Hans R. Haanæs

Preliminary study of low-level laser for treatment of long-standing sensory aberrations in the inferior alveolar nerve

PURPOSE The incidence of inferior alveolar nerve (IAN) damage during removal of third molar teeth has been reported to be as high as 5.5% and up to 100% during sagittal split osteotomy. Sensory aberrations in the IAN persisting for longer than 6 months leave some degree of permanent disability. The purpose of this double-blind, clinical trial was to examine the effects of low-level laser (LLL) treatment using a GaAIAs laser (820 nm, Rønvig, Denmark) on touch and temperature sensory perception after a long-standing postsurgical IAN injury. PATIENTS AND METHODS Thirteen patients were divided into two groups, one of which received real LLL (4 x 6 J per treatment along the distribution of the IAN to a total of 20 treatments) and the other placebo LLL. The degree of mechanoreceptor injury as assessed by Semmes Weinstein Monofilaments (North Coast Medical, San Jose, CA) were comparable in the two groups before treatment. The degree of thermal sensitivity disability as assessed using a Thermotester (Somedic AB, Stockholm, Sweden) to examine the indifferent temperature threshold was also comparable between the two groups before LLL. RESULTS Subsequent to LLL, the real laser-treated group showed a significant improvement in mechanoreceptor sensory testing (P = .01) compared with the placebo group, as manifested by a decrease in load threshold (g) necessary to elicit a response from the most damaged area. In addition, the real LLL group reported a subjective improvement in sensory function. There was no significant improvement in thermal sensitivity post-LLL for either the real or placebo laser-treated groups. CONCLUSION It was concluded that LLL can improve mechanoreceptor perception in long-standing sensory aberrations in the IAN.

The effect of soft-laser application on postoperative pain and swelling. A double-blind, crossover study.

The effect of soft-laser application on postoperative pain and swelling was evaluated in a double-blind, crossover study. Twenty-five healthy adults with bilateral identically impacted lower third molars were selected for this study. The teeth were removed in two separate operations. Laser treatment was tested in comparison with placebo laser, with a 40-mW, 830-nm Biophoton laser (Roenvig Dental, Denmark). All surgical procedures and measurements were done by the same surgeon. The following features were statistically analyzed: swelling, trismus, and subjective registration of pain on a visual analog scale. No statistically significant differences were observed in comparison of the experimental side with the placebo side. It may be concluded that soft-laser treatment has no beneficial effect on swelling, trismus, and pain after third molar surgery.

Tissue ingrowth into mandibular intrabony porous ceramic implants

Abstract Porous ceramic (Al 2 O 3 ) implants with pore size of 100–750 μm were placed in the mandible of ten Macaca irus monkeys after surgical preparation of bone defects, After mucoperiosteal flap reflection, a 3 mm deep cavity of 5 mm diameter was drilled through the cortical plate on the buccal aspect of the retromolar region for the insertion of a pellet implant. The wounds were closed with sutures. The animals were sacrificed after 2 weeks, 1 month, 2 months and 3 months. All implants healed primarily. Clinical, radiographic, micro-radiographic and histologic examination revealed ingrowth of fibrous tissue and bone into the interconnecting channels of the ceramic. No adverse tissue reactions were found.

Treatment of oroantral communication

Abstract One hundred and fourteen patients with oroantral communication were operated at the Department of Oral Surgery and Oral Medicine, Dental Faculty, University of Oslo, during the 4-year period 1968–1972. The closure method used was the buccal nonrotating flap technique as described by Moczar in 1930. Five cases (4.3 %) failed to heal primarily. Three of these healed spontaneously within 1 month postoperatively. Preoperative diagnostic procedures are described as well as the Moczar surgical approach and the follow-up regime. Vestibular height was found to have normalized in 88% of the patients examined. The gingival condition was examined before and after surgery in 61 patients. In all these cases, pocket depths were found to have been reestablished to preoperative values within 3 months postoperatively. Requirements of the optimal surgical procedure for closure of oroantral communication are stressed, and the most common errors causing failure or recurrence are listed.

Chemical, physical, and histologic studies on four commercial apatites used for alveolar ridge augmentation

The purpose of this study was to evaluate four commercial apatite products. Subperiosteal alveolar ridge augmentation was performed on the maxilla of rats by implantation of granules of two dense products and of two porous products, and the tissue response was compared with the material characteristics obtained by chemical analysis and infrared spectrometry. None of the apatites caused osteoinduction or osteoconduction; fibrous encapsulation with multinuclear giant cells was observed around all four types. One of the apatites was fluorapatite and not hydroxylapatite, as claimed by the manufacturer. The tissue response to this implant material was dominated by multinuclear giant cells.

A histologic study of experimental oro-paranasal communications in monkeys.

