Dissertations / Theses on the topic 'Mandibular condyle Mandible'

Objectives: This retrospective study aims to compare the effect of different mandibular setback amount by vertical subsigmoid osteotomy (VSSO) on the pattern of condylar remodelling in both metric and morphologic analysis at 1 year post surgery. Materials and Methods: 200 patients diagnosed of mandibular prognathism and had undergone VSSO with various setback amounts from 2007 until 2012 at the Prince Philip Dental Hospital were included in this study. Presurgical and 1 year post surgical Postero-Anterior Cephalogram, Lateral Cephalograms and Cone Beam Computed Tomography (CBCT) Scans were retrieved. Tracings of plain cephalometric radiographs were performed. CBCT data sets were used to create 3D condyles to measure the linear and condylar axis angle value in multiplanar view. Finally the pre and postsurgical 3D condyle-ramus units were superimposed using stable registration point in the condylar neck and ramal area above the lingual to assess the condylar bone remodelling by topographic and multiplanar slide views. Result: From the plain radiographic tracings, there were no significant differences in the changes of ramus inclination angle, intergonial width and total ramus angle between postoperative (T2) and preoperative (T1) values across the setback groups. A gradual increase in the postoperative sagittal condylar axis angle is detected with greater setback in the CBCT multiplanar analysis while other linear and angular condylar changes were not significantly different. 3D Topography (T2 -T1) superimposition analysis of the condylar surface showed no significant relation between the remodelling changes and the setback magnitude except at the superior posterior zone. Multiplanar view (T2-T1) superimposition analysis in the coronal and sagittal planes showed no significant relationship between the remodelling changes and the setback magnitude. However there was higher proportion of positive remodelling following higher setback amount at the midanterior and posteromedial zone in the axial plane. Conclusion: Condyle remodelling is noted to be positive and not detrimental following VSSO. The positive remodelling effect remains stable regardless of the amount of VSSO setback.
published_or_final_version
Dental Surgery
Master
Master of Dental Surgery

Evaluar la dimensión antero- posterior (A-P)/medio-lateral (M–L), y la morfología del cóndilo mandibular en pacientes de 18 a 65 años con patrón esquelético Clase I en tomografías computarizadas Cone Beam. Material y Métodos: 71 tomografías fueron evaluadas mediante el software RealScan 2.0. La dimensión fue determinada por los puntos A (más anterior en el plano sagital), P (más posterior en el plano sagital), M (más interno en el plano coronal), L (más externo en plano coronal). Se evaluó la morfología del cóndilo en dos planos coronal y sagital, clasificándose en: redonda, aplanada, convexa y mixta. La dimensión del cóndilo fue analizada por estadística descriptiva y la morfología mediante distribución de frecuencias. Para el análisis bivariado, se aplicó la prueba de t de Student. Resultado: Se obtuvieron las medidas del diámetro A-P del cóndilo derecho (CD) (8,72mm ± 1,25mm) y el izquierdo (CI) (8,50mm ± 1,50mm), el diámetro M-L del CD (19,24mm ± 2,03mm) y el CI (18,97mm ± 1,87mm). Hubo diferencias significativas en la dimensión M-L del CI del sexo masculino en comparación al femenino (p=0.002). La morfología más prevalente del CD (35,21) y CI (23,94) en plano coronal fue de tipo redonda. Conclusión: La dimensión A-P del cóndilo derecho e izquierdo es similar en ambos sexos; sin embargo, existen diferencias en la dimensión M-L del cóndilo izquierdo del sexo masculino. La morfología del cóndilo derecho e izquierdo más prevalente fue la redonda en plano sagital a excepción del plano coronal.
