Heuristic reasoning and cognitive biases: Are they hindrances to judgments and decision making in orthodontics?

Studies show that our brains use 2 modes of reasoning: heuristic (intuitive, automatic, implicit processing) and analytic (deliberate, rule-based, explicit processing). The use of intuition often dominates problem solving when innovative, creative thinking is required. Under conditions of uncertainty, we default to an even greater reliance on the heuristic processing. In health care settings and other such environments of increased importance, this mode becomes problematic. Since choice heuristics are quickly constructed from fragments of memory, they are often biased by prior evaluations of and preferences for the alternatives being considered. Therefore, a rigorous and systematic decision process notwithstanding, clinical judgments under uncertainty are often flawed by a number of unwitting biases. Clinical orthodontics is as vulnerable to this fundamental failing in the decision-making process as any other health care discipline. Several of the more common cognitive biases relevant to clinical orthodontics are discussed in this article. By raising awareness of these sources of cognitive errors in our clinical decision making, our intent was to equip the clinician to take corrective action to avoid them. Our secondary goal was to expose this important area of empirical research and encourage those with expertise in the cognitive sciences to explore, through further research, the possible relevance and impact of cognitive heuristics and biases on the accuracy of orthodontic judgments and decision making.

Interdisciplinary management of patients with ectodermal dysplasia.

A 15-year-old girl with ectodermal dysplasia who had been treated previously with minimal orthodontic intervention and removal prosthesis was seen and evaluated at the General Practice Program at the University of Kentucky. After consultations with orthodontics and oral and maxillofacial surgery, an interdisciplinary staged treatment plan was developed to address her skeletal and dental issues. The authors briefly review the literature with respect to current therapy for patients with ectodermal dysplasia and present the case as an example of the coordinated care provided for a patient with complex skeletal and dental issues.

The essential work of fracture of thermoplastic orthodontic retainer materials.

OBJECTIVE: To investigate whether oral cleansing agents affect the essential work of fracture (EWF) and plastic work of fracture (PWF) for two types of orthodontic thermoplastic retainer materials. MATERIALS AND METHODS: Polyethylene-terephthalate-glycol (PETG; Tru-Tain Splint) and polypropylene/ethylene-propylene rubber (PP-EPR) blend (Essix-C+) sheets were compared. For each material, six sets of 25 sheets were thermoformed into double-edge-notched-tension specimens; subsets of five specimens were formed with internotch distances (L) equal to 6, 8, 10, 12, or 14 mm, respectively. Sets were stored (160 hours, 25 degrees C) in air (DRY), distilled water (DW), Original Listerine (LIS), mint Crest ProHealth (CPH), 3% hydrogen peroxide (HP), or Polident solution (POL). Specimens were fractured in tension at 2.54 mm/min. Areas under load-elongation curves were measured to determine total work of fracture (W(f)). Linear regressions (W(f) vs L [n = 25]) yielded intercepts (EWF) and slopes (PWF). Ninety-five percent confidence intervals were used to evaluate differences in EWF and PWF estimates. RESULTS: PP-EPR blends showed higher EWFs after storage in HP vs storage in DW. PP-EPR blend showed higher EWFs after storage in CPH vs PETG. After HP storage, PP-EPR exhibited lower PWFs than with any other storage conditions. PP-EPR exhibited higher PWFs than PETG after storage in DRY, DW, and LIS. CONCLUSIONS: Compared with DW, none of the cleansers decreased the energy to initiate fracture. With one exception, no cleanser decreased the energy to continue plastic fracture extension. In PP-EPR blend, increased resistance to fracture initiation was observed with CPH and HP, yet, surprisingly, HP decreased resistance to plastic fracture growth.

Evaluation of orthodontic mini-implant anchorage in premolar extraction therapy in adolescents.

INTRODUCTION: The purpose of this study was to determine the success rate, positional stability, and patient evaluation of orthodontic mini-implants (OMIs). METHODS: Thirteen patients (8 girls, 5 boys; average age, 14 years 10 months) were treated with 82 OMIs measuring 1.6 mm in diameter and 6 mm in length placed in the buccal alveoli (1 unloaded OMI and 1 loaded OMI per quadrant). The right or left side of each arch was randomly selected for immediate loading with up to 250 g of direct force; the contralateral side was loaded 3 to 5 weeks later. Serial impressions, clinical observations, and orthodontic maintenance were performed until adequate space closure was achieved. RESULTS: The overall OMI success rate was 70.73%. As calculated with a mixed-model analysis, there was no statistically significant difference between the success rates of immediately loaded OMIs (80.0%) and delayed loaded OMIs (80.95%). The combined success rate for loaded OMIs (80.49%) was significantly higher than that of unloaded OMIs (60.98%). Patients' motivation for OMI treatment was primarily the desire to avoid headgear. Using a 100-mm visual analog scale, the patients indicated average scores of 54.77 for the amount of pain during OMI placement and 27.10 for the amount of pain during OMI removal. CONCLUSIONS: OMIs are a predictable, effective, and well-tolerated anchorage source for adolescents. Neither the timing of force application nor the force itself precipitated failure of the OMIs. Orthodontic forces can be applied immediately to OMIs. Various anatomic and behavioral conditions unique to adolescents and a clinical learning curve can affect the success rate of OMIs.

Hypodontia as a risk marker for epithelial ovarian cancer: a case-controlled study.

BACKGROUND: Genetic mutations that result in hypodontia also may be associated with abnormalities in other parts of the body. The authors conducted a study to establish the prevalence rates of hypodontia among subjects with epithelial ovarian cancer (EOC) and control subjects to explore possible genetic associations between these two phenotypes. METHODS: The authors recruited 50 subjects with EOC and 100 control subjects who did not have EOC. The authors performed a dental examination on each subject to detect hypodontia, and they reviewed pertinent radiographs and dental histories. They also recorded any family history of cancer and hypodontia. RESULTS: The prevalence of hypodontia was 20 percent for EOC subjects and 3 percent for control subjects. The difference between these two hypodontia rates was significant. This difference implied that women with EOC are 8.1 times more likely to have hypodontia than are women without EOC. The severity of hypodontia was similar between the two groups, with one to two teeth being affected. Maxillary lateral incisors followed by second premolars were the most frequently affected teeth. CONCLUSION: The preliminary data suggest a statistical association between hypodontia of the permanent dentition and EOC. CLINICAL IMPLICATIONS: Genetic analysis of the genes of interest is necessary to explore similarities between hypodontia and EOC further. An association could allow hypodontia to serve as a potential risk marker for EOC.

Racial variations in cephalometric analysis between Whites and Kuwaitis.

The objective of this study is to determine whether (1) Kuwaiti adolescents differ from Caucasian adolescents with respect to their cephalometric values; (2) sex plays a role in the differences between the two groups; and (3) a need exists to develop cephalometric standards for the Kuwaiti population. Standardized cephalometric films were obtained from 36 Kuwaiti females and 32 Kuwaiti males between the ages 11 and 14 years. Only subjects with Class I molar occlusion and a positive overjet of no more than 4 mm were selected. Each subject was age matched with White cephalometric values. Intraexaminer error, paired, and two-sample t-tests were made. The results show that there were significant differences between the Kuwaiti population and the Caucasian population for the majority of the variables tested (P < .01). Sex produced no significant effect on any of the variables studied. The Kuwaiti population has fuller lips, more facial convexity, greater dental protrusion, a more retruded and smaller mandible, and shorter posterior face height than the Caucasian population.