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Biomedical subjects

C Malevez

Publications and source records attributed to C Malevez.

At least 19 recordsLinked to original sources
PubMed2006

Neurosensory disturbances after immediate loading of implants in the anterior mandible: an initial questionnaire approach followed by a psychophysical assessment.

The aim of the study was to assess past and present neurosensory disturbances using a questionnaire and a psychophysical approach in patients treated with immediate loaded implants in the edentulous anterior mandible. A group of 65 patients (age range 30-84 years, mean 58 years, 30 women) was enrolled. All were treated by means of three immediately loaded implants (Branemark Novum System). A self-designed questionnaire was used for data collection. The response rate was 89%. Of the 58 responders, 33% (n=19) reported neurosensory disturbances after implant surgery. Nine of these patients (mean age 56 years, seven women) participated in an objective evaluation and were subjected to a psychological and several psychophysical tests. At the moment of the evaluation none of the nine patients still had clinical complaints. Psychological testing revealed no statistical differences between the patients, who had previously experienced subjective complaints, and the control group. Two-point discrimination and thermal sensation tests revealed no sensory lesions. The light touch sensation test at the lower lip indicated a more frequent reduction of tactility for the test group (p<or=0.03). Neurosensory disturbances can occur in the anterior region of the mandible after implant surgery.

Adult↗
PubMed2006

The neurophysiology of osseointegrated oral implants. A clinically underestimated aspect.

Amputation of a limb or a tooth leads to the loss of a large number of exteroceptors. These play an important role in sensory perception and feedback, which tune the motor control. Even after rehabilitation with a prosthetic device, tactile function remains impaired. This can present a subsequent risk of overloading the prosthesis. The peri-implant interface of oral osseointegrated implants is characterized by the absence of a periodontal ligament, a crucial difference towards the natural dentition, from a biomechanical but also from a neurophysiologic point of view. Patients rehabilitated with osseointegrated implants seem subjectively not much impaired in their masticatory and other oral functions. This observation might be linked to the presence of some peripheral feedback pathway to the sensory cortex. It may be attributed to the activation of receptors in the peri-implant environment (either bone or periosteum). This phenomenon called osseoperception, when it relates to the consciousness of the applied stimuli, has been described for both oral and skeletal implants. In the present review, besides osseoperecption other neurophysiological aspects of oral implants, such their reflex function, will be outlined and their clinical meaning pointed out.

Dental Implantation, Endosseous↗
PubMed2002

[Treatment of cleft lip and palate in the children's Hospital Reine Fabiola in Bruxelles].

The priority in the treatment of facial clefts is to avoid the iatrogenic sequellae by restoring a normal anatomy of the face. The difficulty of this treatment is that the majority of the sequellae are only observed 15 years after the primary treatment. After having treated our children during more than 20 years by a primary closure of the lip at 6 months and closure of the palate by push back according to Veau Wardill at 18 months, we adopted the technique of René Malek since 1981 with early closure of the palate at 3 months then, without undermining of the palatal mucosa, closure of the bony palate with a vomer flap at the age of 6 months. Since 1988, in unilateral complete cleft, we perform a complete closure of the lip and palate at 3 months according to the same surgical principles. The study of the dental casts according to the Golson Yardstick at the age of 10 and the cephalometric study by lateral Xrays at the age of 15 show an excellent facial growth in the majority of the cases with only 6% needing a osteotomy at the end of growth. Moreover the phonation of these children was very good in the majority of the cases, 15% only needing a secondary surgery. The only remaining sequellae are in the auditory field with an abnormal frequency of sero mucous otitis. These could not be improved until now despite the early use of tympanic drains.

Belgium↗
PubMed2002

Midfacial morphology in children with unilateral cleft lip and palate treated by different surgical protocols.

The purpose of this study was to compare cranio-facial, particularly midfacial morphology, in two groups of children with complete unilateral cleft lip and palate (UCLP) treated at two different cleft centres (Hannover. Germany and Brussels, Belgium) following different surgical treatment protocols. A total of 62 children (40 males; 22 females) with non-syndromic UCLP were included in this study at approximately the age of 10. The Hannover group comprised 36 children, who had repair of the lip at a mean age of 5.83 +/- 1.16 months, followed by repair of the hard and soft palate at a mean age of 29.08 +/- 4.68 and 32.25 +/- 4.29 months. respectively. The Brussels group consisted of 26 children who underwent surgical treatment according to the Malek protocol: the soft palate was closed at a mean age of 3.04 +/- 0.20 months, followed by simultaneous repair of the lip and hard palate at a mean age of 6.15 +/- 0.68 months. Midfacial morphology was evaluated by means of cephalometric analysis according to Ross. The children in the Hannover UCLP group did not differ significantly from those in the Brussels group in the anteroposterior dimension of the midface. However, the maxillary plane was significantly more open in the Brussels group due to less posterior vertical maxillary development.

