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Supracrestal bone growth around partially inserted titanium implants in dogs. A pilot study.

8 titanium implants (Nobel Biocare, Göteborg, Sweden) were inserted into edentulous lower premolar areas of 4 dogs so that 6 threads of the implant protruded from the bone crest. Newly-developed perforated dome-shaped titanium space maintainers were fixed to the implant with cover screws. Autogenous bone fragments were placed under the space maintainers. On one side of the arch, the space maintainer was covered with a non resorbable cell occluding barrier. The implant/space maintainers were submerged under coronally positioned flaps. Following a 3-month healing period, there was a mean gain of new bone amounting to 2.5 mm for all specimens. A greater height of bone was found for those sites in which an ePTFE membrane was used; 3.1 mm vs. 1.9 mm (p < 0.05). This study demonstrated the potential of coronal bone growth of the alveolar bone in a protected space around crew implants with exposed treads when placed in the dog.

Alveolar Process↗

Maxillary sinus augmentation using different grafting materials and dental implants in monkeys. Part I. Evaluation of anorganic bovine-derived bone matrix.

The aim of this study was to evaluate clinically, histologically and histometrically the use of anorganic bovine bone matrix (i.e. Bio-oss) as a grafting material for maxillary sinus augmentation procedures. In 4 adult male rhesus monkeys (i.e. Macaca mulatta) the 1st, 2nd and 3rd maxillary molars on one side of the jaws were extracted. The remaining bone between the alveolar crest and the bottom of the sinus was then reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed on one side of the jaws in each monkey and the sinuses were grafted with the bovine bone matrix. At that time, 2 IMZ pure titanium plasma coated implants were immediately placed into the augmented sinuses (i.e. simultaneous implants-loaded group). After 4 months, 2 additional similar implants were placed into these previously augmented sinuses (i.e. delayed implants-loaded group). Four months later, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice of the animals). The contralateral side of each monkey received the same treatment with the exception that the extractions were performed 7 months after those in the opposite side and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous implants-unloaded group and delayed implants-unloaded group) were obtained. Clinically, all loaded implants were stable at the day of sacrifice. Histologically, the grafted sinuses exhibited significant bone formation with integration of the bovine bone matrix particles to the new bone. Direct mineralized bone-to-implant contact was greater for the delayed implant placement groups than for the implants installed simultaneously with the sinus augmentation. Furthermore, the percentage of direct mineralized bone-to-implant contact was greater in the residual bone than in the augmented area. It was concluded that the anorganic bovine bone matrix facilitated bone formation and implant osseointegration in the augmented sinuses and that the delayed implant placement in combination with the sinus augmentation procedure seemed to be preferable.

Alveolar Process↗

Maxillary sinus augmentation using different grafting materials and osseointegrated dental implants in monkeys. Part II. Evaluation of porous hydroxyapatite as a grafting material.

The aim of this study was to evaluate clinically, histologically and histometrically the use of porous hydroxyapatite (i.e. Interpore-200) as a bone grafting material for maxillary sinus augmentation procedures. In 4 adult male rhesus monkeys (i.e. Macaca mulatta) the 1st, 2nd and 3rd maxillary molars on one side of the jaws were extracted and the remaining bone between the alveolar crest and the bottom of the sinus was reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed on one side of the jaws in each monkey, and the sinuses grafted with the porous hydroxyapatite. Two IMZ titanium plasma-sprayed cylinder implants were then immediately placed into the augmented sinus (i.e. simultaneous implants-loaded group). After 4 months, 2 additional similar implants were placed into the previously augmented sinuses (i.e. delayed implants-loaded group). Four months later, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice). The contralateral side of each monkey received the same treatment with the exception that the extractions were performed 7 months after those in the opposite side and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous implants-unloaded group and delayed implants-unloaded group) were obtained. Clinically, all loaded implants were stable at the day of sacrifice. Histologic analysis demonstrated a significant amount of new bone formation in the augmented sinuses. Porous hydroxyapatite graft particles appeared to be integrated to the new bone. The percentage of direct mineralized bone-to-implant contact in the augmented area was greater on the delayed-placed implants than on the simultaneously-placed implants. Also, the percentage of direct mineralized bone-to-implant contact was greater in the residual bone than in the augmented area. It was concluded that this porous hydroxyapatite bone graft enhanced bone formation and bone-to-implant contact in the augmented sinuses and that the delayed implant placement in combination with the sinus augmentation procedure appears to result in a higher percentage of direct mineralized bone-to-implant contact.

