Eustaquio A. Araujo

Attitudes, awareness, and barriers toward evidence-based practice in orthodontics.

INTRODUCTION The purpose of this study was to evaluate the attitudes, awareness, and barriers toward evidence-based practice. METHODS A survey consisting of 35 questions pertaining to the use of scientific evidence in orthodontics was sent to 4771 members of the American Association of Orthodontists in the United States. Each respondents age, attainment of a masters degree, and whether he or she was currently involved with teaching were ascertained. To minimize bias, the survey questions were phrased as an examination of the use of scientific literature in orthodontics. RESULTS A total of 1517 surveys were received (response rate, 32%). Most respondents had positive attitudes toward, but a poor understanding of, evidence-based practice. The major barrier identified was ambiguous and conflicting research. Younger orthodontists were more aware, had a greater understanding, and perceived more barriers than did older orthodontists. Orthodontists involved in teaching were more aware, had a greater understanding, and reported fewer barriers than those not involved with teaching. Those with masters degrees had a greater understanding of evidence-based practice than those without degrees. CONCLUSIONS Educational initiatives are needed to increase the understanding and use of evidence-based practice in orthodontics.

Evaluation of skeletal and dental asymmetries in Angle Class II subdivision malocclusions with cone-beam computed tomography

INTRODUCTION The purpose of this study was to determine whether Angle Class II subdivision malocclusions have skeletal or dental asymmetries between the Class II and Class I sides. METHODS A sample of 54 untreated Angle Class II subdivision patients with pretreatment photos and cone-beam computed tomography (CBCT) scans was used. The photos were used to identify the Class II subdivision malocclusion and to record the amount of crowding per quadrant. Landmarks were plotted on each CBCT volume so that direct 3-dimensional measurements could be made to compare the positions and dimensions of the skeletal and dental structures on the Class II side vs the Class I side. RESULTS Significant differences were found for 2 skeletal measurements: the position of the maxilla relative to the cranial base, and the mandibular dimension from the mandibular foramen to the mental foramen. Statistically significant dental differences were found for the position of the mandibular first molars and canines in relation to the maxilla and the mandible. Statistically significant differences were found for the maxillary first molars and canines in relation to the mandible. CONCLUSIONS There were significant skeletal and dental differences between the Class I and Class II sides. The dental asymmetries accounted for about two thirds of the total asymmetry.

Effect of bone-borne rapid maxillary expanders with and without surgical assistance on the craniofacial structures using finite element analysis.

INTRODUCTION The aim of this study was to analyze stress distribution and displacement of the craniofacial structures resulting from bone-borne rapid maxillary expanders with and without surgical assistance using finite element analysis. METHODS Five designs of rapid maxillary expanders were made: a tooth-borne hyrax expander (type A); a bone-borne expander (type B); and 3 bone-borne surgically assisted modalities: separation of the midpalatal suture (type C), added separation of the pterygomaxillary sutures (type D), and added LeFort I corticotomy (type E). The geometric nonlinear theory was applied to evaluate the Von Mises stress distribution and displacement. RESULTS The surgical types C, D, and E demonstrated more transverse movement than did the nonsurgical types A and B. The amounts of expansion were greater in the posterior teeth in types A and B, but in types C, D, and E, the amounts of expansion were greater in the anterior teeth. At the midpalatal suture, the nonsurgical types showed more anterior expansion than did the posterior region, and higher stresses than with the surgical types. Type B showed the highest stresses at the infraorbital margin, anterior and posterior nasal spines, maxillary tuberosity, and pterygoid plate and hamulus. CONCLUSIONS The 3 surgical models showed similar amounts of stress and displacement along the teeth, midpalatal sutures, and craniofacial sutures. Therefore, when using a bone-borne rapid maxillary expander in an adult, it is recommended to assist it with midpalatal suture separation, which requires minimal surgical intervention.

