Postoperative function after implant insertion in vascularized bone grafts in maxilla and mandible

Bone response to unloaded titanium implants in the fibula, iliac crest, and scapula: an animal study in the Yorkshire pig

The reconstruction of extended maxillary and mandibular defects with prefabricated free flaps is a two stage procedure, that allows immediate function with implant supported dentures. The appropriate delay between prefabrication and reconstruction depends on the interfacial strength of the bone-implant surface. The purpose of this animal study was to evaluate the removal torque of unloaded titanium implants in the fibula, the scapula and the iliac crest. Ninety implants with a sandblasted and acid-etched (SLA) surface were tested after healing periods of 3, 6, and 12 weeks, respectively. Removal torque values (RTV) were collected using a computerized counterclockwise torque driver. The bicortical anchored 8mm implants in the fibula revealed values of 63.73 Ncm, 91.50 Ncm, and 101.83 Ncm at 3, 6, and 12 weeks, respectively. The monocortical anchorage in the iliac crest showed values of 71.40 Ncm, 63.14 Ncm, and 61.59 Ncm with 12 mm implants at the corresponding times. The monocortical anchorage in the scapula demonstrated mean RTV of 62.28 Ncm, 97.63 Ncm, and 99.7 Ncm with 12 mm implants at 3, 6, and 12 weeks, respectively. The study showed an increase of removal torque with increasing healing time. The interfacial strength for bicortical anchored 8mm implants in the fibula was comparable to monocortical anchored 12 mm implants in the iliac crest and the scapula at the corresponding times. The resistance to shear seemed to be determined by the type of anchorage (monocortical vs. bicortical) and the length of the implant with greater amount of bone-implant interface.

Pain, function, and psychologic outcome before, during, and after intraoral tumor resection

PURPOSE

The aim of the present study was to determine the quality of life of patients with respect to pain before, during, and after ablative intraoral tumor surgery.

PATIENTS AND METHODS

The Bochum Questionnaire on Rehabilitation was used to determine 147 items including the morphologic, functional, and psychosocial aspects of rehabilitation. One thousand six hundred fifty-two of 3,500 patients (47.2%) (413 women and 1,239 men) completed the questionnaire. The statistical investigation was carried out using 2-sample (independent) and paired (dependent) t tests.

RESULTS

Pain and the functional impairment of chewing and swallowing are the most important parameters before treatment. Immediately after surgical treatment, other variables, such as speech intelligibility and mobility disorders in the head, neck, and shoulder regions, became more apparent. Pain was reported in the shoulder region in 38.5% and in the neck in 34.9% of patients after surgery. The temporomandibular joint was painful in 20.1%, the oral cavity in 18.7%, and the face in 8.2%. Pain was described by 7.4% of patients in other regions of the head. Seventy-five percent of 1527 patients were not taking pain medications during the investigation. The rate of physiotherapy consequently applied after surgery was less than 10%.

CONCLUSIONS

Quality of life after ablative intraoral surgery is not greatly affected by pain. Because functional disorders play the dominant role in the impairment of postoperative quality of life, functional reconstruction, using microvascular techniques, and early rehabilitation, including physiotherapy, should be intensified.

Functional reconstruction of maxilla with free latissimus dorsi-scapular osteomusculocutaneous flap

Restoration of oral and nasal function together with facial appearance is still challenging in maxillary reconstruction. Use of a composite flap transfer merely to fill the defect results in unsatisfactory functional and aesthetic outcomes. The authors present a reconstructive procedure for complex maxillary defects using the latissimus dorsi-scapular rib osteomusculocutaneous flap. Some modifications for the reconstruction of the nasal cavity and the hard palate contributed to excellent postoperative functions. Five cases of extended maxillary defect were reconstructed using a novel procedure between February of 1997 and October of 2000. The hard palate was reconstructed with a vascularized scapular angle. The infraorbital rim was reconstructed with a vascularized rib if it was required. A prop bone graft, replacing the zygomatic buttress, was added between the infraorbital rim and the hard palate. The latissimus dorsi muscle flap, which was supported by a skeletal framework and obliterated the remaining cavities around the bone grafts, was left exposed into the nasal cavity, and an 8-French (no. 10) nasal airway tube was placed as a stent in the nasal meatus for 3 weeks after surgery. A skin graft was applied on the scapular angle to reconstruct the oral side of the hard palate. If required, facial skin defect was repaired with a latissimus dorsi musculocutaneous flap or scapular flap. No major complications at the recipient or the donor sites occurred postoperatively in any of the five cases. In cases in which the eyeballs were preserved, almost normal facial appearance was obtained and an orbital extirpation case showed an acceptable postoperative appearance. All five patients returned to an unrestricted diet and their speech was assessed as normal by a speech test. Nasal breathing through the re-epithelialized meatus was possible in all cases. The reconstructed nasal cavity was maintained for more than 6 months in all cases and for more than 2 years in one early case. Rhinometry demonstrated normal function, and histologic findings of the re-epithelialized mucosa over the muscle flap in the nasal cavity revealed a nearly normal architecture. This technique simplifies the reconstructive procedure of massive maxillary defects, including those in the lateral wall of the nasal cavity. It also improves the postoperative oral and nasal functions of the patients.

Skull base reconstruction and rehabilitation

This article separates skull base reconstruction into the surgical procedures available for immediate reconstruction of a small base defect and the secondary rehabilitative procedures that may be performed at a later date, usually for functional or cosmetic needs.

Influence of the prosthetic restoration modality on bone loss around dental implants placed in vascularized iliac bone grafts for mandibular reconstruction

OBJECTIVES

Is bone loss associated with implants placed in vascularized iliac crest bone grafts for mandibular reconstruction dependent on the prosthetic restoration modalities used?