Alveolar Process↗

Maxillary sinus augmentation using different grafting materials and dental implants in monkeys. Part IV. Evaluation of hydroxyapatite-coated implants.

The aim of this study was to evaluate clinically, histologically and histometrically the use of hydroxyapatite-coated dental implants in conjunction with maxillary sinus augmentation procedures. In 4 adult male Rhesus monkeys (Macaca mulatta) the 3 maxillary molars on 1 side of the jaws were extracted and the remaining bone between the alveolar crest and the floor of the sinus was reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed in each monkey and the sinuses were grafted with a porous hydroxyapatite bone graft (Interpore-200). At the same time, 2 hydroxyapatite-coated cylinder implants (IMZ) were immediately placed into the augmented sinuses (i.e. simultaneous-implants-loaded group). Four months later, 2 additional similar implants were placed into the previously augmented sinuses (i.e. delayed-implants-loaded group). After 4 months, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice of the animals). The contralateral side of each monkey received the same treatment with the exception that removal of the maxillary molars was performed 7 months after those in the opposite side, and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous-implants-unloaded group and delayed-implants-unloaded group) were obtained. Clinically, all loaded and unloaded implants were stable the day of sacrifice. Histologically, the grafted sinuses exhibited a significant amount of new bone formation with integration of the porous hydroxyapatite graft particles and hydroxyapatite-coat of the dental implants to the new bone. Histometric analysis indicated that on the loaded side the implants placed simultaneously with the sinus lift procedure exhibited greater direct mineralized bone-to-implant contact than the delayed placed implants. In addition, the percentage of direct mineralized bone-to-implant contact was significantly greater in the residual bone in comparison to the augmented area in all groups. Loading of the implants exhibited a positive effect on the percentage of direct mineralized bone-to-implant contact in the augmented area. It could be concluded that hydroxyapatite-coated implants may be of benefit when used in conjunction with sinus augmentation procedures.

Alveolar Process↗

Implant placement and simultaneous ridge augmentation using autogenous bone and a micro titanium mesh: a prospective clinical study with 20 implants.

This prospective clinical study evaluated bone regeneration around 20 dental implants placed in 15 patients (mean age 39.7 years). Peri-implant bone defects were augmented with autogenous bone grafts harvested intraorally from the mandible (chin or retromolar area). Augmented sites were covered with an individually trimmed micro titanium mesh which was rigidly affixed with microscrews to the residual jaw bone. Height of implant exposure (mean 6.5 mm), i.e. dehiscencies (80%) or fenestrations (20%), and graft height (mean 6.2 mm) were measured in an apico-coronal direction using a periodontal probe. At re-entry (mean interval 6.6 months) the titanium mesh and microscrews were removed and bone regeneration assessed. The mean height of the integrated bone graft was 5.8 mm corresponding to a mean bone fill of 93.5%. The overall postop healing course was excellent with only one site developing a soft tissue dehiscence with subsequent mesh exposure (complication rate 5%). This study demonstrated that a micro titanium mesh in combination with autogenous bone grafts is effective for treatment of peri-implant bone defects.

Adolescent↗

Horizontal osteotomy for reconstruction of the narrow edentulous mandible.

The aim of this retrospective study was to evaluate the applicability of a horizontal osteotomy procedure for reconstruction of a narrow edentulous mandible in order to enable insertion of implants. In 7 edentulous patients a narrow inferior alveolar ridge was reconstructed with autogenous bone grafts harvested by a horizontal osteotomy procedure (mean width of the top of the alveolar crest before grafting 1.3 +/- 0.3 mm, after grafting 5.6 +/- 0.6 mm). Insertion of endosseous implants (10 Brånemark implants, 8 ITI Bonefit implants) was performed 3 months after the grafting procedure. Implant supported overdentures were fabricated 3 months after implantation. At regular time intervals a standardized clinical and a radiographic evaluation was performed. All grafted sites showed sufficient bone volume for insertion of the implants at the moment of implantation. At time of evaluation (mean 37 +/- 14.6 months, range 14-68 months) all implants and overdentures functioned well. None of the patients showed a disturbed sensitivity of the lip or chin region. It is concluded that reconstruction of a narrow edentulous mandible with autogenous bone grafts harvested by an intraoral horizontal osteotomy was shown to be a reliable preimplantology procedure with potential applicability in this group of patients.

