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Biomedical subjects

A J Haas

Publications and source records attributed to A J Haas.

16 recordsLinked to original sources
PubMed2005

Inadvertent administration of magnesium sulfate through the epidural catheter: report and analysis of a drug error.

We present two reports of pregnant women in labor who inadvertently received a magnesium sulfate solution in their epidural space. Both women received approximately 9 mg of magnesium sulfate, and neither of them demonstrated any signs or symptoms of focal neurological toxicity. Once the mistakes were discovered and appropriate medication was delivered, the patients attained an acceptable level of analgesia.

Adult↗
PubMed2000

Nonsurgical rapid maxillary expansion in adults: report on 47 cases using the Haas expander.

Rapid maxillary expansion (RME) in the adult is thought to be an unreliable procedure with several adverse side effects and, consequently, surgically assisted RME is considered the preferred procedure. The purpose of this paper is to study the efficacy of nonsurgical RME, and to determine the incidence of complications such as relapse of the expansion, pain and tissue swelling, tipping of the molars, opening rotation of the mandible and gingival recession. Rapid maxillary expansion using a Haas expander was examined in 47 adults and 47 children. A control group of 52 adult orthodontic patients who did not require RME was also studied. Students' t-test, and the analysis of variance followed by the Scheffe test were used to determine if there were significant differences among time periods and among the 3 study groups. The mean transarch width increase was similar in adults and children who had RME; 4.6 +/- 2.8 compared to 5.7 +/- 2.4 mm for the molars and 5.5 +/- 2.4 compared to 5.7 +/- 2.5 mm for the second premolars. In the adults, transarch expansion and the correction of the posterior crossbites were stable following discontinuance of retainers (mean 5.9 years). If the expander was properly fabricated, and turned no more than once a day, the procedure was well-tolerated. Rapid maxillary expansion in adults flared the molars buccally only 3 degrees per side. The mandibular plane and lower facial height were unchanged. The adults achieved 18% of their transmolar expansion at the height of the palate and the remainder with buccal displacement of the alveolus. The children achieved 56% of their expansion by an increase at the height of the palate with the remainder due to displacement of the alveolus. There was some buccal attachment loss (0.6 +/- 0.5 mm) seen in the female subjects associated with RME, but the extent was clinically acceptable. This resulted in significantly longer clinical crowns, but rarely caused exposure of buccal root cementum. Complications were infrequently observed or of minimal consequence. The results indicate that nonsurgical RME in adults is a clinically successful and safe method for correcting transverse maxillary arch deficiency.

Adolescent↗
PubMed2000

Relapse in Angle Class II Division 1 Malocclusion treated by tandem mechanics without extraction of permanent teeth: A retrospective analysis.

Ideal orthodontic treatment should achieve long-term stability of the occlusion. The mandibular incisor segment has been described as the segment that is most likely to exhibit relapse after treatment and retention. Therefore, relapse of this is a challenge that clinicians need to address. The purpose of this study is to evaluate the amount of relapse that may occur in Angle Class II Division 1 patients, treated orthodontically with tandem mechanics. All cases in this study were treated without extraction of permanent teeth, and the patients were followed for at least 2 years after the end of the retention phase of treatment. Six predictors were investigated at pretreatment, posttreatment, and postretention periods. A synopsis of this study shows the correction of lower incisor crowding as measured by the irregularity index was stable over 5.2 years of postretention follow-up; but longer follow-up time revealed increased relapse of incisor irregularity. Intermolar width increased during treatment and remained stable in the follow-up period. Overjet and overbite corrections and changes in the lower incisor to mandibular plane angle were also stable in the follow-up period. In addition, the amounts of overjet correction and loss of expansion of intercanine distance after treatment were associated with increased irregularity index in the follow-up period. It appears the discrepancies between this and previously published works are sufficiently dramatic that the whole question of treatment philosophy and long-term stability may need to be reevaluated.

Cephalometry↗
PubMed1999

A retrospective study of Angle Class I malocclusions treated orthodontically without extractions using two palatal expansion methods.

