Lip Thickness Research Articles

Perioral Anthropometric Indices: Its Relevance in Reconstructive Surgery

Background: The perioral region plays an important role in facial recognition, gender classification, esthetics, facial expression, speech and eating. Aim: To establish normative perioral data for South-East, Nigerian children Methods: A sample of 120 healthy subjects within the age range of 1 to 5 years were enrolled in this study. Two dimensional photographs of the face were captured non-invasively using a Nikon D 90 camera, ten perioral landmarks were identified and four indices deduced Results: It was observed that vertical mouth height index, upper lip thickness and lip index in the males showed higher values when compared to the females which indicates sexual dimorphism (P≤0.05). Most children in our cohort were classified as having a thick lip index, mouth of intermediate height in relation to the height of the face, thick upper and lower lip thickness index, narrow mouth in relation to the width of the eyes. The mean values of Vermillion height of Lower lip and Lower Lip Thickness Index was also observed to be consistently higher when compared to upper lip in both sexes. Conclusion: The study presents a primary data base for perioral anthropometric indices of children in South-East Nigerian which can aid ethnic specific postoperative evaluation of congenital or post-traumatic orofacial reconstructive surgeries.

Reconstruction of Macrocheilia on the Lower Lip Through Bilateral Limited Excision and a Stepwise Single-Stage Approach (BLESS).

The surgical management of macrocheilia secondary to port-wine stains is complicated. This study aimed to propose an innovative method for treating macrocheilia on the lower lip. Patients who underwent the reconstruction of macrocheilia on the lower lip through the innovative approach were examined. Their preoperative and postoperative standard photographs were taken to evaluate the changes in lip length and thickness. The scores on Vancouver scar scale (VSS) and visual analog scale (VAS) were evaluated. Thirty-two patients who underwent the reconstruction of macrocheilia were examined. A follow-up of 12.2 months (6-36 months) was conducted. The lower lip contour and the mentolabial groove were reconstructed to normal appearance. The lip length was shortened from 5.38 ± 0.49 cm pretreatment to 4.59 ± 0.30 cm posttreatment (p = .016). The exposed vermilion was shortened from 2.05 ± 0.48 cm to 1.26 ± 0.12 cm posttreatment (p < .01). The mean VSS and VAS scores were 2.2 ± 1.5 and 8.4 ± 1.3, respectively. The bilateral limited excision and stepwise single-stage approach were safe and effective for reconstructing prominent macrocheilia on the lower lip. The technique was also easy to command for the beginners.

Relationship of Nasolabial Angle with Maxillary Incisor Proclination and Upper Lip Thickness in North Indian Population.

The aim of the study was to evaluate the relationship between nasolabial angle (NLA) with maxillary incisor proclination (U1-NA) and upper lip thickness (ULT). Pretreatment lateral cephalometric radiographs of 120 patients were taken, and NLA, U1-NA, and basic ULT measurements were obtained for each patient. Descriptive statistics were calculated for all the variables involved in the study. The correlation was found using the Pearson correlation coefficient (r) test. p < 0.01 was considered statistically significant. The mean values of NLA, upper incisor proclination, and ULT were found to be 91.38° ± 7.10°, 34.21° + 5.17°, and 15.38 ± 1.76 mm, respectively. r (r = -0.583) was found between NLA and upper incisor proclination and (r = -0.040) for NLA and ULT. There is a statistically significant relationship between NLA and U1-NA. Garg H, Khundrakpam D, Saini V, et al. Relationship of Nasolabial Angle with Maxillary Incisor Proclination and Upper Lip Thickness in North Indian Population. Int J Clin Pediatr Dent 2022;15(5):489-492.

Experimental and numerical investigations on the unsteady flow and film cooling characteristics of the trailing edge cutback