Adult↗

Long-term evaluation of osseointegrated implants inserted at the time or after vertical ridge augmentation. A retrospective study on 123 implants with 1-5 year follow-up.

The purpose of the present study was to evaluate retrospectively, after 1 to 5 years of prosthetic loading, 123 implants consecutively inserted at the time of vertical ridge augmentation in 4 clinics. At the time of the implant surgery, 3 different techniques were used: the implants were allowed to protrude 2 to 7 mm from the bone level and a titanium reinforced expanded-polytetrafluoroethylene (e-PTFE) membrane was positioned to protect either the blood clot (Group A, 6 patients), or an allograft (Group B, 11 patients), or an autograft (Group C, 32 patients). The annual implant evaluation was carried out according to a standard protocol utilized for long term studies with endosseous implants inserted in non-regenerated bone. Only 1 implant failed immediately after the second stage surgery and after 1 month it was substituted with a new implant. All the remaining implants appeared clinically stable, no signs of radiolucency were present at the bone-implant interface, therefore, they could be defined successfully osseointegrated. The radiographic analysis showed stable bone crest levels with a mean bone loss of 1.35 mm for the Group A, of 1.87 mm for the Group B and of 1.71 for the Group C during the period of observation. Only 2 implants demonstrated an increased crestal bone loss of 3.5 mm and 4 mm respectively at the first year examination. On the base of these results, we can confirm previous long term studies on regenerated bone and we can conclude that vertically augmented bone with GBR techniques responds to implant placement like native, non-regenerated bone.

Adult↗

Lateral ridge augmentation using different bone fillers and barrier membrane application. A histologic and histomorphometric pilot study in the canine mandible.

Lateral ridge augmentation has become a standard treatment option to enhance the bone volume of deficient recipient sites prior to implant placement. In order to avoid harvesting an autograft and thereby eliminating additional surgical procedures and risks, bone grafting materials and substitutes are alternative filler materials to be used for ridge augmentation. Before clinical recommendations can be made, such materials must be extensively studied in experimental models simulating relevant clinical situations. The present pilot study was conducted in three dogs. Different grafting procedures were evaluated for augmentation of lateral, extended (8 x 10 x 14 mm) and chronic bone defects in the mandibular alveolar ridge. Experimental sites received tricalcium phosphate (TCP) granules or demineralized freeze-dried bone allograft (DFDBA) particles. Barrier membranes (ePTFE) were placed for graft protection. These approaches were compared to ridge augmentation using autogenous cortico-cancellous block grafts, either with or without ePTFE-membrane application. After a healing period of six months, the sites were analyzed histologically and histomorphometrically. Autografted sites with membrane protection showed excellent healing results with a well-preserved ridge profile, whereas non-protected block grafts underwent bucco-crestal resorption, clearly limiting the treatment outcome. The tested alloplastic (TCP) and allogenic (DFDBA) filler materials presented inconsistent findings with sometimes encapsulation of particles in connective tissue, thereby reducing the crestal bone width. The present pilot study supports the use of autografts with barrier membranes for lateral ridge augmentation of extended alveolar bone defects.

Alveolar Process↗

Evaluation following functional loading of titanium fixtures placed in ridges augmented by deproteinized bone mineral. A human case study.

