Search PubMed⌕ Search

Biomedical subjects

D B Tuinzing

Publications and source records attributed to D B Tuinzing.

At least 37 records · Page 2Linked to original sources
PubMed1999

Histological observations of a bilateral maxillary sinus floor elevation 6 and 12 months after grafting with osteogenic protein-1 device.

OBJECTIVE: The purpose of this case study was to analyze the tissue formed in a maxillary sinus, 6 and 12 months after grafting with recombinant human osteogenic protein-1 (OP-1) linked to a collagen carrier of bovine origin. PATIENT AND METHODS: A 49-year-old woman referred for bilateral sinus floor elevation, was grafted with an OP-1 device. After 6 months, a biopsy was taken from one of the grafted areas. After 12 months, during implant placement, 5 biopsies were taken from the grafted area and the maxillary host bone. Biopsies were processed without decalcification for histological analyses. RESULTS: The biopsy taken after 6 months contained newly formed bone, fibrotic tissue and device remnants. After 12 months, however, bone was absent from all biopsies which were taken from the grafted area, while particles of the collagen carrier were still abundant. Inflammatory cells were observed between remnants of the collagen carrier in the grafted area. CONCLUSION: This study indicates that an onset of new bone formation, which was observed after 6 months, did not persist. 12 months after grafting no bone was present in the biopsies from the grafted area, while the collagen carrier had remained. Lack of mechanical loading, as a result of postponing implant placement from 6 to 12 months, may have resulted in resorption of the emerging bone which was present 6 months after grafting.

Biopsy↗
PubMed1999

Biodegradable osteosynthesis in mandibular advancement: a pilot study.

In this pilot study four patients are presented who underwent bilateral sagittal split osteotomies of the mandibular ramus for mandibular advancement. Biodegradable osteosyntheses were used for internal fixation. All patients were from the same dentofacial category: mandibular retrognathia with a low to normal mandibular plane angle. In two patients cylindrical self-reinforced polyglycolide (PGA) rods were used for internal fixation of the osteotomy segments. Long-term evaluation showed a complete ossification at the sites of biodegradable rods. In two other patients, self-reinforced poly(L-lactide) (PLLA) screws with a diameter of 2 mm were used to stabilize osteotomy segments. The two different techniques of osteosynthesis and the problems encountered are discussed.

Absorbable Implants↗
PubMed1999

Psychologic implications of surgical-orthodontic treatment in patients with anterior open bite.

Two hundred eighty-two patients who received surgical-orthodontic treatment to correct anterior open bite were retrospectively evaluated by interview and questionnaires to determine the motivation and expectations before treatment, experience during treatment, psychosocial impact, functional and esthetic results, and satisfaction. All patients underwent a Le Fort I osteotomy, and 126 patients also received a bilateral sagittal split advancement osteotomy. The mean follow-up was 6 years. The most important reasons for treatment, as cited by the patients, were biting and chewing problems (28%), dissatisfaction with facial appearance (26%), and symptoms of temporomandibular joint (TMJ) dysfunction (21%). Patients with anterior open bite had a critical attitude toward facial appearance; therefore, esthetic aspects should be taken seriously. The expectations on chewing ability, phonetics, nasal passage, and facial appearance were met by the treatment; however, expectations on TMJ function, interincisal relationship, and biting ability were not completely fulfilled. There was a subjective improvement of TMJ sounds in 27% and a worsening in 14% of the patients. Dysesthesia of the infraorbital nerve was noticed in 4% of patients and of the mental or inferior alveolar nerve in 23% of the patients. Chewing and biting abilities improved in 53% and 73%, respectively. Facial appearance, self-confidence, and social interaction had improved. Patients had expected more information before and psychologic support after treatment. Despite the relapse of open bite in 20% of the patients, 75% were satisfied with the dental and 85% with the facial appearance.

Adolescent↗
PubMed1998

Preimplant surgery of the bony tissues.

