Combined bone and soft-tissue augmentation surgery in temporo-orbital contour reconstruction

Temporal hollowing due to temporal muscle atrophy after standard skull base surgery is common. Various techniques have been previously described to correct the disfiguring defect. Most often reconstruction is performed using freehand molded polymethylmethacrylate cement. This method and material are insufficient in terms of aesthetic results and implant characteristics. We herein propose reconstruction of such defects with a polyetheretherketone (PEEK)-based patient-specific implant (PSI) including soft-tissue augmentation to preserve normal facial topography. We describe a patient who presented with a large temporo-orbital hemangioma that had been repaired with polymethylmethacrylate 25 years earlier. Because of a toxic skin atrophy fistula, followed by infection and meningitis, this initial implant had to be removed. The large, disfiguring temporo-orbital defect was reconstructed with a PEEK-based PSI. The lateral orbital wall and the temporal muscle atrophy were augmented with computer-aided design and surface modeling techniques. The operative procedure to implant and adopt the reconstructed PEEK-based PSI was simple, and an excellent cosmetic outcome was achieved. The postoperative clinical course was uneventful over a 5-year follow-up period. Polyetheretherketone-based combined bony and soft contour remodeling is a feasible and effective method for cranioplasty including combined bone and soft-tissue reconstruction of temporo-orbital defects. Manual reconstruction of this cosmetically delicate area carries an exceptional risk of disfiguring results. Augmentation surgery in this anatomic location needs accurate PSIs to achieve satisfactory cosmetic results. The cosmetic outcome achieved in this case is superior compared with previously reported techniques.     

The use of mouldable acrylic for restoration of the temporalis flap donor site

Despite the wide popularity of the pedicled temporalis myofascial flap, aesthetic management of the temporalis donor site has received little attention. A technique for immediate camouflage of the temporalis flap donor site with cold-cure methyl methacrylate, either alone or in combination with residual muscle in the temporal fossa, is presented. A retrospective evaluation of this technique in 34 consecutive patients was undertaken, with particular reference to the aesthetic results and morbidity associated with the use of cold-cure acrylic for this form of reconstruction. Apart from transient postoperative swelling and neuropraxia, no major or lasting complications associated with the use of cold-cure acrylic were recorded. The aesthetics of the camouflaged temporalis donor site by acrylic alone, or when combined with part of the temporalis muscle, was judged objectively to be excellent in 25 patients, satisfactory in 3 patients, and poor in 2 patients. 4 patients who did not have acrylic reconstruction, but had part of the temporalis muscle transposed to conceal the anterior fossa depression, leaving the posterior fossa unreconstructed, were judged mostly as satisfactory. Histology of the soft tissues around an acrylic implant after nearly 2 years confirmed the good biocompatibility of this material. It is concluded that this technique is a safe and reliable method for immediate camouflaging of the temporal fossa after harvesting a temporalis muscle flap.     

A concept for a biologically derived,parabolic implant design

It has become widely accepted that modern titanium dental implants are successful and predictable. However, there is bone loss in relation to any interface (microgap) that occurs between the implant parts when the microgap is in proximity or apical to the osseous crest. The principle of biologic width may be responsible for such bone remodeling in an apical manner. A new, biologically derived implant design that conceptually may minimize bone remodeling and promote better bone and overlying gingival contours and stability is suggested. The parabolic occlusal platform of this design is in harmony with the biologic width of the soft tissue around the circumference of the implant when the proximal bone is occlusal to the facial and lingual bone. Preservation of proximal bone for an isolated implant, and between implants, will help support and maintain physiologic and cosmetic gingival contours and papillae. This is of particular importance in esthetic areas, where interproximal bone loss between implants or between an implant and an adjacent tooth may cause a reduction in gingival papilla height.     

