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2.
JAMA Otolaryngol Head Neck Surg ; 144(6): 513-518, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29801027

RESUMO

Importance: Spontaneous cerebrospinal fluid leaks (sCSF-L) of the temporal bone are associated with obesity, calvarial thinning, and obstructive sleep apnea (OSA), and the incidence has doubled in the past decade. It is currently unknown if OSA is independently associated with skull thinning. Objective: To determine if patients with OSA have thinner skulls than patients without OSA. Design, Setting, and Participants: A retrospective cohort study of patients who underwent a level 1 polysomnogram (PSG) and also had high-resolution computed tomographic (CT) imaging of the head from January 2010 to March 2017 at Indiana University was carried out. Patients with moderate to severe OSA (apnea-hypopnea index [AHI]≥25/h) and without OSA (AHI<5/h) were matched for age and body mass index (BMI, calculated as weight in kilograms divided by height in meters squared). Interventions: Measurement of calvarial thickness, extracranial zygoma thickness, skull base height and tegmen dehiscence (>4 mm) when blinded to OSA status. Main Outcomes and Measures: Primary outcomes were calvarial, skull base, and zygoma thickness differences between patients with OSA vs those without OSA. Results: A total of 22 933 patients had a PSG and 1012 also had head CT imaging. Of the 1012 patients with both PSG and CT, the mean (SD) age was 50.8 (16.2) years and 624 (61.7%) were women. Those patients with moderate to severe OSA (56) and without OSA (58) were matched for mean (SD) age (50.3 [6.5] vs 49.8 [6.1] years]) and BMI (37.4 [8.1] vs 38.6 [6.8]). Patients with OSA had thinner mean (SD) calvaria (2.73 [0.67] vs 2.47 [0.52] mm; difference, -0.26 mm; 95% CI, -0.49 to -0.04; Cohen d, 0.44) and thinner skull bases (5.03 [1.40] vs 4.32 [1.28] mm; difference, -0.71; 95% CI, -1.23 to -0.19; Cohen d, 0.53). The mean (SD) extracranial zygoma thickness was the same (4.92 [0.87] vs 4.84 [0.84] mm; difference, -0.07 mm; 95% CI, -0.39 to 0.24). The tegmen mastoideum was dehiscent in nearly twice as many patients with OSA as those without (37% vs 20%; difference, 17%; 95% CI, 0.4-32). Conclusions and Relevance: Obstructive sleep apnea was independently associated with intracranial bone (calvaria and skull base) thinning and not with extracranial (zygoma) thinning. These findings support a possible role of OSA in the pathophysiologic development of sCSF-L.


Assuntos
Crânio/diagnóstico por imagem , Crânio/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Tomografia Computadorizada por Raios X , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Estudos Retrospectivos , Base do Crânio/diagnóstico por imagem , Base do Crânio/fisiopatologia , Zigoma/diagnóstico por imagem , Zigoma/fisiopatologia
3.
J Biol Regul Homeost Agents ; 31(4): 1005-1012, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29254306

RESUMO

The zygomatico-maxillary complex functions as the principle buttress of the face and is the cornerstone to an individual’s aesthetic appearance. Its fracture not only creates cosmetic deformities owing to its position and facial contour, but can also cause disruption of ocular and mandibular functions. The aim of this study was to evaluate the quality, efficacy and impact of internal fixation of zygomatic complex fractures on functional and cosmetic outcomes. A prospective study was carried out on 100 patients who were divided according to the classification and the severity of injury. Subjective evaluation was submitted based on the patient’s perception of signs and symptoms in the preoperative and postoperative periods. Intraoperative and postoperative assessment of bone reduction quality was made according to the type of the fracture and related difficulties; also, the difference between these groups was observed as functional and esthetic outcome. To optimize the treatment of zygomatic bone fractures, a pre-designed questionnaire was used for subjective evaluation of symptoms and treatment outcome. In 70% of cases, ophthalmologic consultation was taken and was most common in type VII fractures (100% cases). Neurosensory disturbance was the most common finding (60%), followed by diplopia (56R%), pain upon mouth opening (54%) and malar depression (50%). Out of all possible 400 fracture sites in 100 patients of zygomatic complex fractures, 266 (66.5%) fractures were detected by clinical examination, in contrast to 330 (82.5%) on radiological examination, which were highest at zygomatic-maxillary buttress (93%) followed by infraorbital rim (91%) and almost equal among fronto-zygomatic site (72%) and zygomatic arch (74%). The scores from the questionnaire for annoyance were significantly higher for paraesthesia (23%) than for trismus (10%), pain (8.5%), or deformity (8.25%). Residual deformity and pain significantly influenced the total satisfaction. Conclusively, there are many treatment modalities available for zygomatic complex fractures, and the preferred methods should be selected on the basis of fracture type, fracture severity, pre-operative signs and symptoms. Regarding the requirements of fracture site exposure and actual fixation, one priority should be to minimize postoperative complications, morbidity and residual deformities.


