Oral respiration associated with obstruction of the nasal airway is a common finding among patients seeking orthodontic treatment. The primate experiments reported here are part of a series designed to test some of the current hypotheses regarding the relationship between mouth breathing and dental malocclusions, that is, between deviations in ...

The standard measurements of the properties of orthodontic wire are of limited value to the orthodontist, and clinical impressions of wire behavior are unreliable. This article discusses the properties of clinical relevance to the selection of wires for the initial alignment of irregular teeth. These concepts are illustrated by measurements ...

Correction of widths and axial inclinations with a transpalatal lingual arch has the advantage of distributing forces across the arch, thus minimizing undesirable side effects. The proper shape of an arch to deliver the required force systems for both unilateral and bilateral width change was determined by using an analytical ...

Chewing patterns of ten dentate and eleven edentulous test subjects were recorded by a computer based on light-emitting diodes and photosensitive detector-surfaces (Selspot-system). A comparison of the mandibular pattern between the two groups was made with respect to chewing rhythm and degree of mandibular displacement and velocity. Differences could be ...

The major mechanical signals or stimuli in orthodontic therapy are the stress and the resultant strain or deformation in the periodontal supporting tissues. These signals are translated into biologic cellular activities by some yet unclear mechanisms. Direct action by the stresses and strains upon the cells as well as by ...

The maximum bite force and the ability to perform a requested interincisor bite force was tested on eight healthy subjects with normal dentition and on five full denture wearers under various conditions. Anaesthesia of temporomandibular joint (TMJ) capsular and/or periodontal receptors, with or without simultaneous vibration-induced increase of muscle receptor ...

Reconstructing the biomechanics of early hominid mastication is a key element in most models of hominid differentiation. Traditionally, osteological features marking muscle attachment surfaces have served as a reference system from which the vector geometry of the masticatory force system and resultant force distributions could be predicted. To augment traditional ...

A new tool for measuring tooth movement--laser holography--offers an accurate, noninvasive approach for determining movement in three dimensions. This in vitro study is designed to establish the required force system applied on the crown of a maxillary incisor that would produce different centers of rotation, as in lingual tipping, translation, ...

Mandibular movements in wearers of complete dentures were registered before and after rehabilitation with new dentures by light-emitting diodes (LEDs). The duration of the opening, closing and occlusion phases as well as the whole chewing cycle were studied. The closing phase had the longest duration of the three phases, 0.36 ...

We have examined the frequency response of cold-wire thermometers using 2.5-micro platinum wires with laboratory-produced salt layers. The salt layers are produced by exposure to a saline aerosol to simulate the marine environment. The frequency response was determined by measuring the response of the coated wires to a white thermal ...

The holographic technique, recently developed for precise and accurate measurement of tooth displacements, was used to study the three-dimensional motion of human teeth. Maxillary central incisors were loaded with forces of 300 grams and 500 grams. Translations and rotations in three-dimensions were measured over 45 seconds. The experimental results, presented ...

A controlled pulsating-force system for the orthodontic movement of teeth was designed and its biologic effects were examined, with the dog serving as an experimental model. This system was applied to the maxillary right second premolar while a continuous force was delivered to the maxillary left second premolar. After a ...

The effects of wire size, lumen size, and wire type on the production of force by closed coil springs were determined. Force production was affected as follows: (1) Keeping the lumen size constant, an increase in wire size produced an increase in force. (2) Keeping the wire size constant, an ...

Condylectomy or condylectomy with immediate alloplastic condylar replacement was performed in six young and six adult rhesus monkeys to investigate the role of the mandibular condyl in facial growth. The experimental findings support the hypothesis that the condyle does not have a primary influence on mandibular growth and that alterations ...

There is disagreement as to whether the mandibular condyles are stress-bearing or stress-free during mastication. In support of alternative models, analogies have been drawn with Class III levers, links, and couple systems. Physiological data are reviewed which indicate that maximum masticatory forces are generated when maxillary and mandibular teeth are ...

A technique has been described for fitting a removable partial denture framework to the master cast prior to adapting it in the mouth. Emphasis should be placed on maintaining the original contour of the framework throughout the procedure. The amount of metal removed should be only that necessary to seat ...

This study was undertaken to determine if electromyography with biofeedback can be utilized to produce a more reliable determination of rest vertical dimension than conventional methods such as phonetics and swallowing. It was found that: 1. Electromyography with biofeedback appeared to produce a more consistently reliable determination of rest vertical ...

The role of enantiomorphs (mirror images) as units of coding of symmetrical patterns was investigated. Simple symmetrical matrices were presented tachistoscopically for 0.3 sec and were immediately followed by 0.3 sec presentation of the same matrix but with half of its cells occluded. The subjects were required to reproduce the ...

The results of this study showed that: 1. The design of a retainer with a mesial rest in conjunction with a buccal I-bar or a wrought-wire and cast lingual arm exhibited the most favorable distribution of vertically applied forces. 2. Retainer designs with a distal rest tend to move the ...

