Thesis (Doctoral)--Eberhard-Karls-Universität zu Tübingen, 1935.

Bayer. Ludwig-Maximilians-Unviersität, 1934

Thesis (doctoral)--München, 1934.

Thesis (Doctoral)--Ludwig-Maximilians-Universität zu München, 1934.

Thesis (Doctoral)--Ludwig-Maximilians-Universität zu München, 1934.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

No description available.

A mandíbula dos Squamata é composta por duas hemimandíbulas cada uma composta por diversos ossos. Na região posterior, as hemimandíbulas se conectam ao crânio através do osso quadrado e na região anterior se encontram conectas pela sínfise mandibular, que tem um importante papel anatômico, limitando o movimento independente das hemimandíbulas influenciando assim o grau de cinese da mandíbula. A existência de variação morfológica na sínfise mandibular já foi apontada por diversos autores, no entanto somente alguns estudos detalhados foram feitos sobre esta estrutura, a grande maioria deles em Serpentes. Segundo estes autores os lagartos e as serpentes Scolecophidia apresentariam a sínfise mandibular rígida, enquanto que os mosassaurídeos e as demais serpentes possuiriam uma sínfise mandibular livre. A sínfise livre é um dos caracteres utilizados por diversos autores para unir as Serpentes e os mosassauros no clado Pythonomorpha, esta hipótese foi questionada por alguns autores que acreditam que a sínfise mandibular livre é uma convergência evolutiva nestes dois clados. Diversas famílias de lagartos não apresentaram as cartilagens de Meckel fundidas como era esperado e somente uma das famílias de Scolecophidia apresentava a fusão das cartilagens de Meckel na região sinfisial. A perda da conexão das cartilagens de Meckel seria o primeiro passo para a formação de uma sínfise livre, sua ocorrência em diversas famílias reforça a hipótese de que a sínfise mandibular livre presente nos mossasauros e serpentes Alethinophidia seria uma convergência evolutiva. Também foi possível estabelecer, com base nas morfologias observadas, as transformações necessárias para o surgimento de uma sínfise livre como a das serpentes Alethinophidia. / The Squamate mandible is formed by two hemimandibles each one composed of several bones. In the posterior region, the hemimandibles are connected to the skull by the quadrate bone. In the anterior region these are connected to each other by the mandibular symphysis, which has an important anatomical role, limiting the independent movement of the hemimandibles. Several authors noted the existence of morphological variation in the mandibular symphysis, but only a few detailed studies were made about this structure, the majority of them focusing on Serpentes. These authors claim the lizards and the Scolecophidia snakes possess a rigid mandibular symphysis while the mosasaurs and the rest of the snakes would possess a free mandibular symphysis. The free symphysis is one of the characters used by several authors to support the existence of the Pythonomorpha clade formed by the mosasaurs and the snakes, the existence of this clade is questioned by several authors that believe the presence o the free symphysis to be a convergence in this two groups. Contrary to what was expected, the connection of Meckels cartilages were absent in several lizards families while it was present in only one scolecophidian family. The loss of Meckels cartilages connection would be the first step to the formation of a free symphysis, its occurrence in several families reinforces the hypothesis that the free symphysis could have evolved independently in the mosasaurs and the Alethinopidia snakes. Based on the morphologies observed in this study it was also possible determinate the steps necessary for the evolution of a free symphysis.

Jaw disease in kangaroos and wallabies, while uncommon in animals living in the free state, is a major cause of death in captive macropods. There are two major schools of thought regarding its aetiology. The first accepts the findings of Fox (1923) and considers the disease to be actinomycosis while the second believes jaw disease to be one manifestation of necrobacillosis. Regardless of the belief of the authors the clinical and pathological descriptions indicate the condition attacking macropods throughout the world is a single disease. / Over one hundred affected macropods were examined during the course of this study and few species were found to be spared from jaw disease. Cases of lumpy jaw most commonly occurred in the winter months. All ages of macropods were affected although a higher prevalence was recorded in younger animals; however this may have been a reflection of the age of macropods in the zoo under study. The most common site of infection was the premolar and anterior molar region of the oral cavity, regardless of the age of the animal. The gross pathological findings were similar to the descriptions of affected animals by various authors throughout the world. The site of infection could generally be recognized at the gingival crevice, commonly between teeth, and excessive calculus formation associated with gingivitis and gingival recession was a common finding in affected animals. Penetration of the gingival mucosae by plant fibre was not found to be a significant predisposing factor in the initiation of the disease. (For complete abstract open document.)

