Wide Mouth Opening Research Articles

Prey capture kinematics of horned frogs (Anura: Ceratophryidae).

Horned frogs, members of the Ceratophryidae family, encompass a group of anurans varying in size and behavior, yet unified by morphological and behavioral traits enabling them to adopt a megalophagous diet (i.e., large prey feeding). Although the group has been the focus of numerous studies, our understanding of its feeding behavior remains limited. In this study, we characterize the feeding mechanism in five species representing the three extant genera of ceratophryid anurans, both in terrestrial and aquatic environments. We also explore the ability of Chacophrys pierottii to adjust feeding behavior based on prey type. Our findings show that all species are capable of widemouth opening, displaying an asymmetric feeding cycle. While tongue usage is the primary method for capturing prey on land, ceratophryids may use their forelimbs to manipulate prey into their mouths, exhibiting different behavioral patterns. C. pierottii shows modulation of its feeding kinematics and is also capable of some modulation of its feeding in response to prey properties.

Paleoradiological and scientific investigations of the screaming woman mummy from the area beneath Senmut's (1479-1458 BC) Theban tomb (TT71).

The Screaming Mummy of Cairo Egyptian-Museum Store, is an anonymous woman with a wide-open mouth coded as CIT8, discovered beneath Theban Tomb 71 (TT71) which is the burial site of Senmut's relatives, the architect of 18th-Dynasty Queen Hatschepsut (1479-1458 BC). The study aims to evaluate if combining computed tomography (CT) with scientific investigations and archeological data of the Screaming Mummy CIT8 will reveal information about its physical appearance, health, cause of death, and mummification. We CT-scanned the mummy and created reconstructed images. Scanning-Electron-Microscope (SEM), Fourier-Transform-Infrared-Spectroscopy (FTIR), and X-ray-Diffraction-Analysis (XRD) were used to investigate mummy skin, hair, and wig samples. We compared our findings to previous data. Computed tomography estimated the age of death to be 48.1 years ±14.6 based on the pubic symphyseal surface. CT detected mild-to-moderate teeth attrition, and joints degeneration. The desiccated brain and viscera remained in situ. FTIR revealed the wig is formed of midrib date palm that shows in CT as spiral low density fibers. The wig fibers are partially coated with a thick substance that is inspected as black consolidation and identified as crystalline by XRD, comparable to material found in an ancient wig-making workshop. FTIR showed that the skin, hair, and wig samples were treated with imported juniper resin had anti-bacterial and insecticidal properties. The skin and wig samples contained frankincense, and the hair sample contained henna. Combining the advantages of paleoradiology to the scientific investigations, provided enhanced comprehension of the mummy CIT8 and ancient Egyptian wig structure and material. CT scanning non-invasively showed the mummy's inner and exterior morphology, and estimated the age of death as 48 years. CT evaluated the mummification technique based on retained viscera and absence of embalming packs. The scientific tests revealed expensive imported embalming materials, contradicting the traditional belief that the non-removal of the viscera implied poor mummification, resulting in careless embalmers sealing the mouth. The widely opened mouth could be a result of facial expression of suffering before death, fixed by cadaveric spasm. The study also explores how rigor mortis, tissue decomposition, burial techniques, and postmortem alterations may contribute to a mummy's screaming appearance.

Botulinum Toxin Versus Dextrose Prolotherapy: Which is More Effective for Temporomandibular Joint Subluxation? A Randomized Clinical Trial

Botulinum toxin type A (BTX-A) therapy or dextrose prolotherapy (DP) has been used to treat temporomandibular joint (TMJ) disorders. However, the superiority of one method over the other has not been studied in patients with TMJ subluxation. Therefore, this study aims to answer the following clinical question: among patients with TMJ subluxation, do those undergoing BTX-A injection into lateral pterygoid muscles, compared to those undergoing intra- and periarticular DP injections, have better outcomes in terms of locking episodes and patient satisfaction? A randomized clinical trial was implemented in adult patients with TMJ subluxation. The sample was composed of patients with TMJ subluxation with painful open-locking during wide mouth opening and/or yawning at baseline. The subjects were treated randomly with one of two treatment techniques with equal numbers as follows: one-session BTX-A injection into lateral pterygoid muscles (BTX-A group) or three sessions of dextrose injections around TMJ (prolotherapy group). The predictor variable was the treatment technique (BTX-A or prolotherapy injections). The primary outcome variable was the frequency of locking episodes. The secondary outcome variable was patient satisfaction. The primary outcome variable was recorded at baseline and 8-12months following the injections. The secondary outcome variable was recorded only 8-12months following the injections. Descriptive and bivariate statistics were computed. The data were analyzed with the Wilcoxon and Mann-Whitney U tests. The baseline sample was composed of 30 patients with TMJ subluxation. However, the follow-up sample comprised 25 subjects: 11 (9 females, 2 males; 25.64years) in the BTX-A group and 14 (10 females, 4 males; 32.37years) in the prolotherapy group. Locking episodes decreased significantly in the two groups with no significant difference (P<.01). Seven patients in the BTX-A group (7 of 11 patients; 63.6 percent) and eight (8 of 14 patients; 57.1 percent) in the prolotherapy group reported no complaint of locking at the end of follow-up, with no significant difference between the groups (P>.05). Patient satisfaction showed no significant difference between the groups (P>.05). These findings suggested that BTX-A injection is no more effective than DP for any outcome variables of TMJ subluxation assessed.

