Morphometric evaluation of alveolar bone after orthodontic treatment of multiple impacted teeth in the unilateral maxillary anterior region.

INTRODUCTION: This study aimed to investigate the height and thickness of alveolar bone by cone-beam computed tomography imaging after orthodontic treatment in the unilateral maxillary anterior region and speculate on reasons for the difference in alveolar bone morphology. METHODS: This study selected 11 patients (3 males and 8 females; mean age, 9.42 ± 1.45 years). Cone-beam computed tomography was performed for these 11 patients before and after treatment using Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). Labial and palatal alveolar bone thickness (BT) at root apices and different levels along the roots and loss of alveolar bone height was measured for each impacted tooth and its contralateral homonymous tooth. RESULTS: After orthodontic therapy, all 3 impacted anterior teeth had different degrees of loss of labial alveolar bone height compared with the normal side (central incisor: -1.5 mm, P <0.005; lateral incisor: -1.06 mm, P <0.01; canine: -0.59 mm, P < 0.01). The lateral incisors also showed palatal alveolar bone height loss compared with the unaffected side (-0.8 mm, P <0.005). Alveolar BT at root apices of impacted canines was 1.14 mm thicker than the normal side (P <0.005). Central and lateral incisors were similar to the normal side. The thickness of the alveolar bone at 8, 10, and 12 mm of the impacted canine position was still larger than that on the healthy side, whereas the difference in average thickness between the healthy and affected side had been significantly reduced compared with pretreatment measurements. CONCLUSIONS: There is satisfactory retention of alveolar bone height in canines after orthodontic treatment; however, alveolar bone loss is slightly worse at central and lateral incisors. Retention of alveolar BT was normal for impacted anterior teeth, whereas excess apical alveolar BT at the canines, although still present, was substantially less significant than had been observed before treatment.

What impact do personality traits have on self-perception of dental aesthetics?

BACKGROUND: Malocclusion has significant social, psychological and physical impacts on the quality of life. This study aimed to study psychosocial impact of dental aesthetics among students, and how it was modified by personality traits. METHODS: Chinese version of Eysenck Personality Questionnaire Short Scale of (EPQ-RSC) and Chinese version of Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) were used to investigate 555 undergraduate students, aged 18 to 24 years. The participants and investigators self-rated their own dental aesthetics using the Aesthetic Component (AC) of the Index of Orthodontic Treatment Need (IOTN). The malocclusion was assessed by two independent investigators using the Dental Health Component (DHC) of IOTN. RESULTS: No statistically significant difference was found for gender (p = 0.829) nor for majors (p = 0.598) in the psychosocial impact of dental aesthetics. Total and subscale PIDAQ scores differed significantly among the 3 IOTN grades. PIDAQ scores strongly correlated with Eysenck personality. The dimensions of extraversion and neuroticism, and dental health component grades had significant impact on participants' psychosocial well-being of dental aesthetics. CONCLUSIONS: Neurotic people with high self-concerns perceived greater psychosocial impact. Outgoing people appear to be less affected psychosocially by dental aesthetics.

The position and morphology characteristics of multiple impacted anterior teeth in the unilateral maxillary area: A retrospective study based on cone-beam computed tomography.

INTRODUCTION: This study investigated the position and morphologic characteristics of multiple impacted anterior teeth in the unilateral maxillary area. METHODS: Cone-beam computed tomography images of 21 patients (11 males and 10 females; median age 9.42 years [9.08-11.29]) with multiple teeth impacted were collected and imported into Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). The vertical height, crown orientation, twist direction, and root curvature of each impacted tooth were described. The crown length, root length, and root canal width of impacted and homonym teeth were measured. RESULTS: The positions of the impacted lateral incisors are lower than that of the other 2 anterior teeth. Most crowns of impacted central incisors are positioned distally, labial surfaces in mesial torsion, with most roots, bent toward the distal and labial. Crowns of impacted lateral incisors are positioned mesiolabially, with labial surfaces mostly in distal torsion, and most roots bent toward the mesial and labial. Crowns of impacted canines are mostly positioned mesiolabially, with labial surfaces in mesial torsion. The crowns and roots of the impacted central and lateral incisors were shorter than those of the homonym (P <0.05); however, the difference in crown length is clinically negligible, and there was no difference in root canal widths. There was no difference in the comparison of parameters for the canine group. CONCLUSIONS: There are certain rules in the vertical height, crown orientation, twist direction, and root curvature of multiple impacted anterior teeth in the unilateral maxillary area. Root development of impacted central and lateral incisors was restricted.

The relationship between local alveolar bone housing and size of canine in maxillary canine-lateral incisor transposition: A retrospective cone-beam computed tomography-based study.