Assuntos
Fixação Interna de Fraturas/métodos , Complicações Pós-Operatórias/fisiopatologia , Cirurgia Plástica/métodos , Zigoma/cirurgia , Fraturas Zigomáticas/cirurgia , Adulto , Técnicas de Diagnóstico Oftalmológico , Diplopia/etiologia , Diplopia/patologia , Diplopia/fisiopatologia , Diplopia/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Dor/patologia , Dor/fisiopatologia , Dor/psicologia , Parestesia/etiologia , Parestesia/patologia , Parestesia/fisiopatologia , Parestesia/psicologia , Satisfação do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/patologia , Complicações Pós-Operatórias/psicologia , Estudos Prospectivos , Inquéritos e Questionários , Índices de Gravidade do Trauma , Resultado do Tratamento , Trismo/etiologia , Trismo/patologia , Trismo/fisiopatologia , Trismo/psicologia , Zigoma/lesões , Zigoma/fisiopatologia , Fraturas Zigomáticas/patologia , Fraturas Zigomáticas/fisiopatologia , Fraturas Zigomáticas/psicologia
4.
Am J Orthod Dentofacial Orthop ; 148(3): 466-78, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26321345

RESUMO

INTRODUCTION: In this study, we aimed to evaluate the effects of maxillary protraction using traditional labiolingual arches and implant-type protraction devices before orthopedic treatment of patients with skeletal Class III malocclusion. METHODS: A 3-dimensional finite element model of the maxillofacial bones with high biologic similarity and including the sutures was constructed. Through stress and displacement calculations, a biomechanical study was performed for the maxillofacial bones, mandible, and sutures. RESULTS: We quantified detailed changes in the sutures with 2 protraction methods to analyze their effects on the growth of the maxillofacial bones. CONCLUSIONS: (1) The labiolingual arch is suitable for skeletal Class III patients with crossbite and deep overbite. The frontomaxillary and zygomaticomaxillary sutures played major roles in the forward displacement and counterclockwise rotation of the maxilla. The temporozygomatic and pterygopalatine sutures did not change significantly. (2) The implant type of protraction device is suitable for skeletal Class III patients with crossbite and open bite. Both the frontomaxillary and zygomaticomaxillary sutures played decisive roles in the forward displacement and clockwise rotation of maxilla. The temporozygomatic and pterygopalatine sutures showed small changes. (3) The labiolingual arch caused less stimulatory growth on the maxilla, whereas the implant caused greater stimulatory growth on the maxilla. Protraction with the labiolingual arch is more suitable for early skeletal Class III patients at a younger age; protraction with an implant is applicable to skeletal Class III patients in the late mixed dentition or early permanent dentition.


Assuntos
Aparelhos de Tração Extrabucal , Ossos Faciais/fisiopatologia , Análise de Elementos Finitos , Imageamento Tridimensional/métodos , Má Oclusão Classe III de Angle/terapia , Maxila/fisiopatologia , Procedimentos de Ancoragem Ortodôntica/instrumentação , Desenho de Aparelho Ortodôntico , Adolescente , Fatores Etários , Fenômenos Biomecânicos , Suturas Cranianas/crescimento & desenvolvimento , Suturas Cranianas/fisiopatologia , Dentição Mista , Ossos Faciais/crescimento & desenvolvimento , Feminino , Osso Frontal/fisiopatologia , Humanos , Mandíbula/crescimento & desenvolvimento , Mandíbula/fisiopatologia , Maxila/crescimento & desenvolvimento , Palato/fisiopatologia , Rotação , Osso Esfenoide/fisiopatologia , Estresse Mecânico , Osso Temporal/fisiopatologia , Zigoma/fisiopatologia
5.
J Oral Maxillofac Surg ; 72(1): 167.e1-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23945516

RESUMO

PURPOSE: This study investigated stress distribution in maxillas that underwent surgically assisted palatal expansion (SARPE). MATERIALS AND METHODS: Five maxillary models were built: no osteotomy (M1), Le Fort I osteotomy with a step in the zygomaticomaxillary buttress (M2), Le Fort I osteotomy with a step in the zygomaticomaxillary buttress and the pterygomaxillary disjunction (M3), Le Fort I osteotomy without a step (M4), and Le Fort I osteotomy with pterygomaxillary disjunction and no step (M5). Displacement coherence and maximum stress (MS) analyses were used for all models. RESULTS: Areas of tension spread to the maxilla and the region between the alveolar ridge and the palate and a critical point in the median suture for M2, M3, M4, and M5. In M2 and M4, MS spread farther toward and over the pterygoid process, contrary to what was found in M3 and M5. M3 had a better performance than the other models, and the tensile stress was interrupted by the posterior osteotomy, thus avoiding possible damage to the sphenoid bone or difficulties in expanding the posterior region of the maxilla. CONCLUSIONS: The steps in the zygomaticomaxillary buttress and the pterygomaxillary disjunction seem to be important to decrease the harmful dissipation of tensions during SARPE.