Electrical activity in the masseter muscles and tooth contact vibrations were recorded simultaneously from subjects tapping their teeth slowly into maximal intercuspidation and again with maximal frequency. High speed cinephotography was also used with four of the ten subjects. Three main parts could be distinguished on the obtained graphical representation ...

Multivariate analysis of the craniofacial skeleton from subjects with Angle's four occlusal categories showed a similar pattern but with varying degrees of separation depending upon which parameters were included in the analysis. Generally it appeared that the maxillary jaw and mandibular arch parameters contributed most to the discrimination to the ...

A wide variety of instruments have been developed for oral force monitoring. Most of the instruments, however, have employed bite elements which were too thick for measurement of biting forces when the teeth are nearly in contact and probably stretched the stomatognathic muscular system beyond its maximum power of contraction. ...

The mechanical mobility of the temporo-mandibular joint (TMJ) was measured by applying small sinusoidal forces at different frequencies to the teeth and measuring the resultant motion of the teeth. Velocity/force ratios were recorded versus frequency at maxillary and mandibular teeth and the results were interpreted in terms of linear spring-mass-dashpot ...

For purely transverse orthodontic tooth movements, the center of rotation is defined as that point on the long axis or its extension which remains stationary during the movement and around which the rotational component of the tooth displacement takes place. For tooth movements having both vertical and transverse components, no ...

Early short-term use of the chin cup resulted in the following significant findings in Class III skeletal problems: 1. A decrease in the gonial, mandibular, and SNB angles. 2. An increase in posterior facial height as a result of increased ramal height. 3. A faster and more pronounced result in ...

Tooth gliding occurs frequently both in the opening (55.9%) and closing (60.5%) chewing strokes. The average glide length was 1 mm. Good occlusions could not be distinguished from poor occlusion on the basis of frequency and length of gliding contacts. The greater the component of lateral movement during the closing ...

A comparison of biting attack induced by electrical stimulation of the cat hypothalamus with natural feline predatory attack revealed a high degree of similarity between the two behaviors. All major components of natural attack could be elicited by hypothalamic stimulation in cats not showing spontaneous attack, including stalking approach to ...

A technique is described that incorporates an extracoronal attachment within an overdenture to provide increased retention. This type of retentive attachment is easily fabricated. It's durability, simplicity, adjustability, and adaptability to a wide variety of situations make it most useful. The retentive attachment may be used with either removable partial ...

In September, 1973, a live male 2-3 day old white-tailed deer (Odocoileur virginianus) with multiple anomalies of the head and forelimbs was found near Lethbridge, Alberta. Notable gross findings inculded brachygnathia inferior, atypical incisor tooth alignment, medially folded ears, humero-radial arthrogryposis and bowing of the radius and ulna. Hematologic determinations ...

The mammalian mandible, and in particular the human mandible, is generally thought to function as a lever during biting. This notion, however, has not gone unchallenged. Various workers have suggested that the mandible does not function as a lever, and they base this proposition on essentially two assertions: (1) the ...

The study reported here was undertaken in an attempt to contribute, from a theoretical standpoint, to the knowledge and understanding of optimum force theory, particularly as it may be relevant to canine retraction. The following statements are derived from my analysis of the applicable published literature and the results of ...

Photoelastic stress analysis by means of simulated load application on model structures was used to visualize the forces that are induced within the supporting bone structures during various tooth movements. A comprehensive picture of the stress patterns produced by these forces, in addition to the degree of stress distribution, was ...

This article describes a highly systematic modifcation of the edgewise technique that incorporates the principle of light continuous force application. It is a re-evaluation of our earlier article in view of the experience gained in applying this treatment approach in a teaching clinic. The classification of cases according to retraction ...

Microducers and modified cephalometric roentgenogram techniques were used to study maximum biting forces and moments in an adult male. The force at the second molar was approximately 10% greater than that at the first molar. At the second molar, the moment of force was approximately 15% less than its value ...

A method has been developed for measuring the threshold level of sensibility to axial pressures applied to the incisor teeth in man. Eight subjects were investigated, four with support reduced by up to 60% as a result of chronic periodontal disease. Reduced alveolar support appears to have no significant effect ...

Biting on hard particles during chewing sometimes produced motor pauses but more often abrupt atypical terminations of the EMG patterns occurred. A series of tests with different experimental biting and chewing situations were performed. The results indicate that the motor inhibition that occurs during biting and chewing mainly are of ...

The morphology, the width and the appearance frequency of the zone completely and partially destructed periodontal fibres on human teeth were studied in the stereomicroscope. This zone was present between the most apical border of identifiable, epithelial attachment remnants and the most coronal intact periodontal fibres, and consisted of only ...

Shock-induced biting and threat by the male painted turtle (Chrysemys picta marginata) were studied in three experiments. When restrained facing each other, the turtles threatened and bit other turtles in response to electric shock. Shock alone caused turtles to threaten an unshocked turtle; the movements of a shocked turtle were ...

On coral reefs, biting teleosts form a major component of reef fish assemblages.
Nevertheless, they have been largely overlooked in functional research, while their ramsuction
feeding counterparts have received considerable attention over the past few
decades. This thesis therefore examines the functional basis of biting in coral reef fishes,
with a focus on the ...