The film cooling characteristics of the trailing edge cutback slot of a high pressure turbine were experimentally and numerically investigated. The unsteady flows have an important effect on the mixing process of the mainstream and coolant flow, resulting in deteriorated film performance. To illustrate the interaction between the unsteady flows and coolant injection, eight blowing ratios ranging from 0.3 to 1.2 were considered for the baseline cases. Pressure sensitive paint measurements were conducted to acquire the adiabatic film cooling effectiveness distribution. The counter-intuitive decrease of the film cooling effectiveness was confirmed and further revealed. Particle image velocimetry showed that the unsteady flow patterns downstream of the trailing edge slot varied with increasing blowing ratio. Furthermore, the high-fidelity RANS/LES hybrid method was employed to resolve the detailed flow fields. The numerical method was carefully validated, and it successfully predicted the unsteady flows and mixing process. The spanwise vorticity showed that the two branches of the shedding vortices alternatively become strong. At the blowing ratio of 0.75, the strength of the two branches was comparative, yielding the worst cooling performance. Additionally, the density ratio and lip thickness to slot height ratio were investigated. Thus, the density ratio affects the coolant velocity ratio, causing the forward movement of the inflection point of the film cooling effectiveness map. The decrease of the lip thickness to slot height ratio leads to the reduction of the strength of the shedding vortices and therefore increases the film cooling effectiveness.

Effect of varying velocity ratio and separation distance on thin lip coaxial jet

Purpose In comparison to a nozzle with a larger/finite separation distance (Thanigaiarasu et al., 2019), a thin-lip nozzle (Srinivasarao et al., 2017) minimizes drag. Coaxial nozzles with thin lips are an appropriate tool for studying high subsonic jets because it does not create a dominant re-circulation zone. This study aims to analyze the characteristic of separation distances, between primary and secondary nozzles, within the range of 0.7–3.2 mm which can be considered a thin lip. Design/methodology/approach A separation distance of 0.7 (Papamoschou, 2004), 1.7 and 2.65 mm (Lovaraju and Rathakrishnan, 2011) is considered for the present study. The main nozzle exit Mach number is maintained at a subsonic condition of Mach 0.6, and the co-flowing nozzle exit Mach number is varied from 0% (secondary jet stopped/single jet) to 100% (Mach 0.6) in steps of 20% with respect to the main nozzle exit Mach number. A comparison was made between these velocity ratios for all three lip thicknesses in the present study. Design mesh and analysis were done by using Gambit 2.6.4 and Fluent 6.12. Velocity contours and turbulence contours were studied for qualitative analysis. Findings When lip thickness increases from 0.7 to 2.65 mm, the potential core length (PCL) of the primary jet decreases marginally. Additionally, the PCL of the primary jet elongates significantly as the velocity ratio increases. The primary shear layer is dominant at 20% co-flow (20 PCF), less dominant at 60% co-flow (60 PCF) and almost disappeared at 100% co-flow (100 PCF). Concurrently, the secondary shear layer almost disappeared in 20 PCF, dominant in 60 PCF and more dominant in 100 PCF. Different zones such as initial merging, intermediate and fully merged zones are quantitatively and qualitatively analyzed. Practical implications Co-flow nozzle is used in turbofan engine exhaust. The scaled-down model of a turbofan engine has been analyzed. Core length is directly proportional to the jet noise. The PCL signifies the jet noise reduction in a high-speed jet. For a low-velocity ratio, the potential core is reduced and hence can reduce the jet noise. At the same time, as the velocity ratio increases, the mass flow rate of the coaxial increases. The increase in the mass flow increases the thrust of the engine. The aircraft engine designer should analyze the requirement of the aircraft and choose the optimal velocity ratio coaxial nozzle for the engine exhaust (Papamoschou, 2004). Originality/value There have been many research studies carried out previously at various lip thickness such as 0.4 (Georgiadis, 2003), 0.7 (Papamoschou, 2004), 1.5 (Srinivasarao et al., 2014a), 1.7 (Sharma et al., 2008), 2 (Naren, Thanigaiarasu and Rathakrishnan, 2016), 2.65 (Lovaraju and Rathakrishnan, 2011), 3 (Inturiet al., 2022) and 3.2 mm (Perumal et al., 2020). However, there is no proper study to vary the lip thickness in this range from 0.7 to 3.2 mm to understand the flow behavior of a co-flowing jet.

Influence of Lip Appearances and Tooth Shade on Smile Attractiveness Perception.

This study determined the effect of lip thickness, lipstick color, and tooth shade on the smile attractiveness perceptions of dentists, laypersons, dental students, and other faculty students. A set of 27 smile photographs was prepared with different lip thicknesses (Tk, thick; M, medium; and Tn, thin), lipstick shade (R, red; P, pink; and O, orange), and tooth shades (0M1, 0M3, and A1). A total of 212 Thai participants in four rater groups (dentists, laypersons, dental students, and other faculty students) rated smile attractiveness using a visual analog scale (VAS). Statistical analyses were performed using the Kruskal-Wallis test and pairwise analysis at a 0.05% level of significance. Tk or M lip thickness was associated with more smile attractiveness than Th lip thickness. The R lipstick is more attractive than the P and O lipsticks. The 0M1 tooth shade appeared to be the most attractive for laypersons and other faculty students, whereas tooth shades (0M1, 0M3, or A1) did not influence the smile attractiveness perception of dentists and dental students. The smile attractiveness perception was influenced by the lip appearance and tooth shade for each rater group, which are essential for an attractive smile design.