Long‐Term Stability of Contour Augmentation With Early Implant Placement Following Single Tooth Extraction in the Esthetic Zone: A Prospective,Cross‐Sectional Study in 41 Patients With a 5‐ to 9‐Year Follow‐Up

Background: Early implant placement with simultaneous contour augmentation is documented with short‐ and medium‐term studies. The long‐term stability of contour augmentation is uncertain. Methods: In this prospective, cross‐sectional study, 41 patients with an implant‐borne single crown were examined twice, in 2006 and 2010. Clinical, radiologic, and esthetic parameters were assessed at both examinations. In addition, a cone beam computed tomographic (CBCT) image was obtained during the second examination to assess the dimensions of the facial bone wall. Results: All 41 implants demonstrated ankylotic stability without signs of peri‐implant infection at both examinations. The clinical parameters remained stable over time. Satisfactory esthetic outcomes were noted, as assessed by the pink and white esthetic score (PES/WES) indices. Overall, the PES scores were slightly higher than the WES scores. None of the implants developed mucosal recession over time, as confirmed by values of the distance between implant shoulder and mucosal margin and cast measurements. The periapical radiographs yielded stable peri‐implant bone levels, with a mean distance between implant shoulder and first visible bone‐implant contact value of 2.18 mm. The CBCT analysis demonstrated a mean thickness of the facial bone wall ≈2.2 mm. In two implants (4.9%) no facial bone wall was detectable radiographically. Conclusions: This prospective cross‐sectional study demonstrates stable peri‐implant hard and soft tissues for all 41 implants examined and satisfactory esthetic outcomes overall. The follow‐up of 5 to 9 years confirmed again that the risk for mucosal recession is low with early implant placement. In addition, contour augmentation with guided bone regeneration was able to establish and maintain a facial bone wall in 95% of patients.     

Stability of Contour Augmentation and Esthetic Outcomes of Implant‐Supported Single Crowns in the Esthetic Zone: 3‐Year Results of a Prospective Study With Early Implant Placement Postextraction

Background: Early implant placement is one of the treatment options after tooth extraction. Implant surgery is performed after a healing period of 4 to 8 weeks and combined with a simultaneous contour augmentation using the guided bone regeneration technique to rebuild stable esthetic facial hard‐ and soft‐tissue contours. Methods: In this prospective study, 20 patients were treated with an implant‐born single crown and followed for 3 years. Clinical, radiologic, and esthetic parameters were recorded to assess treatment outcomes. Results: At the 3‐year examination, all 20 implants were successfully integrated, demonstrating ankylotic stability and healthy peri‐implant soft tissues as documented by standard clinical parameters. Esthetic outcomes were assessed by the pink esthetic score (PES) and white esthetic score (WES) and confirmed pleasing results overall. WES values were slightly superior to PES values. Periapical radiographs showed minimal crestal bone loss around used bone‐level implants with a mean bone loss of 0.18 mm at 3 years. Only two implants revealed bone loss between 0.5 and 1.0 mm. One of these implants had minor mucosal recession <1.0 mm. Conclusions: This prospective study evaluates the concept of early implant placement and demonstrated successful tissue integration for all 20 implants and stable bone‐crest levels around implant–abutment interfaces according to the platform‐switching concept. The midterm 3‐year follow‐up revealed pleasing esthetic outcomes and stable facial soft tissues. The risk of mucosal recession was low, with only one patient showing minor recession of the facial mucosa. These encouraging results need to be confirmed with a 5‐year follow‐up examination.     

Guided bone regeneration for single tooth replacements by oral implants

Single tooth replacement is a good indication for an oral implant. However, bone regeneration, is often required to improve the bone quantity and the contour of the overlying soft tissues. Guided Bone Regeneration (GBR) using membranes is a good technique to restore local bone defects within a six months period. With this technique it is crucial that a membrane properly separates the bony and soft tissues and creates a space around a bony defect for bone ingrowth. This article describes the indications and contra-indications for GBR, the technique and the possible complications.     

