Factors associated with assault-related firearm injuries in male adolescents.

PURPOSE: To identify factors associated with an increased prevalence of assault-related firearm injuries in male adolescents. METHODS: This study is a retrospective comparison of two samples of adolescent males from the same geographic localities regarding their involvement in the juvenile justice system (court involvement) and injury status (current or prior firearm injury at the time of the study). The subjects included adolescent male patients admitted to an urban, Level I trauma center for assault-related firearm injuries (court-involved and noncourt- involved, n = 65); and incarcerated juvenile offenders (prior firearm injury and no known firearm injury, n = 267). RESULTS: Two-thirds of the male assault-related pediatric firearm injury victims treated over a two-year period were involved in the juvenile justice system (court involved). Court-involved adolescents were almost 22 times more likely to have sustained an assault-related firearm injury, when compared to noncourt-involved patients with firearm injuries. Additional analysis documented recent substance use and/or involvement in criminal offenses in 82% of the victims. For most of the juvenile offenders (88%), court involvement preceded their injuries. Analysis of the injury patterns revealed an increased prevalence of truncal injuries (injuries to thorax or abdomen) in the court-involved victims, when compared to their noncourt-involved peers (40% and 14% for the court-involved and noncourt-involved samples, respectively; p <.05). Incarceration was associated with a 17-fold increase in the firearm injury prevalence over the court-involved, but not incarcerated, sample. CONCLUSIONS: These results suggest that involvement in substance use and/or the criminal justice system is associated with an increased risk of firearm injuries in male adolescents, and that an increased level of involvement in the juvenile justice system is associated with a concomitant increase in firearm injuries.

Bone grafting for the alveolar cleft defect.

Seventy-five percent of all cleft lip and palate patients have osseous defects of the alveolus. Bone grafting of this defect normalizes facial and dental function. Failure to reconstruct the osseous deformity may result in oronasal fistula, fluid reflux, speech pathology, anteroposterior deficiency of the maxilla, transverse deficiency of the maxilla, lack of bone support for the incisors and cuspids, dental crowding, and facial asymmetry. Bone grafting unifies the maxilla and is best done after the majority of facial growth is complete and the secondary dentition is erupting. This is known as secondary bone grafting and yields the best results. The dentofacial deformity of cleft lip and palate is best managed by coordination of dental development, surgery and orthodontics.

In vitro stability of biphasic calcium phosphate ceramics.

Biphasic calcium phosphate ceramics consist of both beta-tricalcium phosphate and hydroxyapatite. This study was performed to examine the in vitro stability of biphasic calcium phosphate ceramics in deionized distilled water and in physiological solutions. Biphasic calcium phosphates of two different molar ratios and pure hydroxyapatite and pure beta-tricalcium phosphate granules were tested. X-ray diffraction data were obtained before and after immersion. Surface morphology was compared using scanning electron microscopy. The pure beta-tricalcium phosphate and the beta-tricalcium phosphate in the biphasic calcium phosphate ceramics gradually converted to apatite. Needle-like apatite crystals were observed on the surface of biphasic calcium phosphate and beta-tricalcium phosphate, but hydroxyapatite showed no change.

Mandibular anatomy as it relates to rigid fixation of the sagittal ramus split osteotomy.

Rigid fixation of osteotomy segments is frequently used to reduce relapse and allow for early mobilization of the mandible following the sagittal ramus split osteotomy. This study evaluated cortical bone thickness in the retromolar area of 49 human mandibles to determine if there is an advantage (in terms of cortical thickness) to placement of screws for rigid fixation at the external oblique ridge versus placement at the inferior border. The mandibles were sectioned vertically at three sites in the retromolar area, corresponding to the bone available for rigid fixation of the sagittal osteotomy. Cortical bone thickness was measured at the external oblique ridge and 5 mm above the inferior border. The buccal and lingual cortices were found to be significantly (P less than .001) thicker at the external oblique ridge than at the inferior border. This suggests that there may be an advantage in terms of stability to placement of internal fixation screws at the superior border.

Mandibular ramus anatomy as it relates to the medial osteotomy of the sagittal split ramus osteotomy.

The sagittal split ramus osteotomy is probably the most frequently used procedure for correction of mandibular skeletal dentofacial deformities. Despite numerous improvements in the technique in the 30 years since the procedure was introduced, a number of troublesome complications still occur. These include unfavorable fracture during surgery, paresthesia, and relapse. The purpose of this study was to determine where fusion of the buccal and lingual cortical plates occurs in the upper mandibular ramus, as it is thought that placement of the horizontal medial osteotomy above the point of fusion (without any intervening medullary bone) may lead to unfavorable fracture during splitting. Forty-nine human mandibles were sectioned vertically at three locations perpendicular to the surface of the ramus and the occlusal plane. Measurements were made to locate vertically the point of fusion of the buccal and lingual cortical plates relative to the lingula and to the depth of the sigmoid notch. The point of fusion occurred between 7.5 and 13.3 mm above the lingula. Only 2% of mandibles had fusion at or below the level of the lingula in the anterior ramus, whereas in the posterior ramus, 6.1% of mandibles were fused at that level. At a level halfway from the lingula to the sigmoid notch, 20% of mandibles were fused in the anterior ramus, whereas in the mid- to posterior ramus, the incidence was as high as 39%. The location of the medial horizontal osteotomy should be at or just above the tip of the lingula. A higher level of cut may be associated with an increased difficulty in splitting or incidence of unfavorable fracture.

Cytotoxicity of amalgams, alloys, and their elements and phases.