The aim of this investigation was to clinically evaluate the periimplant tissues of titanium fixtures, placed in regions augmented using deproteinized bone mineral, after initial functional loading. The original material included 18 individuals (mean age 71+/-9 years) treated using a graft material, Bio-Oss (6 Patients), or Bio-Oss+autogenous bone mixture (12 patients) for alveolar ridge augmentation. 6 titanium fixtures were placed at the time of ridge augmentation. 46 fixtures were placed at a second surgical stage, median 9.5 months after augmentation. Augmentation included crest width (26 fixtures), crest height and width (12 fixtures) and sinus floor lift (14 fixtures) procedures. In addition, 16 fixtures were placed in regions of adequate bone volume. Reconstructions were placed and patients were recalled on a yearly basis. After 4-6.5 years of functional loading, the reconstructions were removed and assessments of fixture stability and periimplant mucosal conditions were made. At this time, 3 patients (13 fixtures) were lost to follow-up (1 deceased, 1 declined to participate, and 1 too ill to attend). In the remaining 15 patients, 7 fixtures were lost due to osseo-disintegration, 2 in one patient in the mandible, and 5 in a second patient in the maxilla. Both individuals were smokers. The remaining 32 fixtures were clinically stable. Periimplant mucosa was healthy with a mean modified sulcular bleeding index of 0.1+/-0.2 and a mean probing depth of 1.5+/-1.1 mm. Radiographic evaluation showed alveolar bone levels at or above the level of the first fixture thread. There were no perifixtural radiolucencies. The survival rate, which coincided with success rate, for fixtures placed in conjunction with ridge augmentation using deproteinized bone mineral was 100% for non-smokers and 43% for smokers after 4-6.5 years of functional loading. No fixture loss occurred in non-augmented areas.

Aged↗

Healing of human extraction sockets filled with Bio-Oss.

The aim of this study was to investigate the healing of human extraction sockets filled with Bio-Oss particles (Geistlich Pharma AG, Wolhusen, Switzerland). In 21 subjects, providing a total of 31 healing sites, at least one tooth was scheduled for extraction and the extraction sites for implant therapy. The dimensions of the alveolar ridge at the extraction sites were considered insufficient and required augmentation concomitant with tooth extraction. There were three treatment groups. In group A, the extraction sockets were covered with a Bio-Gide membrane (Geistlich Pharma AG) and in group B the extraction sockets were filled with Bio-Oss. The extraction sockets in group C were left to heal spontaneously. Biopsies from the extraction sites were collected at the time of implant installation. Samples from group A showed large amounts of lamellar bone and bone marrow and small proportions of woven bone. Sites grafted with Bio-Oss (group B) were comprised of connective tissue and small amounts of newly formed bone surrounding the graft particles. Only 40% of the circumference of the Bio-Oss particles was in contact with woven bone. Sites from group C were characterized by the presence of mineralized bone and bone marrow.

Adult↗

Orthodontic movement in bone defects augmented with Bio-Oss. An experimental study in dogs.

OBJECTIVE: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss. MATERIAL AND METHODS: 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. RESULTS: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. CONCLUSION: During the orthodontic tooth movement the graft material (Bio-Oss) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

Alveolar Process↗

Peri-implant bone regeneration using recombinant human bone morphogenetic protein-2 in a canine model: a dose-response study.

The objective of this study was to evaluate the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) dose on alveolar ridge augmentation and dental implant osseointegration. Bilateral, 5 mm supraalveolar, peri-implant defects were surgically created in 6 beagle dogs. rhBMP-2 (0.05, 0.1 or 0.2 mg/ml) in an absorbable collagen sponge (ACS) carrier was molded around the fixtures and wounds were closed. Treatment variations were alternated between animals (incomplete block design). Animals were sacrificed at week 8 postsurgery. Nine of twelve jaw quadrants healed uneventfully. Two jaw quadrants exhibited wound failure by week 4 and one by week 8 postsurgery. Radiographic bone regeneration was observed in defects without wound failure from week 4 postsurgery. Radiolucent voids of variable size and shape were observed and regressed over time. In weeks 6 through 8, there was an apparent increase in bone density and trabecular structure, while bone height and volume decreased. Histometric analysis revealed limited differences in bone regeneration between experimental conditions. Bone regeneration area averaged (+/- SD) 1.0 +/- 0.5, 3.5 +/- 1.4 and 2.3 +/- 0.4 mm2 for the 0.05, 0.1 and 0.2 mg/ml dose, respectively. There were no significant differences in osseointegration. Osseointegration in newly formed bone averaged 19 +/- 4%, 18 +/- 10% and 21 +/- 6% for the 0.05, 0.1 and 0.2 mg/ml rhBMP-2 sites, respectively. Collectively, the data suggest that there are no dramatic differences in bone induction and osseointegration within the selected dose and observation interval.

