To overcome with shortcomings of analytical method, a non-traditional approach named adaptive neuro-fuzzy inference system is proposed under the class of artificial intelligent techniques. This article presents this neuro-fuzzy approach for desired path generation by 5-degrees-of-freedom manipulator. The estimation of percentage error between actual path and adaptive neuro-fuzzy inference system–generated path is done with respect to x, y, and z directions, respectively. Furthermore, the error between actual and predicted values regarding joint parameters is calculated for a certain arm matrix. The prototype of 5-degrees-of-freedom medical-assisted manipulator is developed at CSIR-CSIO Laboratory Chandigarh, which is also termed as patient-side manipulator to be utilized in robot-assisted surgery. Through the simulation runs, in this work, it is found that the results from adaptive neuro-fuzzy inference system approach are quite satisfactory and acceptable.

The prime objective of this work is to deal with the kinematics of spatial hybrid manipulators. In this direction, in 1955, Denavit and Hartenberg proposed a consistent and concise method, known as D-H parameters method, to deal with kinematics of open serial chains. From literature review, it is found that D-H parameter method is widely used to model manipulators consisting of lower pairs. However, the method leads to ambiguities when applied to closed-loop, tree-like and hybrid manipulators. Furthermore, in the dearth of any direct method to model closed-loop, tree-like and hybrid manipulators, revisions of this method have been proposed from time-to-time by different researchers. One such kind of revision using the concept of dummy frames has successfully been proposed and implemented by the authors on spatial hybrid manipulators. In that work, authors have addressed the orientational inconsistency of the D-H parameter method, restricted to body-attached frames only. In the current work, the condition of body-attached frames is relaxed and spatial frame attachment is considered to derive the kinematic model of a 7-degree of freedom spatial hybrid robotic arm, along with the development of closed-loop constraints. The validation of the new kinematic model has been performed with the help of a prototype of this 7-degree of freedom arm, which is being developed at Council of Scientific & Industrial Research–Central Scientific Instruments Organisation Chandigarh to aid the surgeon during a medical surgical task. Furthermore, the developed kinematic model is used to develop the first column of the Jacobian matrix, which helps in providing the estimate of the tip velocity of the 7-degree of freedom manipulator when the first joint velocity is known.

The main focus of this work is to extend the applicability of D-H parameter method to develop a kinematic model of a hybrid manipulator. A hybrid manipulator is a combination of open- and closed-loop chains and contains planar and spatial links. It has been found in the literature that D-H parameter method leads to ambiguities, when dealing with closed-loop chains. In this work, it has been observed that the D-H parameter method, when applied to a hybrid manipulator, results in an orientational inconsistency, because of which the method cannot be used to develop the kinematic model. In this article, the concept of dummy frames is proposed to resolve the orientational inconsistency and to develop the kinematic model of a hybrid manipulator. Moreover, the prototype of 7-degree-of-freedom hybrid manipulator, known as a surgeon-side manipulator to assist the surgeon during a medical surgery, is also developed to validate the kinematic model derived in this work.