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Biomedical subjects

F Lauwers

Publications and source records attributed to F Lauwers.

At least 19 recordsLinked to original sources
PubMed2005

Maxillofacial intraoral distraction osteogenesis followed by elastic traction in cleft maxillary deformity.

We present a case of severe maxillary hypoplasia in a 16 years old cleft patient treated by distraction osteogenesis maxillary advancement. Initial evaluation showed vertical and antero-posterior maxillary deficiencies, and a Class III malocclusion. Two intraoral distractors (Zurich Pediatric Maxillary Distractor, KLS Martin, Tuttlingen, Germany) were placed in a high Le Fort I osteotomy. An initial advancement of 11 mm was obtained, but the resulting occlusion was unsatisfactory (end-to-end occlusion). The consolidation period was reduced to 3 weeks to allow the mechanical manipulation of the newly formed bone with Class III elastics. An additional advancement of 3 mm, caused by elastic orthodontic traction produced both normal skeletal relationship and satisfactory occlusion. This observation shows that it is possible to carry on a skeletal maxillary displacement by interdental elastics before the complete fusion of the callus. After 12 months of postoperative follow-up no osseous relapse could be detected and the occlusal result was stable.

Adolescent↗
PubMed2004

[Caustic burns. Clinical study of 24 patients with sulfuric acid burns in Cambodia].

Over a period of 12 years, 24 burns have been treated by a Cambodgian and French team (Doctors of the World). This experience has revealed some characteristics of this population: (1) a majority of young women (2/3), (2) victims of assault (20 cases). These notions are found in the medical literature particularly South East Asia. All cases are of a third degree. Every surgeon, every anesthetist should apply emergency measures which are recalled here. The aims is to close all the burns surface through a skin graft within a month. However the patients are treated 6 months to 2 years after the burn and have, at this stage, terrible sequella (22 patients). Treating them requires the coordinated efforts of a multidisciplinary specialized team. The challenge is to save the eyes, the mouth, the nose and give back a "human" face to these young burns who are often rejected because of their handicap. Enabling them to smile again is a strong commitment from the surgeon and from the patient who has to undergo multiple operations and a long treatment over the years.

Adolescent↗
PubMed2004

[Frontal muscular balance and botulinum toxin].

A good knowledge of the anatomy of the muscles of upper third of the face and their function, a good understanding of the famous Frontal Muscular Balance, to consider the anatomic and histological modifications induced by ageing in the cutaneous layer and the muscular function of the underlying "peaucier muscles", are essential for a better approach and for an easy and safe use of botulinum toxin, remarkable product, and for avoiding its operator-dependent risks.

Botulinum Toxins, Type A↗
PubMed2004

X-ray high-resolution vascular network imaging.

This paper presents the first application of high-resolution X-ray synchrotron tomography to the imaging of large microvascular networks in biological tissue samples. This technique offers the opportunity of analysing the full three-dimensional vascular network from the micrometre to the millimetre scale. This paper presents the specific sample preparation method and the X-ray imaging procedure. Either barium or iron was injected as contrast agent in the vascular network. The impact of the composition and concentration of the injected solution on the X-ray synchrotron tomography images has been studied. Two imaging modes, attenuation and phase contrast, are compared. Synchrotron high-resolution computed tomography offers new prospects in the three-dimensional imaging of in situ biological vascular networks.

Animals↗
PubMed2001

Craniofacial differences according to the body mass index of patients with obstructive sleep apnoea syndrome: cephalometric study in 85 patients.

We examined the craniofacial characteristics of patients with obstructive sleep apnoea syndrome (OSAS) and correlated them with the body mass index (BMI (weight (kg) x height (m2)). Eighty-five men with OSAS diagnosed by conventional polysomonography were divided into two groups according to their BMI (< 30 and > or = 30). Cephalometry was analysed by using 31 measurements of the size of the bone structures, their relationships and the size of the airways. The groups were comparable for age and the apnoea-hypopnoea index (mean 49, standard deviation (SD) 23). Patient with a BMI < 30 had a shorter anterior floor of cranial base, a smaller mandible and retroposition of the mandible compared with severly obese patients. These skeletal differences were associated with narrower velopharyngeal and linguopharyngeal spaces. This study sh ows that there is a craniofacial difference between two populations, divided according to their BMI.

Body Mass Index↗
PubMed2001

FSH secretion patterns during pregnant and nonpregnant luteal periods and 24 h secretion patterns in male and female dogs.

