Lip Position Research Articles

The validity of using profile predictions for class III patients planned for bimaxillary orthognathic surgery

This study assessed whether preoperative class III patients could recreate their facial difference based on a profile photograph. Twenty class III pre-surgery bimaxillary orthognathic patients used CASSOS (SoftEnable Technology Ltd.) to manipulate a distorted soft tissue image of them until they felt it resembled their current soft tissue profile. Patients were able to move their upper lip and lower chin backward and forwards, as well as the lower chin up and down. Differences in the mean absolute distance between the patient-perceived position of the upper lip (Labrale superious) and chin (Pogonion) and the actual position of their upper lip and chin were measured on two occasions. Intra-patient reproducibility was found to be excellent (ICC 0.93 to 0.98). All differences were statistically significantly greater than 3mm, and would be clinically significant. Patients were better at re-creating their AP chin position rather than their AP upper lip and vertical chin positions. Approximately half of patients undergoing surgical correction of their class III skeletal pattern were unable to correctly identify their pre-surgical facial profile. Given the lack of awareness of their profile, this questions the validity of using profile planning for informed consent.

Determinants of Upper Lip Form: An Analysis Using Geometric Morphometrics

Orthodontics and orthognathic surgery can alter an individual's facial form, and it is the clinician's goal to predictably control changes in the facial soft tissues to achieve treatment goals. Within the facial profile, controlling projection of certain structures, such as the chin, is predictable, as the soft-tissue response to hard-tissue changes in such areas is predictable. The upper lip, on the other hand, presents a different challenge. While multiple studies have shown relationships between advancement of the upper incisor and advancement of the soft-tissue lip, unlike the chin, the anterior position of the upper lip is only a small component of upper-lip profile esthetics. Given the structure of the upper lip, the angulation plays a prominent role in upper-lip profile esthetics besides just its anteroposterior projection. No direct or indirect relationships have been established between the maxillary incisal orientation and upper-lip angulation. The clinical significance in understanding the upper lip to hard-tissue relationship is to predictably control the upper-lip angulation in orthodontics and/or orthognathic surgery in patients with dentofacial deformities. In the absence of reliable data, planning often becomes overly subjective or arbitrary, which could lead to poor esthetic outcomes. To the author's knowledge, there are no studies that analyze the relationship between the hard tissues and the upper-lip angulation. This is presumably the case because of the difficulty in comparing the contours of the hard and soft tissues in these non-linear structures. Any “parallelism” cannot be reliably measured in a reliable or quantitative way using conventional cephalometric or other linear techniques.A retrospective cross-sectional study was designed to analyze cone beam computerized tomography (CBCT) scans from 104 patients, using geometric morphometrics. The contour of the hard tissue was evaluated by taking a point below anterior nasal spine (ANS) at the point of greatest convexity between ANS and maxillary alveolus, as well as the most anterior point of the maxillary alveolar bone between the central incisors. Once these points were identified, 3 semi-landmarks were taken at equidistant points between these in order to best trace the curvature of this area. For the soft-tissue analysis, subnasale and labrale superioris were identified and, once again, 3 semi-landmarks were taken at equidistant points between these landmarks to map the upper-lip curvature.The data were then compiled, giving a total of 1040 data points, 520 hard-tissue and 520 soft-tissue points. While the results of the principal components analysis and partial least squares are pending, the initial data show a positive correlation between contour of the alveolar bone and teeth and the upper-lip position and form.Based on these findings, it appears that the upper-lip contour in the dentofacial deformity patient can be predictably controlled by manipulating the position of the maxillary alveolus and incisor position via orthodontic and surgical means.