Purpose: An open mouth approach is used in voice therapy for enhancing speech and voice production and relaxing the laryngeal musculature. The acoustic and physiological consequences of an open jaw posture, however, have not been clearly understood due to a paucity of cross-system studies taking the age effect into consideration. The major aims of this study are twofold (1) to examine if the geriatric voice may be improved using an “open jaw” posture and (2) if an aging effect on the voice of normal healthy adults can be detected through acoustic and physiological measures Method: The main part of this study involved simultaneous multi-channel voice recordings obtained from 85 healthy adults aged between 38 and 93 years. A convenience sampling strategy was used to recruit at least five females and five males in each of four age groups, 35-59 years (35+), 60-69 (60+), 70-79 (70+), and above 80 (80+). For simultaneous acoustic, electroglottographic (EGG), and jaw displacement recordings, participants were asked to perform two tasks which included a sustained vowel task and a sentence production task. The sustained vowel task involved sustaining the vowel /a/ in five different conditions, an isolated vowel /a/ produced at normal, low, and high pitch levels and the vowel /a/ initiated with a consonant (/m/ and /h/). The sentence production task involved production of the sentence 'We saw two cars,' containing the vowels /i, ɔ, u, a/. For simultaneous airflow-EGG recordings, participants were asked to sustain the vowel /a/ at normal pitch. For simultaneous airflow-air pressure-EGG recordings, participants were asked to repeat /pa/ five times in one breath. Participants were asked to perform all of the tasks using two jaw postures (normal and open). A series of univariate analysis of variances were used to identify instrumental measures sensitive for discriminating between the four age groups and the two jaw postures. A follow-up perceptual study was conducted to determine the effect of an open jaw posture on vowel intelligibility and voice clarity. A quota sampling strategy was used to recruit 40 normal hearing participants, including 20 females (age range = 18-42 years, mean = 25.3, SD = 7.9) and 20 males (age range = 18-47, mean = 23.6, SD = 6.7). These listeners were presented with vowels segmented from the sentences recorded in the first experiment and asked to perform a vowel identification and a voice clarity discrimination task. The vowel samples were taken from 40 speakers, with five females and five males in each of the four age groups (35+, 60+, 70+, and 80+). The percentages of correct vowel identification for voices produced with normal and open jaw postures were compared. The percentages of vowels judged as 'clearer' in a normal-open jaw contrast pairs were also calculated for comparison. Results: Significant age group effects were found in this study for both genders on fundamental frequency (F0), voice onset time (VOT) (/ka/), open quotient (OQ), and speed quotient (SQ), with additional age differences detected for females on %jitter, %shimmer, signal-to-noise ratio (SNR), and the second formant frequency (F2), and for males a significant age group effect was found on VOT (/tu/). Results for both females and males revealed significant open jaw posture effects on F0, F2, VOT (/ka/), MFR, SPL and vowel space area. In addition, for females significant posture effects were found on F1, subglottal pressure and the H1-H2 amplitude difference, and for males, significant posture effects were found on %jitter and VOT-/tu/. Results from the follow-up perceptual study revealed that an open jaw posture was associated with better vowel identification and better voice clarity. Conclusions: A selection of instrumental measures was shown to be useful for detecting voice changes due to aging. Instrumental and perceptual evidence was found that an open jaw posture was associated with positive changes in vocal behaviours, including improved phonatory stability, vocal power, and voice clarity.