Age Factors↗
PubMed2001

Craniofacial distraction osteogenesis: a review of the literature: Part 1: clinical studies.

A review of the literature dealing with distraction osteogenesis (DO) of the craniofacial skeleton, provided by a PUBMED search (National Library of Medicine, NCBI; revised 3 April 2000) from 1966 to December 1999 was conducted. Key words used in the search were distraction, lengthening, mandible, mandibular, maxilla, maxillary, midface, midfacial, monobloc, cranial, craniofacial and maxillofacial. This search revealed 285 articles. One hundred and nine articles were clinically orientated and were analysed in detail in this study. The type of distraction, indications, age, type of surgery, distraction rates and rhythms, latency and contention periods, amount of lengthening, follow-up period, relapse, complications and the nature of the distraction device were analysed. This review revealed that 828 patients underwent DO of the craniofacial skeleton; 579 underwent mandibular DO, 129 maxillary DO, 24 simultaneous mandibular and maxillary DO and 96 midfacial and/or cranial DO. Craniofacial DO has proven to be a major advance for the treatment of numerous congenital and acquired craniofacial deformities. Treatment protocols and success criteria for craniofacial DO are suggested on the basis of these results. There is still, however, a lack of sufficient data, especially on follow-up and relapse, so that treatment strategies have to be validated by long-term studies in the future.

Adolescent↗
PubMed2001

Anterior esthetic rehabilitation on teeth and dental implants optimized with Procera technology: a case report.

With the latest developments of the Procera system, all-ceramic crowns have become an attractive solution to provide functional and esthetic rehabilitation on teeth and dental implants. The Procera AllCeram crown and Procera Abutment embrace the concept of computer-assisted design and computer-assisted machining (CAD/CAM) and can be used together for optimal esthetic result. The purpose of this case report was to illustrate the advantages of these new components for complex anterior rehabilitation. Three natural teeth and a Procera Abutment were restored using four Procera AllCeram crowns. Treatment planning and esthetic benefits are discussed.

Aluminum Oxide↗
PubMed2001

Clinical and radiographic evaluation of the papilla level adjacent to single-tooth dental implants. A retrospective study in the maxillary anterior region.

BACKGROUND: The regeneration of gingival papillae after single-implant treatment is an area of current investigation. This study was designed to determine: 1) whether the distance from the base of the contact point to the crest of the bone would correlate with the presence or absence of interproximal papillae adjacent to single-tooth implants, and 2) whether the surgical technique at uncovering influences the outcome. METHODS: A clinical and radiographic retrospective evaluation of the papilla level around single dental implants and their adjacent teeth was performed in the anterior maxilla in 26 patients restored with 27 implants. Six months after insertion, 17 implants were uncovered with a standard technique, while 10 implants were uncovered with a technique designed to generate papilla-like formation around dental implants. Fifty-two papillae were available for clinical and radiographic evaluation. The presence or absence of papillae was determined, and the effects of the following variables were analyzed: the influence of the 2 surgical techniques; the vertical relation between the papilla height and the crest of bone between the implant and adjacent teeth; the vertical relation between the papilla level and the contact point between the crowns of the teeth and the implant; and the distance from the contact point to the crest of bone. RESULTS: When the measurement from the contact point to the crest of bone was 5 mm or less, the papilla was present almost 100% of the time. When the distance was > or = 6 mm, the papilla was present 50% of the time or less. The mean distance between the crest of bone and the most coronal papilla level (interproximal soft tissue height) was 3.85 mm (SD = 1.04). When comparing the conventional and modified surgical technique, the relation shifted from 3.77 mm (SD = 1.01) to 4.01 mm (SD = 1.10), respectively. CONCLUSIONS: These results clearly show the influence of the bone crest on the presence or absence of papillae between implants and adjacent teeth. The data also show a positive influence for the modified surgical technique, aimed at reconstructing papillae at the implant uncovering.

Adult↗
PubMed2000

Adsorption of peroxidase on titanium surfaces: A pilot study.