To evaluate the anterior-posterior (A-P)/medial-lateral (M-L) dimension, and morphology of the mandibular condyle in patients aged 18 to 65 years with Class I skeletal pattern on Cone Beam Computed Tomography scans (CBCTs). Materials and Methods: Seventy one CBCTs were evaluated using RealScan 2.0 software. The dimension was determined by points A (most anterior in the sagittal plane), P (most posterior in the sagittal plane), M (most interior in the coronal plane), L (most exterior in the coronal plane). The morphology of the condyle was evaluated in two coronal and sagittal planes, being classified as: round, flat, convex or mixed. The size of the condyle was analyzed by descriptive statistics and the morphology by frequency distribution. For the bivariate analysis, the Student’s t-test was applied. Results: Measurements were obtained for the A-P diameter of the right condyle (RC) (8.72mm ± 1.25mm) and the left condylar (LC) (8.50mm ± 1.50mm), the M-L diameter of the RC (19.24mm ± 2.03mm) and the LC (18.97mm ± 1.87mm). There were significant differences in the male M-L dimension of the LC compared to the female (p=0.002). The most prevalent morphology of RC (35.21) and IQ (23.94) in the coronal plane was round.. Conclusion: The A-P dimension of the right and left condyle is similar in both genders; however, there are differences in the M-L dimension of the left male condyle. The most prevalent morphology of the right and left condyle was round in the sagittal plane with the exception of the coronal plane.
Revisión por pares

O presente estudo analisou os efeitos da fratura de côndilo unilateral, no período de crescimento. Para tanto, foram utilizados 50 ratos jovens, linhagem Wistar, com peso até 100g. Sob anestesia geral foi realizada no grupo experimental fratura do processo condilar no lado direito com desvio e no grupo controle-operado, foi feito apenas acesso cirúrgico ao côndilo. O sacrifício dos animais foi feito aos três meses de idade. A mandíbula foi desarticulada sendo obtidas as incidências radiográficas axial do crânio seco e lateral das hemi-mandíbulas. Foram feitas mensurações cefalométricas por meio de um sistema de computador. Foram aplicados os testes estatísticos “t” de Student entre os grupos e teste “t” de Student para dados pareados entre os lados, dentro de cada grupo.Houve diferença significante entre os grupos para o lado direito no comprimento das porções anterior (p=0,001) e posterior (0,017) da maxila e altura do ramo mandibular (p=0,001). Houve diferença significante entre os lados para o comprimento da mandíbula (p<0,001) e altura do ramo mandibular (p<0,001), nos grupos experimental e controle-operado. Houve diferença significante para a altura do corpo mandibular (p=0.001) e para o comprimento das porções anterior (p=0,002) e posterior (p=0,001) da maxila apenas no grupo experimental. Os resultados obtidos permitiram concluir que uma fratura de côndilo mandibular experimental durante o período de crescimento em ratos levou a uma assimetria da mandíbula na altura do corpo mandibular, com conseqüências também para a maxila.
The present study analyzed the effects of the condyle fracture were analyzed in the growing period in this study. Fifty young Wistar rats weighting 100g were used. Under general anestesia fracture of the condilar process on the right side with deviation was performed in the experimental group, while only the made surgical access was performed in the sham-operated group. The animals were sacrifized with three months of age. The mandible was disarticulated, and radiographic projections axial of dried skull and lateral of the hemimandible were obtained. Cephalometric mensurations through a computer system were made. Statistical tests "t" of Student between the groups and paired test "t" of Student among the sides, inside of each group were applied. There was a significant different among the groups to the right side in the length of the anterior portion (p=0,001) and posterior (0,017) of the maxilla and height of the mandibular ramus (p=0,001). There was significant difference among the sides for the length of the mandible (p <0,001) and height of the mandibular ramus (p<0,001), in the height of the body mandibular (p=0.001) and for the length of the anterior portions (p=0,002) and posterior (p=0,001) of the maxilla just in the experimental group. The obtained results allowed to conclude that a experimental fracture of mandibular condyle during the growing period in rats induced an asymmetry of the mandible in the height of the mandibular body, with also consequences to the maxilla.

