Comparison of interpupillary distance and combined mesiodistal width of maxillary central incisor teeth in two ethnic groups of Northeast India: An in vivo study

Anthropometric measurements of the face can be used as a guide in selecting proper sized anterior teeth. Aim: The aim of this study is to evaluate the relationship between the interpupillary distance (IPD) and the combined mesiodistal width of maxillary central incisors (MDW of MCIs) to establish their morphometric criterion and their significance in two ethnic groups of Northeast India. Methodology: A total of 120 participants consisting of 60 indigenous students each from Assam and Meghalaya in the age group of 18–25 years were selected after taking their written consent. Standardized facial frontal photographs of all the participants were taken using a digital camera in such a manner that maxillary anterior teeth were visible. The photographs were uploaded onto the computer and saved in a file. Anthropometric measurements of IPD and combined MDW of MCIs in centimeters were made using both Adobe Photoshop® 7.0 software program and manually using a digital vernier caliper on the developed photographs to a same size of 15 cm × 10 cm. Data obtained were tabulated and analyzed using Student ”t”-test and Pearson correlation test. Results: The present study reveals a positive correlation with a high degree of statistical significance between IPD and combined mesiodistal width of maxillary central incisors among all the samples irrespective of gender and ethnicity where P < 0.01. Conclusion: IPD can be used as a guide in determining the suitable mesiodistal dimension of the maxillary central incisors.

Evaluation of validity of cone beam CT (CBCT) measurements compared to direct method on human dry mandibles

Introduction: Cone beam computed tomography (CBCT) has its wide range of uses in dentistry most commonly as an aid in preoperative planning of dental implant treatment. However, in order to determine the best application of CBCT in dentistry, it is necessary to analyze the accuracy of data obtained related to distance measurements. The present in-vitro study was undertaken to evaluate the accuracy of radiographic linear measurements on CBCT images by comparing them to direct measurements in human dry mandibles. Materials and methods: Ten human dentulous dry mandibles were selected for the study. Four anatomical sites (Site A, B, C, and D) with two anatomical reference points for each site were selected on dry mandibles for measurement. The reference points were made as 3 mm depressions on the mandible with Marathon micromotor hand piece and diamond bur. These depressions were filled by guttapercha. All the selected mandibles were scanned using Sorodex Cranex 3Dx CBCT Machine. After the CBCT scan was obtained, the direct measurements at each site were recorded using digital vernier calipers with an accuracy of 0.01mm. Results: Comparison of CBCT measurements with direct measurements at 4 anatomical sites revealed no statistical difference (p value >0.05). Correlation of CBCT measurements with direct measurements revealed strong correlation at site site A (0.965), site B (r=0.899), D (r=0.975) and moderate correlation at site C (r=0.571). Conclusion: According to present study, CBCT technique can be recommended for linear measurements in the mandible.

Morphometry of the Orbital Region: "Beauty Is Bought By Judgment Of The Eyes.

Objective: This study aimed to assess the orbital index which varies with race, regions, within the same race and periods in evolution. The knowledge of this index is therefore important in various aspects such as in interpretation of fossil records, skull classification in forensic medicine and in exploring the trends in evolutionary and ethnic differences. The documented ranges of this index in different nationalistic groups will assist in skull identification. Method: Sixty eight skulls were obtained from the Anatomy Department of University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi for the present study. To prevent interobserver and intraobserver error two individuals measured the parameters independently with predetermined procedures. Vernier calipers accurate to 0.1mm and a 30mm ruler were used to measure the width and height of the orbits and a tapeline was used to measure the length and width of the skull. Result: The mean orbital height was found to be 33.47 ±1.56mm and 33.65 ±1.53mm whereas the mean orbital width was 42.06 ±1.68mm and 41.87 ±1.73mm on the right and left sides respectively. The mean orbital index was 79.65 ±4.02mm and 80.49 ±4.67mm on right and left sides respectively. The mean width of the skull was 128.71±5.94mm whereas the mean height of skull was 130.96 ± 4.07mm. Data obtained was statistically analyzed. Conclusion: Comparison of results from previous studies makes it evident that there is a large variation of the anatomical characteristics of the orbital cavity, not only due to the diversity of the used parameters, but also due to ethnic differences, the different measurement method and sample size. Data collected in the present investigation could serve as data base for the quantitative description of human orbital morphology during normal growth and development considering sex and ethnic related variation.

Morphometry of Human Fetal Ear Ossicles: A Human Cadaveric Study.

Aim: Most of the studies were on adult ossicles. In this present work, the aim is to study the morphometry of the ear ossicles in the human fetuses and use of the study in medical applications. Materials and Methods: This study is performed on 100 sets of middle ear ossicles, each set consisting of Malleus, Incus and Stapes, which were taken from 50 fetal cadavers left and right sides of both. Result: The morphometric data of malleus and incus in their length are 5.21mm and 4.85mm, the height of the stapes is 2.52mm. The indices of malleus, incus and stapes are 51.28, 67.54 and 88.12mm. Conclusion: The study of morphometry in the ear ossicles of the human fetal cadavers can be useful for prosthetic surgical reconstruction.