The present study demonstrates the in vitro and in vivo adsorption of peroxidase onto titanium surfaces. Titanium foils (mean +/- SEM: 365 +/- 2 mm(2), n = 114) were incubated during 30 min with lactoperoxidase (4 mg in 5 mL 100 mM phosphate buffer pH 7). After 15 washings by H(2)O, titanium foils were incubated with o-phenylenediamine (6 mg/mL) and H(2)O(2) (7 mM) during 30 min. The reaction was then stopped by the addition of HCI 1M and the absorbance of the liquid phase was read on a spectrophotometer at 492 nm. In vitro adsorbed lactoperoxidase onto titanium surfaces was 0.70 +/- 0.05 ng/mm(2) (mean +/- SEM, n = 30). X-ray photoelectron spectroscopy confirmed the incorporation of protein nitrogen onto titanium surfaces: the nitrogen atomic percentage increased from 0.9 +/- 0.3 to 12.7 +/- 0.2% (n = 3) and from 3.7 +/- 0.1 to 14.4 +/- 0. 4% (n = 5) when titanium foils were incubated in the lactoperoxidase solution during 30 min and 24 h respectively. In vivo, oral peroxidases adsorbed on titanium healing abutments from 0.01 to 0.58 ng/mm(2) (n = 19) after 2 weeks in the oral environment.

Adsorption↗
PubMed2000

Maxillary distraction osteogenesis: a method with skeletal anchorage.

Maxillary distraction osteogenesis is a challenging technique to treat severe maxillary retrusion. Maxillary advancement by distraction has the advantage to provide new bone in combination with simultaneous expansion of the soft-tissue functional matrix. Cleft lip and palate patients can present with severe maxillary retrusion and Class III malocclusion. Two 13-year-old patients, born with non-syndromic cleft lip and palate, underwent maxillary distraction--one had a bilateral, the other a unilateral complete cleft lip and palate. Maxillary advancement was performed using an external distraction device in combination with titanium miniplates as a skeletal maxillary anchorage. After a complete Lefort I osteotomy with pterygomaxillary disjunction, a latency period of 3 days was respected. On the fourth postoperative day, distraction was initiated at the rate of 1 mm/d. Preoperative clinical photographs, dental casts, lateral cephalograms, and panoramic radiographs were taken. Further lateral cephalograms were obtained after the latency period, after completion of the active period of distraction, at the completion of the consolidation period, and at 6 and 12 months postoperatively. The aesthetic outcome was excellent and skeletal advancement of 8 and 7 mm was measured without dentoalveolar compensations.

Adolescent↗
PubMed2000

Maxillary distraction osteogenesis: a two-dimensional mathematical model.

Patients with cleft lip and palate with severe maxillary retrusion usually have a mandible with anterior-superior autorotation and subsequent overclosure and loss of the vertical facial dimension. Maxillary distraction osteogenesis can correct the sagittal maxillomandibular relationship and should simultaneously reestablish vertical dimension through maxillary vertical height increase and clockwise rotation of the mandible to restore facial balance. We present a two-dimensional mathematical model in the sagittal plane, which reestablishes sagittal and vertical skeletal deficiencies and proper occlusal alignment for planning maxillary advancement with distraction osteogenesis in patients with cleft lip and palate. The model is illustrated in a case of a 13-year-old boy with a complete bilateral cleft lip and palate and severe maxillary retrusion. The two-dimensional mathematical model described in this article allows the surgeon and orthodontist to calculate in a simple and accurate way the ideal distraction vector to advance the maxilla to its desired position.

Adolescent↗
PubMed1999

Maxillary distraction in cleft lip palate patients: a review of six cases.

Cleft lip and palate patients can present with a maxillary retrusion with tendency to Class III malocclusion after cleft repair. Maxillary distraction osteogenesis is a technique that provides simultaneous skeletal advancement and expansion of the soft tissues. Six nonsyndromic cleft lip and palate patients, ages 12 to 16 years (mean, 13.8 years), underwent maxillary distraction; four had a unilateral and two a bilateral cleft lip and palate. After an incomplete LeFort I osteotomy; a latency period of 3 days was respected. On Postoperative Day 4, distraction was initiated through anterior traction on a Delaire facial mask using distraction forces of 900 gm. Photographs and lateral cephalometric radiographs were obtained preoperatively and 4 months after distraction. A cephalometric analysis was performed to compare the sagittal dentocraniofacial morphology before and after distraction. The aesthetic improvement obtained by maxillary distraction osteogenesis during the permanent dentition to correct maxillary retrusion in our cleft lip and palate patients was impressive. Skeletal advancement varying from 1 to 3.5 mm (mean, 1.7 mm) was found. However, significant dentoalveolar compensations occurred in three patients. This was due to the dental anchorage of the distraction device and can be avoided only by the use of skeletal fixation.

