Interalar Width Research Articles

Regression methods to investigate the relationship between facial measurements and widths of the maxillary anterior teeth

In rehabilitating edentulous patients, selecting appropriately sized teeth in the absence of preextraction records is problematic. The purpose of this study was to investigate the relationships between some facial dimensions and widths of the maxillary anterior teeth to potentially provide a guide for tooth selection. Sixty full dentate Malaysian adults (18-36 years) representing 2 ethnic groups (Malay and Chinese), with well aligned maxillary anterior teeth and minimal attrition, participated in this study. Standardized digital images of the face, viewed frontally, were recorded. Using image analyzing software, the images were used to determine the interpupillary distance (IPD), inner canthal distance (ICD), and interalar width (IA). Widths of the 6 maxillary anterior teeth were measured directly from casts of the subjects using digital calipers. Regression analyses were conducted to measure the strength of the associations between the variables (alpha=.10). The means (standard deviations) of IPD, IA, and ICD of the subjects were 62.28 (2.47), 39.36 (3.12), and 34.36 (2.15) mm, respectively. The mesiodistal diameters of the maxillary central incisors, lateral incisors, and canines were 8.54 (0.50), 7.09 (0.48), and 7.94 (0.40) mm, respectively. The width of the central incisors was highly correlated to the IPD (r=0.99), while the widths of the lateral incisors and canines were highly correlated to a combination of IPD and IA (r=0.99 and 0.94, respectively). Using regression methods, the widths of the anterior teeth within the population tested may be predicted by a combination of the facial dimensions studied.

Quantitative use of photography in orthognathic outcome assessment

This study reports an independent audit of two aspects of orthognathic surgery, namely control of inter-alar width and mandibular outline asymmetry. Measurements were taken from standardized photographs of a consecutive series of 27 patients, using an on-screen digitizing program (IPTool). All patients had undergone bimaxillary osteotomies involving maxillary impaction and/or advancement, by one surgeon, using a cinch suture for nasal width control. Nine–twelve months after surgery, inter-alar width had increased by just 0.08 cm mean (SD 0.3). Four patients showed an increase of just over 2 mm, whilst six showed a small reduction. Based on ratios of size (area) and shape (compactness) of the right and left mandibular segments, there was a small overall improvement in mandibular symmetry (0.019 and 0.005 respectively). Whilst in most of the patients the need for surgery was primarily the correction of antero-posterior and vertical discrepancies, five patients with demonstrable asymmetry showed a clear improvement. In three patients whose asymmetry scores were very mild pre-treatment, there was a small, measured increase in asymmetry, but not to a degree that would be clinically noticeable. At a time when 3D imaging is still unavailable to many clinicians, the results of this study suggest that appropriate measurements taken from carefully standardized conventional photographs can provide a valid and objective means of assessing treatment outcome.

Correlation between Facial Measurements and the Mesiodistal Width of the Maxillary Anterior Teeth

One of the most difficult aspects during the selection of maxillary anterior teeth for a removable prosthesis is determining the appropriate mesiodistal width of the six maxillary anterior teeth. Many attempts have been made to establish methods of estimating the combined width of these anterior teeth, and improving the esthetic outcome. The proportion of facial structures and the relationship between facial measurements and natural teeth could be used as a guide in selecting denture teeth. The aim of this study was to verify the relation between the combined mesiodistal width of the six maxillary anterior teeth and the facial segments: the width of the eyes, the inner canthal distance (ICD), the interpupillary distance (IPD), the interalar width, and the intercommissural width (ICm). Standardized digital images of 81 dentate Brazilian subjects were used to measure both facial and oral segments when viewed from the frontal aspect through an image processing program. To measure the distance between the upper canines on a curve, accurate casts were made from the upper right first premolar to the upper left first premolar. The Spearman rank correlation coefficient was conducted to measure the strength of the associations between the variables (alpha = 0.05). The results showed a significant correlation between all facial elements and the combined mesiodistal width of the six teeth, when observed from the frontal aspect. The ICD, IPD, and ICm showed the highest probability of being correlated to the mesiodistal width of the teeth (p = 0.000). This article considers facial analysis with digital photography as a practical and efficient application to select the mesiodistal width of artificial anterior teeth in an esthetically pleasing and natural appearance during an oral rehabilitation treatment.

