Maxillary and mandibular bone reconstruction with hip grafts and implants using Frialit-2 implants

Many types of osseointegrated implants that are very reliable and supported by scientific medium- and long-term studies are presently available. Often, unfavorable anatomic situations require bone augmentation procedures either prior to or at the same time as implant placement. Some of these procedures present limits. Using versatile implant systems is desirable in cases such as advanced osseointe-. gration, intraoral bone grafts or guided bone regeneration techniques, or major surgical reconstruction with bone grafts from the hip. The aim of this study was to evaluate the efficacy of the Frialit-2 implant in 29 clinical cases of maxillary and mandibular reconstruction using different bone augmentation techniques, and to consider its success ratio through a 1- to 5-year follow-up.     

Maxillary sinus augmentation using mandibular bone grafts and simultaneous installation of implants. A surgical technique

This paper presents a specific technique for maxillary sinus augmentation and simultaneous placement of implants in partially edentulous patients. In such patients, there is from time to time insufficient interarch distance for any type of onlay grafting. Health, non-smoking patients without previous or present sinus pathology, where the radiological and clinical examination revealed insufficient height and/or width of the remaining alveolar process in the posterior maxillary region, were selected. They were operated on using a mandibular bone graft obtained from the symphyseal region between the mental foramina and placed in the maxillary sinus. The recipient site was prepared by cutting in a rectangular shape the lateral sinus wall into the sinus lining. The bone wall was then separated towards the lateral nasal wall by rotating the inferior portion of the cut sinus wall medially. In the space thus created, the bone graft was placed. Fixtures were installed at the same session. The method described has proved to be uncomplicated to perform under local anesthesia and no major disadvantages for the patient or pre- or postoperative complications have so far been observed.     

Maxillary and mandibular displacement in hemifacial microsomia: a longitudinal Roentgen stereometric study of 21 patients with the aid of metallic implants.

OBJECTIVE: To record maxillary and mandibular displacement with articular growth and in response to bimaxillary surgical repositioning in patients with hemifacial microsomia (HFM) and to observe ipsilateral corpus/ramus growth in severely affected children. DESIGN: Prospective roentgen stereometric analysis (mean age 7 years 10 months to 18 years 0 months) and retrospective profile and panoramic roentgenograms. Mean total observation period was 9 years 1 month. SETTING: Department of Plastic and Reconstructive Surgery, Malm? University Hospital (Malm?, Sweden). PATIENTS: Twenty-one patients consecutively diagnosed from 1976 through 1988 with HMF, five of whom had bimaxillary surgery. INTERVENTIONS: Surgery was performed at the Department of Plastic and Reconstructive Surgery. Implants were inserted at the initial reconstructive surgical procedure under general anesthesia. Roentgen examinations were performed in connection with continued clinical evaluations and treatment. MAIN OUTCOME MEASURES: Stereo roentgenograms were digitized at the Department of Orthopedic Surgery, Malm? University Hospital (Malm?, Sweden). RESULTS: Displacement of the jaws with articular growth and in response to bimaxillary surgical repositioning varied interindividually with no apparent common pattern. Relapse displacement occurred several years after bimaxillary surgery. Mandibular growth changes were found in the corpus/ramus area and alveolar process on the affected side. CONCLUSIONS: A marked interindividual variability of maxillary and mandibular displacement indicates that the relevance of statistical analysis of HFM growth data may be questioned. We would suggest that precise and accurate longitudinal recordings of growth and response to surgery in individual HFM patients be more appropriate.     

Maxillary changes under complete dentures opposing mandibular implant-supported fixed prostheses

PURPOSE: The aim of this study was to determine whether a condition similar to Combination Syndrome occurs in patients rehabilitated with a maxillary complete denture opposing a mandibular implant-supported fixed prosthesis. MATERIALS AND METHODS: Standardized clinical procedures measured fit, occlusal integrity, and bone loss in the anterior maxilla in 11 edentulous subjects meeting these requirements, from the patient pool of the Implant Centre, United Dental Hospital, Sydney. RESULTS: A mean annual loss of 0.17 mm in the anterior maxillary ridge height was not statistically significant (P > 0.05). However, increased pressure in the anterior maxillary ridge during occlusion and loss of posterior occlusal contacts in retruded position were noted on one or both sides in all subjects. CONCLUSION: Loss of posterior occlusion could not be related to anterior maxillary bone loss. However, to maintain the integrity of the prostheses and their supporting structures, it is important to schedule periodic recall appointments for review of the occlusion.     

Maxillary and mandibular occlusal photographs

Taking occlusal photographs can be challenging; they are by far the most difficult images to obtain. Achieving an ideal photograph of every arch may not always be possible. In patients with limited range of motion of the mandible, an oversized or hyperactive tongue, an excessive gag reflex, or reduced flexibility of lips and checks, the goal of an ideal occlusal photograph may not be achieved. Nevertheless, patience, practice, and attention to detail can often provide a satisfactory result.     

