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Biomedical subjects

G Bettega

Publications and source records attributed to G Bettega.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Mandibular growth, its environmental interactions].

A thorough knowledge of mandibular growth is necessary for proper comprehension of growth disorders and malformations affecting the lateral cranio-facial region. The growth mechanisms are complex and multifactorial, the mandible itself is subdivided into two heterogeneous and interdependent segments, as far as growth is concerned. These are the ramus and the corpus. The ramus is interacting with the middle cranial base through the TMJ and the temporo-pterygoid muscle belt. The mandibular body is interacting with the maxilla and the anterior cranial base. Its occlusal role is a function of the adaptive capacity of the alveolodental region.

Alveolar Process↗
PubMed2001

[Morphological alterations of oto-mandibular syndromes].

Otomandibular dysplasia is a congenital malformation defined by a certain degree of temporomandibular or pterygomandibular hypoplasia. The syndrome is characterised by the variability of clinical findings, but the three major features are auricular, mandibular and maxillary hypoplasia. All the laterofacial structures may be affected. The deformity is usually unilateral but bilateral cases exist; a lot of associated malformations have been described. Multiple classification systems have been published. Some of them are very complex, but it is possible to define a simple diagnostic diagram based on ethiopathogenic data. Bilateral involvement affects predominantly the zygoma, and concerns hereditary syndromes. When the mandibular hypoplasia is evident Franceschetti or Goldenhar syndrome is suspected; otherwise Treacher-Collins syndrome is probable. Unilateral cases are not, in general, hereditary and the hypoplasia predominates on the mandible. The difference between hemifacial microsomia or mandibular dysplasia is made by the presence of associated laterofacial deformities.

Ear, External↗
PubMed2001

Sleep apnoea and Turner's syndrome.

A 32-yr-old female with Turner's syndrome and anatomical craniofacial abnormalities, presented with obstructive sleep apnoea syndrome. This was initially treated by nasal continuous positive airway pressure and secondarily cured by maxillomandibullar advancement osteotomy. Anatomical upper airway abnormalities and hormonal factors, which predispose Turner patients to develop obstructive sleep apnoea syndrome, are discussed. A systematic assessment and treatment of sleep-disordered breathing is probably of interest in these patients.

Adult↗
PubMed2001

[Bilateral labio-maxillo-palatal clefts. Therapeutic evaluation].

The wide diversity of bilateral facial clefts makes it most difficult to assess surgical success, particularly in terms of long-term outcome. The aim of this work was to examine the rationale for the current protocol used for cleft surgery at the Grenoble University Hospital. In a first group of 28 children, a 3-step surgical protocol was applied. The first two steps were performed between 4 and 8 months with at least 3 months between each procedure. Skoog's unilateral cheilo-rhino-uranoplasty was used, associated with a periosteal tibial graft. The third step, performed between 10 and 12 months, was for staphylorraphy. Outcome was analyzed at 15 years and evidenced the deleterious effect of excessive and asymmetrical premaxillary scars, of the 2-step cheiloplasty and of columella lengthenings from the lip. The frequency of secondary revision of the superior labial vestibule and the medial labial tubercule (43%) was considered to be high; this procedure should be re-examined as should be osteotomy (32% revision). Palatine closure, acquired in 82% of the cases and premaxillary stability, achieved in 86%, would appear to favor use of the periosteal tibial graft. The osteogenic capacity of this graft tissue was less satisfactory after a second harvesting (from the same tibia three months later). These results have led us to modify our protocol, favoring early and total closure of the bony palate and continued use of the periosteal tibial graft. We now use the following operative protocol: premaxillary alignment using an active orthopedic plate at 2 months, lip adhesion associated with staphylorraphy and passive palatine contention plate at 3 months, definitive bilateral cheilo-uranoplasty associated with a single periosteal graft at 7 months. The preliminary results with this protocol in a group of 12 children have shown better quality scars, more harmonious maxillary arches, an excellent occlusion of the deciduous dentition, and preservation of the positive results obtained with the periosteal tibial graft.

Adolescent↗
PubMed2001

[The French Journal of Stomatology and Maxillofacial Surgery: what is the future?].

UNLABELLED: A scientific journal reflects the dynamics of a specialty and should allow wide diffusion of clinical as well as fundamental research findings in order for all practitioners to keep up with changes in their specialty. These objectives are totally different from a journal designed to meet teaching objectives where general reviews, technical notes or clinical cases are in the forefront. The purpose of this work was to determine the current role of the Revue de Stomatologie et de Chirurgie Maxillo-faciale in an attempt to determine future perspectives. MATERIAL AND METHODS: A Medline research was conducted for the period 1998-2000 to ascertain what French papers in the field of stomatology and maxillo-facial surgery had been published in indexed international reviews devoted to the specialty or related areas. The results obtained were compared with articles submitted for publication in the Revue de Stomatologie et de Chirurgie Maxillo-Faciale in 1999. RESULTS: Nineteen French papers were published in indexed international journals. These papers included 10 original articles, 8 cases reports and one technical note. The 10 original articles issued from 8 different centers and the 19 papers from 12 centers. During 1999, 96 papers were submitted to the Revue de Stomatologie et de Chirurgie Maxillo-Faciale for publication. Before acceptation, these papers included original articles (25%) case reports (45%) and technical notes or reviews (30%). In all, 18 original articles issuing from 10 different centers, the same centers that had published in the indexed international journals, were published. DISCUSSION: Considering that the substance of a scientific review lies in the abundance of its original articles, whether the work reports fundamental or clinical research, but more particularly clinical research for a surgery review, one is obliged to observe that the volume of French publications produced annually is insufficient to fullfil the objectives of a truly scientific journal. The 45% submission rate of case reports is in line with this observation. The number of international publications clearly does not explain this situation since globally, over a 2.5 year period, the number of original articles published was to order of one-third of the number published in the Revue de Stomatologie et de Chirurgie Maxillo-Faciale in the single year of 1999, and since the teams involved were the same.