Assuntos
Análise de Elementos Finitos , Maxila/cirurgia , Osteotomia de Le Fort/métodos , Técnica de Expansão Palatina , Processo Alveolar/fisiopatologia , Dente Pré-Molar/fisiopatologia , Fenômenos Biomecânicos , Simulação por Computador , Suturas Cranianas/fisiopatologia , Humanos , Incisivo/fisiopatologia , Maxila/fisiopatologia , Modelos Anatômicos , Modelos Biológicos , Dente Molar/fisiopatologia , Palato/fisiopatologia , Osso Esfenoide/fisiopatologia , Osso Esfenoide/cirurgia , Estresse Mecânico , Zigoma/fisiopatologia , Zigoma/cirurgia
6.
Cranio ; 31(4): 300-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24308104

RESUMO

The purpose of this series of case studies was to determine if the frontal plane position of the cranial bones and atlas could be altered using dental orthotics, prescriptive insoles, or both concurrently. The cranial radiographs of four patients were reviewed for the study. Three of the patients were diagnosed as having a temporomandibular joint (TMJ) dysfunction and a preclinical clubfoot deformity. The fourth patient was diagnosed as having a TMJ dysfunction, a preclinical clubfoot deformity and a Catetgory II sacral occipital subluxation, as designated in the chiropractic's Sacro Occipital Technique (SOT). Each patient had a series of four cranial radiographs taken using a modified orthogonal protocol. In two patients, improvement towards orthogonal was achieved when using both prescriptive dental orthotics and prescriptive insoles concurrently. Improvement towards orthogonal was less apparent when using only the prescriptive dental orthotic. No improvement or a negative frontal plane shift was noted when using only the prescriptive proprioceptive insoles. In the third patient, the frontal plane position of the cranial bones and atlas increased (away from orthogonal) when using the generic proprioceptive insoles alone or in combination with a prescriptive dental orthotic. In the fourth patient, the frontal plane position of the cranial bones improved using the dental orthotic. However, the proprioceptive insoles, when used alone or in combination with the dental orthotic, increased the frontal plane position of the cranial bones and atlas. This study demonstrates that changes in the frontal plane position of the cranial and atlas bones can occur when using proprioceptive insoles and/or dental orthotics.


Assuntos
Atlas Cervical/fisiopatologia , Pé Torto Equinovaro/terapia , Órtoses do Pé , Aparelhos Ortodônticos , Aparelhos Ortopédicos , Crânio/fisiopatologia , Transtornos da Articulação Temporomandibular/terapia , Zigoma/fisiopatologia , Pé Torto Equinovaro/complicações , Pé Torto Equinovaro/fisiopatologia , Humanos , Processo Mastoide/fisiopatologia , Propriocepção , Radiografia , Estudos Retrospectivos , Crânio/diagnóstico por imagem , Osso Esfenoide/fisiopatologia , Osso Temporal/fisiopatologia , Transtornos da Articulação Temporomandibular/complicações
7.
Head Face Med ; 8: 33, 2012 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-23217096

RESUMO

INTRODUCTION: Grafting of autologous adipose tissue can be recommended in some cases of facial plastic surgery. Rhabdomyosarcoma is a type of cancer that can also affect the orbit. Enucleation of the eye can cause atrophy of the corresponding hemiface and decreased orbital growth. CASE REPORT: We report a case of a female patient with a medical history of surgical enucleation of the right eyeball, who had received rhabdomyosarcoma radiation therapy in her youth. The patient presented with a depression in the right zygomatic region. We took a dermal-fat flap from the abdominal region, which had been previously treated. RESULTS: The surgical outcome, 48 hours, and much clearly 31 days after the surgery, revealed that the right zygomatic region had returned to its proper anatomical shape, although there were still signs of postoperative edema. DISCUSSION: Very damaged tissues, like those exposed to radiation therapy, are generally not suitable for grafting of adipose tissue. CONCLUSIONS: In the described case, we achieved a technically and aesthetically satisfying result despite the patient's medical history involving several perplexities about the use of autologous dermal-fat tissues, because of prior radiation therapy exposure. The clinical case shows that even a region exposed to radiation therapy can be a valid receiving bed for dermal-fat grafting.


Assuntos
Enucleação Ocular/efeitos adversos , Procedimentos de Cirurgia Plástica/métodos , Gordura Subcutânea/transplante , Zigoma/cirurgia , Adulto , Atrofia/etiologia , Atrofia/cirurgia , Blefaroplastia/métodos , Estética , Enucleação Ocular/métodos , Neoplasias Oculares/patologia , Neoplasias Oculares/radioterapia , Neoplasias Oculares/cirurgia , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Radioterapia Adjuvante , Rabdomiossarcoma/patologia , Rabdomiossarcoma/radioterapia , Rabdomiossarcoma/cirurgia , Medição de Risco , Transplante Autólogo , Resultado do Tratamento , Zigoma/fisiopatologia
8.
Int J Oral Maxillofac Surg ; 41(1): 66-73, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21996084

RESUMO

Midfacial fractures rank first concerning maxillofacial traumatology. Collisions of two heads or head to object are the main causes for these fractures. An investigation based on a transient simulation using the finite element method was performed. A biomechanical head model was created and tested. A transient collision of two heads was simulated. The results were compared to a typical real patient case. This comparison revealed an identical fracture pattern, which can be interpreted as a clinical match of the simulation. The results of this study show the validity of biomechanical investigations, which may serve as a method to better understand maxillofacial fracture patterns. These results will be used for the optimization of fracture therapy or trauma prevention in the future.