Something Beautiful and Powerful: Politics, Art, and Bread and Puppet Theater

Something Beautiful and Powerful: Politics, Art, and Bread and Puppet Theater

Young Women and Disgust in Contemporary Norwegian Comics: A Close Reading of Ane Barstad Solvang's Frykt &amp; medlidenhet

Young Women and Disgust in Contemporary Norwegian Comics: A Close Reading of Ane Barstad Solvang's <i>Frykt</i> &amp; <i>medlidenhet</i>

Diagnostic Accuracy of Mallampati Score in Patients under General Anesthesia Effect: A Cross Sectional Study.

Introduction: Difficult airway management has been linked to significant morbidityand death, and it is a fundamental and important problem for anesthesiologists.Traditional clinical predictors are used to examine the airway prior to surgery.Objectives: To compare the diagnostic accuracy of Mallampati score at both positions (supine and upright) with phonation to predict difficult laryngoscopy and intubation in patients after anesthesia administration.Methodology: This cross-sectional study was conducted at Department of Anesthesia, Dow University of Health Sciences/Civil Hospital Karachi from July 2019 to January 2020. Patients on list for elective surgeries (like ENT surgery, general surgery,ophthalmologic, neurosurgery, obstetric surgery, bypass surgery and orthopedicsurgery) under general anesthesia were selected. Mallampati score was estimatedwith certain conditions like full extension of head, wide open mouth and extrudedtongue with phonation at two positions i.e., supine position and upright position.Easy or difficult laryngoscopy and intubation was noted at both positions using Mallampati test.Results: Enrolled patients are of age between 20-80 years and of both genders i.e.,male and female. Sensitivity, specificity, negative predicted value, positive predictedvalue, and overall diagnostic accuracy of the Mallampati score at upright positionwas found to be 79%, 100%, 94%, 98% and 98% respectively. Sensitivity, specificity,negative predicted value, positive predicted value, and overall diagnostic accuracyof the Mallampati score at supine position was found to be 22%, 97%, 36%, 95%and 92% respectively.Conclusion: Patients with difficult laryngoscopy and intubation for general anesthesia have higher diagnostic accuracy of Mallampati score in upright position as compared to supine position with phonation.&#x0D; Keywords: Mallampati score, supine versus upright position with phonation, laryngoscopy, intubation.

Cover to Uncover

Multiple historical accounts (programme brochures and reviews) describe female Dada artists dancing with alienating, concealing masks and costumes at various Dada Soirées from 1916 to 1919. In her ‘Three Dada dances’ of 1916, writer, singer and performer Emmy Hennings’ face was covered in a Cubist mask, attracting the spectator’s attention by its frightening wide-open mouth and its radically deformed nose. In a similar and equally terrifying costume, interdisciplinary artist Sophie Taeuber performed her ‘ Dances’ of 1917. Their complete disguise, which obscured all references to gender and individuality, suggested that both Hennings and Taeuber fully disappeared behind their unsettling body masks. However, investigating the physical body masks from a contemporary perspective places these historical Dada performances in a radical new light. In ‘Cover to Uncover: Masked performance and gender in Emmy Hennings’ and Sophie Taeuber’s Dada dance’, Sophie Doutreligne explores the abstract Dada masks through the metaphorical concept of masquerade. She considers Hennings’ and Taeuber’s Dada body mask as a second, gender-neutral skin to their (obviously) gendered bodies. Starting from this premise, Doutreligne investigates if and how these Dada artists applied their abstract body masks to effectively destroy the traditional gender constructions that contributed to the consummation of their bodies on stage. She argues that it was exactly by performing with and certainly not behind their grotesque Dada masks that these female artists successfully escaped from their erased position in a male dominated Dada art scene. Their de-gendered Dada body masks allowed them to explore deviating and desired scripts of womanhood through the medium of dance.

