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Greg J Huang

Publications and source records attributed to Greg J Huang.

17 recordsLinked to original sources
PubMed2006

Methods to evaluate profile preferences for the anteroposterior position of the mandible.

INTRODUCTION: Facial profile disharmonies in the anteroposterior (AP) position of the mandible are among the most frequent reasons that patients seek orthodontic treatment. Various methods are available for assessing profile preferences, and differences between them could affect treatment decisions. The purposes of this study were to compare and contrast 3 methods of evaluating profile preferences for the AP position of the mandible. METHODS: Facial profile preferences of white orthodontists (n = 28) and white (n = 56) and Japanese-American (n = 55) laypeople were evaluated. The esthetic significance of variations in the AP position of the mandible was investigated by using 3 methods: a traditional semantic differential scale, the Perceptometrics method (Health Programs Intl, Wellesley, Mass), and the implicit association test (IAT). RESULTS: Findings from the semantic differential scale show that, overall, there is a general preference among orthodontists and laypeople for an orthognathic profile (P <.001). Findings from the Perceptometrics method indicate that orthodontists consider the most pleasing profile to be more forward than do lay subjects (P <.001). The IAT results show a positive bias among all 3 groups toward orthognathic profiles and a negative bias toward profiles with mandibular retrognathism or prognathism. The IAT suggested that laypeople were more tolerant of mandibular prognathism in men than in women (P <.01), and more tolerant of mandibular retrognathia in white women than in men (P = .03). CONCLUSIONS: These results support the benefits of using both implicit and explicit methods to assess facial profile preferences.

Adult↗
PubMed2006

Bigfoot lives?

Explore the source record for details and available documents.

Consensus↗
PubMed2006

Third-molar extraction as a risk factor for temporomandibular disorder.

BACKGROUND: Although third-molar extraction is common in the U.S., there are few reports on the relationship between third-molar extraction and temporomandibular disorder (TMD). The aim of this study was to investigate this potential association. METHODS: The authors enrolled study subjects on their 15th birthdays and followed them continuously for a minimum of five years. The authors ascertained exposure (third-molar extraction) and outcome (TMD) via electronic dental insurance records. A survival analysis design estimated the relative risk of experiencing TMD after third-molar extraction. They considered sex, dental care utilization and other potentially confounding variables in the analyses. RESULTS: A total of 34,491 subjects met the inclusion criterion. Fifty percent of all subjects had third molars removed by the age of 20 years, and 391 subjects had claims indicating TMD. The adjusted relative risk of experiencing TMD after third-molar extraction was 1.6 (95 percent confidence interval, 1.3 to 2.0). Calculation of the population risk indicated that 23 percent of all TMD cases in this age group might be due to third-molar extraction. CONCLUSIONS: Third-molar extraction appears to be a risk factor for TMD. CLINICAL IMPLICATIONS: Dental providers should be aware of the risk of experiencing TMD related to third-molar extraction and take measures to minimize trauma to the joint during extraction.

Adolescent↗
PubMed2005

The effectiveness of phase I orthodontic treatment in a Medicaid population.

BACKGROUND: The effectiveness of early orthodontic treatment for Medicaid-enrolled children in the mixed dentition was assessed and compared with results in a population of private-pay patients. MATERIAL: Pre- and posttreatment casts from 196 subjects treated with interceptive orthodontics in the mixed dentition were evaluated by using the peer assessment rating (PAR) index and the index of complexity, outcome, and need (ICON). Ninety-six of the patients were treated at Odessa Brown Community Clinic in Seattle; their treatment was paid by Medicaid. One hundred private-pay patients were treated at the University of Washington graduate orthodontic clinic. The Medicaid and private-pay populations were comparable with respect to initial severity of malocclusion, as assessed by both indexes. RESULTS: PAR and ICON scores fell by similar amounts in the Medicaid (44.1% and 37.5%, respectively) and private-pay (46.8% and 37.3%, respectively) populations. Thus, the groups exhibited similar degrees of improvement with interceptive orthodontic treatment. According to the PAR and ICON, midline discrepancy, overjet, and esthetics exhibited the greatest improvement. The Medicaid population missed significantly more appointments and had poorer oral hygiene than the private-pay group, but these factors did not appear to worsen the outcomes, as measured by the 2 indexes. An appliance with 2 bands and 4 brackets was the most commonly used, and it produced the most significant treatment effect. CONCLUSIONS: Phase I orthodontic treatment significantly reduces malocclusion severity in Medicaid and private-pay populations. There was no difference in initial severity or final outcome, as assessed by the PAR and ICON, between Medicaid and private-pay populations. The degree of improvement in PAR scores did not appear to be associated with compliance.