Assuntos
Análise de Elementos Finitos , Crânio/lesões , Fraturas Zigomáticas/etiologia , Aceleração , Fenômenos Biomecânicos , Simulação por Computador , Módulo de Elasticidade , Elasticidade , Humanos , Modelos Biológicos , Órbita/fisiopatologia , Fraturas Orbitárias/etiologia , Fraturas Orbitárias/fisiopatologia , Estresse Mecânico , Zigoma/fisiopatologia , Fraturas Zigomáticas/fisiopatologia
9.
Ann Chir Plast Esthet ; 57(3): 296-8, 2012 Jun.
Artigo em Francês | MEDLINE | ID: mdl-22079812

RESUMO

Alloplastic malar augmentation has become a routine procedure associated with few complications. Among them, authors have described bony erosion and resorption. The case presented here illustrates an unusual case of maxillary bone erosion after silastic malar augmentation. Implants were surgically removed and no more surgical intervention was performed. After 15 months, contrast-enhanced CT scan has showed nearly complete bony regrowth to an almost normal state. Considering resorption phenomenons following silastic chin implants, Peled et al. reported no long-term sequellae after implant removal and bony regrowth to the presurgical state after 9 months. Accordingly, we conclude that these phenomenons, even spectacular, are always reversible after implants removal and that treatment should just consist in ablation of the offending prosthetic material.


Assuntos
Regeneração Óssea/fisiologia , Reabsorção Óssea/etiologia , Reabsorção Óssea/fisiopatologia , Dimetilpolisiloxanos , Doenças Maxilares/etiologia , Doenças Maxilares/fisiopatologia , Próteses e Implantes , Zigoma/cirurgia , Reabsorção Óssea/diagnóstico por imagem , Remoção de Dispositivo , Seguimentos , Humanos , Masculino , Doenças Maxilares/diagnóstico por imagem , Pessoa de Meia-Idade , Falha de Prótese , Radiografia Panorâmica , Tomografia Computadorizada por Raios X , Avulsão Dentária/etiologia , Avulsão Dentária/fisiopatologia , Zigoma/fisiopatologia
10.
J Oral Maxillofac Surg ; 69(4): 1166-74, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20685023

RESUMO

PURPOSE: The aim of the present study was to determine whether plates with only 1 screw pair can be used for Le Fort I fracture management. Good postoperative results motivated the direct application of mandible fixation principles to the fractured midface region without additional experimental research. However, the amount and distribution of the forces in the midface region is different from those on the mandible. MATERIALS AND METHODS: Testing was conducted on plastic anatomic models. The validity of the experimental model was tested before the fixation techniques were compared. Standard miniplates and miniscrews were used for fixation of the maxilla. The model surface strain analysis was conducted using the noncontact object grating method, which enabled the surface strain measurement without direct influence on the measured model. RESULTS: In 2 screw pair fixation, the outer screw pair has little effect on the local strain distribution, but it lowers the contact forces along the crack. One screw pair fixation is stable enough for fixation, but it has a greater strain peak at the crack edges. CONCLUSION: Our results showed that 1 screw pair per plate was enough for stable fixation, and 2 or more screw pairs should only be used when the bone fragment at the fracture site cannot sufficiently transmit forces along the crack.


Assuntos
Placas Ósseas , Parafusos Ósseos , Fixação Interna de Fraturas/instrumentação , Fraturas Maxilares/cirurgia , Processo Alveolar/fisiopatologia , Fenômenos Biomecânicos , Fixação Interna de Fraturas/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Maxila/fisiopatologia , Fraturas Maxilares/classificação , Modelos Anatômicos , Osso Nasal/fisiopatologia , Fotografação/métodos , Plásticos/química , Estresse Mecânico , Zigoma/fisiopatologia
11.
Am J Orthod Dentofacial Orthop ; 136(3): 361-6, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19732670

RESUMO

INTRODUCTION: In this finite element study, we compared the stress patterns along the various craniofacial sutures with maxillary protraction with and without expansion. METHODS: Two 3-dimensional analytic models were developed, 1 simulating maxillary protraction and the other simulating maxillary protraction with expansion. The model consisted of 108799 10 node solid 92 elements (tetrahedron), 193633 nodes, and 580899 degrees of freedom. RESULTS: The overall stresses after maxillary protraction with maxillary expansion were significantly higher than with a facemask alone. The magnitude of stress on the craniofacial sutures with maxillary protraction alone was in the range of a few millinewtons per square millimeter, whereas, with maxillary protraction with maxillary expansion, the stresses ranged from a few newtons per square millimeter to a few hundred newtons per square millimeter. The pattern of stress distribution also differed with the 2 treatment modalities as did the sutures experiencing maximum and minimum stresses. CONCLUSIONS: The osteogenic potential of such low stresses after maxillary protraction can be questioned. High stresses generated in various craniofacial sutures after maxillary protraction with expansion are responsible for disrupting the circummaxillary sutural system and presumably facilitating the orthopedic effect of the facemask.