Accuracy of static fully guided implant placement in the posterior area of partially edentulous jaws: a cohort prospective study.

A cohort prospective study was conducted to assess the three-dimensional positioning accuracy of the implant between pre-surgical and the final implant position using a static fully guided approach in the posterior area of the jaws. A total of 60 implants (30 patients) were digitally analyzed after superimposing the Digital Imaging and Communications in Medicine (DICOM) files obtained from the Cone Beam Computed Tomography (CBCT) pre- and post-implant placement. The software calculations included deviations at the implant shoulder and at the implant apex, global deviation (3D offset), and angle deviation. Statistical analysis was performed with α = 0.05. Considering the total number of implants, mesiodistal, buccolingual, and apicocoronal mean deviations at the shoulder and implant apex were equal or below 0.21 ± 0.69mm, and only the buccolingual mean deviation at the apex reached up to 0.67 ± 1.06mm. The mesiodistal and apicocoronal deviations were not statistically significant at both the shoulder and apex levels of the implant. The mean total angular deviation was 5.62° ± 4.09. The main limitation of this surgical approach was the requirement for a wide mouth opening. Static fully guided surgery for dental implant placement exhibits minimum deviations respect to presurgical planning. The main limitation in the posterior areas is the requirement for a wide mouth opening. Even with minimum deviations clinically acceptable, precautions and safety margins must be respected when using static full-guided surgery to place dental implants.

An innovative 'Prop technique' of mouth opening in post-COVID-19 mucormycosis maxillectomy: Finding a new way with minimal efforts.

General anaesthesia is associated with damage to teeth, particularly during laryngoscopy. Dental injury is more probable when pre-existing dental pathology or risk factors are present. Post-coronavirus disease -2019 mucormycosis is a rare, fulminant, lethal, angio-invasive, opportunistic fungal disease and is increasingly recognised in diabetic and immunocompromised patients. Since the flange of the laryngoscope blade appears to be the source of tooth injury, alternate methods of wide mouth opening during laryngoscopy should be examined, especially when mouth opening is limited. In this case series, we have studied 12 cases of maxillectomies with an aim to improve restricted mouth opening by using the 'Prop technique' resulting in a minimum hinging force of the flange of the blade on teeth. Preoperatively, patients were warned about the possibility of dental injuries during anaesthesia or surgery.

Conventional vs. digital impression technique for manufacturing of three-unit zirconia bridges: Evaluation of patients’ perception, preference, and treatment comfort

INTRODUCTION: Taking an impression of the oral cavity, which accurately recreates the prosthetic field, the surrounding hard dental and soft tissues, is one of the main and most important stages in the process of making any fixed prosthetic structure. AIM: The aim of the present study is to compare the comfort and satisfaction of patients in need of prosthetic restoration of a defect in the dentition, using conventional and digital impression techniques and to determine their preference for any of them. MATERIALS AND METHODS: The satisfaction of 36 patients in need of prosthetic rehabilitation treatment with conventional and digital impression techniques was analyzed and compared. After completing the stages of conventional and digital impressions, patients were asked to complete a comparative questionnaire of 9 questions using a numerical rating scale (NRS), stating their preference for one of the two techniques. RESULTS: Regarding the conventional impression technique, we obtained the lowest average values according to the criteria “general discomfort” (6.44±2.09), “total time for execution of the impression technique” (6.14±1.53), and “nausea” (6.17±2.86). The results of the same criteria in digital impression technology showed a significantly better response. All examined patients preferred the digital impression technique in cases where more than one impression had to be taken. DISCUSSION: Our results show that patients identify digital impressions as more comfortable for them. Differences in the level of comfort, which included nausea, difficulty breathing, discomfort in the TMJ with a wide open mouth, were statistically significant (p <0.001). CONCLUSION: In terms of patient comfort and satisfaction, the digital impression technique is better perceived than the conventional one.