Relationship between the Widths of Maxillary Anterior Teeth, Interalar Width and Inner Canthal Distance

Relationship between the Widths of Maxillary Anterior Teeth, Interalar Width and Inner Canthal Distance

Quantitative Assessment of Nasal Changes After Maxillomandibular Surgery Using a 3-Dimensional Digital Imaging System

To evaluate nasal changes after maxillomandibular surgery by means of images taken with a 3-dimensional digital camera. Thirty-two patients (26 female and 6 male) with preoperative and postoperative 3-dimensional photographs were studied. The patients underwent maxillary movement with impaction (upward rotation), maxillary movement with lengthening (downward rotation), or maxillary movement without rotation. With the 3-dimensional imaging software, preoperative and postoperative calculations were performed for interalar width, internostril width, nasal tip projection, and columellar length from the 3-dimensional digital images. The nasolabial angle was also measured. Postoperative interalar and internostril widening was significant (P<.05) for all 3 categories of maxillary movement. However, there was no statistically significant change in nasal tip projection and columellar length. Interestingly, movement of the maxilla with upward rotation did show a statistically significant decrease in the nasolabial angle. Changes to the nose clearly occur after orthognathic surgery. There was a statistically significant increase in postoperative interalar width and internostril width with maxillary movement. However, no clear correlation could be determined between amount of change and maxillary movement. Interestingly, maxillary advancement did not show any significant change in nasal tip projection or columellar length, with data showing both increases and decreases in measurements. The nasolabial angle in patients who underwent maxillary advancement with impaction (upward rotation) was the only measurement that showed a statistically significant increase.

An analysis of maxillary anterior teeth: Facial and dental proportions

The size and form of the maxillary anterior teeth are important in achieving pleasing dental and facial esthetics. However, little scientific data have been defined as criteria for evaluating these morphological features. This study analyzed the clinical crown dimensions of maxillary anterior teeth to determine whether consistent relationships exist between tooth width and several facial measurements in a subset of the Turkish population. Full-face and anterior tooth images of 100 Turkish dental students viewed from the front and engaged in maximum smiling were recorded with digital photography under standardized conditions. Gypsum casts of the maxillary arches of the subjects were also made. The dimensions of the anterior teeth, the occurrence of the golden ratio, the difference between the actual and perceived sizes, and the relationship between the anterior teeth and several facial measurements by gender were analyzed using the information obtained from both the computer images and the casts. One-sample, 2-sample, and paired t tests, and repeated-measures analysis of variance and Duncan multiple-range tests were performed to analyze the data (alpha=.05). The dimensions of the central incisors (P<.05) and canines (P<.01) varied by gender. The existence of the so-called "golden proportion" for the maxillary anterior teeth as a whole was not found. Significant differences emerged when the mean ratios between various perceived widths were compared with their ideal golden ratios (P<.01). Proportional relationships between the bizygomatic width and the width of the central incisor, and the intercanine distance and the interalar width in women were observed. The maxillary central incisor and canine dimensions of men were greater than those of women in the Turkish population studied, with the canines showing the greatest gender variation. Neither a golden proportion nor any other recurrent proportion for all anterior teeth was determined. Bizygomatic width and interalar width may serve as references for establishing the ideal width of the maxillary anterior teeth, particularly in women.

Nasal airway changes after Le Fort I—impaction and advancement: anatomical and functional findings

Abstract.Twenty patients were studied prospectively to assess intranasal anatomical changes and functional changes resulting from a one-piece Le Fort I-osteotomy with anterior and superior positioning of the maxilla. Presurgical and 3 months postsurgical rhinological inspection, anterior rhinomanometry and acoustic rhinometry were performed. Interalar width was measured and cephalograms were used to assess maxillary movement. Rhinoscopically, three septal perforations (15%) were noticed. Turbinate enlargement was less common postoperatively. Interalar width increased significantly. These findings correlate with a significant increase in cross-sectional diameter at the Isthmus nasi revealed by acoustic rhinometry 3 months postoperatively. The mean total nasal airflow measured by anterior rhinomanometry was unchanged indicating no increase in resistance despite decreased intranasal dimensions in cases where the impaction is not higher than 5mm.