Vascularized cranial bone grafts for mandibular and maxillary reconstruction. The parietal osteofascial flap

The authors have performed 13 cases of vascularized cranial bone grafts for reconstruction of maxillofacial defects since 1986. Two types of flaps were used: the parietal osteofascial flap pedicled to the parieto-temporal fascia based on the superficial temporal artery and the temporalis osteomuscular flap pedicled to the temporalis muscle based on the deep temporal artery. Zygomatico-orbital complex, maxilla and mandible were reconstructed and hemifacial microsomia was also treated. The results of vascularized cranial bone grafts pedicled to fascia were as good as those of grafts pedicled to muscle. There were no major complications. Two types of vascularized cranial bone grafts seem to be useful in reconstruction of maxillofacial defects with avascular recipient beds because of their good blood supply. The parietal osteofascial flap has additional advantages including easy rotation of the flap to the defect, particularly a mandibular defect, and versatile use of fascia without bulkiness for reconstruction of soft tissue defects. This flap can be designed as a full- or partial-thickness cranial bone graft with good vascularity. In this paper, our technique for mandibular and maxillary reconstruction using the parietal osteofascial flap is introduced, and the results compared with our temporalis osteomuscular flap technique are reported.     

Porous hydroxylapatite as a bone graft substitute in mandibular contour augmentation: a histometric study

The buccal contour of the mandible was augmented in 17 dogs with 5 X 7.5 X 20 mm blocks of porous hydroxylapatite (HA) on one side and two-layered split rib autografts on the other. Both specimens were retrieved at three, six, 12, 24, and 48 months. Undecalcified sections were prepared for microradiography, light and UV microscopy, and histometry. A transmitted light video image digitizing system was used to trace implant and graft perimeters and calculate cross sectional areas. This system was also used to measure graft density and calculate bone and soft tissue compositions. The HA matrix, bone and soft tissue compositions of implant specimens were measured with a backscattered scanning electron microscope imaging digitizing system. All grafts became increasingly resorbed with time whereas all implants remained intact. Mature osteotonic bone ingrowth was present in all implants except one which failed to unite with the mandibular cortex. The mean graft areas decreased from 30.8 mm2 at three months to 0.7 mm2 at 48 months, while the implant areas averaged 35.5 mm2 and remained stable. The graft specimens were composed of 46.6% bone and 53.4% soft tissue or fluid space. The implant specimens were composed of 34.5% HA matrix, 28.6% bone, and 33.9% soft tissue. The HA matrix had a surface area of 9.8 mm2/mm3 that was 61.9% covered with bone ingrowth and 38.1% covered with soft tissue or fluid space. In contrast to the rapid resorption of graft onlays, the porous HA matrix demonstrated a long-term permanence with maintenance of contour and osseous incorporation over the four-year duration of this study.     

Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study

Objectives: The aim of the present study was to evaluate the dimensional changes of peri‐implant tissues obtained by implant placement, bone and soft tissue augmentation, prosthetic reconstruction and 1 year of function using a new, non‐invasive method for volumetric measurements. Materials and Methods: In 16 patients, the missing central or lateral maxillary incisor was reconstructed with an implant‐supported single crown. Impressions were taken before (t1), after implant placement with guided bone regeneration using DBBM and a PTFE membrane (t2), after soft tissue augmentation (t3), immediately after crown placement (t4) and 1 year later (t5). The cast models were optically scanned and digitally superimposed allowing qualitative and quantitative analysis of alterations of the labial peri‐implant tissue contour. In addition, the crown length and papilla height were measured at crown placement (t4) and after 1 year (t5). Results: Fifteen patients were available for recall after 1 year. During therapy, a mean gain in distance in the labial direction of 1.27±0.67 mm was observed after the surgical procedures. One year after crown insertion, a mean loss of 0.04±0.31 mm in the labial direction was recorded. During the same period, the crown length increased by a mean of 0.22±0.57 mm and the papilla height by 0.07±0.61 mm. The degree and pattern of tissue change following crown insertion were highly variable between individuals, irrespective of the amount and quality of previously augmented tissues. Conclusions: The clinical procedures were effective in augmenting peri‐implant tissue volume that remained stable to a high degree within 1 year after crown insertion. Large inter‐individual variations regarding the tissue alterations were observed. To cite this article:
Schneider D, Grunder U, Ender A, Hämmerle CHF, Jung RE. Volume gain and stability of peri‐implant tissue following bone and soft tissue augmentation: 1‐year results from a prospective cohort study
Clin. Oral Impl. Res. 22 , 2011; 28–37.
doi: 10.1111/j.1600‐0501.2010.01987.x     

Investigating the cause of late deformity following fronto-orbital remodelling for metopic synostosis using 3D CT imaging

Purpose

Late deformity/indentation is well-recognised following fronto-orbital remodelling (FOR) for metopic synostosis. We hypothesise that if damage to temporalis muscle were a contributor, the thickness of soft tissue and bone in the affected area would be reduced.