Analysis of Smile Characteristics of Adult Female Subjects with Skeletal Class II Division 2 Malocclusion

Aim: The objective of this study was to evaluate the smile characteristics of adult females with Angle Class II division 2 malocclusion compared to Angle Class I malocclusion. Materials and Methods: Two frontal photographs were taken for 30 orthodontically untreated female adult subjects with age range (18-30) years, at rest and posed smile from a fixed (1.5m) distance between the camera and the subjects. The 30 subjects were divided into 2 groups, 15 for Class II div 2 subjects and 15 for Class I subjects. The camera was focused only on the mouth, showing from the nose to the chin. Included in the capture area frame, an L shaped ruler with millimeter markings mounted on an adjustable tripod on the right side of the patient which was used to standardize the capture area. The photographs were exported to a computer, and uploaded to Adobe Photoshop CS2 where 13 soft tissue land marks were analyzed. Results: comparison between 13 soft tissue land marks for Class II div2 females and Class I females showed significant difference in lower facial height , lower lip thickness, lower lip length , maxillary incisal display, smile height and smile arch. And showed insignificant difference in rest of the measured parameters Conclusions: Angle’s Class II div.2 female subjects have significant lower mean values of the lower facial height, lower lip length, lower lip thickness than Class I female subjects. They also have significant shorter smile height. Incisor display than Class I female subjects. A higher percentage of non-consonant smile arcs were found among Class II division 2 females and it was found to be statistically significant between both groups.

Effect of bypass ratio on sonic underexpanded co-flow jets with finite lip thickness

Abstract The characteristics of a sonic under-expanded coaxial jet with lip thickness 1.5D p (where D p is the exit diameter of primary jet equals 10 mm) with the primary jet operating at nozzle pressure ratio (NPR) of 3, 4 and 5. For NPR 3 operating primary jet, the secondary jet operates at NPR 2.5, 1.4 and 1.27. For primary jet NPR 4, the secondary jet operating NPR is 3.2, 1.6 and 1.4. For NPR 5 primary jet, the secondary jet NPR is 3.8, 1.89 and 1.52. The study is performed using a co-flow nozzle of bypass ratio (BR) 6.4, 1.4 and 0.7. The core length of the primary jet is used as a measure to quantify the mixing of the primary jet in the presence of coaxial jet. The shock structure present in the near field was viewed using shadowgraph technique. Centreline pitot pressure distribution, radial spread and waves present in the jet core were analyzed. The results show that the mixing associated with the high bypass coaxial jet is superior to the low bypass coaxial jet. This mixing superiority associated with high bypass coaxial jet prevails all levels of expansion.

Hispanic adolescent lip response to extraction and nonextraction orthodontic treatment

In orthodontics, treatment aims to improve the patient's occlusion and overall facial appearance. Extraction of 4 first premolars may improve the occlusion, but it may negatively impact a patient's facial harmony and create a "dished-in" appearance. Although many studies in orthodontic literature reviewed Caucasian patient soft-tissue change throughout extraction treatment, there is a void in the literature regarding Hispanic patients, who have different soft-tissue characteristics and may respond differently to extraction therapy. This study aimed to determine the influence of first premolar extractions on soft-tissue profile in Hispanic adolescents and whether there is a correlation between pretreatment lip strain and lip movement throughout treatment. Lateral cephalograms and study models of 60 Hispanic patients were evaluated at pretreatment and posttreatment stages. Patients were divided into nonextraction and extraction groups and further subdivided on the basis of pretreatment lip strain. Cephalometric analyses were compared between the groups and subgroups, and a correlation analysis was conducted. There was a significant difference in lip position change between nonextraction and extraction groups. There was a significant increase in upper vermillion lip thickness in the extraction group. There was no significant difference in lip position change between the minimal and moderate-severe lip strain extraction groups. There was no significant correlation between pretreatment crowding or lip strain and lip position change. Hispanic patients' lips may retract less than Caucasian patients' lips in response to extraction treatment. Pretreatment lip strain and crowding may have less effect on retrusive lip movement than in Caucasian patients.