Assuntos
Suturas Cranianas/fisiopatologia , Ossos Faciais/fisiopatologia , Análise de Elementos Finitos , Maxila/patologia , Ortodontia Corretiva/métodos , Técnica de Expansão Palatina , Fenômenos Biomecânicos , Criança , Simulação por Computador , Módulo de Elasticidade , Aparelhos de Tração Extrabucal , Osso Frontal/fisiopatologia , Humanos , Imageamento Tridimensional/métodos , Maxila/fisiopatologia , Modelos Biológicos , Osso Nasal/fisiopatologia , Cavidade Nasal/fisiopatologia , Desenho de Aparelho Ortodôntico , Ortodontia Corretiva/instrumentação , Osteogênese/fisiologia , Técnica de Expansão Palatina/instrumentação , Osso Esfenoide/fisiopatologia , Estresse Mecânico , Osso Temporal/fisiopatologia , Zigoma/fisiopatologia
12.
Clin Biomech (Bristol, Avon) ; 24(8): 606-12, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19631428

RESUMO

BACKGROUND: As an initial step to study facial muscle strengthening by loaded neuromuscular electrical stimulation, we examined the feasibility of applying load to the zygomaticus major, quantified the maximal isometric force of the muscle by volition and electrical stimulation, and compared the measured forces with the results of facial kinematic analysis and electrodiagnostic study. METHODS: Eleven healthy subjects and two female patients with chronic unilateral facial palsy were enrolled. A custom made plastic bridge instrument with a centrally mounted load cell was attached at the mouth angle and to the skin overlying the zygomatic bone using double-sided adhesive tape to provide isometric resistance to skin movement during the muscle contraction. FINDINGS: The force by maximal voluntary contraction of the zygomaticus major averaged 196.4 g force and the contraction force by maximally tolerated stimulation reached 60.1%, on average, of the force by maximal voluntary contraction in normal subjects. There was a significant correlation only between the force by maximally tolerated stimulation and the amplitude of compound muscle action potentials. The force by maximal voluntary contraction of the paralytic side in the patients showed 32.3% and 20.1% of the mean value of the normal subjects. INTERPRETATIONS: This study demonstrates that an isometric load was possibly applied and a significant intensity of electrical stimulation could be tolerated and delivered to the isometrically loaded facial muscle. The isometric loading would be utilized for loaded facial neuromuscular electrical stimulation therapeutically and also for measurement of the force generation capacity of the zygomaticus major diagnostically.


Assuntos
Terapia por Estimulação Elétrica/métodos , Músculos Faciais/fisiopatologia , Paralisia Facial/prevenção & controle , Paralisia Facial/fisiopatologia , Contração Isométrica , Resistência Física , Suporte de Carga , Adulto , Músculos Faciais/inervação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esforço Físico , Zigoma/fisiopatologia
13.
J Craniofac Surg ; 20(2): 275-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19258910

RESUMO

Frontofacial advancement by distraction osteogenesis using the rigid external distraction device has become an accepted treatment for the deformity associated with craniofacial dysostoses (e.g., Crouzon, Apert, and Pfeiffer syndromes). The technical and physiological principles of osteogenesis distraction are well understood. This study documents the pattern of calcification at the osteotomy sites after distraction by analysis of serial three-dimensional computed tomography (CT) scans. The CT scans of 25 patients (11 with Crouzon, 6 with Apert, and 8 with Pfeiffer syndrome) were analyzed. Eleven individual areas along the osteotomy lines were assessed for evidence of bone formation. Scores were assigned within 4 categories ranging from no bone, calcification without bridge formation, a bony bridge, to complete bony infill (>95%). The scans were reviewed on 2 separate occasions by 2 independent assessors. There was high concordance both for intraobserver and interobserver scores. Rigid external distraction frame removal was undertaken after a 6-week consolidation period. All CT scan timings were calculated from this date. Of the 25 patients studied, 16 patients had CT scans available at 3 to 6 months, 12 at 9 to 12 months, and 7 at or more than 18 months. The scans were available in standard coronal slices with three-dimensional reconstructions. Bone formation is most consistently seen in the pterygoid region with calcification consistently occurring earlier and more completely in this area. Bone formation was often delayed in the orbital region and severely delayed or absent in the frontal region and zygomatic arches. There was no significant difference in the order or quality of bony union for the 3 underlying craniofacial dysostoses. This preliminary study confirms the clinical impression that bone formation after distraction is greatest in the pterygoid regions. The clinical implications of these findings are discussed.