Nasolabial Angle in Profiles Perceived as Attractive: A Scoping Review

Context: The nose and lips area play an important role in facial appearance and nasolabial angle (NLA) can be considered as a determinant factor for attractiveness. The perception of beauty and attractiveness is vastly influenced by media and thus, can change with trends over time. The aim of this study was to conduct a systematic review of literature on NLA in faces perceived as attractive over time and in different ethnic groups. Evidence Acquisition: This study was performed following preferred reporting items for systematic reviews and meta-analyses extension for Scoping Reviews (PRISMA-ScR) guideline. We conducted an electronic search using PubMed, Scopus, and Embase databases with the employment of MeSH and free text terms "beauty"[MeSH], "esthetics"[MeSH], "soft tissue", "nasolabial angle", "attractive" and "cephalometric analysis". The inclusion criteria were studies that indicated facial attractiveness by a panel of at least 10 judges, evaluated the soft tissue profile characteristics, and reported the preferred NLA. Results: The search results revealed 271 related articles, of which 21 studies investigated NLA as a conducive factor in profile attractiveness and were included in the review. The range of preferred NLA was 86° to 107° for men and 84° to 123.12° for women. Conclusions: The most pleasing lip position and subsequently NLA is influenced by variables including the observer and subject’s gender, and their ethnic background as well as time. Over all, NLA in faces perceived as attractive is more obtuse in women than men. Compared to white norms, NLA is more acute among Chinese and African-Americans, while amongst Iranian women, it is not distinctly far from North American Caucasians. Over the course of time, preferred NLA has significantly changed in women but has been unwavering in men.

Identification of Orthodontic Extraction Predictors in End-On Class II Malocclusion

BJECTIVE: This study was designed to determine the different treatment predictors which help in the extraction and non-extraction decision of an end-on Class II malocclusion case. METHODOLOGY: The pretreatment records of 240 adult subjects aged 15-40 years with bilateral end-on Class II molar relationship were retrospectively selected and categorized under extraction (120) and non-extraction (120) treatment categories. The extraction cases were planned for different combinations of premolar extractions. The independent variables i.e., the cephalometric and orthodontic cast measurements were obtained from the recruited sample. Binary logistic regression analysis was applied using SPSS software. RESULTS: Increased upper and lower incisor inclinations (p < 0.001) and procumbent upper lip (p = 0.004) was statistically significant in the extraction group. According to the regression model, the odds of extraction treatment were 1.12 times greater than non-extraction treatment for every one degree increase in upper and lower incisor inclinations, respectively. The chances of extraction treatment were 1.6 times higher than non-extraction treatment for every 1 mm increase in the distance of upper lip to S-plane. CONCLUSIONS: The upper and lower incisors inclinations and upper lip position are the critical factors affecting the extraction decision in adult patients with end-on Class II molar relationships. Overjet, dental crowding and the vertical growth pattern were found to be clinically insignificant in opting for an extraction treatment plan for such cases. KEYWORDS: Treatment, Angle Class II, tooth extraction, non-extraction

Influence of lip posture and malocclusion type on incisor trauma

The aim of our study was to establish the relationship between the severity of the maxillary incisors’ trauma, the type of malocclusion and the lip posture. This retrospective descriptive survey was conducted over a period of 3 months on 54 complete orthodontic files, at the dento-facial orthopedic department of the Dental Care Center of Casablanca (CCTD). The aesthetic analysis of RICKETTS was performed on pre-treatment lateral cephalograms. The data were collected through a questionnaire containing socio-demographic variables, clinical variables related to the trauma, type of dental malocclusion and lip posture. The Chi2 test was used to evaluate the different variables, the difference was found to be significant when p ⩽ 0.05. According to our study, patients between 13 and 18 years of age appear to have an increased risk of trauma. Class II division 1 was the most frequent in the traumatized population (56%) and overjet greater than 3 mm was the most common (48%) with a highly significant difference. Lip incompetence was most frequent in the traumatized population (68%) and the reduced length of the upper lips was frequent (50%) with a significant difference. Dental trauma, especially in the anterior sector, is frequent in adolescent patients. Increased overjet and inadequate lip posture are two major risk factors for incisor trauma. Early orthodontic treatment might prevent dental trauma in these patients.

