Mandibular canal-related parameters interpreted in panoramic images and CBCT of mandibular third molars as risk factors to predict sensory disturbances of the inferior alveolar nerve

The aim of this study was to determine whether cone beam computed tomography (CBCT) before mandibular third molar removal can improve the risk assessment for neurosensory disturbances of the inferior alveolar nerve (IAN) compared to panoramic radiography (PAN). One hundred and six mandibular third molars examined by PAN and CBCT were removed. A temporary sensory disturbance of the IAN was present in 20 cases; a permanent disturbance was found in one case. Three blinded observers assessed radiographic risk factors in PAN and CBCT images. Positive (PPV) and negative (NPV) predictive values and positive (LR+) and negative (LR?) likelihood ratios were calculated for all parameters for all observers. Inter-observer reproducibility was expressed as both the percentage accordance and the kappa-statistic. Generally, the PPV and LR + were the same for PAN and CBCT, and there was good inter-observer reproducibility. The highest PPV and LR + for PAN were found when part of the roots were positioned inferior to the lower white border line of the canal, and for CBCT when the canal was positioned between the roots of the tooth. In conclusion, parameters assessed in PAN and CBCT are not reliable risk factors for neurosensory disturbances of the IAN, and CBCT appears not to improve the risk assessment.     

Studies on N2 cement in man and monkey—cement lead content,lead blood level,and histologic findings

N2 Normal and N2 Medical were analyzed for lead content and yielded a positive result. Blood lead level measurements were performed on four patients before and after root fillings made with N2 Normal or gutta-percha /Kloroperka-NØ. No detectable differences were found. After six months, the teeth were extracted and examined histologically. Inflammatory changes and particles of N2 cement were found in the pulp tissue. Pulpotomies were made in 20 teeth from five baboons, and N2 cement was applied to the wound surfaces of each. The teeth were extracted one month, one year, and two years later. Histologic examination showed particles of the N2 cement in vessels, macrophages, and multinuclear giant cells.     

Postoperative changes of the soft tissue profile after mandibular vestibulolingual sulcoplasty with free skin grafting

Soft tissue changes of the upper and lower lips and the chin after mandibular vestibulolingual sulcoplasty with free skin grafting have been evaluated between one and five years postoperatively. Increases in chin prominence averaging 2.5 mm appeared within the first year after the operation. Prominence of the chin then remained unchanged at least through five years. A mean decrease in the height of the lower lip of 2.6 mm was found. These changes are possible complications of mandibular vestibulolingual sulcoplasty with free skin grafting, and must be considered in the final choice of preprosthetic surgery to be performed on a given patient.     

Reconstruction of bone and soft tissue in extensive facial defects

Autogenous iliac and rib grafts are used for the reconstruction of the maxilla and the mandible. Immobilization is assured by use of internal rigid fixation with reconstruction plates or lag screws; in the maxilla, miniplates may be used as well. An immediate reconstruction of chin defects is undertaken with a rib graft. For other defects of the mandible and maxilla, secondary reconstruction via an extraoral approach, without incision of the oral mucosa, is recommended to reduce the danger of infection as much as possible. Defects in facial soft tissue must be closed with local or distant flaps before bone transplantation is begun.     

Advancement genioplasty with and without soft tissue pedicle: An experimental investigation

To determine whether maintaining a soft tissue pedicle to the genial segment decreases the amount of bone resorption following an advancement genioplasty, 12 rhesus monkeys (Macaca mulatta) underwent advancement genioplasty of 5–6 mm. The insertion of the digastric musculature and lingual soft tissues on the genial segment was maintained in six of the animals, and six had all soft tissues stripped. Cephalometric analysis of remodeling in the anterior part of the mandible indicated that the pedicled genial segments underwent significantly less resorption than the free graft segments (P < 0.05). The results of this study indicate that soft tissue pedicles to the genial segments should be maintained during advancement genioplasty to minimize the amount of bone resorption in the post-operative period.     

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.     

Dental and facial injuries following sports accidents: a study of 130 patients

Details of injuries to the face and teeth have been collected over a five-year period. One hundred and thirty patients were seen with injuries resulting from 21 different sports. Estimates of the numbers of people playing various team sports in the Bradford area suggest that the incidence of facial injuries is most common in rugby, followed by soccer and cricket. Miniature motor cycling and horse-riding are the most dangerous individual sports. The ages of injured patients varied widely in different sports, but the severity of injuries sustained is less than those due to other causes.