Assuntos
Disostose Craniofacial/cirurgia , Osso Frontal/cirurgia , Osteogênese por Distração/métodos , Osteogênese/fisiologia , Procedimentos de Cirurgia Plástica/métodos , Acrocefalossindactilia/cirurgia , Adolescente , Calcificação Fisiológica/fisiologia , Criança , Pré-Escolar , Fixadores Externos , Seguimentos , Osso Frontal/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Lactente , Órbita/fisiopatologia , Órbita/cirurgia , Osteogênese por Distração/instrumentação , Osteotomia/métodos , Procedimentos de Cirurgia Plástica/instrumentação , Osso Esfenoide/fisiopatologia , Osso Esfenoide/cirurgia , Fatores de Tempo , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem , Zigoma/fisiopatologia , Zigoma/cirurgia
14.
Cleft Palate Craniofac J ; 46(2): 187-96, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19254065

RESUMO

OBJECTIVE: To determine whether premature sagittal craniosynostosis is associated with developmental instability in the skull by analyzing fluctuating asymmetry in skull shape. DESIGN: Cranial shape was quantified by collecting coordinate data from landmarks located on three-dimensional reconstructions of preoperative computed tomography (CT) images of 22 children with sagittal craniosynostosis and 22 age-matched controls. A fluctuating asymmetry application of Euclidean distance matrix analysis (EDMA) was used to quantify and compare asymmetry in cranial shape using these landmark data. RESULTS: In contrast to expectations, the sagittal craniosynostosis group did not show a statistically significant increase in the overall level of fluctuating asymmetry relative to the control group. However, we discerned statistically significant localized increases in fluctuating asymmetry in the sagittal craniosynostosis group at pterion and the anterior clinoid processes (alpha = .05). We also determined a significant correlation of fluctuating asymmetry values between the two groups (r = .71). CONCLUSIONS: We conclude that there is no evidence of a role for system-wide developmental instability in the etiology of nonsyndromic sagittal craniosynostosis. However, the localized evidence of asymmetry at the anterior clinoid processes in the sagittal synostosis group suggests an association with the tracts of dura mater that attach there.


Assuntos
Craniossinostoses/fisiopatologia , Osso Parietal/crescimento & desenvolvimento , Fenômenos Biomecânicos , Estudos de Casos e Controles , Cefalometria/métodos , Suturas Cranianas/crescimento & desenvolvimento , Suturas Cranianas/fisiopatologia , Dura-Máter/crescimento & desenvolvimento , Dura-Máter/fisiopatologia , Feminino , Osso Frontal/crescimento & desenvolvimento , Osso Frontal/fisiopatologia , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Lactente , Masculino , Modelos Biológicos , Cavidade Nasal/crescimento & desenvolvimento , Cavidade Nasal/fisiopatologia , Órbita/crescimento & desenvolvimento , Órbita/fisiopatologia , Osso Parietal/fisiopatologia , Osso Esfenoide/crescimento & desenvolvimento , Osso Esfenoide/fisiopatologia , Estresse Mecânico , Osso Temporal/crescimento & desenvolvimento , Osso Temporal/fisiopatologia , Tomografia Computadorizada por Raios X/métodos , Zigoma/crescimento & desenvolvimento , Zigoma/fisiopatologia
15.
Am J Orthod Dentofacial Orthop ; 134(1): 53-9, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18617103

RESUMO

INTRODUCTION: The goal of this study was to analyze the strains induced in the sutures of the midface and the cranial base by headgear therapy involving orthopedic forces. Does the mechanical signal induced in the sutures sufficiently account for a growth-influencing effect? METHODS: A finite element model of the viscerocranium and the neurocranium was used. It consisted of 53,555 tetrahedral elements and 97,550 nodes. The strain induced in the sutures of the cranial base and the midface when applying orthopedic headgear forces of 5 and 10 N was computed and recorded with an interactive measurement tool. RESULTS: The magnitude and the distribution of the measured strains depended on the level and the direction of the acting force. Overall, the strain values measured at the sutures of the midface and the cranial base were moderate. The measured peak values at a load of 5 N per side were usually just below 20 microstrain irrespective of the force direction. A characteristic distribution of strain values appeared on the anatomical structures of the midface and the cranial base for each vector direction. The measurements based on the finite element method provided a good overview of the approximate magnitudes of sutural strains with orthopedic headgear therapy. The signal arriving in the sutures is apparently well below threshold, since the maximum measured strains in most sutures were about 100 fold lower than the minimal effective strain. A skeletal effect of the orthopedic headgear due to a mechanical effect on sutural growth cannot be confirmed from these results. CONCLUSIONS: The good clinical efficacy of headgear therapy with orthopedic forces is apparently based mainly on dentoalveolar effects, whereas the skeletal effect due to inhibition of sutural growth is somewhat questionable.


Assuntos
Suturas Cranianas/fisiopatologia , Aparelhos de Tração Extrabucal , Análise de Elementos Finitos , Adolescente , Fenômenos Biomecânicos , Simulação por Computador , Elasticidade , Ossos Faciais/fisiopatologia , Osso Frontal/fisiopatologia , Humanos , Masculino , Maxila/fisiopatologia , Seio Maxilar/fisiopatologia , Desenvolvimento Maxilofacial/fisiologia , Modelos Biológicos , Osso Nasal/fisiopatologia , Osso Occipital/fisiopatologia , Órbita/fisiopatologia , Base do Crânio/fisiopatologia , Osso Esfenoide/fisiopatologia , Estresse Mecânico , Osso Temporal/fisiopatologia , Zigoma/fisiopatologia
16.
Ann Plast Surg ; 53(5): 473-80, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15502465