STATEMENT OF PROBLEM: The rationale of preimplant surgery is the creation of an environment that is favorable to the function and long-term survival of endosseous dental implants. Indications for this type of surgery depend on anatomic conditions, implant type, and design of the superstructure. One essential requirement for successful implantation is the presence of sufficient bone in which the implants are placed. Besides the quantity of bone, the quality of bone and the intermaxillary relation play an important role. PURPOSE: This article presents an overview of several techniques for specific implant conditions.

Alveolar Process↗
PubMed1998

Correction of post-traumatic asymmetry by mandibular angle reduction: report of two cases.

We present two patients with post-traumatic mandibular asymmetry, caused by flaring of a fragment containing the mandibular angle in between two fractures. No occlusal disturbance was evident in either case. Instead of refracturing or ramus osteotomies, the asymmetry was corrected by transoral ostectomy of the mandibular angle with good aesthetic results.

Adult↗
PubMed1998

Management of posttraumatic malocclusion caused by condylar process fractures.

PURPOSE: The aim of the study was to evaluate the results of orthognathic surgery in cases with posttraumatic malocclusion as a long-term complication of condylar process fractures. PATIENTS AND METHODS: A retrospective study on 21 patients with posttraumatic malocclusions attributable to condylar process fractures was performed. In group I, 15 patients were treated for asymmetric malocclusion with unilateral or bilateral mandibular ramus osteotomies. In group II, six patients were treated for anterior open bit with either a Le Fort I osteotomy (n=5) or a bilateral ramus osteotomy (n=1). All patients had clinical and radiographic follow-up for at least 1 year. RESULTS: Stable dental and cephalometric results were obtained in all patients except the one in group II who was treated with bilateral sagittal split osteotomies. In two cases, both in the asymmetric group, minor occlusal interferences had to be treated by equilibration in the early postoperative period. CONCLUSIONS: Orthognathic surgery is a predictable and stable method for the treatment of posttraumatic malocclusion due to condylar process fractures. Maxillary orthognathic surgery is successful in correcting symmetric anterior open bites due to bilateral condylar process fractures. Because posttraumatic malocclusion is a rare complication after closed treatment of condylar process fractures, and it can be treated satisfactorily using orthognathic surgery, routine open reduction and fixation of condylar process fractures is not indicated to prevent posttraumatic malocclusion.

Adolescent↗
PubMed1998

Alveolar and skeletal dimensions associated with lower face height.

In this study, the relationships between the lower face height and the structure of the frontal alveolar and basal bone were investigated. The areas and the dimensions of the anterior alveolar and basal midsagittal cross-sectional bone from the maxilla and the mandible were recorded on lateral cephalograms from 460 untreated adults. An index was calculated dividing the sagittal by the vertical dimension of the midsagittal cross-sectional area. The subjects with a normal overbite between 0.5 and 4 mm (N=165) were divided into three groups according to the lower face height. A larger lower face height coincided with a larger maxillary alveolar and basal area and with a smaller mandibular alveolar index. Correlations between the lower face height and the maxillary alveolar index and the mandibular alveolar and basal area were low. It is concluded that long-faced subjects have a large mandibular alveolar height, which is more associated with a narrowed shape than with a large volume of the symphysis.

Adolescent↗
PubMed1998

Condylar remodelling and resorption after Le Fort I and bimaxillary osteotomies in patients with anterior open bite. A clinical and radiological study.