The aim of this study was to investigate the secretion patterns of FSH: (i) during the canine oestrous cycle with particular attention to the luteal period; and (ii) during 24 h in male and female dogs. Plasma FSH concentrations were measured by a highly specific homologous canine immunoradiometrical (IRMA) assay using monoclonal antibodies specific for canine FSH. In the first study, FSH concentrations were measured daily from +/- 15 days before until 150 days after the LH surge in groups of pregnant (n = 5) and nonpregnant (n = 5) Beagle bitches. Day 0 of the cycle was the day of the preovulatory LH peak as measured by LH radioimmunoassay. In the second study, FSH concentrations were measured at 1 h intervals for 24 h in five bitches at day 120 after the LH surge and in five males. From day 35 to day 40 after the LH peak, FSH concentrations were higher in pregnant than in nonpregnant luteal phases. A significant and abrupt decrease in FSH concentrations was observed at about the time of parturition (day 65) and was followed by lower FSH concentrations during lactation compared with nonpregnant bitches. FSH concentrations in nonpregnant animals were fairly constant from the end of oestrus to mid-anoestrus. In both post-lactation and anoestrous bitches, plasma concentrations of FSH increased consistently as anoestrus progressed. No significant differences in the mean hour-to-hour patterns of FSH secretion were observed over 24 h and no differences were detected between male and female dogs. However, a clear pulsatile pattern of secretion was observed in all individuals, both males and females, with an apparent 4.8 h interval between peaks. The results of this study demonstrate major differences in FSH secretion between pregnant and nonpregnant bitches. This finding indicates that there are differences in the regulation of the hypothalamo-pituitary-ovarian axis during pregnancy, possibly related to changes in activity of the corpus luteum. The results of this study also demonstrate a pulsatile pattern of FSH secretion in both male and female bitches, with a 4.8 h interval between peaks, and confirms the progressive increase in plasma FSH concentrations observed during anoestrus.

Animals↗
PubMed2000

[Upper airway changes after mandibular setback osteotomy. Concerns for obstructive sleep apnea].

INTRODUCTION: Cases of obstructive sleep apnea syndrome have been described after setback osteotomy. Although such cases are rare, they emphasize the importance of taking into account the structure of the upper airways when performing this type of procedure. We studied the modifications provoked in the upper airways by mandibular setback osteotomy performed for dysmorphism. MATERIAL AND METHOD: We conducted a retrospective cephalometric study in a series of 25 patients. Preoperative and late postoperative films were digitalized to obtain a precise measurement of the bone displacements and changes in the caliber of the retrovelar and retrolingual spaces. The statistical analysis examined the parameters modified by surgery, particularly airway parameters, and those factors which influenced these modifications. RESULTS: We observed a reduction in the retrolingual space [mean 1.7 mm (p < 0.05)] and displacement of the hyoid bone [mean 2 mm lowering compared with the bi-spinal plane (p < 0.05) and 4.1 mm setback in the Francfort projection (p < 0.01)]. These modifications were not correlated with the mandibular setback (measured as the gonial mental angle) but were strongly dependent on variations in the gonial angle. In 20% of the cases, mandibular setback produced a paradoxical effect: enlargement of the airways. DISCUSSION: Little work has been done on the modifications in the upper airways provoked by osteotomies. Mandibular setback osteotomy can, though only a few cases have been reported, create an anatomic situation favoring obstructive sleep apnea. This series demonstrated the very wide variability of the effects on the upper airways. CONCLUSION: The risk of apnea should be included as an important parameter in assessing indications for setback osteotomy.

Cephalometry↗
PubMed1999

[What are the objectives of a humanitarian reconstructive plastic surgery mission?].

What is the place of plastic and reconstructive surgery within the field of general surgery in developing countries? A limited personal experience (15 missions, 220 operated patients), and a more extensive experience of colleagues working in the field for several years, constitute the starting point for discussion. General surgery represented 80% of all surgical activity in the 1970s, but has progressively become more specialized. Analysis of the type of operations shows that the most frequent techniques are simple procedures (skin grafts, local autoplasties). "Basic" plastic surgery corresponds to local possibilities and the population's real needs. The authors describe the demands usually encountered during their missions (Africa, South East Asia). They emphasize the long-term involvement of the same team, at the same site, with the same program to pass on knowledge and, for the surgeon, to experience the richness of another world.

Adult↗
PubMed1999

[Two or three things about the PMSI in stomatology and maxillofacial surgery].