Analysis of Variance↗
PubMed2005

Long-term posttreatment changes measured by the American Board of Orthodontics objective grading system.

BACKGROUND: The American Board of Orthodontics (ABO) developed the objective grading system (OGS) to evaluate cases submitted as part of the phase III examination for board certification. This study examines the long-term changes in 6 of the 8 criteria measured by the board, with an emphasis on the relationship between posttreatment results and subsequent improvement or worsening. MATERIAL: One hundred subjects were randomly chosen from the postretention archives of the Department of Orthodontics at the University of Washington. Pretreatment peer assessment rating (PAR) scores and posttreatment and postretention OGS scores were measured on study casts. The ABO criteria studied were alignment, marginal ridges, buccolingual inclinations, occlusal contacts, occlusal relationships, and overjet. Interproximal contacts and root angulations were not scored. RESULTS: The mean overall OGS score at posttreatment was 21.5 points. At postretention, this score had improved significantly, by approximately 4 points. When comparing posttreatment scores and long-term changes, similar patterns were seen for all criteria, except alignment; increased posttreatment scores were associated with increased long-term improvement. Well-treated cases tended to deteriorate, and poorly finished cases tended to improve, illustrating a regression to the mean. Alignment was the only criterion associated with a mean long-term worsening, as well as a less predictable pattern of change. CONCLUSIONS: The results of this study indicate that settling occurs after orthodontic treatment, and that the attainment of perfect occlusal results does not ensure stability.

Adolescent↗
PubMed2005

Retrospective analysis of long-term stable and unstable orthodontic treatment outcomes.

INTRODUCTION: The purpose of this study was to compare groups of patients with the most stable and the most unstable treatment results as rated by the peer assessment rating (PAR) index to identify factors associated with stability. All factors with significant crude odds ratios were investigated to create a multiple logistic regression model that could be used to predict stability. METHODS: The sample of 86 patients (30 male, 56 female), from the post-retention archives at the University of Washington, was not restricted to specific malocclusion types or treatment modalities with the exception of Angle Class III patients, who were excluded. The sample was divided into 2 groups, stable (n = 45) and unstable (n = 41), based on post-retention unweighted PAR scores and PAR score changes between posttreatment and post-retention. Model and radiographic measurements were made before treatment, after treatment, and after retention (average 14.4 years). RESULTS: The results showed that male sex and a sustained period of growth were related, and both were associated with increased instability. The initial severity of malocclusion, as graded by the PAR index and the irregularity index, was negatively correlated with post-retention stability-ie, patients with more severe index scores before treatment tended to be less stable. Differences in American Board of Orthodontics scores after treatment were diminished after retention. CONCLUSIONS: The factors associated with predicting stability were pretreatment arch length, pretreatment PAR score, molar classification, and sex.

Adolescent↗
PubMed2005

Eligibility for publicly funded orthodontic treatment determined by the handicapping labiolingual deviation index.

INTRODUCTION: Access to orthodontic care for Medicaid patients has been limited, in part because of orthodontists' reluctance to treat severe malocclusions for low reimbursements. Limited orthodontic treatment in the mixed dentition (phase 1 treatment) has been proposed to address this issue, because the intent of phase 1 treatment is to improve or prevent severe malocclusions. Orthodontists might be more willing to provide shorter, simpler treatment. The purpose of this study was to determine whether phase 1 treatment would reduce malocclusion severity to the extent that eligibility for subsequent Medicaid-funded treatment was significantly reduced. METHODS: Eligibility was determined by the handicapping labiolingual deviation (HLD) index, which is used by several states for this purpose. Eligibility was also determined with the index of complexity, outcome, and need (ICON). This allowed us to compare these 2 indexes. Pre-phase 1 and post-phase 1 index scores were calculated by using study casts from 193 patients treated at the University of Washington orthodontic clinic and the Odessa Brown Children's Dental Clinic, both in Seattle. RESULTS: Using the HLD index, we found that eligibility for orthodontic treatment decreased by 62% after phase 1 treatment. This change was statistically significant at P < .0001. The ICON found significantly more treatment need before phase 1 (90%) than did the HLD index (35%) (P < .0001). CONCLUSIONS: Early interceptive treatment significantly reduces eligibility for comprehensive Medicaid-funded orthodontic treatment. The HLD index is a useful tool for determining Medicaid eligibility.

Adolescent↗
PubMed2004

Orthodontic care in an insured population in Washington: demographic factors.

