A study to correlate various facial landmarks with intercanine distance

Ideal interaction of dental and facial beauty proportions highly influences a harmonious facial appearance. Racial anatomical variations have been significantly noted and using these norms during prosthodontic rehabilitation will be greatly helpful in successful treatment outcome. Aim: The present study aims to correlate various facial landmarks (interpupillary distance [IPD], intercanthal width, bizygomatic width [BZW], and interalar width) with intercanine distance (ICaD) in Indian young adults to determine the mesiodistal width of the maxillary anterior teeth in edentulous patients. Setting and Design: This is an observational cross-sectional study. Materials and Methods: This study was conducted in 500 individuals ranging in age from 18 to 28 years. IPD, intercanthal width, BZW, and interalar width were measured with a digital caliper (accuracy - 0.01 mm). A “T-” shaped flat metal plate called “canine tip marker” was made to mark the tips of the maxillary canines, which were further measured with the digital caliper. The data were summarized in table form and were statistically analyzed. Statistical Analysis Used: Student's t-test and ANOVA test were used. Results: A significant correlation (P < 0.001) was found between these landmarks with ICaD, in which interalar width shows highest degree of correlation (r = 0.639). ANOVA test showed that maximum number of individuals had < 5% variability range between actual values and calculated values of ICaD for all extraoral facial landmarks except intercanthal width. Conclusion: Combination of various facial and oral factors should be considered while selecting artificial teeth. Regression equations obtained can be well used during teeth selection to achieve a significant result.

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.

Distância interpupilar e convergência na população présbita / Interpupillary distance and convergence in the presbyopic population

Objetivo:Determinar as medidas da distância interpupilar (DIP) e convergência ocular na população présbita com pupilômetro de reflexo corneano.Métodos:Cento e sessenta pacientes, com idades entre 41 e 85 anos, sendo 66 do sexo masculino e 94 do sexo feminino, foram avaliados com medida da DIP longe e de perto com PRC.Resultados:A média da idade foi de 55,9 ± 11,5 anos, com DIP média de 65,02 ± 2,78 e 62,47 ± 3,15mm para o sexo masculino e feminino, respectivamente. A média da convergência foi de 5,00 ± 0,5mm. Houve forte correlação direta entre o aumento da DIP e a convergência.Conclusão:Este estudo sugere que a DIP média é pouco menor na população présbita feminina e que existe variação da convergência de acordo com a DIP do paciente.

Objective:To determine the measurements of interpupillary distance (IPD) and ocular convergence in the presbyopic population with corneal reflex pupillometer.Methods:160 subjects (66 males and 94 females) aged 41 to 85 years have their measurements of IPD done - far and near - by CRP method.Results:The mean age was 55.9 ± 11.5 years; the average IPD was 65.02 ± 2.78 and 62.47 ± 3.15 mm for male and female respectively. Also, the average convergence was 5.00 ± 0.5 mm. There was a strong direct correlation between the increase in IPD and convergence.Conclusions:This study suggests that the average IPD is slightly smaller in presbyopic female population, and there is variation in the convergence according to the IPD of the subject.

The Congruity between the Optical Center of Spectacles and Pupillary Center

This study was performed to survey the congruities between the optical centers and pupillary centers and to bring out the optical health in Korea. One hundred outpatient were enrolled in this study, whose visual acuities were better than 20/40 with their glasses. We investigated the difference between interpupillary and interoptical center distance, the horizontal and vertical balance of optical centers, and the relation between optical decentering and dizziness. Thirty-six percent of spectacles were revealed to have inappropriate optical centers. In 25(69%) of 36 inappropriate spectacles, the difference between interpupillary distances and interoptical distances was over 4.0mm. In 7(47%) of 15 patients who complained of dizziness, optical centers were decentered. A large number of patients were wearing the optically decentered spectacles. The patients who complain of dizziness are needed to have the position of the optical centers of their spectacles checked.

The Congruity between the Optical Center of Spectacles and Pupillary Center

This study was performed to survey the congruities between the optical centers and pupillary centers and to bring out the optical health in Korea. One hundred outpatient were enrolled in this study, whose visual acuities were better than 20/40 with their glasses. We investigated the difference between interpupillary and interoptical center distance, the horizontal and vertical balance of optical centers, and the relation between optical decentering and dizziness. Thirty-six percent of spectacles were revealed to have inappropriate optical centers. In 25(69%) of 36 inappropriate spectacles, the difference between interpupillary distances and interoptical distances was over 4.0mm. In 7(47%) of 15 patients who complained of dizziness, optical centers were decentered. A large number of patients were wearing the optically decentered spectacles. The patients who complain of dizziness are needed to have the position of the optical centers of their spectacles checked.

Clinical Evaluation of the Interpupillary Distance and the Distance Between Optical Centers in Spectacles Wearers

The authors analysed the interpupillary distance, the distance between optical centers and the distance from the upper margin of the lens to the optical center in 297 spectacles wearers. The results were as follows: 1. Among the 297 glasses wearers, myopic glasses wearers accounted for 226 persons(76.09%), and hyperopic glasses wearers for 71 persons(23.91%). 2. Among the 297 glasses wearers, the distance between optical centers coincided with the interpupillary distance in 51 persons(17.17%), and was incongruous in 246 persons(82.83%). 3. Among the 297 glasses wearers, the distance from the upper margin of the lens to the optical center was the same in both eyes in 152 persons(51.19%), and was incongruous in 145 persons(48.81%). 4. Among the 246 persons in whom the distance between optical centers of their glasses did not coincide with the interpupillary distance, the horizontal prismatic effects of both eyes overpassed the aberration of tolerance of ophthalmic dispensing in 46 persons(18.70%), and the maximum horizontal prismatic effect of one eye was 5.85 prism diopters. 5. Among the 145 persons in whom the distance from the upper margin of the lens to the optical center of their glasses did not coincide in both eyes, the vertical prismatic effects overpassed the aberration of tolerance of ophthalmic dispensing in 48 persons(33.10%), and the maximum vertical prismatic effect was 2.47 prism diopters.