Biomedical subjects

Stephen L Engroff

Publications and source records attributed to Stephen L Engroff.

4 recordsLinked to original sources

PubMed2005

Strength analysis of titanium and resorbable internal fixation in a mandibulotomy model.

PURPOSE: Mandibulotomy is used to access various tumors of the tongue base, posterior oral cavity, pharynx, parapharyngeal space, and cranial base. Internal fixation using titanium plates and screws is the most common method of stabilization. These have the potential for interference with radiotherapy delivery. This in vitro study compares the strength of titanium and resorbable internal fixation in a mandibulotomy model by analyzing the force required for plate and screw breakage. MATERIALS AND METHODS: Red oak wood board was used to simulate the mandible. Titanium and resorbable plates and screws in various configurations were used to stabilize pieces of the wood. They were arranged in 6 different groups. The specimens were individually tested with a vertical load, while the test machine recorded the force-versus-displacement behavior automatically. RESULTS: Plate type and configuration affected the applied load required to induce displacement of the simulated mandibulotomy. Heating and cooling the resorbable plates prior to strength testing also affected the load-versus-displacement curve. CONCLUSIONS: Overall, the titanium system we studied exhibited greater resistance to deformation from a vertical load than did the resorbable plate groups.

Absorbable Implants↗

PubMed2005

Fibula flap reconstruction of the condyle in disarticulation resections of the mandible: a case report and review of the technique.

Segmental resection of the mandible with disarticulation of the temporomandibular joint is occasionally required in the management of extensive tumors. The reconstruction of these deformities is complex, frequently involves staged procedures, and may result in significant deformity and loss of function for patients. The fibula free flap has become a standard treatment option for primary restoration of segmental mandibular deformities. However, little is published about its role in reconstructing the mandibular condyle. This paper describes a simplified technique for primary reconstruction of mandibular defects, including the mandibular condyle, in disarticulation resections of the mandible utilizing the fibula free flap.

Adult↗

PubMed2004

Osteonecrosis of the jaws associated with the use of bisphosphonates: a review of 63 cases.

PURPOSE: Bisphosphonates are widely used in the management of metastatic disease to the bone and in the treatment of osteoporosis. We were struck in the past 3 years with a cluster of patients with necrotic lesions in the jaw who shared 1 common clinical feature, that they had all received chronic bisphosphonate therapy. The necrosis that was detected was otherwise typical of osteoradionecrosis, an entity that we rarely encountered at our center, with less than 2 patients presenting with a similar manifestation per year. PATIENTS AND METHODS: We performed a retrospective chart review of patients who presented to our Oral Surgery service between February 2001 and November 2003 with the diagnosis of refractory osteomyelitis and a history of chronic bisphosphonate therapy. RESULTS: Sixty-three patients have been identified with such a diagnosis. Fifty-six patients had received intravenous bisphosphonates for at least 1 year and 7 patients were on chronic oral bisphosphonate therapy. The typical presenting lesions were either a nonhealing extraction socket or an exposed jawbone; both were refractory to conservative debridement and antibiotic therapy. Biopsy of these lesions showed no evidence of metastatic disease. The majority of these patients required surgical procedures to remove the involved bone. CONCLUSIONS: In view of the current trend of increasing and widespread use of chronic bisphosphonate therapy, our observation of an associated risk of osteonecrosis of the jaw should alert practitioners to monitor for this previously unrecognized potential complication. An early diagnosis might prevent or reduce the morbidity resulting from advanced destructive lesions of the jaw bone.

Administration, Oral↗

PubMed2003

Mandibulotomy fixation: a laboratory analysis.

PURPOSE: Mandibulotomy is an access osteotomy technique associated with significant complications. Critical evaluation of available fixation systems is required to aid in the selection of the most stable fixation method. This study was designed to provide data on the stability of traditionally used plating configurations and a low-profile 2.0-mm locking plate (mandibular locking plate, Synthes MLP; Synthes Maxillofacial, Paoli, PA). MATERIALS AND METHODS: An in vitro red oak model was used to evaluate the stability provided by the study fixation devices. Five groups were studied as follows: group 1, two 4-hole 2.0-mm nonlocking miniplates; group 2, two 4-hole 2.0-mm mandibular locking plates; group 3, one 6-hole 2.0-mm mandibular locking plate; group 4, one 6-hole 2.4-mm nonlocking rigid plate; and group 5, control (uncut red oak blocks). Each specimen was tested with vertical loads applied over the osteotomy site. The force-versus-displacement behavior was recorded for each specimen and analyzed statistically. RESULTS: Plate type and configuration affected the resistance to vertical peak load (kilogram/force [kgf]) and the fixation stiffness (kgf/mm). The greatest peak load (58.92 kgf) and stiffness (7.07 kgf/mm) was found with group 2 specimens. The differences in system stiffness were statistically significant (P <.05), as were the peak loads for groups 1, 2, and 3. The control group (nonosteotomized red oak) had markedly higher values of peak load and stiffness (484 kg and 83 kg/mm, respectively). Group 2 specimens exhibited increased resistance to flexion. CONCLUSIONS: Two 2.0-mm locking plates provided the greatest resistance to vertical load.

Biomechanical Phenomena↗