Review: Gordon Parks: The Flávio Story, edited by Paul Roth and Amanda Maddox

Review: <i>Gordon Parks: The Flávio Story</i>, edited by Paul Roth and Amanda Maddox

On the Nature of the Transparent Teeth of the Deep-Sea Dragonfish, Aristostomias scintillans

Summary The dragonfish is a voracious predator of the deep sea with an arsenal of tools to hunt prey and remain concealed. In contrast to its dark pigmented skin, the dragonfish is equipped with transparent teeth. Here, we establish the structure, composition, and mechanical properties of the transparent teeth for the first time. We find the enamel-like layer to consist of nanocrystalline hydroxyapatite domains (∼20 nm grain size) embedded in an amorphous matrix, whereas in the dentin layer the nanocrystalline hydroxyapatite coats nanoscale collagen fibrils forming nanorods. This nanoscale structure is responsible for the much-reduced Rayleigh light scattering, which is further ensured by the sufficiently thin walls. Here, we suggest that the nanostructured design of the transparent dragonfish teeth enables predatory success as it makes its wide-open mouth armed with saber-like teeth effectively disappear, showing no contrast to the surrounding blackness of the fish nor the background darkness of the deep sea.

Клінічна ефективність лікування пацієнтів з функціональними розладами скронево-нижньощелепного суглоба із застосуванням запропонованих методів

Aim. The main purpose of our research is to improve the efficiency of diagnosis and treatment at patients with dentition defects and functional disorders of the temporomandibular joint with a help of individual tire and special patient approaches.Materials and methods. During the examination of patients with dental defects and functional disorders of the temporomandibular we examined the condition and the localization of dentition defects, analyzed diagnostic models and used radiographic methods such as orthopantomography and 3D tomography, as well as 3D condylography. At this stage of study we have examined 120 patients aged from 25 to 65 years. According to the clinical features and methods of treatment, patients were divided into the following groups:– patients with defects of dental rows, dention defects and functional disorders of the TMJ, examined and treated by conventional methods (group 1, 60 people).– patients with dention defects and functional disorders of the TMJ, examined and treated with the proposed methods using the articulation system, 3D scanner 3SHAPE and individual tire (group 2, 60 people). We have proposed a special method of manufacturing an individual tire for patients with functional disorders of the temporomandibular joint. Our complex treatment of the temporomandibular joint dysfunction hasn’t performed quickly, it includes occlusal ratios and selective grinding of occlusal surfaces, conducting of a condylography and application of an Aqualizer for 3-4 weeks which finally leads to production of temporary esthetic dentures.Results. After the proposed treatment that lasts 6 months, we found a significant reduction of patients with pain of the TMJ, that contains in 1 group 15 patients and in 2 group – 4 patients. However, it should be noted that these patients had significantly lower intensity and duration of joint pain than before treatment. The intensity of pain during lower jaw movements at patients of both groups after treatment decreased, however, the number of patients was 12 at first group but the level before treatment contains 43 people (72.5 %). At the second group, the number of patients with joint pain during movements of the mandible before treatment was 44 and after six months it was significantly reduced to 4 patients. The number of patients with wide-open mouth pain at the first group decreased from 45 (77.5 %) to 11 and at the 2-nd group from 48 patients to 5 patients. It should be noted that all indicators were better in 2 group. Hence, as you can see it indicates the high efficiency of the proposed treatment and proposed by us individual tire design.Conclusions. 1. Our individual tire design allows us to individualize it’s thickness depending on the condition and position of joint heads, furthermore localization of the dentition defect on both sides of the dental row, as well as to carry out gradual lifting of a bite and achieve great esthetic result at the lateral area.2. The proposed step-by-step treatment at patients with functional disorders of the TMJ involves the analysis of occlusal ratios with obligatory usage of Aqualizer for 3– 4 weeks. The next stage of treatment include the manufacture of temporary fixed structuresk, and the usage of the proposed functional individual tire for 3–6 months. The next stage include permanent aesthetic non-removable dentures (metaloplastic, metal-ceramics or zirconium dentures) and finally relaxation elastic tire for 3–6 months as a prevention of the dysfunction syndrome.3. After 6 months of the proposed treatment we found a significant decrease at the number of patients with pain of the TMJ that was 4 patients, compared with the group of patients who received conventional treatment – 15 patients. The number of patients with wide open mouth pain in 1group decreased from 45 to 11, and in 2 group from 48 patients to 5 patients. Clicks and crunches during wide-opening at the TMJ before treatment were detected in 1 group at 21 patients and in 2 group at 18. After 6 months of treatment these symptoms were detected at 9 patients in 1 group, and at 3 patients in 2 group, who achieved proposed by us treatment.Key words: dysfunction of the temporomandibular joint, dentition defects, individual tire, condylography, temporary and permanent dentures.