Craniofacial growth of Class III subjects six to sixteen years of age

OBJECTIVE To characterize the mixed-longitudinal craniofacial growth of untreated, white, Class III subjects 6 to 16 years of age. MATERIALS AND METHODS Serial cephalograms of 19 females and 23 males with Class III malocclusion were evaluated at three time points (6-8, 10-12, and 14-16 years of age). A similar number of Class I controls were randomly selected and matched for age and sex. The cephalograms were traced and digitized, and 20 variables were evaluated. Growth patterns were quantified, and class and sex differences were evaluated using multi-level analyses. RESULTS In comparison with Class I subjects, Class III subjects had significantly (P ≤ .05) larger mandibular plane angles, gonial angles, mandibular ramus heights, mandibular corpus lengths, and SNB angles, with differences that were maintained between 6 and 16 years of age. Maxillary lengths and ANB angles were significantly smaller and remained smaller in Class III subjects than in Class I subjects. Lower face height, maxillary-mandibular differential, and mandibular body length were also significantly larger and increased significantly more between 6 and 16 years of age in Class III subjects. The WITS appraisal was significantly smaller in Class III subjects and decreased significantly more over time. Most linear measures showed significant sex differences favoring males; the angular measures and anteroposterior (AP) maxillomandibular relationships showed no sex differences. CONCLUSIONS The AP maxillomandibular relationship of Class III subjects worsens over time. AP discrepancies are primarily due to excessive mandibular growth, which produces a protrusive, hyperdivergent phenotype. The AP discrepancies of males are larger than those of females, with differences increasing over time.

Evaluation of marginal alveolar bone in the anterior mandible with pretreatment and posttreatment computed tomography in nonextraction patients

INTRODUCTION Our objectives were to evaluate marginal alveolar bone height in the anterior mandible after orthodontic treatment and to assess any correlations between morphologic and treatment changes. METHODS We used 57 pretreatment and posttreatment cone-beam computed tomography images (17 male and 40 female subjects; 22 Class I, 35 Class II; average age, 18.7 ± 10.8 years; average treatment time, 22.7 ± 7.3 months) to measure cortical bone thickness, ridge thickness, distance from the apex to the labial cortical bone, and the distance from the cementoenamel junction to the marginal bone crest. Changes in the cementoenamel junction to the marginal bone crest distance were correlated with pretreatment measurements and treatment changes. RESULTS Although there were great variations, the average facial and lingual vertical bone losses were 1.16 ± 2.26 and 1.33 ± 2.50 mm, respectively. The incisor-mandibular plane angle changes were also highly variable, averaging 2.4°. CONCLUSIONS Orthodontic treatment causes changes in alveolar bone height and cortical bone thickness around the mandibular incisors. Although pretreatment cortical bone thickness, ridge width thickness, and specific tooth movements all play roles in what happens to the bone during treatment, incisor inclination was not correlated with alveolar bone height changes.

Evaluation of immediate soft tissue changes after rapid maxillary expansion

OBJECTIVE: To evaluate immediate soft tissue changes following rapid maxillary expansion (RME) in growing patients, using cone beam computed tomography (CBCT). METHODS: Twenty-three consecutive patients (10 male, 13 female) treated by RME were selected. Patients were scanned using CBCT prior to placement of the rapid maxillary expander (T0), then immediately following full activation of the appliance (T1). Defined landmarks were then located on the pre- and post-treatment orientated images. Change in landmark position from pre- to post-treatment was then measured. In addition to landmarks, 10 direct measures were made to determine distance change without regard to direction to measure soft tissue change of the lips. RESULTS: Significant transverse expansion was measured on most soft tissue landmark locations. All the measures made showed significant change in the lip position with a lengthening of the vertical dimension of the upper lip, and a generalized decrease of anterior-posterior thickness of both the upper and lower lips. CONCLUSIONS: Significant changes in the soft tissue do occur with RME treatment. There is a transverse widening of the midface, and a thinning of the lips.

Extraction vs no treatment: Long-term facial profile changes.

INTRODUCTION Long-term soft tissue response to extraction orthodontic treatment has been a subject of interest for years. The purposes of this study were to investigate long-term soft tissue profile changes in an extraction sample and to compare them with profile changes in an untreated sample. METHODS A premolar extraction-treated sample (n = 47) and an untreated control sample (n = 57) were studied. Descriptive statistics were collected, and individual t tests were used for comparison and contrast of the treated and untreated samples. RESULTS We found that the untreated soft tissue profile changed in the downward and forward direction. The treated soft tissue profile change was similar, but with more of a forward component than in the untreated sample. Most noteworthy was the finding that the soft tissue profiles of both the untreated and the treated samples were similar at the end point. CONCLUSIONS The following conclusions were derived from the study. (1) There was no substantive difference in the soft tissue profiles of the samples, but there were some differences in the directional changes between them. (2) The changes for the untreated sample were the greatest for the lips and the chin, with the change occurring in the downward and forward direction. (3) The soft tissue profiles of the extraction sample also had the greatest measurable changes in the lips and the chin, but the changes had more of a forward component than they did in the untreated sample. (4) Extraction treatment does not adversely impact soft tissue profile changes over time.

