Search

Purpose: This study evaluated whether reattachment of the trochlea is necessary to assure normal postoperative extraocular muscle movements after orbital roof exploration and trochlea detachment. Patients and Methods: This was a retrospective review of 889 operative records of one surgeon practicing at a level I trauma center between January 1, 1992 and December 31, 1998. Three hundred twenty-four of these cases were trauma related, 97 of which involved the upper facial third or upper midface. From this group, 15 patients required orbital roof exploration with trochlea detachment. Age, gender, cause of injury, form of craniofacial injury, method of repair, materials used, date of first notation of intact extraocular movement, and date of last follow-up were recorded and analyzed. Results: From among the 15 patients requiring orbital roof exploration and repair, 14 (93%) were male, with a mean age of 34.7 ± 15.2 years. Eight (53%) were involved in motor vehicle accidents, 3 (20%) in motorcycle accidents, and 4 (27%) in high-energy impacts. Most (95%) had injuries that included the frontal sinus, the naso-orbital-ethmoid region (60%), and the orbital rims (60%). After bitemporal flap reflection, careful subperiosteal dissection, supraorbital and supratrochlear nerve repositioning, and trochlea detachment, simple reapproximation of the orbital soft tissues to the reconstructed orbit resulted in satisfactory extraocular muscle movements in all cases. Conclusions: When careful subperiosteal dissection is used, simple reapproximation of the soft tissues adjacent to the reconstructed orbital roof, without reattachment of the trochlea, is all that was necessary to assure satisfactory extraocular muscle movements postoperatively. © 2000 American Association of Maxillofacial Surgeons

Objective: The purpose of this in vitro investigation was to determine whether the number or pattern of placement of positional screws affected their ability to resist vertical loads resembling mastication. Materials and Methods: Standardized bone substitutes were secured with varying numbers of 17.0-mm-long, 2.0-mm outer diameter, self-tapping titanium screws (W. Lorenz Surgical, Jacksonville, FL) in various patterns using a positional screw technique. These patterns included one, two, three, four, and five screws in a linear pattern; two screws in a vertical pattern; three screws in an L-pattern, inverted-L pattern, backward-L pattern, inverted-backward-L pattern, and right and left diagonal pattern; four screws in a box pattern; and five screws in a domino pattern. Five models of each group were fabricated along with a control group. The models were secured in a jig and subjected to vertical loads by an Instron 8511.20 Mechanical Testing Unit (Canton, MA) until failure. Common engineering standards, including yield load, yield displacement, stiffness, maximum load, and displacement at maximum load, were measured, and means and standard deviations were derived and compared for statistical significance with an analysis of variance (ANQVA) and Scheffe multiple comparison test. Results: Screw number and pattern of placement affected the mechanical characteristics in resistance to vertical load. Screw numbers less than three and all linear patterns were the least effective. The three-screw L patterns, as a category, provided greater resistance to vertical loads than either the three-screw linear or three-screw diagonal patterns. The addition of more than three screws in geometric patterns offered no greater benefit than the three-screw L patterns. Conclusions: In this in vitro study, the three-screw L patterns were the most effective and efficient when using the positional screw technique.

Purpose: The purpose of this investigation was to determine whether routine laboratory testing affected the clinician's preoperative evaluation and decision-making process for patients undergoing general anesthesia or intravenous sedation in the oral and maxillofacial surgery office. Patients and Methods: This was a prospective evaluation of the records of 458 who required an office general anesthetic or intravenous sedation for routine dentoalveolar surgery. The patients ranged in age from 15 to 54 years and were categorized as American Society of Anesthesiologists Classification I or II. Fifty-two percent were female. All patients underwent a history and physical examination, complete blood cell count, and urine analysis. Female patients were tested for pregnancy by measuring the serum beta human chorionic gonadotropin level. All patients older than 40 years of age were further evaluated by posterior-anterior and lateral chest radiographs, as well as electrocardiography. On the day of surgery, the data were reviewed and analyzed, and specific components of the history were reassessed. The results of the decision-making process were evaluated by one investigator. Results: From the 458 patients initially enrolled, 78 failed to return on the appointed day. Of the 235 patients requiring general anesthesia who did return on the appointed day, five had aberrant laboratory values (2%). These consisted of one patient with a low hematocrit, one with a low red blood cell count, one with a low white blood cell count, and two with a urine analysis positive for blood. No procedure was canceled based on the aberrant data. Of the 145 patients requiring intravenous sedation who did return on the appointed day, six had aberrant laboratory values (4%). Two patients exhibited elevated white blood cell counts, two possessed low red blood cell counts, one known to have diabetes had an elevated urine glucose, and one patient with an elevated human chorionic gonadotropin level realized that her menstrual cycle was delayed. The latter two patients had their procedures deferred. Conclusions: Based on the results of this study, a good history and physical examination and then reassessment of key portions of the history were the major factors in the development of the anesthetic treatment plan. Laboratory data had little if any effect on the decision-making process.