A comparison of interalar width and intercanine distance in Malay males and females

The interalar width of the nose and the intercanine distance were measured in 266 Malay subjects (111 males and 155 females) randomly selected from the students of the School of Medical Sciences. University Sains Malaysia in Kota Bharu, Malaysia. The mean interalar width of the nose in male subjects was 39.8 +/- 2.3 mm (range 34-45 mm) and in female subjects 36.2 mm +/- 2.2 mm (range 30-41 mm). There is a statistically significant difference (t = 12.9: p < 0.05) in the nasal width between male and female Malay subjects. This agrees with the findings of other similar studies that males have wider noses than females. The mean maxillary intercanine distance in male subjects was 36.7 = 2.6 mm (range 30-42 mm) and in female subjects 36.2 = 2.3 mm (range 30-42 mm). The anterior maxillary arch is significantly wider in Malay subjects compared to Chinese from Singapore (Keng 1986) as p < 0.05 and to Caucasians (Sawiris 1977) as p < 0.05. There is a significant correlation (r = 0.312; p < 0.05) between the nasal width and the intercanine distance in female subjects but not in male subjects.

The relationship between the width of the mouth, interalar width, bizygomatic width, and interpupillary distance in edentulous patients

The width of the mouth, interalar width, bizygomatic width, and interpupillary distance were measured in edentulous patients. The widths varied widely, even when the population was separated into groups by sex and/or race. When mean values were studied, black men differed significantly from black women, white women, and white men in interalar and bizygomatic widths; white women differed from the other groups in all widths. No correlation was found between the widths for the population as a whole, nor when the population was further divided into race, sex, or group. When artificial teeth were chosen for eight randomly selected patients using a method recommended for each of the widths, the same mold was dictated by two methods for seven patients, and by three methods for five patients.

Interalar width as a guide in denture tooth selection

This study was undertaken to determine the relationship of the IAW, measured between at the widest dimension of the alae of the nose, and two other measurements of maxillary anterior teeth. The other measurements, both of which are significant in the selection and arrangement of artificial teeth used in complete dentures, were the ICTW and the ARCD measured from the distal surface of the maxillary canine on one side of the arch to the distal surface of the canine on the opposite side of the arch. No distinction was made between either the sex or the age of the subjects. The mean ICTW of 35.35 mm was 3% greater than the mean IAW of 34.28 mm. The mean ARCD of 44.85 mm was 31% greater than the mean IAW of 34.28 mm. This mean ARCD compares favorably (<1 mm difference) with a constructed ARCD of 45.8 mm from a tooth dimension study by Shillingburg et al. 8 The ARCD was 44.85 mm. This measurement had not been made in the previous study examining the relationship of interalar distance to ICTW. When the IAW was plotted against the intercanine cusp tip width, a fairly strong correlation coefficient of 0.413 was exhibited. A weaker but definite correlation coefficient of 0.217 was observed when the interalar width plotted against the circumferential arc distance from distal surface to distal surface of the maxillary canines.

A clinical evaluation of techniques to determine the combined width of the maxillary anterior teeth and the maxillary central incisor

In this study, techniques to determine the combined width of the maxillary anterior teeth and the maxillary central incisor widths were evaluated. Measurements were obtained from the dental casts of 45 men and 45 women and related to their intercommissural width, interalar width, bizygomatic width, sagittal cranial diameter, interbuccal frenum distance, philtrum width, and age. Correlation coefficients were calculated for all relationships.

The value of the nose width as an esthetic guide in prosthodontics

A radiographic method was used to measure the interalar and interalar-fold widths of the nose on 80 men and women. These distances were compared to the subjects' intercanine distances as measure on artificial stone casts. In 56 of the subjects, the width of the skeletal nasal aperture was measured and compared to the intercanine distance. From the results of this study, the following conclusions can be drawn. 1. There was no significant relationship between the intercanine distance and the interalar width of the nose in the 80 men and women who served as subjects in this study. 2. There was no significant relationship between the intercanine distance and the interalar-fold width of the nose in the 80 men and women in this study. 3. The presence or absence of a significant relationship between the intercanine distance and the width of the skeletal nasal aperture was not demonstrated conclusively in this study. 4. The results of this study show that the width of the nose would not be a reliable guide for selecting or arranging artificial anterior teeth, provided one concurs that they should be the same size and shape and occupy the same position as their natural predecessors.