JOURNAL OF DENTISTRY (SHIRAZ UNIVERSITY OF MEDICAL SCIENCES)
Year:2001 | Volume:2 | Issue:3 (3)|Papers Count:8

Restoration of severely damaged teeth requires comprehensive, carefully planned pretreatment. Usually, the teeth with fractures or caries extended up to or below the alveolar crest can be treated by conventional surgical crown lengthening at the expense of supporting bone. Forced eruption or extrusion of teeth is an alternative procedure to overcome problems with dental esthetics and removing of supporting tissues.Two case reports are used as a basis for reviewing the forced eruption with and without supracrestal fibrotomy.

The present clinical & histologic trial was designed to investigate the inductive effect of palatal connective tissue on the alveolar mucosa. 11 subjects 19-49 years of age showing good performance in oral hygiene were selected from Shiraz dental school patients. The test tooth (incisor, canine or premolar) had keratinized gingiva equal of less than 2 mm. This tooth together with the adjacent mesial and distal teeth should be free of gingivitis or periodontitis. The base line clinical measurements were done on the test tooth and mesial and distal adjacent teeth.Surgical phase included a mucosal flap at recipient site (with minimal thickness) at the mucogingival line of the test tooth extending somewhat to buccal of adjacent mesial & distal teeth. The remaining tissue on the bone of the area was removed and the bone was exposed. At the donor site (palate), a mucosal flap was reflected and a piece of connective tissue with thickness of 1-2 mm was removed and sutured at the recipient site & then it was covered by overlying flap. The sutures were removed after 7 days. Maintenance phase was performed by regular follow up visits up to 6 months.Six months postoperatively the base line measurements were repeated. Biopsy specimens were obtained from the grafted area and the adjacent intact alveolar mucosa. The specimens were fixed and sent for histologic examination.Data analysis showed that the keratinized and attached gingiva of test teeth and the adjacent mesial & distal teeth increased significantly clinically the added keratinized gingiva was tightly bound to underlying tissues. The probing depth & gingival recession of test teeth did not increased significantly.The light microscopic histoligic examination showed keratinization in 80% of cases. In 30% of cases dense well organized collagen bundles was seen in lamina propria.This study proved that palatal connective tissue graft can induce nonkeratinized alveolar mucosa into masticatory mucosa.

Headgear provides an extra-oral anchorage and is needed in many treatment procedures. Application of a headgear needs a complete knowledge of the involved active and reactive forces. The main goal of this study was to make clear the very events of a cervical headgear use. The finite element method of analysis was chosen to accomplish the research. A 3D F.E.M. model consisting of a cervical headgear and two separate blocks as the terminal molars were designed and a 200 grf. Was applied at each side and the results were obtained. The most important result was the consideration of the elastic deformation of the outer bow and its effect on the force delivered to the terminal molar. A brief discussion of the differences between the manual calculation of the forces and the results obtained by the F.E.M. was presented at the end of the article.

Most malocclusions have a vertical component, as well as, anterior-posterior malrelationship. Information about the vertical balance and the importance of growth in strategic sites of the face is emphasized as a determining factor in successful treatment. Most experienced clinicians agree that, malocclusions with marked vertical facial imbalance, are generally more difficult to treat and treatment results is definitely harder to maintain than the primarily ant-post discrepancies. Openbite is the result of abnormal vertical development that is inefficient to permit teeth to meet their antagnoists, in the opposite arch. The ethiology of openbite generally may be: 1) Disturbances or mechanical interferences with eruption and alveolar growth and 2) Skeletal Imbalance.In this study by utilizing of openbite definition, a group of 2365, 9-11 years old students in Shiraz primary schools were examined clinically and also by cephalomentric evaluation.Prevalence of anterior openbite was found to be about 3.08%, which was slightly, greater for female group.Correlating openbite with sagital discrepancy, children with CL.II occlusion were affected more frequently than children with CL.I and CL.III occlusion. Other results were as follow: 1) it was found that, UFH/LFH ratio was less for openbite subjects, upper face height is almost normal but lower face height was sufficiently greater so as to make the total face height of openbite subjects greater than that of normal subjects.2) Jarabak Index significantly decreased.3) The SN-MP and PP-MP angle were greater than normal.4) The Saddle, Articular and Gonial angles were increased which is a determining factor of vertically growth pattern of openbite subject.5) SN-GOGN angle had a high correlation with basal plane angle, occlusal-mand. Plane, SNOcclusal and jarabak, therefore, these angular measurements, could be known to be reliable in the assessment of facial growth pattern and also and indication of the effect of mandibular position in anterior posterior and/or in vertical discrepancies.

Stainless steel crowns are one of the most common useful devices for restoration of the primary teeth which are endodontically treated or involved with structural defects such as severe caries, hypoplasia and traumatic injuries. Beside its noticeable advantages, there are some problems (complications) that limit the indications and practical usage of these crowns. According to the standards suggested by American Academy of Pediatric dentistry (1987), absence of marginal adaptation and insufficient extension of the margins are the most important factors resulting in gingival inflammation and periodontal problems around the crowns. Some other complications such as impaction of adjacent to permanent teeth, corrosion of amalgam fillings adjacent the crowns and occlusal interferences may also be noticed when using these prefabricated crowns over primary teeth. In general we may suggest that if appropriate restoration of primary teeth using different operative techniques is possible, it is preferable not to cover them with S.S. Crowns and the use of these crowns must be limited to the cases in which there is no other way to restore the severely destroyed weakened tooth structure.Aim: The aim of this study is to characterize the possible complications of S.S. Crowns beside its various advantages and to insist on the restoration and build up fillings of the destroyed primary teeth using different operative techniques.