STUDY DESIGN

Eleven vascularized iliac crest bone grafts for mandibular reconstruction were examined after ablative tumor surgery. Forty implants loaded for at least 1 year were observed for up to 6 years. Horizontal and peri-implant bone loss was assessed for 2 groups: 6 patients with implant-supported bridges and 5 patients with implant-retained overdentures.

RESULTS

Horizontal bone loss reached a steady state around 2 mm after an observation time of 2 years. Bony pockets had a depth of less than 1 mm. The described pattern was nearly independent of the prosthetic restoration modality used. The implant survival rate was 97.6%.

CONCLUSIONS

Vascularized iliac crest bone grafts are safe implant-bearing areas. Implant-retained overdentures can be used with as good a longterm efficacy as the more complicated implant-supported bridges.

Comparisons of bone volumes and densities relating to osseointegrated implants in microvascularly reconstructed mandibles: a study of cadaveric radius and fibula bones

The study was designed to compare the dimensions and densities of two frequently used bone donor sites with regard to placement of endosseous dental implants in microvascularly reconstructed mandibles. A total of 40 radii and of 40 fibulae were investigated. Fifty two percent of the fibulae had adequate bone volume for the positioning of four 10 mm implants, while this figure was 55% for the radii. After using the 'double barrel' technique the placement of four 10 mm implants succeeded in 87% of all the fibulae. Due to the lack of bone length required, this special technique was not possible in the radii investigated. Cortical thickness and density of bone were higher in the radii when compared with the fibulae. In each bone the central and distal parts presented the highest values of cortical thickness and density. Although the radius offers enough substantial bone for implant placement in some cases this cannot be used for clinical purpose, as only hemicortical grafts can be obtained. Otherwise the resulting donor site morbidity would be intolerable. In conclusion, our results support the clinical experience that the fibula is today's 'work horse' donor site for reconstruction of the mandible.

Reconstruction of the severely resorbed (Class VI) jaws: routine or exception?

After disappointing results with conventional preprosthetic procedures endosseous implants in combination with alveolar ridge augmentation opened up new prospects in reconstructive surgery. A total of 64 patients who underwent three-dimensional reconstruction of the alveolar ridge and insertion of endosseous implants for severe resorption were evaluated retrospectively. Despite the postoperative infection rate of 20.3% (13 patients), only 4.1% of the 266 inserted implants were lost in the long term. This indicates that augmentation using free autogenous iliac bone grafts and implants have a success rate of approximately 96% despite difficult initial situations. This success was mainly related to the soft tissue condition covering the graft. A technique for soft tissue dissection, especially in the maxilla, is presented.

Changes in bite force and occlusal contacts in patients treated for mandibular prognathism by orthognathic surgery

PURPOSE

The purpose of this study was to evaluate changes in bite force and occlusal contacts before and after orthognathic surgery in patients with mandibular prognathism and to compare the findings with those in controls with normal occlusion.

PATIENTS AND METHODS

Bite force and occlusal contacts were analyzed in 23 (7 male and 16 female) patients with mandibular prognathism before and after sagittal split ramus osteotomy, and in 20 (10 male and 10 female) controls with normal occlusion. The bite force and occlusal contacts were simultaneously measured by a computerized occlusal analysis system, the T-Scan system, immediately before surgery, and at 6 weeks, 3 months, 6 months, and 1 year postoperatively.

RESULTS

Both the bite force and occlusal contacts in the patients were significantly less than those in the controls before surgery. Although both the bite force and occlusal contacts in the patients were improved by the orthognathic surgery, neither approached the level in the controls within 1 year. Bite force was correlated with the number of occlusal contacts in both patient and control groups.

CONCLUSION

The postoperative masticatory function does not reach control levels even 1 year after the orthognathic surgery for mandibular prognathism. Therefore, further adjustment of the occlusion should be considered before the end of treatment.

Comparative densitometric study of iliac crest and scapula bone in relation to osseous integrated dental implants in microvascular mandibular reconstruction

The study was designed to compare dimension and density of four frequently used bone donor regions (the iliac crest, the lateral border of the scapula, the radius and the fibula) with regard to placement of endosseous dental implants in microvascular mandibular reconstruction. The first part of the study reports on the results of bone dimension and density findings for iliac crest and scapula bone. Nearly all of the iliac crests had adequate dimensions for the positioning of four 10 mm implants. In 63% of the scapulae, it was possible to place four 10 mm implants. In the case of the scapula, half of the female subjects lacked enough available bone for the insertion of four 10 mm implants because of their inadequate width. Bone density and cortical thickness was found to be similar in the iliac crest and scapula. Age and side do not have an important influence on cortical bone dimensions and density. In contrast to the iliac crest, the lateral margin of the scapula astonishingly showed increasing values for bone density and increasing thickness of the cortex. Analogical advanced biological age works in conformity with the scapula flap. The results could, together with other clinical criteria, contribute to the choice of the best individual alternative in mandibular reconstruction.

Interdisciplinary microvascular reconstruction of maxillary, midfacial and skull base defects

Microvascular reconstruction techniques are increasingly used for reconstructive purposes in the maxilla, the midface and the cranial base. In the maxillary area, they provide the possibility of a safe closure of nasoantral perforations which are too large for local coverage with or without additional bony reconstruction (n = 14). A basis for prosthodontic rehabilitation with implant-borne dentures is also provided. Additional free bone grafts are often a prerequisite for implant insertion. In reconstruction of the midface, microvascular techniques can separate functional units, provide tissue augmentation and give orbital support (n = 12). In skull base and cranial defects, a safe coverage of duraplasties and scalp reconstructions is achieved (n = 9).