A sample of 259 patients with vertical maxillary hyperplasia, mandibular hypoplasia and anterior vertical open bite, collected from three different institutions, was analysed regarding temporomandibular joint (TMJ) sounds, condylar remodelling, and condylar resorption. All patients underwent Le Fort I osteotomies, and bilateral sagittal split advancement osteotomies were performed in 117 patients. Intraosseous wire fixation was used in 149 and rigid internal fixation in 110 patients. Cephalometric and orthopantomographic radiographs were available before surgery, immediately after surgery, one year postoperatively and at the latest follow up. The mean follow up was 69 months (range 20-210 months). The number of patients with TMJ sounds decreased from 38% to 31%. At the latest follow up 23.6% of the patients showed condylar remodelling, 7.7% unilateral condylar resorption and 7.7% bilateral condylar resorption. Condylar contours, as assessed on orthopantomographic radiographs, were classified as five different types. Condyles with preexisting radiological signs of osteoarthrosis or having a posterior inclination were at high risk for progressive resorption. Female patients with severe anterior open bite, high mandibular plane angle and a low posterior-to-anterior facial height ratio, who underwent a bimaxillary osteotomy, were prone to condylar resorption. Bone loss was predominantly found at the anterior site of the condyle. The incidence of condylar resorption was significantly higher after bimaxillary osteotomies (23%) than after only Le Fort I intrusion osteotomies (9%). Avoidance of intermaxillary fixation by using rigid internal fixation tended to reduce condylar changes, in particular in patients who underwent only a Le Fort I osteotomy. Rigid internal fixation in bimaxillary osteotomies resulted in condylar remodelling in 30% and progressive condylar resorption in 19% of the patients. Condylar changes were not significantly different after using either miniplate osteosynthesis or positional screws in bilateral sagittal split osteotomy procedures.

Adolescent↗
PubMed1998

Sinusfloor elevation and grafting with autogenous iliac crest bone.

Insufficient bone height in the posterior area of the maxilla, due to expansion of the maxillary sinus and atrophic reduction of the alveolar process of the maxilla, represents a contra-indication for insertion of dental implants. This anatomic problem can, in many cases, be solved by augmentation of the floor of the maxillary sinus. This surgical technique was introduced by Tatum. The so-called top hinge door method creates a new floor of the maxillary sinus at a more cranial level. Underneath this new floor the existing space is filled with a bone graft. Implantation in the alveolar process with increased bone height allows insertion of dental implants. This sinus grafting technique was used in the present study. In total, 62 sinusfloor elevations were performed with cancellous iliac bone grafts in 42 patients. In those 62 augmented sinuses, 161 ITI screw type implants were inserted. The follow-up was 1-6 years after implantation. In 2 cases infections occurred. One implant needed an extended integration time. No implants were lost. The ITI solid screw implant appears to be a suitable implant following sinusfloor elevation operations, due to its rough surface, its shape and the size of the thread. The sinusfloor elevation procedure with autogenous cancellous bone graft appears to be a valuable and reliable pre-implantological procedure, provided a proper pre-operative investigation and careful surgery are performed. This procedure allows dental implant placement with a high success rate.

Adult↗
PubMed1998

Stability of transverse maxillary dental arch dimensions following orthodontic-surgical correction of anterior open bites.

A sample of 130 patients with vertical maxillary hyperplasia; mandibular hypoplasia with a high mandibular plane angle; narrow, tapered maxillary dental arch form; and anterior vertical open bite were collected from three different institutions to evaluate the stability of transverse maxillary arch dimensions after correction of the open bite. Surgical treatment consisted of Le Fort I or bimaxillary osteotomies. Intermolar, interpremolar, and anterior arch widths were measured three-dimensionally on dental casts using a Reflex microscope, and transverse stability after orthodontic or surgical maxillary expansion was analyzed. Orthodontic expansion followed by a one-piece Le Fort I intrusion osteotomy was performed in 77 patients, and surgical maxillary expansion by a multisegment Le Fort I intrusion osteotomy was performed in 53 patients. The increase of transverse arch width and the relapse after orthodontic or surgical expansion were not significantly different. The transverse arch width in these two groups did not relapse in 20% of the patients after a mean follow-up of 69 months. An additional bilateral sagittal split osteotomy had no detectable effect on stability. Patients who underwent a multisegment Le Fort I osteotomy stabilized with rigid internal fixation showed better transverse stability than those with intraosseous wire fixation and maxillomandibular fixation. Maxillary intermolar and interpremolar arch width relapses were not correlated with tongue interposition or loss of interdigitation. The relapse of these arch widths showed significant correlations with clockwise rotation of the mandible but not with changes of overbite or overjet.