Absorbable Implants↗

Augmentation of the narrow traumatized anterior alveolar ridge to facilitate dental implant placement.

Traumatic tooth loss leads to alveolar resorption especially in sagittal direction. This can be due to avulsion of bone substance during the accident itself or due to resorption of the alveolar crest that takes place afterwards. Shortage of bone can prevent proper positioning of dental implants unless the volume of bone is increased before implantation. In the maxillary anterior area, this is also an esthetic problem. Several treatment modalities have been presented to augment the bone. This report reviews the latest literature on bone grafting, bone substitutes, guided bone regeneration, osteocompression and distraction which are potentially useful in the anterior maxilla. A special emphasis is paid to the versatility of using a crestal split osteotomy, by means of chisels and osteotomes to widen the narrow ridge. Three examples are illustrated showing onlay grafting, preservation of alveolar width with alloplastic coral material and lateral widening of a narrow maxillary alveolar ridge, using the crestal splitting technique.

Adult↗

Single-tooth implant treatment in the anterior region of the maxilla for treatment of tooth loss after trauma: a retrospective clinical and interview study.

The aim of this study was to evaluate the results of single-tooth implant treatment in patients where teeth have been lost as a result of trauma. Also, the patients' and professionals' opinions regarding the final outcome of treatment were assessed. Thirty-four patients with 42 lost teeth were evaluated by clinical and radiographic examinations and interviews 2-5 years after treatment. A professional who had not taken part in the treatment evaluated the implant crowns. Central maxillary incisors were the most frequently lost and replaced teeth after trauma (75%) followed by lateral incisors (21%). In patients with incomplete growth, implant treatment was generally postponed until completion of growth. Lack of space was treated by presurgical orthodontics (7%) or by selecting an implant with a reduced diameter (5%). Deficiency of bone was seen in 17% and was treated by bone grafting or local augmentation prior to implant surgery. Patients who had lost two or more teeth after trauma were all subjected to bone grafting. Preservation of roots in the alveolar process seemed to maintain the bone volume enabling better conditions for later implant placement. Forty-one implants (97.6%) were integrated successfully. Complications were few and of minor importance (9.5% before and 12% after cementation of crowns) and could all be managed. No or minimal bone loss was seen. In general, the patients felt that they received good care and that they were well informed about their treatment. Some patients reported that the local anesthesia procedure was not pain-free, but 71% of the patients experienced the treatment as pain-free. For each of the variables (color, shape, height, and size of the crowns), the highest degree of satisfaction was noted in 93-98% of the patients and 91-95% of the single evaluating professional. Given that the patients have finished growth and a careful treatment planning and timing are performed, the functional and esthetical outcome of single-tooth implant treatment today is excellent and can be recommended for replacing tooth losses after trauma in the anterior region of the maxilla.

Adolescent↗

3D volume rendering using multislice CT for dental implants.

OBJECTIVES: To determine the precision and accuracy of three-dimensional (3D) volume rendering spiral multislice computed tomography (CT)-based linear measurements of the mental foramen for dental implants, in vitro, and their precision, in vivo. METHODS: Five cadaver heads were imaged by multislice spiral CT (Toshiba Aquilion) with 0.5 mm thick axial slices (0.5 mm/0.5 s of table feed) at 0.5 mm interval reconstructions. The image data sets were transferred to a networked computer workstation. Using computer graphics the data were analysed with a 3D volume rendering technique using Vitrea software. Two oral and maxillofacial radiologists, independently, made electronic linear measurements from the superior border of the mental foramen to the crest of the alveolar process. The soft tissues were removed and physical measurements made using a 3 Space (Polhemus, Colchester, VT, USA) electromagnetic digitizer with a personal computer running Windows 98. The same linear measurements of 15 patients using the same imaging methodology were performed and the precision was analysed. RESULTS: The findings showed no statistically significant inter- or intra-observer differences in vitro and in vivo, or between imaging and physical measurements in vitro (P>0.05). CONCLUSIONS: 3D multislice spiral CT imaging allows highly accurate measurements for dental implant placement in proximity to the mental foramen. Computer graphics software, using volume rendering is suitable for implant planning.