RESUMO

Complex maxillofacial fractures demand a detailed understanding of the three-dimensional (3D) pattern of injury. Evaluation of the outcome of the facial fracture repair additionally requires optimal demonstration of fracture gap, bony union, fibrous callus or incorporation of fracture ends, presence of incomplete fusion, or pseudoarthrosis. Although 3D computed tomography (CT) is reliably used for the diagnosis of complex facial fractures, its value in facial fracture healing is unknown. An experimental study was conducted to determine the accuracy of 3D spiral CT scans in evaluating facial fracture healing during the early and late postoperative periods. In 10 adult Wistar Albino rats, a standardized bone defect (3 mm) was created within the mid portion of each zygomatic arch (n = 20). At 10 and 20 weeks postfracture, gap distance displayed by 3D CT and plane radiography (posteroanterior) were measured. At 20 weeks postfracture, intraoperative measurement was also performed. A comparison between 3D CT, radiography, and intraoperative findings was performed. At 10 weeks postfracture, the fracture sites displayed larger bone defects in imaging with 3D CT than with plane radiography. The difference between groups was statistically significant (P < 0.05). The mean defect size imaged by 3D CT was 0.91 +/- 0.82 mm (standard deviation) and by plane radiography was 0.42 +/- 0.16 mm. At 20 weeks postfracture, the mean defect size imaged by 3D CT was 0.56 +/- 0.64 mm, and by plane radiography was 0.38 +/- 0.22 mm. The difference between groups was not statistically significant (P > 0.05). The defect size imaged by both plane radiography and 3D CT was significantly less than the measurement obtained from the intraoperative assessment (P < 0.05). It was concluded that 3D CT has limited benefit in the detection of newly formed bone at week 10 and in the detection of fibrous callus, which can eventually give rise to the bony tissue. Plane radiography is more valid during the early postoperative period (week 10), because it can detect the fibrous callus and newly formed bone more precisely. Gap distance between fracture ends could be determined by 3D CT accurately at week 20, although there was a tendency, which was not statistically significant, to overestimate the amount of bone defect measured by 3D CT when compared with that of plane radiography.


Assuntos
Consolidação da Fratura , Imageamento Tridimensional , Fraturas Cranianas/diagnóstico por imagem , Tomografia Computadorizada Espiral , Zigoma/lesões , Animais , Regeneração Óssea , Consolidação da Fratura/fisiologia , Masculino , Ratos , Ratos Wistar , Fraturas Cranianas/fisiopatologia , Fatores de Tempo , Zigoma/diagnóstico por imagem , Zigoma/fisiopatologia
17.
Rev. otorrinolaringol. cir. cabeza cuello ; 64(1): 32-38, abr. 2004. ilus
Artigo em Espanhol | LILACS | ID: lil-418348

RESUMO

La hiperplasia coronoídea es una condición patológica poco frecuente, con 79 casos publicados a la fecha. Su etiología es desconocida. Corresponde a un alargamiento exagerado de las apófisis coronoídes, cuyo signo clínico principal es la disminución franca de la apertura bucal. Presenta características histológicas normales. Puede ser uni o bilateral. El diagnóstico definitivo se obtiene mediante un estudio imagenológico completo de la región. El tratamiento habitual consiste en la coronoidectomía, complementada con fisioterapia, con resultados clínicos satisfactorios. En el presente reporte se realiza una revisión bibliográfica del tema a propósito de dos casos clínicos.


Assuntos
Humanos , Masculino , Adolescente , Adulto , Articulação Temporomandibular/fisiopatologia , Hiperplasia/etiologia , Hiperplasia/terapia , Mandíbula/fisiopatologia , Modalidades de Fisioterapia , Zigoma/fisiopatologia , Fatores Sexuais , Hiperplasia/diagnóstico , Procedimentos Cirúrgicos Bucais/métodos , Amplitude de Movimento Articular , Transtornos da Articulação Temporomandibular/etiologia
18.
Angle Orthod ; 73(1): 12-20, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12607850

RESUMO

The purpose of this study was to analyze the stress distribution patterns within the craniofacial complex during rapid maxillary expansion. Therefore, a finite element model of a young human skull was generated using data from computerized tomographic scans of a dried skull. The model was then strained to a state of maxillary expansion simulating the clinical situation. The three-dimensional pattern of displacement and stress distribution was then analyzed. Maximum lateral displacement was 5.313 mm at the region of upper central incisors. The inferior parts of the pterygoid plates were also markedly displaced laterally. But there was minimum displacement of the pterygoid plates approximating the cranial base. Maximum forward displacement was 1.077 mm and was seen at the region of the anteroinferior border of the nasal septum. In the vertical plane, the midline structures experienced a downward displacement. Even the ANS and point A moved downward. The findings of this study provide some additional explanation of the concept of correlation between the areas of increased cellular activity and the areas of dissipation of heavy orthopedic forces. Therefore, the reason for the occurrence of sensation of pressure at various craniofacial regions, reported by the patients undergoing maxillary expansion could be correlated to areas of high concentration of stresses as seen in this study. Additionally, the expansive forces are not restricted to the intermaxillary suture alone but are also distributed to the sphenoid and zygomatic bones and other associated structures.