Dental Research↗
PubMed2000

A simulator for maxillofacial surgery integrating 3D cephalometry and orthodontia.

OBJECTIVES: This paper presents a new simulator for maxillofacial surgery that gathers the dental and maxillofacial analyses together into a single computer-assisted procedure. The idea is to first propose a repositioning of the maxilla via the introduction of 3D cephalometry applied to a 3D virtual model of the patient's skull. Orthodontic data are then integrated into this model, using optical measurements of plaster casts of the teeth. MATERIALS AND METHODS: The feasibility of the maxillofacial demonstrator was first evaluated on a dry skull. To simulate malformations (and thus simulate a "real" patient), the skull was modified and manually cut by the surgeon to generate a given maxillofacial malformation (with asymmetries in the sagittal, frontal, and axial planes). RESULTS: The validation of our simulator consisted of evaluating its ability to propose a bone repositioning diagnosis that would restore the skull to its original configuration. An initial qualitative validation is provided in this paper, with a 1.5-mm error in the repositioning diagnosis. CONCLUSIONS: These results mainly validate the concept of a maxillofacial numerical simulator that integrates 3D cephalometry and guarantees a correct dental occlusion.

Cephalometry↗
PubMed2000

Obstructive sleep apnea syndrome. fifty-one consecutive patients treated by maxillofacial surgery.

The place of surgical treatment in obstructive sleep apnea syndrome (OSAS) remains unclear. Uvulopalatopharyngoplasty (UPPP) has a response rate of 41% overall and only 5% when retrolingual narrowing is present. Thus, in cases with suspected hypopharyngeal collapse maxillofacial surgery has been proposed with improved results. The Stanford group has designed a step-by-step surgical procedure tailored to the specific anatomical abnormalities encountered in each patient. The goal is to avoid a full maxillomandibular advancement osteotomy (MMO), at least in a subgroup of patients, beginning with a limited mandibular osteotomy (with or without hyoid myotomy and hyothyroidopexy and with or without UPPP) (phase 1 surgery). In this procedure MMO is performed as the second or third step (phase 2 surgery). The present study reports on our prospective experience with 51 consecutive patients (64 surgical procedures) treated by the step-by-step maxillofacial surgery previously described by the Stanford team. Only 2 of the 53 patients initially treated were lost for follow-up. Surgery was considered a success if the postoperative apnea and hypopnea index (AHI) was less than 15/h with at least a 50% reduction. Forty-four patients had phase 1 surgery. The success rate was 22.7% (10 of 44). The mean AHI was unchanged with a trend for reduction in the apnea index. Twenty patients had maxillomandibular advancement surgery (phase 2) (13 failures of phase 1, 7 patients primarily because of facioskeletal deformities). The AHI decreased from 59 +/- 29/h to 11 +/- 9/h after phase 2. Of the patients 75% (15 of 20) were considered to have had a successful outcome. In conclusion, phase 1 does not seem effective in most patients with OSAS. The results of phase 2 surgery are successful in young patients with severe OSAS even if the surgical technique is more aggressive.

Female↗
PubMed2000

[Functional evaluation of intraoral reconstructive surgery. A valuable tool: articulatory evaluation of the acoustic signal].

Functional tests are needed to assess the quality of reconstructive surgery after treatment of intraoral cancers. Quality of Life tests are subjective and Cinefluoroscopy is a demanding and non-comparative procedure. We develop here a method to test the capacity of patients to maximize use of their articulatory space. We recorded a corpus of sounds. These sounds were analyzed with classical signal processing procedures. By comparison with a non-distorded sound database, it was possible to evaluate speech disorders, localize the defect, and provide a guide for rehabilitation. This method is an objective, reproductible, and comparative measurement tool.

Cohort Studies↗
PubMed1999

[The chondrocranium of an 18 mm human embryo. A 3-dimensional computer-assisted reconstruction].

INTRODUCTION: Three-dimensional reconstruction of histologic structures is still a real challenge. This is the reason why very few specimens are published, especially for the head. MATERIAL AND METHODS: The chondrocranium of an 18-mm human embryo was reconstructed from serial histologic sections. The three-dimensional reconstruction was based on a software used in geology and adapted to medical applications. This software was able to smooth the reconstructed model, i.e. to correct the distortions due to the histologic preparation. RESULTS: The chondrocranium model is presented. To facilitate spatial orientation, we added the reconstruction of Merkel cartilage, of Reichert cartilage, of the vertebrae, and of the cerebrum. The different portions of the chondrocranium are described. DISCUSSION: The three-dimensional result is described and advantageously compared to the rare wax models available. The morphological differences are detailed. CONCLUSION: This technique of three-dimensional reconstruction with its smoothing procedure is a very well adapted method for reconstruction of histologic structures. The results presented confirm the educational value of this tool, which is otherwise a powerful instrument of morphogenic study.

Anatomy, Cross-Sectional↗
PubMed1998

Oncocytoma of the eyelid: an aggressive benign tumor.

OBJECTIVE: The authors report the case of an 83-year-old patient with a benign oncocytoma of the inferior eyelid. DESIGN: INTERVENTIONal case report. INTERVENTION: Treatment consisted of a large orbital exenteration followed by reconstruction with a pedicled temporalis muscle flap. MAIN OUTCOME MEASURES: Histologic evaluation and clinical follow-up were measured. RESULTS: After a year of follow-up, there was no sign of local recurrence. CONCLUSIONS: Oncocytomas, even if benign, must be considered as very aggressive tumors and treated accordingly.

Adenoma, Oxyphilic↗