Adolescent↗
PubMed1998

Alveolar and skeletal dimensions associated with overbite.

The aim of this study was to investigate whether in the maxilla and in the mandible the structure of the anterior medial sagittal alveolar and basal bone is related to the overbite. A total of 460 untreated adult subjects were divided into four groups with either deep bite, normal overbite, end-to-end bite, or open bite and were compared. The overbite, lower face height, and anterior alveolar and basal midsagittal cross-sectional areas from the maxilla and the mandible were assessed on lateral cephalometric radiographs. An index was calculated, dividing the sagittal by the vertical dimension of the midsagittal cross-sectional area. A deeper bite coincided with smaller lower face height, larger alveolar and basal areas, and a more widened shape of the symphysis. If the lower face height was introduced as a covariable, the open bite group showed significantly smaller maxillary and mandibular alveolar and basal cross-sectional areas compared with the end-to-end group, the normal overbite group, or the deep bite group. Vertical variation of the overbite probably coincides with a relative hyperdevelopment or hypodevelopment of the symphysis.

Adolescent↗
PubMed1997

The value of long-term follow-up of mandibular advancement surgery in patients with a low to normal mandibular plane angle.

The objective of this study was to evaluate retrospectively the stability of mandibular advancement via bilateral sagittal split osteotomies. Two fixation methods were compared: intermaxillary fixation (IMF) and rigid internal fixation (RIF). The hypothesis was that, in patients with a low to normal mandibular plane angle (MPA) in retrognathia, the bilateral sagittal split osteotomy (BSSO) to advance the mandible is a predictable and stable procedure and that no significant changes occur after 1 year. Twelve patients with mandibular deficiency with a low to normal MPA (mean 24.7 degrees, range 20.3 degrees-30.7 degrees) underwent BSSO with IMF. The follow-up period was at least 5 years (mean 6.3, range 5-9.1 years). Cephalometric analysis using a commercial software package was performed on radiographs that were taken immediately preoperatively (T0), within 6 weeks postoperatively (T1), 1 year postoperatively (T2), and at least 5 years postoperatively (T3). The average advancement at B point was 4.7 mm (range: 3-7 mm). The assessment of B point in regard to relapse showed no significant change. One patient showed a relapse due to condylar resorption. Forty-five consecutive patients were treated with RIF. Radiographs were taken preoperatively (T0), 6 weeks postoperatively (T1), and 1 year postoperatively (T2). This group had a mean MPA of 26.2 degrees, range 10 degrees-32 degrees. The average B-point advancement was 4.4 mm (range 1-10 mm). No patient showed a clinically significant relapse at T2.

Adult↗
PubMed1997

Skeletal and dento-alveolar stability of Le Fort I intrusion osteotomies and bimaxillary osteotomies in anterior open bite deformities. A retrospective three-centre study.

A sample of 267 patients with maxillary hyperplasia, a Class I or Class II/I occlusion and anterior vertical open bites, collected from three different institutions, was analysed regarding stability after surgical corrections. Skeletal and dento-alveolar stability of the maxilla, and positional changes of the mandible and of the incisors were evaluated. All patients underwent Le Fort I intrusion osteotomies and in 92 patients segmentation of the maxillae was performed. An additional bilateral sagittal split advancement osteotomy was performed in 123 patients. Intraosseous wire fixation was used in 153 patients and rigid internal fixation in 114 patients. Cephalometric radiographs were collected before orthodontic treatment, before surgery, immediately after surgery, one year postoperatively and at the latest follow up. The mean follow up was 69 months (range 20-210 months). It can be concluded that patients with anterior open bites, treated with a Le Fort I osteotomy in one-piece or in multi-segments, with or without bilateral sagittal split osteotomy, exhibited good skeletal stability of the maxilla. Rigid internal fixation produced the best maxillary and mandibular stability. The mean overbite at the longest follow up was 1.24 mm and a lack of overlap between opposing incisors was present in 19%. The overbite did not differ significantly between the different treatment procedures, probably due to compensatory movements of the mandibular and maxillary incisors.