Management of Habitual Temporomandibular Joint Dislocation by Eminectomy

Temporomandibular joint (TMJ) dislocation(luxation) occurs when the condyle moves out of the glenoid fossa upon mouth opening and is locked anteriorly to the articular eminence. The dislocation leads to protective contraction or spasm of masticatory muscles, which reinforces the locked state, with or without pain. Usually, the episodes are triggered by any activities that lead to wide mouth opening such as yawning, laughing, and prolonged, excessive mouth opening during a dental or medical exam. It is a distressing and embarrassing situation for the patient. Repetitive dislocation of TMJ is defined as recurrent or habitual TMJ luxation. There are many treatment modalities available ranging from conservative approach to surgical approach. However, conservative approaches usually offer only a temporary solution and they have significant failure rate. Surgical approaches are available with varying degrees of success. Eminectomy is the most predictable surgical treatment for recurrent TMJ luxation. Herein, we report a case of a 47-year old male patient who was diagnosed with bilateral recurrent TMJ luxation that was successfully treated through bilateral eminectomy.

AN EVALUATION ON PERFORMANCE OF PCA IN FACE RECOGNITION WITH EXPRESSION VARIATIONS

Appearance-based recognition methods often encounter difficulties when the input images contain facial expression variations such as laughing, crying or wide mouth opening. In these cases, holistic methods give better performance than appearance-based methods. This paper presents some evaluation on face recognition under variation of facial expression using the combination of PCA and classification algorithms. The experimental results showed that the best accuracy can be obtained with very few eigenvectors and KNN algorithm (with k=1) performs better than SVM in most test cases.

The Relationship of the Articular Eminence with the Mandibular Fossa: Implications for Temporomandibular Joint Mechanics

The temporomandibular joint varies from most joints in that it is ginglymoarthrodial, both a hinge and a gliding joint. Early opening of the mouth produces a rotational movement at the joint; however, with wide mouth opening, the mandibular condyle translates anteriorly beyond the articular eminence. In some circumstances, the translation of the mandibular condyle over the articular eminence produces a dislocation of the mandible with concomitant spasm of local musculature, thereby holding the mandible in an open position. In certain circumstances, conservative treatments may prevent future dislocations. However, occasionally, surgeries such as eminectomy may be warranted. Because of the aforementioned relationship of the articular eminence with the movement of the mandible, the anatomy of the articular eminence warrants study in order to attain a better understanding of the temporomandibular joint mechanics. Therefore, this study assessed the angle formed by the anterior and posterior boundaries of the articular eminence and the angle formed between the posterior border of the mandibular fossa with the anterior border of the mandibular fossa (i.e., the posterior border of the articular eminence)—angles A and B, respectively. A total of 102 left sides and 99 right sides were analyzed. The average angle A was 112.5±14.49° (Mean±SD) and the average angle B was 112.4±13.28°. Angles A and B were correlated (r=0.41; p&lt;0.0001). Paired t‐tests revealed no statistically significant difference between angle A, bilaterally (t=1.543(80); p=0.1268). However, there was a statistically significant difference between left‐ and right‐sided angle B (t=4.045(77); p=0.0001). The results of this study suggest that there is bilateral asymmetry among mandibular fossae. Similarly, the anterior and posterior boundaries of the articular eminence do not differ significantly from side‐to‐side. Further study should incorporate the size of the articular eminence and mandibular fossa in relation to the angular data presented here.Support or Funding InformationWV Research Challenge Fund [HEPC.dsr.17.06] and [HEPC.dsr.14.13]This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Restricted mouth opening and its definitive management: A literature review.

This review was intended to discuss the various possible modifications suggested in the literature for prosthetic steps and surgical corrective procedures in nonresponding or complicated cases during rehabilitation of patients with restricted mouth opening. Medline, PubMed, and Google were searched electronically for articles using keywords: microstomia and treatment options for restricted mouth opening. The various articles on prosthodontic rehabilitation in microstomia were segregated. From these, various modifications in the prosthetic steps were reviewed. Oral hygiene maintenance is difficult for patient either due to limited access or due to associated lack of manual dexterity, so dental decay and periodontal problems are more extensive in such patients; hence, tooth loss is a common finding. All prosthetic procedures require wide mouth opening to carry out various steps, starting from tray placement during impression making to the final prosthesis insertion, especially removable prosthesis. Various prosthetic modifications given by authors are included in this review for each step in prosthodontic management. A total of eight stock tray designs, 12 custom tray designs, and 17 removable prosthesis designs are discussed along with fixed (either tooth-supported or implant-supported) and maxillofacial prosthesis. However, some patients require surgical intervention also for the correction of microstomia either for function or for esthetic purpose before prosthetic rehabilitation and are also enumerated here. Among all prosthetic restorative options, removable prosthesis is most difficult for dentist to fabricate as conventional methods are either very difficult or impossible to apply. To get a more accurate final prosthesis, we need to modify these steps according to the existing case. Several modifications available are discussed here which can help while managing these patients.