The correction and relapse of mandibular anterior crowding was evaluated in a population of 58 patients with Angle Class I malocclusion who were treated orthodontically without extraction of permanent teeth. The subjects were retrospectively evaluated from records taken before treatment, posttreatment, and postretention. The postretention period averaged 8 years (minimum of 4 and maximum of 20 years). All cases in Groups A and B were given orthopedic treatment to develop the maxillary apical base in the transverse and anteroposterior planes. Group A was treated with expansion of the inner bow of the face bow appliance (Kloehn), and Group B was treated with the Haas palatal expansion appliance. Both groups were then treated orthodontically with tandem mechanics. The response variables measured were: overbite, overjet, intercanine distance, intermolar distance, and irregularity index. Study groups A and B were not significantly different for subject age, retention, or postretention time. Moreover, the groups did not show significant difference for any of the response variables before treatment. However, there was a statistically significant difference in the treatment times (P =.0133). A statistically significant treatment effect was observed for most response variables in the groups. Overbite, overjet, and irregularity index were significantly reduced, intermolar distance was significantly increased, and intercanine distance showed no significant change in Groups A and B. In the postretention period, there was a tendency for variables to change slightly toward their before treatment values but no compromise of orthodontic correction was noted. The irregularity index in Group A was corrected from 4.8 to 1.1 mm and remained at 1.1 mm in the postretention period. The irregularity index in Group B was corrected from 5.1 to 1.2 mm (P =.0001) and changed slightly from 1. 2 to 1.7 mm (P =.0540) in the postretention period. We concluded that mandibular incisors tended to become more crowded postretention. However, in contrast to previous reports, we calculate this relapse to be small. Neither before treatment nor posttreatment variables were predictive of relapse.

Adolescent↗
PubMed1990

Surgical-orthodontic correction of transverse maxillary deficiency.

A conservative osteotomy of the zygomaticomaxillary buttress in combination with a rapid palatal expansion appliance is a dependable technique for the treatment of horizontal maxillary deficiency in adults. This procedure has been used successfully in 56 patients in our series, but 17 patients (30 per cent) required a midpalatal osteotomy. In two patients, overexpansion was not achieved because of necrosis of the mucosa. In three other patients, expansion had to proceed at a slower pace because of mucosal ulceration. There have been no other complications. The procedure is indicated mainly in those patients with a horizontal deficiency who do not require subsequent surgery, but for some patients it may be the preliminary procedure. Twelve patients (21 per cent) had subsequent orthognathic surgery. Follow-up has been from 1 to 12 years and there has been no relapse. In our opinion, the zygomaticomaxillary buttress is the primary area of resistance to lateral movement of the maxilla by rapid maxillary expansion appliances.

Adult↗
PubMed1989

Surgical-orthodontic correction of transverse maxillary deficiency.

A conservative osteotomy of the zygomaticomaxillary buttress in combination with a rapid palatal expansion appliance is a dependable technique for the treatment of horizontal maxillary deficiency in adults. This procedure has been used successfully in 56 patients in our series, but 17 patients (30 percent) required a midpalatal osteotomy. In two patients, overexpansion was not achieved because of necrosis of the mucosa. In three other patients, expansion had to proceed at a slower pace because of mucosal ulceration. There have been no other complications. The procedure is indicated mainly in those patients with a horizontal deficiency who do not require subsequent surgery, but for some patients it may be the preliminary procedure. Twelve patients (21 per cent) had subsequent orthognathic surgery. Follow-up has been from 1 to 12 years and there has been no relapse. In our opinion, the zygomaticomaxillary buttress is the primary area of resistance to lateral movement of the maxilla by rapid maxillary expansion appliances.

Adult↗
PubMed1984

Surgical orthodontic correction of transverse maxillary deficiency: a simplified approach.

Osteotomy of the zygomaticomaxillary buttress in combination with a rapid palatal exapnsion appliance is a dependable technique for the treatment of horizontal maxillary deficiency in adults. This procedure has been used in 18 patients with excellent expansion in 17. In one patient, expansion was discontinued prior to overcorrection because of pressure necrosis on the palate related to the appliance. This was the only complication. The procedure is indicated mainly in those patients with a horizontal deficiency who do not require subsequent surgery, but for some patients it may be the preliminary procedure. Three patients in this series had subsequent orthognathic surgery. Follow-up has been from 1 to 6 years, and there has been no relapse. In our opinion, the zygomaticomaxillary buttress is the primary area of resistance to lateral movement of the maxilla by rapid maxillary expansion appliances.

Humans↗
PubMed1981

The combined surgical and orthodontic treatment of mandibular prognathism.

Patients with severe mandibular prognathism are best managed with a combined orthodontic-surgical approach. In our patients, the orthodontic treatment consisted of six to eighteen months of presurgical preparation, which in some patients may accentuate the dental deformity. This is done to provide two well-aligned dental arches that will fit accurately at surgery. The surgical procedure used was an oblique subcondylar osteotomy. This was followed by six to eight months of orthodontic treatment to complete dental alignment. Thirty patients were treated using this combined approach, with excellent results and few complications.

Adolescent↗