Introdução: A osteoartrite (OA) é caracterizada como sendo uma doença degenerativa das articulações, apresentando uma reação inflamatória de baixo grau. Dependendo da severidade da osteoartrite, os tratamentos podem ser cirúrgicos ou não cirúrgicos. A condilotomia é uma opção de técnica cirúrgica sem interposição articular, em que se realiza uma fratura guiada, a partir de uma osteotomia oblíqua no processo condilar da mandíbula. Após a cirurgia, o côndilo assume uma posição mais anterior e inferior, com recaptura do disco, possibilitando funcionalidade articular e processo de reparo. Proposição: O objetivo do presente trabalho foi avaliar os efeitos da condilotomia nas estruturas teciduais do côndilo da articulação temporomandibular de coelhos portadores de osteoartrite quimicamente induzida. Materiais e métodos: Foram utilizados dois grupos de animais com degeneração de articulação temporomandibular (ATM) quimicamente induzida. O grupo controle (n=15) acompanhou o grupo teste conforme os tempos de morte dos animais. O grupo teste (n=15) foi submetido à fratura cirúrgica guiada do côndilo mandibular, após 40 dias a partir da indução da doença. A análise histológica da superfície do côndilo mandibular foi realizada considerando-se a severidade da osteoartrite, por meio do escore proposto por Pritzker et al. (2006). Realizou-se a quantificação de colágeno tipo I na camada da cartilagem articular por meio da coloração de Picrossírius, sob efeito de luz polarizada. Os animais foram mortos nos tempos de 20, 40 e 60 dias após a cirurgia. Resultados: A severidade da osteoartrite observada na articulação temporomandibular dos animais do grupo teste no tempo de 60 dias foi comparativamente menor em relação ao grupo teste no tempo de 20 dias e ao grupo controle no tempo de 60 dias. Observou-se um grau maior na severidade da OA no grupo teste de 20 dias em comparação ao grupo controle no mesmo tempo avaliado. A quantidade de colágeno tipo I na camada de cartilagem do grupo controle foi menor em relação ao grupo teste, principalmente na região anterior do côndilo mandibular no grupo controle de 60 dias. Conclusão: A condilotomia é uma técnica cirúrgica eficaz na redução da severidade da osteoartrite quimicamente provocada na superfície condilar da ATM de coelhos. O colágeno tipo III, predominante na camada de cartilagem das articulações com osteoartrite, foi substituído por colágeno tipo I, após a realização da condilotomia.
Background: Osteoarthritis (OA) is a degenerative joint disease, associated with low-grade inflammation. Treatment involves non-surgical and surgical options, depending on the severity of OA. Condylotomy is an alternative procedure that does not require articular interposition, in which an oblique osteotomy of the mandibular condyle is performed to guide the fracture. After surgery, the condyle shifts to an anterior-inferior position, with disk recapture, allowing joint functionality and repair process. Purpose: This study aimed to evaluate the effects of condylotomy on tissue structures of the temporomandibular joint (TMJ) condyle in rabbits with chemically induced OA. Materials and methods: Animals with chemically induced temporomandibular joint (TMJ) degeneration were divided into two groups: control group (n=15), which followed the experimental group as for the time points when deaths occurred; and experimental group (n=15), which underwent surgical fracture guided by osteotomy of the mandibular condyle 40 days after disease induction. Histological analysis of the articular surface of the mandibular condyle was performed considering the severity of OA, using the grading system proposed by Pritzker et al. (2006). The Picrosirius-polarization method was used to quantify type I collagen in the articular cartilage. The animals were killed 20, 40 and 60 days after surgery. Results: The severity of OA in the TMJ of experimental animals at day 60 was comparatively lower than that of experimental animals at day 20 and controls at day 60. Experimental animals showed a higher OA severity grade than controls at day 20. The amount of type I collagen in the articular cartilage of control animals was lower than that of experimental animals, especially in the anterior region of the mandibular condyle of controls at day 60. Conclusion: Condylotomy is an effective surgical technique for reducing the severity of chemically induced OA in the condylar surface of the rabbit TMJ. Type III collagen, which predominates in osteoarthritic articular cartilage, was replaced by type I collagen after condylotomy was performed.