A rare case report of Eagle’s syndrome complicated with chronic mouth opening, its management and complete rehabilitation; dental perspective

&lt;p&gt;Eagle’s syndrome is a rare condition of either elongated styloid process or ossification of its ligaments; which is less appreciated and often ignored condition by clinicians because of its vague symptoms which can be easily confused with other oral or paraoral conditions presenting with similar signs and symptoms. Since it is not a routine clinical problem, it is not given the first priority thought while diagnosing such a case; especially in the absence of sound clinical knowledge and good radiographs. This article is aimed to summarize unusual clinical presentations, diagnosis and standardized tonsil-sparing trans-oral surgical approach for Eagle’s Syndrome case and its unique postoperative management. A&lt;strong&gt; &lt;/strong&gt;80 years old female patient presented with the tendency of uncontrolled wide mouth opening with severe pain in both ears, temporal region; submandibular area extending up to back of neck with intensity on right side. The patient was diagnosed as a case of the Eagle’s syndrome with a unique finding of pain relief on wide mouth opening. The patient was operated for bilateral styloidectomy followed by postsurgical rehabilitation with custom made chin cup appliance and mouth opening exercises. &lt;/p&gt;

Development Of Larvae Rainbow Fish Boesemani (Melanotaenia boesemani): Phase Depreciation of Yellow Egg, Forming Eyes and Opening of Mouth

&lt;p&gt;&lt;em&gt;Abstract &lt;/em&gt;&lt;strong&gt;– One of the factors that caused larval mortality is the availability of food which is not in accordance with the mouth opening. At the same time the larvae require considerable energy to the development of organs. The Completeness of organs used in feed searching as the eyes is also becoming important. The larvae use eyes to see the feed material in their surrounding waters. This study aimed to measure the volume of egg yolk, eye diameter and wide mouth opening during larval development rainbow fish boesemani (&lt;em&gt;Melanotaenia boesemani&lt;/em&gt;). The stages of the research include larval maintenance, depreciation egg yolk observations, calculate the size of the increase in larval eye and mouth openings. The results of this study showed that newly hatched rainbow boesemani larvae have egg yolks, eyes and mouth. The newly hatched larvae have a yolk volume average of 0.053 mm&lt;sup&gt;3&lt;/sup&gt;. Egg yolks will expire at the time of 2 days old larvae. The formation of the eye, has occurred inside the eggs and newly hatched larvae have an average diameter of eye of 0.459 mm. The newly hatched larvae have a wide mouth opening average of 0.229 mm. An larvae older than 21 days and 30 days has a wide mouth opening average of 0.82 mm and 1.725 mm.&lt;/strong&gt;&lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt;&lt;em&gt;Keywords&lt;/em&gt;&lt;/strong&gt; – &lt;em&gt;Rainbow fish Melanotaenia boesemani, larval development, egg yolks, eyes, mouth&lt;/em&gt;&lt;/p&gt;

A Formant Range Profile for Singers

Vowel selection is important in differentiating between singing styles. The timbre of the vocal instrument, which is related to its frequency spectrum, is governed by both the glottal sound source and the vowel choices made by singers. Consequently, the ability to modify the vowel space is a measure of how successfully a singer can maintain a desired timbre across a range of pitches. Formant range profiles were produced as a means of quantifying this ability. Seventy-seven subjects (including trained and untrained vocalists) participated, producing vowels with three intended mouth shapes: (1) neutral or speech-like, (2) megaphone-shaped (wide open mouth), and (3) inverted-megaphone-shaped (widened oropharynx with moderate mouth opening). The first and second formant frequencies (F1 and F2) were estimated with fry phonation for each shape and values were plotted in F1-F2 space. By taking four vowels of a quadrangle /i, æ, a, u/, the resulting area was quantified in kHz2 (kHz squared) as a measure of the subject's ability to modify their vocal tract for spectral differences.