Calvarial bone grafts and temporalis muscle flap for midfacial reconstruction after maxillary tumor resection: a long-term retrospective evaluation of 17 patients

Midfacial reconstruction after radical oncological resection is a challenging endeavor and several options can be employed: prosthethic devices, pedicled flaps (with or without the aid of autologous or alloplastic grafts), and microvascular flaps. Each technique has specific indications, advantages and disadvantages.The use of traditional surgical reconstructive procedures seems to be shifted nowadays by microvascular free flaps. Nevertheless, in our experience the myofascial temporalis flap associated with free calvarial bone grafts demonstrate to be a safe and versatile option in primary midfacial reconstruction. From this point of view the authors have developed a technique for one-stage reconstruction of the orbito-maxillary skeleton and soft tissues and without the use of microsurgical flaps; this surgical procedure can be used only on patients for whom a resection of the cutaneous tissues and exenteratio orbitae are not necessary. The aims of this paper is to describe the surgical technique and to show a retrospective analysis on 17 patients which underwent midfacial radical resection and immediate reconstruction with calvarial bone grafts and temporalis muscle flap along 15 years.     

Pseudomalignant osseous tumor of the temporalis muscle

A case is presented of a 10-year-old girl who had a benign osseous tumor of the temporalis muscle. The tumor appeared to be a variant of the so-called pseudomalignant osseous tumor of the soft tissues and could readily be distinguished from both osteogenic sarcoma and myositis ossificans.     

Technique for fixing a temporalis muscle using a titanium plate to the implanted hydroxyapatite ceramics for bone defects

We devised a technique to fix the temporalis muscle to the transplanted hydroxyapatite implant by using a titanium plate, which is fixed to the hydroxyapatite ceramic implant by screws and achieves good clinical results. The size, shape, and curvature of the hydroxyapatite ceramic implants were determined according to full-scale models fabricated using the laser lithographic modeling method from computed tomography data. A titanium plate was then fixed with screws on the implant before implantation, and then the temporalis muscle was refixed to the holes at both ends of the plate. The application of this technique reduced the hospitalization time and achieved good results esthetically.     

Mandibular connective tissue pedicle flaps in implant dentistry: report of three cases

An increase in soft tissues and alveolar bone in the anterior mandibular area between the canines is necessary to achieve a good esthetic result. The present article describes a technique for gaining bone volume and soft tissue to cover bone defects that would otherwise compromise the final result of prosthetic implant restoration in the anterior mandible. Three patients with anterior mandibular atrophy caused by loss of the mandibular incisors are presented. Particulate autologous bone grafting, the raising of a pediculate connective tissue flap to increase soft tissue, and implant placement were carried out simultaneously. After 2 years of follow-up, the implants were in good clinical and radiologic condition. The problem of atrophy and the lack of soft tissue were thus solved, and an acceptable esthetic outcome was achieved in a single surgical intervention.     