A CBCT Evaluation of Esthetic Preference Regarding the Perceived Facial Attractiveness of Young Korean Female Adults with a Normal Skeletal Pattern.

The aim of this study was to determine the factors that affect esthetic preference regarding the perceived facial attractiveness of young Korean female adults with a normal skeletal pattern using cone-beam computed tomography (CBCT). After reorienting the CBCT images of 40 young Korean female adults, three-dimensional (3D) measurements were analyzed, and five 3D facial images were digitally constructed. A computer-based questionnaire was used to determine perceived facial attractiveness by scoring from 1 (very unattractive) to 10 (very attractive). Esthetic perception and the most influential facial view and component were examined and compared by orthodontists, general dentists, and laypeople to evaluate facial attractiveness. Compared to the unattractive group, the attractive group had significantly greater values for Pog-NB, L1SI-FH, U lip thickness, L lip-U lip, and Nasolabial angle, along with significantly lower values for U1SI-FH and Cant of U lip; the attractive group also had a more retruded U1MP (p < 0.01), L1MP (p < 0.01), U lip (p < 0.05), and L lip (p < 0.01) relative to N, as well as a more retruded U lip (p < 0.05) and L lip (p <0.001) relative to esthetic lines. Orthodontists and general dentists were more likely to consider the profile view. When evaluating facial attractiveness, orthodontists and laypeople more often focused on the lips and chin. When evaluating facial attractiveness, all evaluators showed a high esthetic preference for retroclination and retrusion of the incisors and lips, but there were some differences in how they perceived facial attractiveness. Therefore, the ultimate perception of facial attractiveness needs to be based on the esthetic perceptions of laypeople.

Cephalometric norms in coastal Odisha children

To establish cephalometric norms (skeletal and dental) for Coastal Odisha population of India and to compare it with other Caucasian norms.The Lateral cephalograms of 60 children of 9-16 year age group with normal occlusion and pleasant profile were taken and cephalometric norms were established using Down’s, Steiner’s, Tweeds, Wits, Bjork, Jarabak, McNamara, Ricketts and Schwarz analysis.The study concluded that Overall dimension of cranial base, maxilla and mandible are smaller in Coastal Odia children than that of Caucasians. Odia children are having more proclined upper and lower incisors and smaller upper and lower dental height in anterior and posterior region, steeper mandibular plane angle, greater upper and lower lip prominence but lesser upper lip thickness and strain than Caucasian population.

The Impact of The Labial Flange and Artificial Teeth on Lip Support in Elderly Patients with Maxillary Complete Dentures

Both maxillary complete denture’s labial flange and anterior artificial teeth play important roles in re-establish major support for the upper lip of elderly patients. However, whether the labial flange can be removed and still perceived as aesthetic remain unclear. Objective: To determine the perception of young adults toward the effect of a labial flange and anterior teeth on lip support of an elderly with maxillary complete dentures. Methods: A total of 64 young adults were recruited to evaluate the lip support for facial aesthetics of 30 full-face photographs in 3 different states: with an original complete denture (CD), with a flangeless duplicated denture and without the complete denture. They were rated using a Visual Numerical Scale (VNS) of 10, with 1 being the least attractive and 10 being the most attractive and repeated twice in random order. Soft-tissue profile analysis was performed to determine which facial anatomical landmarks were most important for lip support and aesthetics. Results: The overall VNS rating with CD (6.33 ± 0.58) was significantly higher (p &lt; 0.001) than images with flangeless (5.58 ± 1.01) or without CD (5.23 ± 1.30). The landmarks that showed the most significant changes were in the subnasale area and NLA with original CD (p=0.060, p=0.072) and in frontal lip thickness with flangeless (p=0.082). There are strong correlations between subnasale and NLA and the mean total aesthetic VNS rating of images with CD, but not statistically significant (r=0.708; p=0.118, r=-0.835; p=0.078). Conclusion: The labial flange of a maxillary complete denture plays an important role in lip support and results in the aesthetic perception of the dentures wearer. The anterior teeth alone provide fullness to the lips, but not enough for labial support.

A Retrospective Study Comparing Nose, Lip, and Chin Morphology in Class I, Class II, and Class III Skeletal Relationships in Patients Visiting to the Department of Orthodontics, BPKIHS: A Cephalometric Study.