Few studies have used insurance claims data to investigate demographic factors related to orthodontic care. This study sought to describe age and sex distributions in a large, insured population in Washington. Additionally, the demand for orthodontic care was evaluated with respect to county population, and the impact of the availability of orthodontists was investigated. All orthodontic claims in 2001 were retrieved from the Washington Dental Service database, along with associated provider and patient information. A total of 102,984 claims were included in this study. A large percentage of subjects (86%) were less than 20 years old, with most patients in their early teens. Overall, about 64% of all orthodontic patients were female. The demand for orthodontic treatment was the highest in the counties with the largest populations. Although there was considerable variation in the data, the number of orthodontic claims submitted by general dentists tended to decline as the availability of orthodontists increased.

Adolescent↗
PubMed2003

Distribution of orthodontic services and fees in an insured population in Washington.

Previous attempts to quantify the amount and type of orthodontic therapy provided by nonorthodontists in the United States have relied on survey data. Although there are advantages to surveys, such as control over survey recipients and inclusion of specific questions, they also have limitations, such as low response rates, response bias, and recall bias. This study used insurance claims data from a large dental benefits provider in Washington to assess the distribution of orthodontic services and fees among various dental providers. All orthodontic claims allowed by Washington Dental Service in 2001 were retrieved, along with treatment codes, fees, and demographic information for both patients and providers. A total of 102,984 orthodontic claims were included in the study. General dentists submitted 7.0% of these claims, orthodontists submitted 90.9%, and pedodontists submitted 1.9%. Orthodontists submitted higher average fees for space maintainers, first payments, and records. The percentage of orthodontic treatment preformed by general dentists and pedodontists in this claims-based study was substantially less than what has been previously reported in survey-based studies. Additionally, a smaller percentage of general dentists and pedodontists in this study performed comprehensive treatment, compared with previous studies. This study illustrates the value of insurance claims data to assess the provision of orthodontic care.

Analysis of Variance↗
PubMed2002

Outcomes of planned home births in Washington State: 1989-1996.

OBJECTIVE: To determine whether there was a difference between planned home births and planned hospital births in Washington State with regard to certain adverse infant outcomes (neonatal death, low Apgar score, need for ventilator support) and maternal outcomes (prolonged labor, postpartum bleeding). METHODS: We examined birth registry information from Washington State during 1989-1996 on uncomplicated singleton pregnancies of at least 34 weeks' gestation that either were delivered at home by a health professional (N = 5854) or were transferred to medical facilities after attempted delivery at home (N = 279). These intended home births were compared with births of singletons planned to be born in hospitals (N = 10,593) during the same years. RESULTS: Infants of planned home deliveries were at increased risk of neonatal death (adjusted relative risk [RR] 1.99, 95% confidence interval [CI] 1.06, 3.73), and Apgar score no higher than 3 at 5 minutes (RR 2.31, 95% CI 1.29, 4.16). These same relationships remained when the analysis was restricted to pregnancies of at least 37 weeks' gestation. Among nulliparous women only, these deliveries also were associated with an increased risk of prolonged labor (RR 1.73, 95% CI 1.28, 2.34) and postpartum bleeding (RR 2.76, 95% CI 1.74, 4.36). CONCLUSION: This study suggests that planned home births in Washington State during 1989-1996 had greater infant and maternal risks than did hospital births.

Adult↗
PubMed2002

A custom mandibular distraction device for the rat.

In the last several years, the rat model has been used as a reliable means of studying distraction osteogenesis (DO). This model has several benefits, including lower cost, the availability of molecular reagents for the rat, and the ability to perform a large number of operations in a short time. We have recently developed an external device that is custom-made for the rat mandible and secured at the mandibular ramus. The device consists of a Leone (Florence, Italy) jackscrew distraction assembly (0.2 mm per one-quarter turn), 2 Luhr L-shaped 0.8-mm five-hole microplates, and four 0.8-mm x 3-mm microscrews (Stryker-Leibinger Corp., Kalamazoo, MI) for fixation. Additionally, there is a methylmethacrylate block that is placed on the lingual surface of the angle of the mandible to support the posterior screws. Sterile surgical technique was used, and the same two surgeons performed all operations. To date, we have operated on 153 Sprague-Dawley rats. The procedure has been well tolerated by the animals. We had 17 postoperative deaths (11% mortality), largely as a result of anesthetic complications. There were no wound infections or dehiscence. A mandible fracture was noted in 6 rats (4%), which occurred at the time of device placement. There were no device dislodgments. Postmortem examination showed the device to be well positioned in all rats, with good callous formation at the distraction site. The rats surpassed their preoperative weight after an average of 9.2 days. These results compare favorably with those of other models currently in use. We have developed a device that is currently being used in the study of DO in the rat mandible. Our device is small in size, does not require wide undermining for its placement, and has had a low incidence of device dislodgment or infection. This model has shown great reproducibility and thus should be effective in its application for the histologic and biochemical investigation of DO in the rat.

Animals↗