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A J Vartanian

Publications and source records attributed to A J Vartanian.

8 recordsLinked to original sources
PubMed2000

Bone-screw mandible fixation: an intraoperative alternative to arch bars.

OBJECTIVES: Bone-screw mandible fixation (BSMF) is evaluated as an alternative to intraoperative arch-bar maxillomandibular fixation before plating of mandibular fractures. BSMF is achieved by wire ligation of opposing bone-screws placed in the maxilla and mandible. METHODS: A retrospective evaluation of 23 patients with 40 mandibular fractures who underwent mandibular fracture repairs. BSMF was used instead of arch bars to ensure proper dental occlusion. All fractures were then plated, after which BSMF was removed before termination of anesthesia. RESULTS: Normal occlusion was observed in 21 patients (91.3%), Class II malocclusion was noted in 1 patient (4. 3%), and 1 patient was edentulous. No complications related to the use of BSMF were observed. CONCLUSION: BSMF can serve as a viable alternative to arch-bar maxillomandibular fixation for obtaining temporary intraoperative occlusion. BSMF produces acceptable malocclusion rates and offers the advantages of decreased intraoperative time, lower risk for percutaneous and mucosal wire punctures, and ease of use.

Accidents, Occupational↗
PubMed1999

Both glutamate receptor antagonists and prefrontal cortex lesions prevent induction of cocaine sensitization and associated neuroadaptations.

Behavioral sensitization to psychomotor stimulants is accompanied by a number of alterations in the mesoaccumbens dopamine (DA) system, including DA autoreceptor subsensitivity in the ventral tegmental area (VTA) and DA D1 receptor supersensitivity in the nucleus accumbens (NAc). We investigated the role of excitatory amino acid (EAA) transmission in the induction of cocaine sensitization and these accompanying DA receptor alterations. To do so, we used three glutamate receptor antagonists, the noncompetitive NMDA receptor antagonist MK-801 (0.1 mg/kg), the competitive NMDA receptor antagonist CGS 19755 (10.0 mg/kg), and the AMPA receptor antagonist NBQX (12.5 mg/kg). Rats received daily double injections of either one of these antagonists or saline with either cocaine (15.0 mg/kg) or saline for 5 days. Cocaine sensitization was defined as an increase in horizontal locomotor activity in response to cocaine challenge (7.5 mg/kg) on the third day of withdrawal. All three antagonists prevented the induction of cocaine sensitization. Extracellular single cell recordings revealed that these antagonists also prevented the induction of DA autoreceptor subsensitivity in the VTA and DA D1 receptor supersensitivity in the NAc. To determine whether the relevant glutamate receptors were under regulation by medial prefrontal cortex (mPFC) EAA efferents, we next lesioned the mPFC bilaterally with ibotenic acid at least 7 days before repeated cocaine treatment began. These lesions also prevented the induction of cocaine sensitization and the associated neuroadaptations. Our findings indicate that glutamate transmission from mPFC to the mesoaccumbens DA system is critical for the induction of cocaine sensitization and its cellular correlates.

Adaptation, Biological↗
PubMed1998

Microscopic examination of routine tonsillectomy specimens: is it necessary?

Controversy continues to exist regarding the routine histologic examining of tonsillectomy specimens. Proponents suggest that among other reasons, missing an important diagnosis such as occult malignancy or granulomatous disease and possible medicolegal consequences argue in favor of routine histologic examination. Others state that we should consider the very low yield of significant histologic findings in routine tonsillectomy specimens and its added cost. We performed a retrospective evaluation of all cases of patients who underwent tonsillectomy with or without adenoidectomy between January 1992 and July 1996. Two hundred eighty-eight charts were evaluable. Group 1 consisted of all tonsillectomy specimens that were subjected to gross examination only. Group 2 consisted of all tonsillectomy specimens that were subjected to gross examination as well as microscopic examination. In group 1, no abnormal gross findings were noted. Group 2 consisted of specimens from an older population with a mean age of 21.6 years. There were 43 patients older than 20 years old in group 2, and in all cases except four the preoperative clinical impression correlated with the microscopic findings. Occult malignancy was found in only one of these four patients. No cases of granulomatous disease were discovered. Overall, no patients except one had any change in postoperative treatment on the basis of the results of microscopic examination. We believe that routine microscopic examination of tonsillectomy specimens results in unnecessary cost and consumption of resources and time. Microscopic examination should be done in only selected cases such as in patients with grossly asymmetric tonsils or in patients with a history of malignancy.