Background With the changing paradigm from primarily hard tissue to soft tissue evaluation for orthodontic diagnosis and treatment planning, the priority has shifted to bring about improvement in the profile and smile characteristics of patients. Since not only the esthetics but also the stability of orthodontic treatment is largely determined by the soft tissue envelope, proper positioning of the soft tissue drape becomes paramount. Soft tissues of face, namely, nose, lips, and chin, are of paramount importance not only from an esthetic but also from functional and treatment stability points. Objective To determine the morphological variation of lips, nose, and chin in different skeletal malocclusions. Materials and Methods Lateral cephalograms of 237 patients visiting the department of orthodontics, BPKIHS, were taken, hand traced on matt acetate tracing paper of 0.002″ thickness with 0.3-mm 2B pencil. Samples were divided into 3 skeletal classes based on ANB angle. Measurements were made in relation to the nose, lips, and chin. Data were inserted in to SPSS and analyzed statistically using descriptive statistics, and mean and standard deviation was calculated for each variable. Multiple comparison between groups was done with post hoc Bonferroni test with mean difference significant at p < 0.05. Result On intergroup comparison, a significant difference was found for upper lip thickness (ULT) between Class II and Class III, and lower lip length (LLL) between Class I and Class III, and between Class II and Class III. Significant difference for nasolabial angle (NLA) was found between Class II and Class III. Similarly, a significant difference for the vertical chin parameter (CTV) was found between Class I and Class III, and between Class II and Class III. Conclusion Both upper and lower lip thicknesses were highest for Class III followed by Class I and Class II, respectively. Lip lengths too were found to be highest for Class III skeletal relation. Nasolabial angle was larger in Class II malocclusion when compared to Class I and Class III. Similarly, both nasal length and nasal height measurements were in the order of Class III > Class II > Class I. Both horizontal and vertical chin parameters were larger for Class III sagittal relation.

Inward turning base-bleed technique for base drag reduction

AbstractThis paper consists of CFD and experimental study for shell projectile at angle of attack 00 and at various Mach numbers (0.7, 0.9, 1.0, 1.5 and 2.0), without spin effect. Passive method of base modification is used to reduce base drag. The goal of this study is to reduce base drag by utilising a base bleed approach called the Inward Turning Base Bleed Method (IWTB). The concept of IWTB is to draw relatively high-pressure air behind the driving band and allow it to pass through the bleed holes and direct it into the low-pressure base. This will in turn raise the base pressure and lower the base drag. The study comprises of (i) basic model with a boattail angle of $8^{\circ}$ , (ii) eight different cavity models having different lip thickness and depth thickness ratios and (iii) nine different IWTB configurations for the optimised cavity model. At first, cavity model is optimised by varying the lip thickness and depth thickness ratio. Later IWTB parameters such as the bleed hole entry angles $10^{\circ}$ , $12^{\circ}$ &amp; $15^{\circ}$ , exit bleed hole angles $30^{\circ}$ , $45^{\circ}$ &amp; $60^{\circ}$ , bleed hole diameters 3mm, 4mm, 5mm &amp; 6mm and number of bleed holes i.e., 4 &amp; 8 were studied and optimised. Based on this study, the model with 8 holes, 3mm base bleed hole diameter, $15^{\circ}$ entry and $60^{\circ}$ exit angle gives comparatively lower base drag. CFD result shows, in supersonic region the base drag reduction for optimised shell projectile is $3.08\%$ ; at Mach number 0.9 the base reduction is $75.63\%$ ; and in subsonic region it reduces to $23.53\%$ . CFD results were compared with experimental result, is found to be good and the differences lies within $3.85\%$ .