Abstract Experimental oro-paranasal communications were established in 11 monkeys (Macaca it-its) through the alveoli of the maxillary first or second molars after extraction of one of these teeth. The morphologic changes of the mucous membrane of the maxillary sinus and adjacent tissues following the experimental trauma were studied. Particular attention was focused on the metaplastic changes of the respiratory epithelium of the injured areas. The observation time ranged from 2 d to 12 weeks. Areas of nonreversible epithelial metaplasia to squamous and cuboid-like nonkeratinized epithelium were observed frequently throughout the observation period in the traumatized region. Mesenchymal cell proliferation from the fibrous portion of the maxillary sinus periosteum separated the antrum from the oral cavity completely within 7-14 d following the experimental oro-paranasal communication. Oro-paranasal fistulas did not develop in any of the experimental animals.

Surgical Treatment of Temporomandibular Joints in Patients with Chronic Arthritic Disease: Preoperative Findings and One-Year Follow-Up

Twenty-nine temporomandibular joints (TMJs) in 19 patients with chronic arthritic disease were surgically treated. Nine patients had rheumatoid arthritis (including two with juvenile type), six had ankylosing spondylitis and four had psoriatic arthropathy. Using a preauricular approach, diskectomies with synovectomies were performed in 23 joints (14 patients) with chronic arthritic abnormalities. Diskectomies without synovectomies were performed in six joints (five patients), which proved to have internal derangements unrelated to their chronic arthritic disease. Joints with chronic arthritis showed considerable variation in inflammatory reactions, but were characterized by increased vascularization, synovial proliferation to the articulating surfaces and mostly pannus formation and bone resorption. A response in pain relief was seen in 85% of the patients three months postoperatively and in 79% of the patients 12 months postoperatively, indicating that diskectomy with synovectomy may be favorable in patients with severe TMJ problems due to involvement of chronic arthritic disease.

Further studies on tissue ingrowth into intrabony porous ceramic implants

Porous ceramic Al2O3 implants with pore size of 100-750 micrometers were placed intrabony in the maxillary tuberosity of eight Cercopithecus monkeys. All implants healed primarily. Vital staining of mineralizing tissue was attempted using intravenous injections of tetracycline and calcein. The implants were retrieved after implantation times of 3, 5, 10, 11 and 12 months. Infiltration of fibrous tissue and bone was found in all impants, but the amounts of tissue observed were not significantly greater after the longest implantation times as compared to the 3- and 5-month results.

EXPERIMENTAL ORO-PARANASAL COMMUNICATIONS

Following an experimental oro-paranasal communication, the mucous membrane revealed extensive cellular reactions in the different cell layers of the nasolacrimal duct. These cellular reactions as observed histologically were mainly limited to the injured area. However, increased epithelial cell proliferation extended to other areas of the mucosal membrane as revealed by the autoradiographic observations. Fibrosis of the submucosa was a pronounced phenomenon.The stratified columnar epithelium in an area restricted to the traumatic communication revealed pronounced metaplasia into a non keratinized squamous epithelium.Due to the limited experimental period (6 hours–14 days) no conclusions were drawn as to the problem if the cellular reactions are reversible or not.

Maxillary sinus augmentation with porous titanium granules: a microcomputed tomography and histologic evaluation of human biopsy specimens.

PURPOSE The aim of this study was to assess bone ingrowth into porous titanium granules used for maxillary sinus augmentation. MATERIALS AND METHODS Eighteen biopsy specimens from 17 patients participating in a clinical trial on sinus augmentation using porous titanium granules (PTG) were received in the laboratory. The specimens (trephine cores of 4.5 mm) were obtained 6 months after PTG placement. After being embedded in methacrylate, the samples were scanned in a microcomputed tomography (micro-CT) scanner. Specimens were then cut along the long axis and central slices were ground to 70 μm before staining with hematoxylin and eosin. RESULTS The micro-CT analysis demonstrated an average bone fill of 19% (standard deviation [SD] 5.8%), whereas the graft material occupied 22.7% (SD 4.7%). The volume of newly formed bone decreased with the distance from the residual bone of the sinus floor. Two-dimensional histomorphometric analysis demonstrated a mean area of new bone of 16.1% (SD 9.4%). The PTG alone occupied 25.9% of the total mean area (SD 6.1%). The newly formed bone consisted mainly of woven bone growing in close contact with the granules and bridging the intergranular space. The remaining area was occupied predominantly by nonmineralized connective tissue. There were no signs of inflammation in any of the biopsy specimens. CONCLUSIONS After 6 months, new bone had formed at a similar rate and quality as has been reported for other well-recognized bone graft substitutes. The new bone formed in close contact with the PTG, suggesting that the material is osteoconductive.