Adolescent↗
PubMed1997

Gender-confirming facial surgery: considerations on the masculinity and femininity of faces.

While aesthetic facial surgery performed for reasons of undesired facial masculinity or femininity has had some attention in the literature, there is a lack of information on gender-confirming facial surgery as part of an overall surgical sex reassignment program. In this paper we try to capture some of the sex differences, respectively, of skeleton, musculature and other subcutaneous soft tissues, integument and frame of the face. From this, we come to a description of some general differences of facial appearance between the sexes. In restructuring the skeletal architecture and facial proportions to match the desired gender, these factors should be taken into account.

Cephalometry↗
PubMed1996

Facial corrections in male to female transsexuals: a preliminary report on 16 patients.

PURPOSE: The need for facial corrective surgery to facilitate passing as a member of the other sex occurs in a relatively low percentage of male-to-female transsexuals. The aim of this study was to explore criteria and techniques for facial corrections in male-to-female transsexuals because little is known on objective measures for meaningful facial alterations in the female direction. PATIENTS AND METHODS: In the period 1992 to 1994, 16 male-to-female transsexual patients were eligible for bony facial corrections. Several techniques were used to feminize the masculine appearance: mandibular angle reduction, genioplasty, bimaxillary osteotomy, and zygoma onlay and zygoma sandwich osteotomies. RESULTS: Subjectively good results were obtained. Improvement in quality of life was not objectively assessed. CONCLUSIONS: Facial corrective surgery seems to be promising in selected cases of male-to-female transsexualism. Further research is recommended on quantification of the differences in male and female faces for optimal indications and design of this type of surgery. The psychosocial aspects of the facial surgery and long-term stability of the surgical result also need to be further investigated.

Adult↗
PubMed1996

Inferior positioning of the maxilla by a Le Fort I osteotomy: a review of 25 patients with vertical maxillary deficiency.

In 25 patients with vertical maxillary deficiency, selected for a group of 410 Le Fort I osteotomies, the anterior part of the maxilla was repositioned inferiorly. Four groups could be distinguished. A group (n = 6) with downgrafting of the maxilla alone, fixed with wire osteosynthesis, a group (n = 6) treated with Le Fort I and sagittal split osteotomy with a wire-fixed maxilla, a group (n = 8) with a Le Fort I and vertical ramus osteotomy where the maxilla was fixed with wire and group (n = 5) treated by Le Fort I and vertical ramus osteotomy in which the maxilla had been fixed with miniplate osteosynthesis. In the group of single maxilla repositioning and in bimaxillary group with a plate-fixed maxilla, the range of relapse was -0.3 mm to +1.0 mm (mean + 0.4 mm) and 0 mm to + 1.0 mm (mean + 0.5 mm) respectively, which was not correlated to the distance of inferior repositioning. The bimaxillary cases, in which the maxilla had wire osteosynthesis, showed postoperative relapse ranging from - 1.4 mm to + 3.4 mm (mean + 1.3 mm) (sagittal split osteotomy) and - 1.1 mm to + 3.7 mm (mean + 1.2 mm) (vertical ramus osteotomy). In these cases the outcome of surgical intervention appeared completely unpredictable. If these figures are presented as percentages as is done in the literature in the majority of publications, a misleading impression appears. Likewise information about operation technique, fixation methods and linear measurements of movement and relapse (instead of percentages) are essential in comparing different studies.

Adult↗