Peri-implant Bone Remodeling Around an Extraction Socket: Predictions of Bone Maintenance by Finite Element Method

Purpose: The aim of this study was to investigate peri-implant bone remodeling as a response to biomechanical factors, including implant size and contour, magnitude of occlusal load, and properties of osteogenic bone grafts through the use of a computational algorithm. Materials and Methods: A bone-remodeling algorithm was incorporated into the finite element method, where bone remodeling takes place as a result of the biomechanical alteration caused by dental implant placement and continues until the difference between the homeostatic state and the altered state is minimized. The site-specific homeostatic state was based on a model consisting of a natural tooth. Three long (11-mm) implants and two short (5-mm) implants were investigated. A three-dimensional segment of the mandible was constructed from a computed tomographic image of the premolar region, and an extraction socket was filled with bone graft. Results: Generally, the extent of bone loss in the cortical region was greater and denser bone developed at both the implant crest and apex with increased occlusal loads. The areas between implant threads were prone to bone resorption. Bone graft materials that were relatively stiff and that had high equilibrium stimulus values appeared to cause increased bone loss. Conclusions: Short implants are better for conserving the mechanotransductive signaling environment of the natural tooth than long implants. Also, short implants are predicted to lead to less interfacial bone loss at high loads over the long term, while long implants are associated with a more consistent level of bone loss for different amounts of loading. It is also predicted that in the long term, bone grafts with relatively low elastic modulus lead to lower levels of interfacial bone loss.     

Digital image processing. II. In vitro quantitative evaluation of soft and hard peri‐implant tissue changes.

The aim of this study was to evaluate the ability of computer-assisted densitometric image analysis (CADIA) to detect small changes in mineralized and nonmineralized tissues adjacent to dental implants and to correlate these changes with CADIA values. A section of a pig mandible including all soft tissues and in which a hollow cylinder ITI Bonefit® implant with an artificial mesial and a buccal infrabony defect was placed was used to obtain pairs of standardized radiographs. Series of radiographs were obtained with exposure times of 0.13. 0.20, 0.44. and 0.53 s. Specimens of mineralized or nonmineralized tissues were placed arbitrarily in the defects before each radiographic exposure. The radio-graphs were captured through a video camera, digitized and stored in a personal computer. Every radiographic image was then subtracted from a baseline one without any change. The result of the subtraction was evaluated with CADIA. A linear correlation (r²=0.99) was found between the bone chips (1–5 mg of dry weight) placed in the mesial defect and the CADIA values. Bone chips in the buccal defect (behind the implant), however, were not detected unless their weight reached 14 mg or more. For conventionally exposed radiographs, it was not possible to recognize soft tissue specimens (1–6 mg), either in the buccal or the mesial defect. However, when “underexposed” radiographs (exposure time: 0.13 s) were obtained, a linear correlation (r²=0.80) was calculated for soft tissue specimens in the mesial defect and CADIA values. In normally exposed radiographs. the CADIA system could detect even the smallest change in bone density (bone chip of 1 mg of dry bone weight) and correlated almost linearly with these changes. Provided that the radiographic images are obtained with standardized geometry and normal exposure time. the tissue density changes detected by this system within bone defects represent only mineralized tissue changes. By underexposing radiographs, CADIA may even reveal soft tissue changes around dental implants.     

美学区种植与修复——方法与问题

目的：对上前牙美学区种植义齿的方法和问题进行讨论。方法：选取种植修复后3-5年的病例随访分析检查。患者计58人,男：39;女：17。年龄：24～60岁。其中涉及骨增量者达90%以上,多数病例进行了局部软组织处理。治疗前后均有X光检查记录。外伤患者多即拔即种,骨缺损明显则先期补骨或种植同时进行骨增量。失牙原因为外伤、重龋、正畸相关、牙周病等。修复时除常用美学基台外还采用瓷基台和个性化基台。无论外科处理还是修复方式多采用不同方法相互配合。结果：一例onlay植骨出现软组织张力大移植骨少量暴露致部分骨坏死影响了修复完美,一例因软组织愈合欠佳导致龈乳头退缩,患者不接受软组织成型术,虽采用牙龈瓷弥补美观效果仍欠缺。其余均达到满意效果。结论：恢复前牙缺失的功能与美观是种植修复的热点和难点,把握适应症及种植与修复时机,改善软硬组织质量并完善修复技术可以获得满意的美学效果。     

The dual-zone therapeutic concept of managing immediate implant placement and provisional restoration in anterior extraction sockets

Improvements in implant designs have helped advance successful immediate anterior implant placement into fresh extraction sockets. Clinical techniques described in this case enable practitioners to achieve predictable esthetic success using a method that limits the amount of buccal contour change of the extraction site ridge and potentially enhances the thickness of the peri-implant soft tissues coronal to the implant-abutment interface. This approach involves atraumatic tooth removal without flap elevation, and placing a bone graft into the residual gap around an immediate fresh-socket anterior implant with a screw-retained provisional restoration acting as a prosthetic socket seal device.     