Effect of lip thickness and competency on soft-tissue changes

Improvement in facial esthetics is a major reason for seeking orthodontic treatment. Soft tissues responsible for esthetics show a variable response to the movement of underlying teeth during orthodontics. The purpose of this cross-sectional study was to analyze the response of soft tissues and compare it among groups presenting with different lip thickness and competence. It was carried out on 37 patients with Class I and Class II Division 1 malocclusion who had undergone extractions of maxillary first premolars and had completed their orthodontic treatment. Data were obtained by corresponding lateral cephalometric radiographs taken before and at the end of orthodontic treatment. Association was analyzed with a Pearson correlation test. Differences among groups exhibiting varying competency and lip thickness were tested with an independent sample t test. A P value of≤0.05 was considered statistically significant. Pearson correlation revealed significant associations among incisor tip retraction with lip base retraction (r= 0.68), lip base thinning (r= 0.41) and vermilion retraction (UV) (r= 0.73). Regression analysis showed a moderate increase in lip length (AB) and thickness at vermilion, which were 0.11 mm and 0.15 mm for each mm of incisor retraction at the tip, whereas stronger effects were observed for UV (0.38 mm) and lip base retraction (0.55 mm). There was significantly more lip base thinning (P= 0.03) and UV (P= 0.04) in the incompetent group compared with the competent group. The AB increased significantly in the sample with thicker lips (P= 0.01). Pearson correlation coefficient showed a strong association of lip retraction at the base and vermilion with the incisor movement at the cervical area, for competent and incompetent lips, and thicker and thinner lips. Lip retraction at vermilion and lip base thinning was significantly more in patients with incompetent lips, whereas the AB increased significantly more in the group with thicker lips.

Cephalometric analysis of upper lip thickness as a critical aid in formulating a treatment plan in skeletal Class I malocclusion in adults

It is very crucial to understand that both soft tissue drape and the underlying skeletal malocclusion, are sometimes overlooked and this could be misleading for diagnosis and treatment planning .Therefore a sound knowledge of underlying malocclusion and CTP (cephalometric treatment planning) along with accurate clinical examination can aid in better diagnosis and treatment planning. The objective of this study is to understand that soft tissue drape and underlying skeletal malocclusion in Angle’s class I malocclusion could be misleading in treatment planning and therefore to perform necessary cephalometric hard and soft tissue analysis. Lateral cephalograms were obtained in NHP (Natural head position) position of size (20×25cm) FUJIFILM and lateral cephalograms were obtained on radiographic films. Evaluation of lateral cephalograms and the above mentioned parameters were traced and assessed by manual tracing of 150 lateral cephalogram was done using tracing papers with the help of tracing backlight box .Tracing was done with lead pencil point (0.3 mm HB). 150 patient of central Indian population with Angle’s class I malocclusion full permanent dentition between ages 18-45 years were included. Out of these 150 patients 75 males and 75 females patients are included in the study. Upper lip anterior and lip angle shows moderate positive correlation with W angle. The key ridge shows a strong positive correlation with W angle. The upper lip thickness can be used as a treatment plan predictor in Angle’s class I malocclusion as it is strong correlated with W angle. Soft tissue drape especially the upper lip thickness is an essential parameter along with identification of underlying skeletal malocclusion with cephalometric treatment planning measurement like W angle, for treatment planning of even a simple Angle’s class I malocclusion case.

Experimental and numerical studies of co-flowing jets with finite lip thickness and varying bypass ratio

ABSTRACT The study aims the effect of finite lip thickness and bypass ratio on subsonic and correctly expanded sonic co-flowing jet. The co-flowing jets characteristics were studied for two different lip thicknesses at subsonic Mach 0.6, 0.8, and sonic Mach 1.0 by varying the bypass ratio also the co-flowing jet area. The lip thickness considered for the study case is 1.0Dp and 1.5Dp (Dp – primary nozzle diameter is 10 mm). For experimental setup, the co-flowing duct area was varied the secondary inlet with 4 mm and 5 mm holes. Axial Pitot static tube survey was conducted experimentally. The numerical simulations were also carried by commercial code FLUENT- 6.3.2 for solving the RANS equations using Spalart–Allmaras turbulence model. The flow field has been visualised using numerical contours. The results indicate that for lip thickness 1.0Dp and for low bypass ratio, potential core seems to be thicker. Similar behaviour is observed in 1.5Dp lip thickness. On the other side, for both the lip thickness, 1.0Dp and1.5Dp, as the bypass ratio increases a recirculation zone occurs in the near field region and it becomes dominant. For bypass ratio 6.4 and 1.0Dp lip thickness, the recirculation zone exhibits an outer and an inner vortex.

The influence of mandibular divergence on facial soft tissue thickness in class I patients: a cephalometric study.