Adenoidectomy↗
PubMed1998

When is facial pain trigeminal neuralgia?

The pain of trigeminal neuralgia can be excruciating and debilitating. Fortunately, effective medical and surgical therapies for the disorder exist. Successful treatment hinges on thorough history taking and accurate diagnosis. Diagnostic evaluation of patients with orofacial pain should include complete head and neck, dental, and neurologic examinations combined with radiologic imaging of the head and appropriate laboratory tests.

Analgesics, Non-Narcotic↗
PubMed1997

Effects of the AMPA receptor antagonist NBQX on the development and expression of behavioral sensitization to cocaine and amphetamine.

We examined the effect of 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(f)quinoxaline (NBQX), an antagonist of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) subtype of glutamate receptor, on the development and expression of behavioral sensitization to amphetamine and cocaine in rats. A single injection of NBQX (12.5 mg/kg) administered 30 min prior to cocaine during the induction phase (days 1-5) prevented the development of cocaine sensitization, assessed by responsiveness to cocaine challenge on day 8. This NBQX regimen did not affect development of amphetamine sensitization. Two pretreatment injections of NBQX, one 20 min before and one 70 min after amphetamine on each day of the induction phase (days 1-6), did not affect sensitization of stereotypy but prevented sensitization of post-stereotypy ambulatory hyperactivity (both assessed by responsiveness to amphetamine challenge on day 8). The effect of NBQX on ambulatory sensitization was dose-dependent (attenuation with 12.5 mg/kg, complete prevention with 25 mg/kg). In contrast to its effects on development, NBQX (25 mg/kg) did not prevent expression of sensitization to cocaine or amphetamine. NBQX itself exerted no significant effects on locomotor activity in either drug-naive rats or rats that had received either NBQX or amphetamine repeatedly. These findings support a requirement for AMPA receptor stimulation in the development of locomotor sensitization to cocaine and amphetamine, but suggest a different mechanism for sensitization of amphetamine stereotypy.

Amphetamine↗
PubMedDate not supplied

The forehead lift: endoscopic versus coronal approaches.

Rejuvenation surgery of the upper one-third of the face can be accomplished by a number of well-known techniques and approaches. The objectives of this study were to: (1) determine if endoscopic-assisted forehead lifts achieve the same degree of correction as the coronal/pretrichial forehead lifts, (2) to assess the effect of concurrent blepharoplasty on brow elevation, and (3) to evaluate long-term results of coronal/ pretrichial forehead lifts. The study was a retrospective blinded comparison of pre- and postoperative photographs of patients who underwent forehead lifts. In order to control for the differences in photographs, ratios of distances were measured utilizing standard anthropometric sites of the brow, medial canthus, and subnasale. All reviewed cases were operated on by the same surgeon (S.W. Perkins, M.D.). A total of 140 patients having undergone forehead lift procedures and with 12-month postoperative photographic documentation were included in the study. Of these 121 patients had coronal forehead lifts and 19 had endoscopic-assisted forehead lifts. Results revealed that at 1 year follow-up both methods achieved brow elevation without a significant difference in the approach. Concomitant blepharoplasty had no statistical effect on brow position. Additionally, long-term follow-up on the coronal/pretrichial lifts revealed a gradual drop in brow position over 5 years. We conclude that both endoscopic and coronal/pretrichial forehead lifts provide for comparable elevation at 1-year follow-up. Concomitant blepharoplasty has minimal to no significant effect on brow position. Brow elevation in coronal/pretrichial forehead lifts may be temporary.

Blepharoplasty↗