Purpose: The purpose of this investigation was to determine the distance from the orbital rim to the important soft tissues of the orbital apex using eight reference points to provide clinically useful information for surgical decision making. Materials and Methods: Eight human cadavers were used in this investigation. After circumorbital incisions were made and the canthal ligaments were detached, a careful subperiosteal dissection was performed to the soft tissues of the orbital apex. Four reference lines were established. The first two were based on a horizontal line drawn through the medial and lateral canthal ligaments and a perpendicular to this through the infraorbital foramen. The other two were created at points 45 ° from the first two. Depth measurements were made with a straight probe at the eight points where the lines crossed the orbital rim. Means, standard deviations, and ranges were derived, and statistical differences were calculated between right and left orbits using a paired-samples t-test. Because no right and left differences were noted (P < .05), the data were pooled. Results: The mean distance from the orbital rim to the soft tissues of the orbital apex was 44.1 ± 1.4 mm medially, 38.3 ± 3.0 mm laterally, 44.5 ± 1.72 superiorly, and 39.4 ± 2.9 mm inferiorly. The superomedial distance was 46.3 ± 2.7 mm, the inferomedial distance was 44.1 ± 1.4 mm, the inferolateral distance was 41.4 ± 2.5 mm, and superolateral distance was 39.4 ± 2.8 mm. Conclusions: The distances from the orbital rim to the soft tissues of the orbital apex varied among the eight different reference points (range, 38.3 ± 3.0 mm to 46.3 ± 2.7 mm). No distance was less than 31.0 mm or exceeded 51.1 mm. There was no difference noted (P < .05) between the right and left sides for each of the corresponding reference points.

Purpose: Traumatic occlusion of the internal carotid artery (ICA) is a rare complication of maxillofacial trauma or surgery. This investigation evaluated patient demographics, diagnostic methods, and effective therapeutic modalities associated with blunt carotid injury (BCI). Patients and Methods: This was a retrospective analysis of patient records with an ICD-9-CM diagnosis of carotid injury conducted at MetroHealth Medical Center during the 24-month period between August 1993 and July 1995. Carotid injuries attributable to penetrating trauma were excluded. Age, gender, cause of injury, Glasgow Coma Scale score, Injury Severity Score, type and location of injury, concomitant injury, diagnostic methods, treatment modalities, and outcome were identified, recorded, and analyzed. Results: During the 24-month period, 12 patients (seven males and five females) suffered BCI. These patients were divided into two groups based on cause of the problem. In group I, there were 3,214 blunt trauma patients admitted during the 2-year study, of which 10 patients had BCI, representing 0.31% of blunt trauma patients, and 1.2% of patients with head injuries. Seven patients presented with hemiplegia, two with cranial nerve palsy, and one with perceptual neglect. Ninety percent of the patients had associated injuries. Two patients had surgical intervention, three received anticoagulation, and five had only supportive care. Four of the 10 patients died, four had moderate neurologic deficits, and two survived with only minor neurologic deficits. In group II, two patients developed BCI after surgery. A 52-year-old woman had a carotid injury after right total temporomandibular joint replacement, and a 48-year-old man who underwent surgical removal of a third molar became hemiplegic postoperatively. The first patient recovered after anticoagulation, whereas the second patient, who received only supportive care, has severe neurologic deficits. Conclusions: BCI is an uncommon entity. It is usually recognized when a patient develops an unexplained neurologic deficit, most often hemiplegia, subsequent to trauma or surgery of the head, face, or neck. In the early stages, the diagnosis can be missed by carotid ultrasound or computed tomography. The injury is unrelated to Glasgow Coma Scale score. Symptoms may not develop for days after injury in 50% of patients. Anticoagulation appears to be the most beneficial therapeutic modality.

Oral and maxillofacial surgeons are frequently called on to evaluate and treat patients with facial trauma. While vehicular accidents and interpersonal violence are the most frequent causes, an estimated 44,000 facial injuries are encountered annually from dog bites in the United States. ~ With the exception of a few isolated case reports, discussions of these injuries have been virtually nonexistent in the oral and maxillofacial surgery literature. The purpose of this article is to provide the oral and maxillofacial surgeon with a comprehensive review of the incidence, pathophysiology, diagnosis, and management of facial dog bite injuries (FDB1).