Preservation of Existing Soft‐Tissue Contours in the Transition from a Tooth to an Implant Restoration in the Esthetic Zone Using a Flapless Approach: A Clinical Report

Two‐stage placement of a dental implant is a well‐established method for restoring a missing anterior tooth; however, replacement of an anterior tooth by using two‐stage implant surgery may result in changes in the interdental papilla height and loss of alveolar bone with compromised esthetic results. Alternatively, the use of a one‐stage minimally invasive surgical technique followed by immediate provisionalization may facilitate achievement of esthetic and functional success with minimal discomfort and clinical time. This article presents a clinical case with a single anterior tooth replacement, illustrating ridge preservation with healing, delayed implant placement with immediate provisionalization of the implant to support the soft tissue, and a method of recording the soft‐tissue contour in the final impression to achieve an optimal esthetic result.     

The use of temporal polyethylene implant after temporalis myofascial flap transposition: clinical and radiographic results from its use in 21 patients.

PURPOSE: The use of temporalis myofascial flap (TMF) as a pedicled flap in craniofacial reconstructive surgery is well established. The transposition of temporalis muscle results in a large hollowing of the temporal fossa that leaves the patient with a cosmetic impairment. Reconstruction of this donor site deformity is desirable. One of the established reconstructive techniques is the use of a prefabricated porous high-density polyethylene (HDPE) temporal implant. In order to evaluate results from its use, we retrospectively reviewed a series of 21 consecutive patients. MATERIALS AND METHODS: From October 1999 to October 2004, 21 patients (7 men and 14 women) aged 32 to 85 years (mean, 65) had their surgical defects reconstructed with the use of a TMF. The majority of patients (15 of 21) had squamous cell carcinoma of the maxilla or the maxillary sinus. In 17 patients, the reconstructive procedure was performed simultaneously with the oncological resection, whereas in 4, a secondary reconstruction was performed. In 1 patient, bilateral TMFs were used to cover a total maxillectomy defect. Standard surgical approach was used in all patients during TMF elevation. The temporal defect was reconstructed with the use of a prefabricated sterile HDPE implant (Medpor; Porex Surgical Inc, College Park, GA). Fixation of the implant to the recipient infratemporal fossa was performed with black silk sutures (in 2 patients) or titanium miniscrews (in 19 patients). The manufacturer's instructions for the placement of the implant were followed in all cases. One of the 21 operated patients preoperatively received radiotherapy (RT). Of the remaining 20 patients, 5 underwent postoperative RT. RESULTS: Eighteen patients are alive and free from disease. One died during the perioperative period from myocardial infarction and 2 more from locoregional recurrence of their disease, 18 and 27 months postoperatively. In all 21 patients, the placement of the Medpor temporal implant was successful and no immediate or perioperative complications resulting from its use were encountered, giving an overall success implantation rate of 100%. Follow-up ranged from 9 to 70 months (mean, 39). The condition of the implant was evaluated with computed tomography in 18 of the 21 patients as part of the standard postoperative assessment. Radiographic results of the recipient site did not reveal any abnormalities. In 7 patients, the contour of the HDPE implant could be manually palpated, and in 3, it could be seen to protrude subcutaneously. Esthetic results were judged satisfactory from all patients. The hemicoronal skin flap healed uneventfully in all patients and did not cause a visible scar even to bald male patients. CONCLUSIONS: The reconstruction of the temporal defect after TMF transposition with the use of a Medpor temporal implant is an easy and safe method. The implant does not seem to cause any tissue reaction, and long-term functional and esthetic results are excellent. When properly used and the relevant manufacturers' instructions are carefully followed, the success rate of the method is extremely high.