The aims of this study were to evaluate the association between mandibular divergence and facial soft tissue thickness (FSTT) measured at different profile levels, and the gender difference in FSTT. Lateral cephalograms were used to examine nine linear distances: the glabella area (G-G1), nasal (N-N1) and subnasal area (A-Sn), upper (Sd-Ls) and lower lip thickness (Id-Li), mentolabial sulcus (B-Sm), chin area (Pg-Pg1), gnathion area (Gn-Gn1) and menton area (Me-Me1) in 155 adult Caucasian subjects (79 males, 76 females) from the central Balkan area. Subjects were divided into three groups according to the ANB angle, Wit's appraisal and SN/GoGn angle into normodivergent (28 male, 27 female subjects), hypodivergent (26 males, 25 females) and hyperdivergent (25 males, 24 females). Progressive decreasing in the soft tissue thickness from hypo- towards hyperdivergent group was established in N-N1, A-Sn, Gn-Gn1, Me-Me1. There are significant differences in Gn-Gn1 and Me-Me1 (p < 0.02). Progressive increasing of FSTT happens only at the level of mentolabial sulcus and these differences are significant. Significant gender differences were established for the following distances: N-N1 in hyperdivergent, A-Sn in all three examined groups, the upper lip thickness in normo- and hyperdivergent, the lower lip thickness in hypodivergent, the thickness of mentolabial sulcus in hypo- and normodivergent, Pg-Pg1 in hyperdivergent and Me-Me1 in normodivergent subjects (p < 0.05). Facial soft tissue thickness showed a various degree of dependence on vertical developmental pattern at different levels of measurement. The areas whose thickness is significantly conditioned by this pattern were established: the chin area at level Gn-Gn1, Me-Me1 and the region of the mentolabial sulcus (B-Sm). At most levels, male subjects have thicker soft tissues and these differences are significant for all three groups in the subnasal area.

Conformity between Pacifier Design and Palate Shape in Preterm and Term Infants Considering Age-Specific Palate Size, Facial Profile and Lip Thickness.

This retrospective case-control study is the first to examine the spatial conformity between pacifiers and palates in 39 preterm infants (12 females, 27 males) and 34 term infants (19 females, 15 males), taking into account the facial-soft-tissue profile and thickness. The shape of 74 available pacifiers was spatially matched to the palate, and conformity was examined using width, height, and length measurements. In summary, the size concept of pacifiers is highly variable and does not follow a growth pattern, like infant palates do. Pacifiers are too undersized in width, length, and height to physiologically fit the palate structures from 0 to 14 months of age. There are two exceptions, but only for premature palates: the palatal depth index at 9–11 months of age, which has no clinical meaning, and the nipple length at <37 weeks of age, which bears a resemblance to the maternal nipple during non-nutritive sucking. It can be concluded that the age-size concept of the studied pacifiers does not correspond to any natural growth pattern. Physiologically aligned, pacifiers do not achieve the age-specific dimensions of the palate. The effects attributed to the products on oral health in term infants cannot be supposed.

Lip thickness effect on high bypass co-flowing jet mixing

PurposeThe purpose of this study is to analyse numerically and experimentally the effects of lip thickness (LT) and bypass ratio on co-flowing nozzle under subsonic and correctly expanded sonic jet decay at different Mach numbers.Design/methodology/approachCo-flowing jets from co-flowing nozzles of different LTs, 0.2, 1 and 1.5 Dp (where Dp is the primary nozzle exit diameter = 10 mm), with an annular gap of 10 mm at main jet exit Mach numbers 0.6 have been studied experimentally and the other cases have been performed numerically. The co-flowing jet with 2 mm LT was used for comparison.FindingsCo-flowing jet axial pitot pressure decay, axial static pressure decay, axial velocity decay, radial velocity decay and streamline velocity contours were analyzed. The results illustrate that the mixing of the co-flowing jet with profound LT is prevalent to the co-flowing jet with 2 mm LT, at all Mach numbers of the current study. Also, the LT of the co-flowing jet has a strong impact on jet mixing. Co-flowing jets with 10 mm and 15 mm LT with a constant co-flow width of 10 mm experience a considerably advanced mixing than co-flowing jets with 2 mm LT and a co-flow width of 10 mm.Practical implicationsThe application of bypassed co-flow jet is in turbofan engine operates efficiently in modern civil aircraft.Originality/valueAll subsonic jets are considered correctly expanded with negligible variation in axial static pressure. However, in the present study, static pressure along the centerline varies sinusoidally up to 9% and 12% above and below atmospheric pressure, respectively, for primary jet exit Mach number 1.0. The sinusoidal variation is less for primary jet exit Mach numbers 0.6 and 0.8 in static pressure decay.