Adolescent↗
PubMed1999

Neuro-ophthalmic complication after maxillary surgery.

We report an unusual case of ophthalmoplegia after maxillofacial surgery. A thirteen year old girl with unilateral left cleft lip and palate underwent maxillary advancement by distraction osteogenesis. Postoperatively she developed diplopia. The diplopia was not due to orbital lesions, most often seen after maxillofacial surgery, but to a haemorrhage posterior to the cavernous sinus.

Adolescent↗
PubMed1997

Autologous bone graft to augment the maxillary sinus in conjunction with immediate endosseous implants: a retrospective study up to 5 years.

This study reports the successful use of osseointegrated implants to replace posterior teeth combined with the autogenous bone graft technique in the sinus. Preliminary data (1 to 6 years experience) of this one-stage procedure are presented. A total of 33 patients were treated--44 sinus grafts were augmented with bone from the anterior iliac crest. Reconstruction was completed with ceramic fixed partial dentures, and there was a follow-up of 3 to 80 months (mean 40.2 months) after loading. None of the 44 sinus grafts was lost. Of the 121 implants placed, eight failed, resulting in a failure rate of 6.6% and a cumulative failure rate of 6.8%. Of the 44 prostheses placed in the 44 sinuses, one failed, resulting in a prosthesis stability of 97.7%. Complications were encountered in three patients (three sinuses, eight implants); treatments were administered, symptoms subsided, and the implants integrated in two patients (two sinuses, six implants). One patient lost the two implants and the prosthesis, but the graft integrated. No other complications have since occurred. The results compare favorably with previous reports in terms of implant survival and stability. The implant survival rate approached that of implants placed in uncompromised maxillary bone.

Adult↗
PubMed1996

Marginal bone levels at Brånemark system implants used for single tooth restoration. The influence of implant design and anatomical region.

In this retrospective study of Brånemark system oral implants, 75 consecutive patients were treated with 84 implants for single-tooth replacement from 1988 to 1993. Two implants were lost and not replaced: the first one before the abutment connection, the latter during the first year in function. The cumulative failure rate reached 2.4% during the 5-year period. Seventy-one percent of the implants were located in the incisor/canine region of both jaws. Twenty-six per cent of the implants were inserted in special presurgical or surgical conditions. The mean annual bone loss as scored on radiograph, was 0.8 mm during the first year and 0.1 mm the following years. Different implant designs were used, a more pronounced bone loss was observed for the conical implant. The present data shows that the cumulative failure rate for single Brånemark implants and radiographic bone loss is similar to that found around implants used for the treatment of complete and partial edentulism.

Adolescent↗
PubMed1992

[Treatment of cleft lip and palate: long-term results].

Since 1958, 900 children with cleft lip and palate were operated on at the University Hospital Brugmann in Brussels. Until 1981, the children were operated at 6 months for the lip and at 18 months for the palate with two flap palatoplasties. Since 1982, R. Malek's technique and sequence were adopted. The results after 5 years follow-up are analyzed between two groups of 50 and 49 children operated with the two techniques. Growth of the maxillary arch and phonation are well improved in the second group, but no improvement was observed in terms of hearing.

Child, Preschool↗
PubMed1990

Treatment of palatal fistula by expansion.

Treatment of a large anterior fistula of the hard palate remains a problem. A new approach is presented by expansion of the palatal mucosa by custom-made implants, allowing closure in two layers without tension or extensive undermining.

Child↗
PubMed1990

[Implants: where, when, how, why?].

The concept of osseointegration which means direct contact between bone and implant has provided new possibilities for implantology and a much more serious approach of the method. Implants are placed following a two phases schedule: first a surgical procedure with a sophisticated insertion of the implants and 3 to 6 months later a prosthetic procedure. Implants can be used in many applications: single tooth replacement, partial and total edentulism. Osseous grafts can be added if needed. Connected and non-connected bridges are built on implants with a tendency to use more non-connected bridges. If all the conditions of placement of the implants and of realisation of the prosthetic supra-structures are respected, there are very few complications. Implants are actually the unique possibility to give the patient fixed oral rehabilitation while preserving the remaining bone and teeth.

Dental Implantation, Endosseous↗