Evolution of Upper Jaw Protrusion Mechanisms in Elasmobranchs1

Changes in the feeding mechanism with feeding behavior were investigated using high-speed video and electromyography to examine the kinematics and motor pattern of prey capture, manipulation and transport in the spiny dogfish Squalus acanthias (Squalidae: Squaliformes). In this study, Squalus acanthias used both suction and ram behaviors to capture and manipulate prey, while only suction was used to transport prey. The basic kinematic feeding sequence observed in other aquatic-feeding lower vertebrates is conserved in the spiny dogfish. Prey capture, bite manipulation and suction transport events are characterized by a common pattern of head movements and motor activity, but are distinguishable by differences in duration and relative timing. In general, capture events are longer in duration than manipulation and transport events, as found in other aquatic-feeding lower vertebrates. Numerous individual effects were found, indicating that individual sharks are capable of varying head movements and motor activity among successful feeding events. Upper jaw protrusion in the spiny dogfish is not restricted by its orbitostylic jaw suspension; rather, the upper jaw is protruded by 30 % of its head length, considerably more than in the lemon shark Negaprion brevirostris (Carcharhinidae: Carcharhiniformes) (18 %) with its hyostylic jaw suspension. One function of upper jaw protrusion is to assist in jaw closure by protruding the upper jaw as well as elevating the lower jaw to close the gape, thus decreasing the time to jaw closure. The mechanism of upper jaw protrusion was found to differ between squaliform and carcharhiniform sharks. Whereas the levator palatoquadrati muscle assists in retracting the upper jaw in the spiny dogfish, it assists in protruding the upper jaw in the lemon shark. This study represents the first comprehensive electromyographic and kinematic analysis of the feeding mechanism in a squaliform shark.

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Calculations used for assessment of rapid maxillary expansion

ORL ro ◽

10.26416/orl.30.1.2016.525 ◽

2016 ◽

Vol 1 (1) ◽

pp. 24-26

Author(s):

Ruxandra Bartok ◽

Bogdan Dimitriu Dimitriu ◽

Constantin Vârlan ◽

Radu Stanciu ◽

Georgiana Moldoveanu ◽

...

Keyword(s):

Tensile Strength ◽

Elasticity Modulus ◽

Rapid Maxillary Expansion ◽

Laboratory Animals ◽

Maxillary Expansion ◽

Literature Reference ◽

Bone Changes ◽

Upper Jaw ◽

Materials Used

Rapid maxillary expansion is defined as the release of medio-palatine suture using an orthopedic forces. The role of this procedure is to expand the upper jaw in order to achieve the broadening of the upper arch. This study was initiated to quantify the effects of disjunction and post- treatment bone changes, after an adequate contention which lasted for three weeks. This study is carried on laboratory animals (common breed rabbit) to determine tensile strength and the elasticity modulus of biological materials used in orthdodontics. The results of the study are consistent with those reported in the literature reference.

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POSSIBILITY OF APPLICATION OF TADS IN THE TREATMENT OF PATIENTS WITH DISTAL OCCLUSION CLASS II DIVISION 1 BY ANGLO, COMPLICATED BY THE DESTRUCTION OF THE SECOND MOLAR OF THE UPPER JAW

The Journal of scientific articles Health and Education millennium ◽

10.26787/nydha-2226-7425-2018-20-1-15-19 ◽

2018 ◽

Vol 20 (1) ◽

pp. 15-19

Author(s):

A.A. Dikova ◽

◽

G.V. Stepanov ◽

L.G. Ulyanova ◽

M.A. Postnikov ◽

...

Keyword(s):

Class Ii ◽

Second Molar ◽

Division 1 ◽

Upper Jaw ◽

Distal Occlusion ◽

Class Ii Division 1

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The use of the synthetic osteoplastic material “Klipdent PL” for direct dental implantation with included defects on the upper jaw

Problems of Uninterrupted Medical Training and Science ◽

10.31071/promedosvity2018.01.057 ◽

2018 ◽

Vol 2018 (1) ◽

pp. 57-61

Author(s):

О. V. Lyubchenko ◽

◽

М. S. Kravtsov ◽

Keyword(s):

Dental Implantation ◽

Upper Jaw ◽

Osteoplastic Material

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RAPID PALATAL EXPANSION AND ITS FEATURES

ASJ. ◽

10.31618/asj.2707-9864.2020.2.40.23 ◽

2020 ◽

Vol 2 (40) ◽

pp. 20-22

Author(s):

A.K. Al Dzhafari ◽

S.A. Ulyanovskaya

Keyword(s):

Rapid Maxillary Expansion ◽

Maxillary Expansion ◽

Maxillofacial Region ◽

Posterior Teeth ◽

Anatomical Features ◽

Palatal Expansion ◽

Rapid Palatal Expansion ◽

Congenital Deformities ◽

Upper Jaw ◽

Mid Palatal Suture

Rapid Maxillary expansion or palatal expansion as it is sometimes called, occupies unique niche in dentofacial therapy. Rapid Maxillary expansion (RME) is a skeletal type of expansion that involves the separation of the mid-palatal suture and movement of the maxillary shelves away from each other. RME effects the maxillary complex, palatal vaults, maxillary anterior and posterior teeth, adjacent periodontal structures to bring about an expansion in the maxillary arch. Morphogenesis and anatomical features of the upper jaw determine the choice of the method of rapid palatal expansion with narrowing of the upper dentition, as an effective method for eliminating congenital deformities of the maxillofacial region. The majority of dental transverse measurements changed significantly as a result of RME. The maturity of the maxillofacial structures determines the timing and degree of success of rapid palatal dilatation treatment.

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Dental Inclusion of Canine and Wisdom Tooth in Orthodontics Chemical Necroses

Revista de Chimie ◽

10.37358/rc.18.8.6497 ◽

2018 ◽

Vol 69 (8) ◽

pp. 2191-2196

Author(s):

Cristian Constantin Budacu ◽

Nicoleta Ioanid ◽

Cristian Romanec ◽

Mihail Balan ◽

Liliana Lacramioara Pavel ◽

...

Keyword(s):

Third Molar ◽

Point Of View ◽

Separate Entity ◽

Wisdom Tooth ◽

Facial Aesthetics ◽

The Third ◽

Edentulous Mandible ◽

Canine Guidance ◽

Upper Jaw ◽

Functional Point

Canine plays an important role in the dento-maxillary system. From a functional point of view, it provides the canine guidance, by positioning it in the frontal area, has a role in facial aesthetics. It plays an important prosthetic role by having the longest root and one of the longest arcade teeth. Three molars represent the last teeth that erupt in the arches both in the jaw and in the mandible, which is why they remain the most frequently included.Canine incidence is quite common following the wisdom tooth. It can be unilateral or bilateral and is more common in the upper jaw. The canine may remain included at the vestibular, palatal or between the two bones. A separate entity is the incision of the canine in the edentulous mandible or jaw. The study included 213 cases with dento-alveolar pathology, of which 128 patients were selected with dental inclusion. Our study reports that the first three molars are frequent, followed by the canine as opposed to other studies conducted by Guzduz K in 2011 and Fardi A of the same year bringing the canines first (Fardi, Guzduz). Some studies attribute the first place to the superior canine in terms of frequency, but they are abstracted from the molar three inclusion that they consider as most frequently (Compoy). The most common tooth in inclusion is the third molar (lower and upper) followed by the upper canine; the most commonly affected are women for both canine and molar.

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