Orthodontic Assessment of Lip Prominence in Pakistani population

Introduction: Many reference planes are being used to determine prominence of upper and lower lip for orthognathic face profile. E-line and S-line are being used to determine lip position in local popuation of Multan city of Pakistan. Materials and Method: Execution of present study was done in Nishtar Institute of Dentistry, Multan during the period of November 2019-March 2020. 300 (112 Males and 188 Females) subjects were selected for this study from all provinces of Pakistan. Their radiographic records (Lateral cephalograms) were taken from radiographic department of related institution. Acetate matte sheets were used to construct reference planes by using 3H pencil. Steiner’s E-line and Rickett’s S-line were used to find Upper and Lower lip position from these reference lines. SPSS was used to analyze data after applying independent t-test. Result: Mean Upper and lower lip position from E- line was -1.74mm & -0.33mm and from S-line was 0.82mm and 1.47mm Conclusion: Cephalometric lip morphology assessment in Multan, Pakistani adults by using Steiner’s and Rickettsreference planes on lateral cephalogram is slightly different as compare to other populations

A Long-term Follow-up of Mandibular Deviation Caused by Congenital Cervical Lymphangioma Treated with an Orthodontic Approach

To report a treatment case of mandibular deviation caused by congenital cervical lymphangioma with traditional orthodontic techniques, following-up by 10-year retention. Lymphangiomas, developmental anomalies, can induce various disturbances of swallowing, mastication, speech, breathing, and skeletal deformities as well as psychological stress and anxiety for the patient and their family. Lymphangiomas are benign with virtually no possibility of turning into a malignant lesion, so clinical management aims to treat the patient functionally. A girl, aged 6 years and 4 months, complained about facial asymmetry and anterior crossbite caused by congenital cervical lymphangioma. Her facial profile was the straight type with an adequate lip position. Anterior and right-side posterior crossbites were observed. On the frontal cephalogram, the menton shifted 3.0 mm to the right. A functional appliance with an expander was placed to correct her dental midline deviation and posterior crossbite. After 2-year treatment, the anterior and right-side posterior crossbites were improved. Multibracket treatment began after the growth spurt. After 44-month active treatment, a functional occlusion, including a Class I molar relationship with a proper interincisal relationship, was achieved. A functional occlusion was maintained during a 10-year retention period, while a mandibular downward growth was observed through the retention period. Conventional orthodontic techniques enable functional and stable occlusion even in patients with mandibular deviation caused by congenital cervical lymphangioma, although only using early orthodontic management by itself may have some limitations. The hybrid technique combining functional appliance and intermaxillary elastics proves to be an effective therapy for correcting occlusal cant and mandibular deviation caused by cervical lymphangioma.

Treatment Effects and Lip Profile Changes Following Surgical Mandibular Advancement Versus Premolar Extractions in Class II Div 1 Malocclusion: A Randomized Controlled Trial.

No randomized controlled trial has compared the treatment outcome between surgical mandibular advancement and premolar extractions in class II malocclusion. This 2-arm parallel randomized controlled trial evaluated the treatment effects and lip profile changes in skeletal class II adult patients subjected to bilateral sagittal split ramus osteotomy for mandibular advancement and those treated with premolar extractions. Seventy skeletal class II patients were accessed and forty-six subjects who fulfilled inclusion criteria were distributed randomly into Group CG (patients: 23, mean age: 21.28 ± 2.69 years) and Group SG (patients: 23, mean age: 21.15 ± 2.64 years). Group CG was subjected to extraction of maxillary first premolars and mandibular second premolars followed by implant supported space closure and Group SG was managed by surgical mandibular advancement. Skeletal, dental, and soft-tissue changes were analyzed. The study was single-blinded (statistical analyzer). Groups were closely matched for baseline parameters. In the present trial there was no loss to follow-up. Though overjet and overbite were optimized in both the groups but significant improvement was seen in surgical cases. Group CG demonstrated statistically significant point "A" remodeling, dentoalveolar changes, and increase in nasolabial angle. Group SG exhibited significant sagittal and vertical skeletal improvement and lip position change. Surgical mandibular advancement was found to be a better treatment modality compared to premolars extraction for managing skeletal class II div 1 malocclusion as it permits greater improvement of the profile and skeletal relationship.