Assuntos
Ossos Faciais/fisiopatologia , Análise de Elementos Finitos , Técnica de Expansão Palatina , Crânio/fisiopatologia , Criança , Simulação por Computador , Suturas Cranianas/fisiopatologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Incisivo/fisiopatologia , Maxila/fisiopatologia , Modelos Biológicos , Septo Nasal/fisiopatologia , Base do Crânio/fisiopatologia , Osso Esfenoide/fisiopatologia , Estresse Mecânico , Tomografia Computadorizada por Raios X , Dimensão Vertical , Zigoma/fisiopatologia
19.
Cells Tissues Organs ; 166(3): 283-93, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10765024

RESUMO

The purpose of this study was to examine the response of the zygomaticomaxillary suture (ZMS) to experimental malocclusion in rats. Thirty-two male Wistar rats were divided into two groups. Malocclusion was produced in the experimental group (n = 20) by gluing a wire, 1 mm in diameter, on the upper left first molar. Duration of the procedure was 20 min. In the control group (n = 12), rats were forced to open their mouths for the same time as in the experimental group. Histomorphological changes of the ZMS were examined at intervals of 1, 2, 4 and 8 weeks. The specimens were stained with hematoxylin-eosin and Mallory's azan. The suture in the control group showed a regular functional arrangement of component fibers, and osteoblasts lined the periphery of new bone at the inner half of the suture. On the untreated side in the experimental group, osteoclasts were most abundant after 2 weeks. Histomorphometric quantification of the sutural width revealed that, at the inner half of the suture, the width of the sutural space on the treated side in the experimental group was greater than that in the control group after 4 weeks (p < 0.05). The argyrophilic nucleolar organizer region (AgNOR) technique was used to investigate the transcriptional activity of fibroblasts in the suture. At the inner half of the suture, the number of AgNORs on the untreated side in the experimental group was greater than that on the treated side and that in the control group after 2 weeks (p < 0.05). Around the tip of the suture and at the outer half of the suture, there was no appreciable difference in the AgNOR number between the experimental and control groups. It was concluded that unilateral changes in occlusion had different effects on the treated and untreated sides of the ZMS. Moreover, the inner and outer halves of the suture showed different histological changes in response to experimental malocclusion.


Assuntos
Suturas Cranianas/patologia , Suturas Cranianas/fisiopatologia , Má Oclusão/patologia , Má Oclusão/fisiopatologia , Maxila/patologia , Maxila/fisiopatologia , Zigoma/patologia , Zigoma/fisiopatologia , Animais , Força de Mordida , Contagem de Células , Núcleo Celular/patologia , Masculino , Osteoclastos/patologia , Ratos , Ratos Wistar
20.
Plast Reconstr Surg ; 101(6): 1561-71, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9583487

RESUMO

Potential alteration of the underlying recipient bone resulting from a graft or implant has significant clinical relevance. The present study was designed to evaluate the biomechanical and histologic alteration of facial recipient bone with autogenous bone graft and alloplastic implants over a 1-year period. The bilateral arches of 15 rabbits were randomized between four groups: (1) control (n = 6), subperiosteal exposure of the zygomatic arch was made; (2) onlay (n = 12), bone graft was placed as an onlay to the zygomatic arch; (3) inlay (n = 6), bone graft was placed as an inlay within the zygomatic arch; (4) implant (n = 6), a stainless steel plate was placed as an onlay to the zygomatic arch. Animals were killed 1 year after grafting. In the onlay groups, all steel implants and half of the onlay bone grafts (n = 6) were separated from the zygomatic arch; the remaining onlay bone grafts (n = 6) were left on the zygomatic arch. Three-point breaking strength was measured through the center of the graft/implant site on the zygomatic arch, followed by histologic evaluation and histometric assessment of residual bone density. The findings demonstrated no difference in the breaking strength per unit bone area between the control zygomatic arch group and the onlay group in which the bone graft was left in place. Breaking strength of the zygomatic arch in the former two groups was significantly greater than that in either group in which the onlay bone graft or implant had been removed, and was also greater than the breaking strength in that group in which inlay bone had been placed (p < 0.05). Histologic assessment showed full-thickness conversion in architecture of the zygomatic arch from compact to woven bone beneath onlays of either autogenous bone graft or steel implant; histometric assessment demonstrated an accompanying decrease in bone density in the latter groups relative to the control zygoma (p < 0.05). We conclude that onlay autogenous bone graft and alloplastic implants to the facial skeleton induce transformation of both graft and recipient bone from compact to woven architecture, accompanied by a reduction in bone density. The biomechanical strength of recipient facial bone is significantly weakened if an onlay bone graft or implant is removed. Weakening occurs per unit area of remaining bone, and is therefore independent of any thinning that may occur within the recipient bone because of graft/implant placement. These findings may impact upon decisions to augment stress-bearing regions of the facial skeleton with bone graft or implants, particularly if the graft/implant may eventually require removal.


Assuntos
Placas Ósseas , Transplante Ósseo , Zigoma/cirurgia , Animais , Fenômenos Biomecânicos , Densidade Óssea , Remodelação Óssea , Feminino , Seguimentos , Masculino , Coelhos , Aço Inoxidável , Resistência à Tração , Fatores de Tempo , Transplante Autólogo , Zigoma/patologia , Zigoma/fisiopatologia
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