Previous studies have shown growth hormone and therapeutic low intensity pulsed ultrasound can enhance mandibular growth separately. The aim of this study is to evaluate the concomitant effect of both of these applications on mandibular growth in rat. Methods: 24 male Sprague Dawley rats were divided into four groups, 6 in each. Groups 1, 2, 3, and 4 were designated as untreated control, recombinant rat growth hormone, Low Intensity Pulsed Ultrasound, and combination of both groups respectively. After 21 days of daily treatment on mandibular condylar, mandibles from euthanized rats are dissected, and scanned by MicroComputed Tomography to measure the mandibular bone volume, bone surface area, and condylar bone mineral density. Also Real-time Polymerase Chain Reaction was performed on the extracted livers’ C-fos, C-jun, and IGF-1 genes expressions. Results: Groups 2, 3 and 4 showed significant (p<0.05) growth stimulation when compared to the untreated control group. However, there was no statistical significant difference between groups 2, 3 and 4 with regard to bone volume or surface area. Conversely, condylar bone mineral density for group 4 was significantly reduced than groups 1, 2, and 3. Rats’ weights were not significantly different among the treatment groups after the treatment was performed. Additionally, gene expression study showed that the expression of C-jun, in harvested livers for Group 4 was less than that of Group 2 showing fewer side effects. Conclusion: When growth hormone was applied to rats’ mandible together with therapeutic ultrasound, preferential increase in bone volume, and surface area occurred with the expense of condylar bone mineral density and with less potential side effects.
Pharmaceutical Science

Ziel der vorliegenden Arbeit ist die kritische Würdigung der wissenschaftlichen Auseinandersetzung mit der Position des Kiefergelenks. Neben der Darstellung der anatomischen und physiologischen Grundlagen er-folgt ein geschichtlicher Überblick zur Kondylenpositionierung und deren De-finitionen. In der Betrachtung der Bestimmung der Kondylenposition wird grundsätzlich zwischen dynamischen und statischen Untersuchungsbefunden unterschieden. Unter dynamischen Untersuchungsbefunden versteht man jegliche Registrier-techniken zum Einstellen der zentrischen Kondylenposition, die manuelle und die instrumentelle Funktionsanalyse. Statische Untersuchungsbefunde entspre-chen dem Einsatz bildgebender Verfahren und lassen sich in konventionelle röntgenologische bildgebende Verfahren, konventionelle Tomogramme, Com-putertomographie, digitale Volumen-Tomographie, Magnetresonanztomogra-phie und Hochfrequenzarthrosonographie einteilen. Daneben wurde die Aus-sagekraft verschiedener Untersuchungsverfahren zur Diagnostik einer kranio-mandibulären Dysfunktion gegenübergestellt. Es wurde die anatomische und die pathologische Kondylenposition definiert. In dem Zusammenhang konnte festgestellt werden, dass sich eine pathologi-sche Position nur bedingt anatomisch erklären lässt. Die Frage, ob eine Position als pathologisch angesehen werden kann, richtet sich nur danach, ob der Pati-ent in seinem alltäglichen Leben eingeschränkt ist, was unter anderem Kieferge-lenksschmerzen beinhaltet. Eine Kiefergelenksposition, die anatomisch als pa-thologisch zu bewerten ist, der Patient jedoch schmerzfrei ist, kann als physio-logisch angesehen werden. Das Gelenk hat sich an die neue Position angepasst, es ist vollständig adaptiert. Es gibt aber auch Gelenkpositionen, die röntgeno-logisch unauffällig sind, der Patient jedoch Schmerzen hat; diese Position wird als pathologisch eingestuft. Folglich ist der Adaptationsgrad eines Gelenkes der ausschlaggebende Faktor, ob ein Gelenk als pathologisch oder physiologisch eingestuft werden kann. Gesichert ist, dass die Okklusion einen Einfluss auf das Ausbilden einer krani-omandibulären Dysfunktion hat. Wie groß dieser Einfluss ist, kann auch nach Sichten der Literatur nicht eindeutig geklärt werden. Abschließend wird die Bedeutung der Positionierung des Gelenkes in der Traumatologie, Prothetik und der Dysgnathiechirurgie untersucht. Eine exakte Positionierung des Gelenks ist in allen Bereichen von entscheidender Bedeu-tung. Für diese Teilbereiche der Zahnmedizin gilt, dass eine funktionelle Vor-behandlung hilft, die Kiefergelenkszentrik einzustellen. Diese wird heute als die Position angesehen, in der das Kiefergelenk optimal adaptiert ist. Durch Vorbehandlung lassen sich im Ramen der Dysgnathiechirurgie postoperativ auftretende Beschwerden minimieren.