Perbedaan Posisi Bibir Setelah Perawatan Ortodonti Dengan Ekstraksi Premolar Pertama Menggunakan Analisis Ricketts : Kajian pada Sefalogram Lateral di Klinik Ortodontis Bandung (Laporan Penelitian)

Background: The difference in facial profile after orthodontic treatment is important in orthodontic treatment as one of the goals of orthodontic treatment is to improve facial esthetic. Convex facial profiles that require first premolar extraction are the most common complaints of orthodontic patients in Asia. This profile is characterized by an increased lip profile procumbency. Therefore, any difference in the position of the lips from before and after orthodontic treatment is needed to be evaluated. Some studies proved that there was a significant difference in lip position after orthodontic treatment with the extraction of the first premolar teeth. Ricketts analysis is widely used to determine clinical differences in lip position. Objective: To determine the difference in lip position after orthodontic treatment with extraction of the first premolar using Ricketts analysis. Methods: This study was observational analytic with a cross-sectional study design. The study was conducted on 30 samples of lateral cephalogram radiographs before and after treatment at Orthodontist Clinic Bandung. The difference in lip position after orthodontic treatment and extraction of the first premolar teeth was determined using the Ricketts analysis. The measurement results were statistically analyzed with paired T-tests. Result: There was a difference in the position of the upper and lower lips after orthodontic treatment with first premolar extraction with p <0.001. The distance of the upper and lower lips to the E-line after orthodontic treatment with first premolar extraction was different than before treatment. Conclusion: There is a significant difference of upper and lower lip position before and after orthodontic treatment with first premolar extraction.

Indicators And Preferences Of Facial Profile And Aesthetics

For a successful orthodontic treatment, it is crucial to examine the patient in both frontal and lateral views. Evaluation of the skeletal pattern and softs tissues including nasolabial angle, anteroposterior lip position, labiomental angle, and Lip-chin-submental plane angle must all be considered. Facial profile greatly affects the aesthetic appearance of the patients, however, not every person has the same aesthetic perception. This review aims to point out the indicators of facial profile and the perception of facial profile attractiveness among the different populations. Many studies have evaluated the preferences of facial profile, some of them agreed as a straight profile with normally positioned lips was the most favored, but some differences were noted between orthodontists and laypeople in the perception of the facial profile. Laypeople found a slightly retruded mandible or protruded mandible was found aesthetically pleasing for some populations. Therefore, it is important to involve the patient in treatment planning and decision-making.

Real Time Facial Gesture Recognition using Deep Learning

The human faces have vibrant frequency of characteristics, which makes it difficult to analyze the facial expression. Automated real time emotions recognition with the help of facial expressions is a work in computer vision. This environment is an important and interesting tool between the humans and computers. In this investigation an environment is created which is capable of analyzing the person’s emotions using the real time facial gestures with the help of Deep Neural Network. It can detect the facial expression from any image either real or animated after facial extraction (muscle position, eye expression and lips position). This system is setup to classify images of human faces into seven discrete emotion categories using Convolutional Neural Networks (CNNs). This type of environment is important for social interaction.

Indicators and Preferences of Facial Profile and Aesthetic

For a successful orthodontic treatment, it is crucial to examine the patient in both frontal and lateral views. Evaluation of the skeletal pattern and softs tissues including nasolabial angle, anteroposterior lip position, labiomental angle, and Lip-chin-submental plane angle must all be considered. Facial profile greatly affects the aesthetic appearance of the patients, however, not every person has the same aesthetic perception. This review aims to point out the indicators of facial profile and the perception of facial profile attractiveness among the different populations. Many studies have evaluated the preferences of facial profile, some of them agreed as a straight profile with normally positioned lips was the most favored, but some differences were noted between orthodontists and laypeople in the perception of the facial profile. Laypeople found a slightly retruded mandible or protruded mandible was found aesthetically pleasing for some populations. Therefore, it is important to involve the patient in treatment planning and decision-making.

Changes in the facial soft tissue profile after maxillary orthognathic surgery.