The purpose of this study was to compare the relative cytotoxicity of amalgams, alloys, and their constituent elements and phases, by means of a rapid and sensitive in vitro cell culture test. Pure copper and zinc showed intensive cytotoxicity, significantly greater than that of pure silver and mercury. Pure tin was non-cytotoxic. The gamma-one phase (Ag2Hg3) revealed moderate cytotoxicity, which was significantly decreased by the addition of 1.5% and 5% Sn. However, the addition of 1.5% Zn to gamma 1 containing 1.5% Sn dramatically increased the cytotoxicity of gamma 1 to the same level as that of pure zinc. Whenever zinc was present in amalgams, higher cytotoxicity was revealed. High-copper amalgams showed the same cytotoxicity as a zinc-free low-copper amalgam. The addition of selenium did not reduce the cytotoxicity of amalgam. The cytotoxicity of amalgams was reduced after 24 h. The results of this study suggest that the major contributor to the cytotoxicity of alloy for amalgam is probably copper, while that for amalgam is zinc.

Multicenter clinical trial of ibuprofen and acetaminophen in the treatment of postoperative dental pain.

Pharmacological management of pain for acute and chronic conditions has been guided by a scientific understanding of peripheral and central acting mechanisms for the control of inflammation as well as pain. Oral surgery pain is a reliable model to reference the effectiveness of commonly used analgesics such as ibuprofen and acetaminophen. A total of 706 patients who were experiencing moderate to severe pain received a single dose of ibuprofen, acetaminophen, or placebo. After 6 hours, the degree of pain relief and tolerance was assessed. Ibuprofen has important implications for postoperative pain in clinical practice.

Correction of the deficient alveolar ridge.

The success of a denture is dependent on a good foundation; therefore, construction of the prosthesis begins with extraction of the teeth. The teeth should be maintained as long as possible if they can be restored. When the teeth are extracted, bone resorption usually starts, owing to systemic and local factors. Good communication between the prosthodontist and the oral and maxillofacial surgeon must exist during the diagnostic procedure, must be maintained through the various stages of treatment, and must prevail through the follow-up care of the patient. Each clinician must be aware of both the objectives and the possible limitations of the treatment the other will provide, to ensure optimal care for the edentulous patient. The development of the osteointegrated titanium implant system opens an exciting new avenue with respect to total rehabilitation of the edentulous patient. This is the future, and in our opinion, the preferred technique for mandibular reconstruction.

Overview and historical perspective of oral reconstructive surgery.

Pioneers in the field of dental reconstruction had little to offer their edentulous patients other than prostheses that were generally fitted without preparation or augmentation of the alveolar ridge. By the mid-1940s, the development of surgical procedures and the introduction of new materials offered significant advances. Increased denture retention was achieved by some implant methods and through use of the mandibular staple bone plate. Improvements in hydroxylapatite provided a material that could be used for alveolar ridge augmentation. It proved effective in limiting resorption and increasing attachment to soft and hard tissue. The recent development of purified fibrillar collagen in combination with hydroxylapatite enhances our ability to provide effective, long-lasting dental prostheses.

Collagen/hydroxylapatite implant for augmenting deficient alveolar ridges: twelve-month clinical data.

In a multicenter study, 77 edentulous patients had mandibular augmentation with implants of purified fibrillar collagen combined with dense hydroxylapatite (Alveoform Biograft); 22 of these patients also had maxillary augmentation. Most patients had Class III or IV mandibular atrophy, and had outpatient surgery with the subperiosteal tunneling technique. Temporary splints were worn for 24 hours post-surgery. Mean ridge height was 15.3 mm before surgery and 19.5 mm after 12 months, an augmentation of 4.2 mm. Predictable compaction occurred largely in the first few months after denture loading. Most patients, surgeons, and prosthodontists assessed the results of the procedure as good to excellent at 1 year following implantation. Adverse experiences, largely dehiscence and paresthesia, tended to resolve over time. Sera from ten patients demonstrated antibodies to bovine collagen that were not clinically significant. Alveolar augmentation with collagen/hydroxylapatite achieved clinically significant results that compared favorably with those achieved with other types of ceramic implants.

Long-term evaluation of human teeth after Le Fort I osteotomy: a histologic and developmental study.

Transient pulpal vascular ischemia and direct injury to the apices of the teeth have been implicated as the causes of degenerative and atrophic pulpal changes in experimental animals after Le Fort I osteotomy despite the presence of collateral circulation. The long-term clinical effect of these pathologic changes in human teeth has not been studied. Seventeen maxillary third molar teeth from 10 patients whose postsurgical follow-up ranged from 6 months to 78 months (mean, 40 months) were extracted. The long-term biologic effects of Le Fort I osteotomy on the pulp and on the development of teeth were retrospectively evaluated with clinical and standard histologic techniques. Normal teeth from patients who were not operated on were used as controls. Histologic examination revealed an intact pulpal circulation and minimal pathologic changes in the pulpal tissue. Clinical and radiographic studies showed that the growing teeth developed normally after surgery. The Le Fort I downfracture procedure had little discernible long-term effect on the pulp and on the development of human third molar teeth.

Tomographic evaluation of temporomandibular joints following discoplasty or placement of polytetrafluoroethylene implants.

A retrospective comparison was made of tomographic change in the temporomandibular joint (TMJ) of patients who had been treated by either discoplasty or discectomy with polytetrafluoroethylene (PTFE) disc replacement. Fifty-five PTFE- and 18 discoplasty-treated joints were evaluated. More than 60% of the PTFE-treated joints showed severe, destructive osseous change, whereas none of the discoplasty joints showed such change. Histologic examination of the tissues surrounding removed PTFE implants showed a foreign body giant cell reaction. The severity of radiographic change raises questions about the propriety of PTFE as a disc replacement material.