The Information Systems Medicalization Program (PMSI in French) was created in 1985 for Public Health Service Hospitalisation Structures. It appeared to be directly derived from the North-American Diagnosis Related Groups (DRGs) system. Since them, the PMSI has been progressively developed in private structures as well. The authors have had the opportunity to use the latest version of the computer program which was elaborated in order to share the patients into more than 500 different groups of pathology. These groups were called "Homogeneous Patients Groups" (GHM in French). To each group corresponds a "Synthetic Activity Index" number (ISA in French). It is supposed to be representative of the average cost of the management of each kind of patients, based on the diagnosis and the surgery possibly done. Several astonishing findings have been made. Some of them can be summarized as mentioned below: In maxillofacial Surgery, each group (GHM) seems in fact to be extremely inhomogeneous: for example, total parotidectomy with preservation of the facial nerve belongs to the same group as accessory salivary gland exeresis. Total skin graft is in the same group as free composite osseous flap with vascular anastomosis. Coding a surgical procedure leads often to reduce the ISA number in comparison with the same patient without surgery: "impacted third molar" gives 754 points without surgery but only 658 if surgery is performed. Carcinologic surgery is wholly grouped in the same category, even for rather short procedures as isolated partial glossectomy. This group corresponds to a great number of ISA points (6486) while bimaxillary surgery or free flap transfer gives less than 2500 points. In conclusion, the use of the PMSI to allocate financial means can be extremely dangerous for maxillofacial surgery units and consequently for the quality of the medical care in our Specialty. Further studies are obviously necessary to complete a critical analysis of the current system and to improve it.

Abstracting and Indexing↗
PubMed1999

[Mandibular fractures in sports. Retrospective study of 48 cases].

We present a retrospective study of 48 isolated mandibular fractures related to athletic activities. We studied patient age, sex, sport involved, mandibular location of the fracture and the therapeutic implication. The sex ratio was 4/1 and mean age 24 years. Rugby and cross-country biking were the more frequently involved sports (79%). We recall preventive measures. Miniplate osteosynthesis was used as often as possible in order to avoid intermaxillary fixation (IMF) (40%) or to limit the duration of IMF. This allowed early return to sport activities.

Adolescent↗
PubMed1998

[Tools of the Internet in maxillofacial surgery and oral medicine. Practical applications].

Internet has a wide range of functions applicable in the medical domain. Its use has had a clear impact on routine medical practice. The user can consult colleagues, send and receive multimedia files, order books from the library, access specialized reviews or worldwide scientific data on-line as well as publish results, and participate in forums, telephone or organize teleconferences in real time. Faced with the abundance of the available information flow and the methodological difficulty in extracting precisely useful data, the ordinary user can wander a long time in cyber-space before learning the skills required for efficient navigation. We recall here the fundamental principles of the Internet and describe the types of information the maxillofacial surgeon can use in his everyday practice. Certain unanswered questions are debated as well as certain difficulties related to the use of the Internet in its present state of development.

Computer Communication Networks↗
PubMed1997

[The external carotid vein. Historical review of Paul Launay's work].

The authors, one century later, review the anatomical studies conducted by Launay, a student of Farabeuf, concerning the venous drainage of the face and neck. These studies were based on the analogy between the arterial system and the venous drainage of the external carotid territory. After describing the external carotid vein, the didactic and practical aspects of this study are emphasized.

Carotid Artery, External↗
PubMed1996

[Cephalometric study of changes in the upper airways after orthognathic surgery. Significance in the management of obstructive sleep apnea syndromes. Apropos of 43 cases].

The aim of this work was to study long-term airways space changes after maxillomandibular osteotomy in order to assess benefit of this surgery in case of obstructive sleep apnea syndrome. Preoperative and postoperative cephalometric airway spaces evaluation of 43 patients (who did not have obstructive sleep apnea) was done. Analysis revealed no charge in velopharyngeal space, lingual-pharyngeal augmentation in case of mandibular advancement. Hyoid bone position was not modified by osteotomy. Signification and interest of this finding for patients with obstructive sleep apnea are discussed through literature data.

Adolescent↗
PubMed1996

[A rapid intermaxillary fixation technic].

The authors describe a new intermaxillary fixation (IMF) technique. This technique is particularly easy and quick. It needs usual 4/10 or 5/10 steel wire with a small pearl fixed at one extremity. Four wires are used, passed from lingual side to vestibular side, between premolars. Wires are then linked and intermaxillary fixation is performed. Osteosynthesis is realised by intraoral approach. This technique does not allow to maintain IMF during a long postoperative period. Therefore, it should be reserved for cases where miniplate osteosynthesis will be sufficient. It seems interesting to use this technique for monofocal mandibular fractures, in association with rigid miniplate osteosynthesis.

Bicuspid↗
PubMed1996

[Treatment of a case of multiple tooth agenesis: an orthodontic and implant solution].

Now, the excellent long term results observed in oral implantology allow use of implants in young people. They change habitual prosthetic indications which need healthy teeth mutilations. The authors present a case of multiple dental agenesis in a young girl. She was treated by orthodontic preparation and implants with a good final result (2 years end treatment follow up).

Anodontia↗