ObjectivesTo compare the changes of the soft tissue profile in relation to the displacement of the underlying hard structures in maxillary orthognathic surgery and to contribute to the esthetic prediction of the facial profile after surgical procedures.Materials and methodsWe analyzed the sagittal changes in the facial soft tissue profile related to surgical changes in skeletal structures after maxillary osteotomy in a retrospective study. The study sample comprised 115 adult patients between the ages of 18–50 years who had undergone maxillary orthognathic surgery and interdisciplinary orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. LeFort I osteotomy cases in both maxillary monognathic and bignathic osteotomy procedures were included. All subjects had received rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed and the correlations between hard tissue and soft tissue change ratios were evaluated using a bivariate linear regression analysis. A vertical line through the landmark sella (S) perpendicular to the nasion-sella line (NSL) served as the reference plane.ResultsThe subnasale (Sn) followed the A point (A) by 57%, the soft tissue A point (A′) followed the A point (A) by 73% and the upper lip, represented by the landmark labrale superius (Ls) followed the upper incisor (Is) by 73%; all three in a linear correlation with a mean prediction error of nearly 2 mm.ConclusionThe scatterplots show a linear correlation with a wide spread for all three pairs of reference points. The wide spread and the high prediction error of almost 2 mm indicate low predictability of the expected lip position and Sn.

Correlation between collum angle and lower lip position in different Class II malocclusions - A retrospective cephalometric study

ABSTRACT Purpose: Significance of analysing collum angle in class II malocclusions with respect to lip position may lend greater credibility to variable torque brackets (mainly in the anteriors) that are fast gaining traction. Determine the magnitude of collum angle of maxillary central incisors in Class II division 1, division 2 malocclusions and changes in measurement brought about by variations in lower lip position and incisal contact. Materials and methods: 154 lateral cephalograms were divided into three groups- 55(Angle’s class I), 52 (Angle’s class II division 1) and 47 (Angle’s class II division 2). The collum angle was measured along with lower lip line (in Class II division 2) and lower lip contact (in Class II division 1) malocclusions. Results: The mean collum angles were 2.12 ± 1.43°, −0.84 ± 0.87° and 4.67 ± 2.23° in Groups 1, 2, and 3, respectively. Mean collum angle is significantly increased when the lower lip was found to contact the middle-third of the central incisor(in Group 3)and significantly decreased when the anterior one-third of the lower lip was in contact with the incisal edge of the central incisor (in Group 2). ANOVA followed by Tukey HSD test was carried out to determine statistically significant differences (p < 0.05). Conclusion: Collum angle is significantly decreased in Class II division 1 malocclusions necessitating variable torque prescriptions and segmental mechanics of maxillary anteriors. Appropriate alveolar bone support must be assessed prior to en-masse retraction and intrusion respecting the cortical boundaries. KEY MESSAGES: Variable torque brackets are rapidly gaining credence for their ability to provide sufficient alveolar bone support in different clinical scenarios. In this study, we have emphasized upon utilizing similar mechanics to treat class II malocclusions by utilizing the lower lip position as a reference guide.

Numerical investigation of effects of lip stiffness on reed oscillation in a single-reed instrument

The sound of a single-reed instrument is produced by the interactions among flow, reed oscillation, and acoustic resonance in the resonator. To investigate the effects of lip stiffness on the reed oscillation and acoustic propagation in the single-reed instrument, we conduct a flow simulation coupled with a dynamic beam analysis. The flow and acoustic fields are simulated by solving the three-dimensionalNavier–Stokes equations, while the geometry of the instrument is expressed by the volume penalization method in the computational grids. The lip force on the reed is modeled as a function proportional to the distance between the lip position and reed surface, and the coefficient of lip stiffness was changed in the simulation. The mouthpiece of the instrument was set in the pressure chamber. The results showed that the self-sustained oscillation of reed started by adjusting the initial pressure condition of the chamber without the lip force, and amplitudes of the reed displacement decreased until a stable condition by adding the lip force. The lip stiffness was found to affect the amplitude of reed displacement, indicating the necessity of controlling the lip force to obtain stable oscillation.