Reliability of subjective, linear, ratio and area cephalometric measurements in assessing adenoid hypertrophy among different age groups

OBJECTIVE To test the validity of four different types of lateral cephalometric radiograph (LCR) measurements as a diagnostic test of adenoid hypertrophy in different age groups of mouth-breathing children. MATERIALS AND METHODS Eighty-six mouth-breathing children (male 54.65%, mean age 7.0 ± 2.2 years) were randomly selected from a hospital population. Adenoid obstruction of the nasopharynx was evaluated by subjective, linear, ratio, and area LCR measurements. Each measurement was compared with flexible fiberoptic endoscopy diagnosis. RESULTS Kendall correlation coefficients for agreement between tests were ≥ 0.67 and kappa scores were substantial (≥ 0.64). Higher correlation coefficients and agreement values were found in older age groups. When the sample was stratified by age, the 3- to 5-year-old age group showed lower correlation coefficients and agreement strength for subjective, linear, and ratio measurements. The sensitivity of LCR varied from 71% (ratio) to 84% (linear). The specificity varied from 83% (linear) to 97% (ratio). The positive predictive value varied from 88% (linear) to 97% (ratio). The negative predictive value varied from 70% (ratio) to 78% (linear). The validity of each measure was different among the age groups. CONCLUSIONS LCR is a valid method for measuring adenoid hypertrophy in children from 6 to 12 years old. The diagnosis of adenoid hypertrophy, based on LCR measurements, in children with primary dentition (3-5 years old) should be made with caution. The combination of linear and ratio LCR measurements is a reliable screening tool to determine the need for an ear, nose, and throat evaluation.

Maxillary growth and maturation during infancy and early childhood

OBJECTIVE To describe maxillary growth and maturation during infancy and early childhood. MATERIALS AND METHODS Serial cephalograms (N=210) of 30 subjects (15 females and 15 males) from the Bolton-Brush Growth Study were analyzed. Each subject had a series of six consecutive cephalograms taken between birth and 5 years of age, as well as one adult cephalogram. Twelve maxillary measurements (eight linear and four angular) and seven landmarks were used to characterize maxillary growth. Maturation of the linear measures was described as a percentage of adult status. RESULTS Maxillary and anterior cranial base size increased in both sexes between 0.4 and 5 years of age. The linear anteroposterior (AP) measures (S-SE, SE-N, ANS-PNS) increased almost as much as the vertical measures (S-PNS, SE-PNS, N-A, N-ANS) over the first 5 years. After 5 years of age there was significantly more vertical than AP growth. The size and shape changes that occurred were greatest between 0.4 and 1 years; yearly velocities decelerated regularly thereafter. Overall linear growth changes that occurred between 0.5 and 5 years of age (a span of 4.5 years) were generally greater than the changes in maxillary growth that occurred between 5 and 16 years (a span of 11 years). The linear measures showed a gradient of maturation, with the AP measures being more mature than the vertical measures. Male maxillae were less mature than female maxillae at every age. CONCLUSIONS The maxilla undergoes its greatest postnatal growth change during infancy and early childhood, when relative AP growth and maturation are emphasized.

Open-bite treatment with vertical control and tongue reeducation.

An open-bite malocclusion with a tongue-thrust habit is a challenging type of malocclusion to correct. A 12-year-old girl came for orthodontic treatment with a severe anterior open bite, extruded posterior segments, a tongue-thrust habit, and lip incompetency. Her parents refused surgical treatment, so a nonextraction treatment plan was developed that used palatal temporary skeletal anchorage devices for vertical control and mandibular tongue spurs to reeducate the tongue. Interproximal reduction was also used to address the moderate to severe mandibular crowding. An abnormal Class I occlusion was achieved with proper overbite and overjet, along with a pleasing smile and gingival display.