Retention of metallic and non-metallic double-crown-retained mandibular overdentures on implants: An in-vitro study

PurposeTo evaluate the change in the retention of novel metallic and non-metallic combinations for double-crown-retained mandibular overdentures on implants.MethodsCylindrical bases were used to insert four implants arranged in an arch, with 10 mm inter-implant spacing anteriorly, and 35 mm posteriorly. Five groups (n = 8 each) of different materials combinations were tested for retention: zirconia abutments/PEEK framework (ZP), PEEK abutments/PEEK framework (PP), titanium abutments/PEEK framework (TP), titanium abutments/CoCr framework (TC), and titanium abutments/gold copings/cobalt-chromium framework as the control group (TG). The abutment retention height was 4 mm with 1° convergence angle. The retention was measured in a wet condition using a chewing simulator initially, and then at 100, 200, 500, 1,000, 2,000, 3,000, 5,000, 8,000, and 10,000 insertion/separation cycles, which simulates the removing and inserting of an overdenture three times daily for 10 years of function.ResultsThe initial median retention of all groups ranged from 10.0 to 33.3 N. After 10,000 insertion/separation cycles, the median retention ranged from 10.3 to 35.0 N. The change in the retention after 10,000 cycles was not statistically significant within groups ZP and TG. For groups PP and TP, there was a slight increase in retention with partial significance. The retention of group TC showed fluctuation with a partially significant decrease in retention.ConclusionsThe use of novel metallic and non-metallic combinations in the construction of double-crown-retained mandibular overdentures on implants resulted in acceptable levels of retention and might be recommended for clinical application.     

Postnatal width changes in the internal structures of the human mandible: a longitudinal three-dimensional cephalometric study using implants.

This paper presents case-specific quantitative evidence of the systematic lateral displacement of metallic implants in the mandibles of treated and untreated human subjects between the ages of 8.5 and 15.5 years. This evidence appears to be consistent with the inference of small, but systematic increases in distance between the internal structures of the two sides of the osseous mandible during growth. Such a conclusion, however, is inconsistent with traditional beliefs that the internal structures of the mandibular symphysis fuse at the midline during the first post-natal year and remain dimensionally constant thereafter. We recently published evidence of statistically significant transverse displacement of metallic implants in the mandibular body region for 12 of 28 subjects for whom longitudinal data were available. Of the twelve subjects for whom statistically significant changes were observed, widening occurred in eleven cases and narrowing in one. Matching data are now available on concurrent ramus changes for 22 of the same 28 subjects, including 11 of the 12 for whom statistically significant width changes had previously been noted in the body region. In eight of these 11 subjects, statistically significant widening in the ramus region was also observed. No subject had statistically significant widening in the ramus region without also having statistically significant widening in the body region. No subject had statistically significant trans-ramus narrowing.     

Maxillary sinus augmentation using different grafting materials and dental implants in monkeys

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. Mucaca mulattu) 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.     

The width of lingual mandibular attached gingiva.

One hundred and twenty individuals in good oral health were divided into six groups according to age. Measurements were made on the depth of the gingival sulcus, and the distance from the margin of the free gingiva to the mucogingival junction on the lingual mandibular teeth. The mean, extreme, standard deviation and analysis of variance were computed. A distinct pattern of the width of healthy lingual attached gingiva was found. The largest width was found lingual to the first and second molars with a mean height of 4.7 mm. This was followed by the third molar [3mm] second bicuspid [2.5 mm] first bicuspid [2 mm], and cuspid, lateral and central [1.9mm]. Lingual attached gingiva showed that there was a variation in width with each tooth and between individuals. There was no variation in width of lingual attached gingiva between sexes. The extreme measuremtns ranged from less than 1 mm to 8 mm. The data from the study gives the dentist some indication of the mean and extreme ranges of lingual attached gingiva. This data can serve as a guide in diagnoiss and treatment planning and in selecting procedures to reestablish these zones of attached gingiva.     

Maxillary arch width and buccal corridor changes with Damon and conventional brackets: A retrospective analysis

Objective:To evaluate the effect of Damon self-ligating and conventional bracket systems on buccal corridor widths and areas.Materials and Methods:A retrospective sample of consecutively treated patients using either conventional (CG, n  =  45) or Damon self-ligating (SL, n  =  39) brackets was analyzed to determine any differences in buccal corridor widths and areas both within and between groups. Pretreatment and posttreatment frontal photographs were transferred to Photoshop CC, standardized using intercanthal width, and linear and area measurements were performed with tools in Photoshop CC. Ratios were then calculated for statistical analysis. Relationships between arch widths and buccal corridors were also examined.Results:There were no significant differences in the posttreatment intercanine or intermolar widths either within or between the CG and SL groups. There were no significant differences in any buccal corridor width or area measurement either within or between the CG and SL groups. There were strong correlations with the intercanine width and the corresponding buccal corridor smile width measurements. There was an inverse correlation with the buccal corridor area in relation to the canine and the total smile width.Conclusions:It is likely that posttreatment increases in arch width can be seen in patients treated with either a conventional bracket system or the Damon system. It is highly unlikely that there is any significant difference in buccal corridor width or area in patients treated with the Damon self-ligating system or a conventional bracket system.     

Tissue considerations for mandibular subperiosteal implants.

The criteria for the preoperative evaluation of the residual alveolar tissue for a potential implant patient have been discussed. To ensure a firm epithelial attachment around the implant post, the residual tissue at the point of oral penetration should be: (1) sufficient in amount or thickness and attached to the periosteum, (2) fibrous, not loose, areolar mucosa, and (3) positioned midway over the stress-bearing area for the implant and overlying prosthesis. If the existing tissue does not meet the above criteria, a free palatal graft can be placed over the point of oral penetration to improve the potential for tissue adaptation around the post.