Cephalometric comparison of dentofacial parameters between Yemeni and Caucasian adults

Objective: The purposes of this research were to establish cephalometric standards for Yemeni adults and to compare them with those of the Caucasians. Material and Methods: 100 Yemeni students (fifty males, mean age of 23.6 ± 2.1 years, and fifty female, mean age of 21.5 ± 3.1 years) with normal occlusions and wellbalanced faces were involved in the study. Inclusion criteria were a class I malocclusion with minor or no crowding, the whole teeth is present except third molars and no previous orthodontic, orthopedic or maxillofacial surgery treatment. Five angular and eighteen linear measurements were used for the skeletal, dental and soft tissue analysis. All participant’s lateral cephalometric radiographs were evaluated. The average values and standard deviations for all the angles and linear measurements were determined. The differences for each measurement between the Yemeni and Caucasian participants were calculated using unpaired t–tests. Results: Yemeni subjects had a more retrognathic mandibular positions (P&lt; 0.05), protrusive mandibular incisors (P&lt; 0.01), more protruded lip positions (P &lt; 0.01), deeper mentolabial sulci (P&lt; 0.01) and a steeper mandibular planes (P&lt; 0.001) compared to the Caucasians. Yemeni females had a larger lower face height than Caucasian females (P&lt; 0.001). Conclusions: The study provides specific standards for Yemeni adults and shows that the Yemenis had different skeletal and dentoalveolar cephalometric standards in comparison with Caucasians. Keywords Cephalometric comparison; Skeletal and dental features; Yemeni norms.

Esthetic Considerations in Orthodontics: An Overview

AbstractEsthetics has been an ever-evolving concept and has gained considerable importance in the field of orthodontics in the last few decades. The re-emergence of the soft tissue paradigm has further catapulted the interest of the orthodontist. So much so that achieving a harmonious profile and an esthetically pleasing smile has become the ideal goal of treatment and is no longer secondary to achieving a functional dental occlusion and/or a rigid adherence to skeletal and dental norms. Esthetics in the orthodontic sense can be divided into three categories: macroesthetics, miniesthetics, and microesthetics. Macroesthetics includes the evaluation of the face and involves frontal assessment and profile analysis. The frontal assessment involves assessment of facial proportions, while the profile analysis involves evaluation of anterior–posterior position of jaws, mandibular plane, and incisor prominence and lip posture. Miniesthetics involves study of the smile framework involving the vertical tooth–lip relationship, smile type, transverse dimensions of smile, smile arc, and midline. Microesthetics involves the assessment of tooth proportions, height-width relationships, connectors and embrasures, gingival contours and heights, and tooth shade and color. The harmony between these factors enables an orthodontist to achieve the idealized esthetic result and hence these parameters deserve due consideration. The importance placed on a pleasing profile cannot be undermined and the orthodontist should aim for a harmonious facial profile over rigid adherence to standard average cephalometric norms. This article aims to give an overview of the macro, mini, and microesthetic considerations in relation to orthodontic diagnosis and treatment planning.