Aged↗

Validation of spiral computed tomography for dental implants.

OBJECTIVES: To investigate the accuracy of 2DCT orthoradial reformatted images from spiral computed tomography (CT) for pre-surgical planning of dental implants in proximity to the mental foramen. METHODS: Eight cadaver heads were imaged by spiral CT (S/Xpress, Toshiba-America, Tustin, CA) with 1 mm thick axial slices by 1 mm/sec of table feed. The image data set was transferred to a networked computer workstation. Using computer graphics the data was analysed with 2D orthoradial reformatting using the ToothPix (Cemax, Fremont, CA, USA) protocol. Linear measurements were made by two oral radiologists independently from the superior border of the mental foramen to the crest of the alveolar process and from the inferior border of the mental foramen to the mandibular inferior border. The soft tissues were removed and physical measurements made using a 3 Space (Polhemus, Colchester, VT) electromagnetic digitizer with a personal computer running Windows 95. RESULTS: The differences between the measurements on orthoradial 2DCT images and the physical measurements were not statistically significant (P > 0.05). CONCLUSIONS: Two-dimensional spiral CT imaging allows highly accurate measurements for dental implant placement in proximity to the mental foramen. Computer graphics software, using reformatted reconstruction, is suitable for implant planning.

Aged↗

Premolar enucleation.

A study was made on 27 cases where enucleation of four first premolars was performed simultaneously without introduction of mechanical devices to influence space closure. The results suggested that: 1. Enucleation of premolars can be used to minimize the severity of crowding in arch-length deficiency cases. 2. There is no damage to the remaining teeth and alveolar process when enucleation is accomplished with good surgical technique. 3. The average amount of lingual tipping of the mandibular incisors in approximately four years subsequent to the enucleation procedure was 4.1 degrees. 4. This amount of lingual tipping compares quite favorably with the amount of lower incisor uprighting experienced during growth and could not be considered excessive. 5. The mandible does tend to rotate in a counterclockwise manner following enucleation of four first premolars without appliance therapy. This rotation was considered significant in comparison with the amount of rotation that could be expected from an untreated sample. 6. If orthodontic treatment is planned, the enucleation of the manddibular second premolars in borderline extraction cases to avoid excessive lingual tipping of the mandibular incisors would seem to be questionable. 7. Various combinations of enucleation and tooth extraction may be helpful in treatment planning. 8. With judicious timing the enucleation of four first premolars can minimize the severity of the malocclusion simplifying appliance therapy if proper diagnosis and good surgical technique are employed. 9. Although conventional serial extraction may accomplish similar ends, it would appear that enucleation would offer some advantages in terms of autonomous adjustment of the mandibular incisors and root positioning of mandibular cuspids. 10. Enucleation cases usually require fewer traumatic surgical procedures and less supervision by the orthodontist. 11. The parents should be informed that serial extraction procedures including enucleation may simplify but will not eliminate the need for appliance therapy.

Bicuspid↗

Craniofacial pattern of parents of children having cleft lip and/or cleft palate anomaly.

The craniofacial patterns of 38 sets of parents who had children with cleft lip and/or cleft palate anomalies (experimental group) were compared with the 24 sets of parents of healthy (noncleft) children (control group). Using a computerized program, 248 cephalograms (124 lateral and 124 frontal) were digitized and analyzed. The parents in the experimental group exhibited a distinct craniofacial morphology, including a significant decrease in upper anterior facial height (N-Ans) and total anterior face height (V-Gn). Anterior nasal spine (Ans) and maxillary alveolar process (A) were positioned more anteriorly and superiorly in the experimental group, which contributed to a significant increase in the length of the palate (Ans-Pns) and an anterosuperior rotation of the palatal plane. The cranial base angle in the experimental group was significantly obtuse and the articular angle was smaller than that of the controls. The counterclockwise rotation of the mandible was mitigated by a significant increase in the gonial angle. Parents in the experimental group also tended to have faces which were smaller in both transverse and vertical dimensions.

Adult↗