Osteoarthritis of the temporomandibular joint: a light microscopic and scanning electron microscopic study of the articular cartilage of the mandibular condyle

The aim of this study was to investigate the organization of collagen fibrils and the histopathologic alterations as well as the morphologic aspects of osteoarthritic articular cartilage of the human mandibular condyle. Nine osteoarthritic condyles, three obtained at necropsy and the other six during surgery, were examined by light microscopy and scanning electron microscopy. Light microscopic observations revealed features of progressive and regressive remodeling and the presence of clefts. Scanning electron microscopic observations showed the presence of thick, coiled fibrils at the joint surface and numerous osmiophilic lipid globules scattered between the collagen fibrils. The collagen fibrils were disordered. It was concluded that collagen fiber network disintegration and fatty degeneration comprise the osteoarthritic changes of the articular cartilage of the human mandibular condyle.     

The effects of alcohol and cetylpyridinium chloride on the buccal mucosa of the hamster

The effects of alcohol and cetylpyridinium chloride on normal and abraded hamster buccal pouches were studied in 23 study and 23 control animals over 21 consecutive days. No significant differences were found between the control and study animals, both groups having normal cheek pouch mucosa at the end of the study period.     

The frequency and distribution of skeletal and dental components in Class II orthognathic surgery patients

In an effort to identify the skeletal and dental relationships of Class II malocclusion, lateral cephalograms of 253 adult orthognathic surgery patients (76 male, 177 female) who had a Class II molar and cuspid relationship were traced. One hundred and four of the subjects had had presurgical orthodontic treatment and 148 had not. The most common combination of variables found in this study population was a retrusive maxilla, protrusive maxillary incisors, protrusive mandibular incisors, a retrusive mandible, and a long lower facial height.     

The nature of vertical maxillary deformities: implications for surgical intervention

A study was performed to identify the area within the maxilla where vertical maxillary deformities are expressed. Analysis of the maxillas of individuals who displayed 4 mm or more of the central incisors at rest were compared with those who displayed less than 1 mm. Similarly, individuals who had greater than or equal to 2 mm negative incisor overbite (open-bite) were compared with those who had greater than or equal to 2 mm positive overbite. The results showed that the vertical position of the maxillary skeleton (palate) was similar in all groups. The vertical excess was found to lie within the dentoalveolus. The clinical implications of these results are discussed.     

Aspiration of an unerupted permanent tooth during maxillofacial trauma

Aspiration of teeth during maxillofacial trauma can occur whether or not there is loss of consciousness. Even when all erupted teeth are clinically present, there is a possibility of aspiration of unerupted teeth avulsed from the line of fracture. Many aspirated foreign bodies occur without presenting signs and symptoms and may be missed on the chest radiography because of superimposition by other radiodense structures. When broken or missing teeth or parts of dentures are unaccounted for, aspiration must be considered. In symptomless cases, expiratory anteroposterior chest radiographs are useful in detecting obstructive emphysema or overinflation. Deep inspiratory films or fluorscopy may show a shift of the mediastinum to the affected side. Bronchoscopy is the treatment of choice. Prophylactic steroids and antibiotics are no longer considered effective in reducing morbidity and mortality due to aspiration.     

Calcifying odontogenic cyst with complex odontoma

A calcifying odontogenic cyst associated with a complex odontoma is described. The presence of reduced enamel epithelium showing extensive proliferation accompanied by dentinoid and enameloid formation, and the morphologic connection of the lining epithelium of the cyst with the enamel epithelium, indicate that the possible origin of the cyst is the enamel epithelium of the odontoma.     

Extensive osteolysis of the mandible following devitalization of a tooth by arsenic trioxide

A case of progressive osteolysis of the mandible that consisted of extensive fibrosis and granulation tissue and contained the occluded inferior alveolar artery and the inferior alveolar nerve is described. Arsenic trioxide was suspected as the possible precipitating cause of the lesion, which started with an abrupt onset of paresthesia of the lower lip following its application to the mandibular second molar for devitalization.     

Alveolar ridge augmentation using nonresorbable hydroxylapatite with or without autogenous cancellous bone

A four-year prospective evaluation of the use of nonresorbable, particulate hydroxylapatite (HA) to augment deficient alveolar ridges was performed. The material was used alone and in combination with finely crushed autogenous cancellous bone. Implants were delivered subperiosteally by syringe injection, usually using local anesthesia for Class I to Class III ridges and general anesthesia for Class III and Class IV ridges. The improved ridge height and width were stable. Postoperative resorption with significant loss of ridge height, frequently seen with rib and iliac crest onlayed grafts, was not observed with HA augmentation. Permanent denture construction began as early as three weeks postoperatively and by four to six weeks if HA was combined with autogenous cancellous bone. It was possible to place mandibular staple implants simultaneously or following HA augmentation. Visor osteotomy techniques were improved by use of HA to produce a wider, more convex stable ridge. Although skin, mucosa, or dermal vestibuloplasties were performed as early as three months postoperatively in a small number of patients, there appeared to be a lesser need for vestibuloplasty after HA augmentation than after onlay bone grafting. In addition, prosthodontists performed fewer denture relines after HA augmentation than after onlay bone grafts. The authors believe the most significant factor accounting for these observations is the firm, nonmobile mucosal base resulting from augmentation with HA. The resultant stable, soft tissue base and improved ridge height and contour have contributed to a comfortable, retentive, stable denture for these patients. The prosthetic and surgical procedures are easier to perform and have produced superior, more permanent results than onlay bone grafts and alloplasts. Preliminary studies also point to exciting possibilities for use of HA as a bone substitute/marrow extender in maxillary and mandibular defects, cysts, and clefts and in osteotomies for orthognathic surgery.     

Comparison of the healing and revascularization of onlayed autologous and lyophilized allogeneic rib grafts to the edentulous maxilla

The healing and revascularization of onlayed autologous and lyophilized allogeneic rib grafts to the edentulous maxilla in the Macaca fascicularis monkey were studied using clinical, histologic, and microangiographic methods at varying intervals of up to eight months. Results indicated that healing and revascularization were similar but resorption of the allografts occurred approximately three months later than resorption of the autografts. Both grafting systems appeared to have minimal osteogenic potential. Osteoinduction and the final bony augmentation obtained were less than were seen with comparable autologous and allogeneic interpositional grafts.     

Use of the orthognathic surgery simulating instrument in the presurgical evaluation of facial asymmetry

The use of Orthognathic Surgery Simulating Instrument (OSSI) is described. Two cases of facial asymmetry, one with hemifacial microsomia and one with unilateral condylar hyperplasia, are presented to demonstrate the diagnostic capabilities of the articulator. The OSSI has greatly improved our ability to plan the treatment of cases of gross facial asymmetry.     

Blood loss with use of the Shaw scalpel for the treatment of oral cancer

The Shaw scalpel was used in seven radical operations for oral cancer. The amount of bleeding and postoperative exudate and the occurrence of postoperative complications were compared with that from 12 operations performed with the conventional steel scalpel. The blood loss during the radical neck dissection performed with the Shaw scalpel was 39% of the control value, and no blood transfusions were necessary. There was no increase in the amount of postoperative exudate in the Shaw scalpel group compared with the control group. Skin incision with the Shaw scalpel was accompanied by superficial wound dehiscences in three patients, which healed without any treatment.