Clinical features of all-ceramic restorations in the oral cavity

BACKGROUND: Porcelain veneers make up the particular section of prosthetic dentistry. Veneers are necessary for frontal teeth restorations.&#x0D; AIM: To study the principles of dental preparation and the features of the formation of a natural anatomical contour on all-ceramic restorations.&#x0D; MATERIAL AND METHODS: To achieve a high-quality result of prosthetics with all-ceramic fixed prostheses, it is necessary to take into account many important aesthetic criteria: the shape of the tooth, the inclination of the axes of the teeth, the interdental space and the level of interdental contacts, the gum biotype, its color, the position of the gingival margin, the zenith of the gingival contour; tooth color (shades); the level of the cutting edge of the incisors; the relief of the teeth surface; the smile line and the position of the lower lip.&#x0D; To determine the color-optical characteristics of future prostheses, it is convenient to use the Vitapan 3-D Master Shade Guide color scale.&#x0D; For the manufacture of facings, it is necessary to take into account that the preparation is carried out within the enamel layer, the facings are made only for vital teeth, as clinically possible, while preserving the natural boundaries of the tooth.&#x0D; Prosthetics with ceramic prostheses is not recommended for dental dystopia (lingual, palatal position); significant loss of hard tooth tissues, their increased erasability, incomplete orthopedic treatment, deep bite, parafunctions of the masticatory muscles. Before manufacturing the facings, it is necessary to perform an X-ray examination of the teeth to be restored; assess the state of oral hygiene, determine the color of the future structure, replace all failed fillings, assess the condition of the interdental gap and the contact point.&#x0D; RESULTS: It is necessary to preserve the vestibular relief of the tooth surface, the uniformity of the lining, Contact with the surface (cutting edge) of the antagonist tooth should not be placed on the surface or on the border of the lining, but only on the tooth tissues.&#x0D; The advantage should be given to dissection by partial or complete palatal (lingual) overlap. The facings are fixed with the help of light polymerization composite materials, removing the excess with polishing boron.&#x0D; CONCLUSION: If there are significant risks and the patient refuses orthodontic treatment, the creation of contact points on veneers is a complex clinical task. In addition, with the destruction of the crown part of more than 1/3, the use of veneers is risky due to the increase in the layer of ceramic cladding, there is a possibility of chipping of the lining and the risk of manifestation of pulpitis after preparation. Under such conditions, it is desirable to carry out depulpation of teeth, restoration with zirconium stump pin tabs and prosthetics with zirconium crowns with ceramic lining.

Oral configurations during vowel nasalization in English

Speech nasalization is achieved primarily through the opening and closing of the velopharyngeal port. However, the resultant acoustic features can also be influenced by tongue configuration. Although vowel nasalization is not contrastive in English, two previous studies have found possible differences in the oral articulation of nasal and oral vowel productions, albeit with inconsistent results. In an attempt to further understand the conflicting findings, we evaluated the oral kinematics of nasalized and non-nasalized vowels in a cohort of both male and female American English speakers via electromagnetic articulography. Tongue body and lip positions were captured during vowels produced in nasal and oral contexts (e.g., /mɑm/, /bɑb/). Large contrasts were seen in all participants between tongue position of /æ/ in oral and nasal contexts, in which tongue positions were higher and more forward during /mæm/ than /bæb/. Lip aperture was smaller in a nasal context for /æ/. Lip protrusion was not different between vowels in oral and nasal contexts. Smaller contrasts in tongue and lip position were seen for vowels /ɑ, i, u/; this is consistent with biomechanical accounts of vowel production that suggest that /i, u/ are particularly constrained, whereas /æ/ has fewer biomechanical constraints, allowing for more flexibility for articulatory differences in different contexts. Thus we conclude that speakers of American English do indeed use different oral configurations for vowels that are in nasal and oral contexts, despite vowel nasalization being non-contrastive. This effect was consistent across speakers for only one vowel, perhaps accounting for previously-conflicting results.

A Novel Speech to Mouth Articulation System for Realistic Humanoid Robots

A significant ongoing issue in realistic humanoid robotics (RHRs) is inaccurate speech to mouth synchronisation. Even the most advanced robotic systems cannot authentically emulate the natural movements of the human jaw, lips and tongue during verbal communication. These visual and functional irregularities have the potential to propagate the Uncanny Valley Effect (UVE) and reduce speech understanding in human-robot interaction (HRI). This paper outlines the development and testing of a novel Computer Aided Design (CAD) robotic mouth prototype with buccinator actuators for emulating the fluidic movements of the human mouth. The robotic mouth system incorporates a custom Machine Learning (ML) application that measures the acoustic qualities of speech synthesis (SS) and translates this data into servomotor triangulation for triggering jaw, lip and tongue positions. The objective of this study is to improve current robotic mouth design and provide engineers with a framework for increasing the authenticity, accuracy and communication capabilities of RHRs for HRI. The primary contributions of this study are the engineering of a robotic mouth prototype and the programming of a speech processing application that achieved a 79.4% syllable accuracy, 86.7% lip synchronisation accuracy and 0.1s speech to mouth articulation differential.