INTRODUCTION: This study aimed to use 3-dimensional data to analyze the relationship between local alveolar bone housing and canine size in maxillary canine-lateral incisor transposition. METHODS: Cone-beam computed tomography study data from 31 patients with maxillary canine-lateral incisor transposition were imported into Dolphin Imaging software (version 11.8; Dolphin Imaging and Management Solutions, Chatsworth, Calif) for measurement. The buccal and palatal alveolar thickness of lateral incisor roots at different heights, the maximal thickness of displaced canine, and canine height were measured. Alveolar height-thickness variation curves at the lateral incisor region and maximal thickness of displaced canine were plotted to calculate the appropriate theoretical minimum alveolar heights of total alveolar housing, buccal alveolar housing after concentrating the bone buccally (TMAH-B1), and original buccal alveolar housing (TMAH-B2) required for correcting the transposition of 2 teeth. RESULTS: Canines could only be moved distally above lateral incisors in 5 patients. The mean value of theoretical minimum alveolar heights of total alveolar housing was 14.57 ± 1.75 mm. It was possible to reposition canines distally by concentrating the alveolar bone buccally in the remaining 26 patients. The mean value of TMAH-B1 was 10.86 ± 3.70 mm. Canines could be repositioned distally directly over the buccal aspect of the lateral incisor in 17 patients. The mean value of TMAH-B2 was 9.30 ± 2.35 mm. Canine height was greater than TMAH-B1 in 18 patients; however, only 10 patients were greater than TMAH-B2. CONCLUSIONS: Correction of transposition was difficult in some patients because of the lack of alveolar bone housing. Repositioning was possible when the height of the canine was higher than a certain height. An accurate assessment of the relationship between alveolar housing and tooth size is recommended.

The Psychosocial Impact of Dental Esthetics in Undergraduates with Borderline Malocclusion.

Background: The study investigates the existing correlation between self-perceived malocclusion, the psychosocial impact of dental esthetics, and whether this link involves personality traits. Methods: The 179 questionnaires from 615 undergraduates in Wenzhou were used for analysis after applying the exclusion criteria. The Psychosocial Impact of the Dental Aesthetics Questionnaire (PIDAQ) was administered to evaluate participants' perceptions of the psychosocial impacts of malocclusion. The need for orthodontic treatment was assessed using the Index of Orthodontic Treatment Need (IOTN). The Chinese version of the Eysenck Personality Questionnaire-Short Scale (EPQ-RSC) evaluated participants' personality characteristics. The Kruskal-Wallis test was used to assess differences between the IOTN-Dental Health Component (DHC) and expectations of orthodontic treatment. Linear regression was applied with PADAQ and its subscale scores against possible variables. Results: The total and subscale PIDAQ scores were positively correlated with neuroticism. Total PIDAQ scores, the DHC, and the Aesthetic Component (AC) were significantly positively correlated with the subjective AC. The DHC was significantly negatively correlated with extroversion. Conclusions: We confirmed a modest link between the need for orthodontic treatment and the psychosocial impact of dental esthetics.

The differences of root morphology and root length between different types of impacted maxillary central incisors: A retrospective cone-beam computed tomography study.

INTRODUCTION: The purpose of this trial was to use 3-dimensional data to analyze the differences of root morphology and root length between 3 different types of impacted maxillary central incisors. METHODS: Cone-beam computed tomography images of 126 patients with impacted maxillary central incisors were included in this retrospective study. On the basis of the angle of the impacted incisor to the palatal plane, we categorized the tooth as labial inversely impacted, labially positioned, or palatal impacted incisor. In each category, the early and late dental age groups were classified according to the method of Nolla. The total root length of both impacted and homonym teeth, length of the nondilacerated part of the root, length of the dilacerated part of the root, the angle between the crown and root, and root direction, were measured in the sagittal-view sections using Dolphin Imaging software (version 11.9; Dolphin Imaging and Management Solutions, Chatsworth, Calif). RESULTS: Compared with the early dental age groups, the length of the dilacerated portion of the root and rate of dilaceration for inverse labial and labially positioned impactions increases, and crown-root angle decreases (P <0.05). The dilacerated part of the root bent labially, and the root morphology shows an obvious L-shaped curve. The length of the nondilacerated part of the root for palatal impactions is greater(P <0.05). The dilacerated part of the root bends palatally, and the root morphology shows a continuous C-shaped curve. CONCLUSIONS: Obstruction from the alveolar bone will cause different root morphology. Root morphology of labial impactions shows an obvious L-shaped curve; palatal impactions show a continuous C-shaped curve.

Agreement of young adults and orthodontists on dental aesthetics & influencing factors of self-perceived aesthetics.

BACKGROUND: The aim of this study is to assess the agreement between orthodontist's and Chinese young adult's self-perceived aesthetics, the normative treatment need based on the Index of Orthodontic Treatment Need (IOTN), and the main factors affecting the self-perceived aesthetics. METHODS: A random sample of 348 Chinese young adults (116 males and 232 females) aged 17-24 years were recruited in this study. Two orthodontists were involved in rating the cases. Orthodontic treatment need was assessed according to the Index of Orthodontic Treatment Need, including Aesthetic components and Dental Health Components (AC and DHC). Personality traits were assessed according to Eysenck Personality Questionnaire (EPQ). Cohen's kappa test was used to assess the agreement, and spearman's correlation coefficient was used to analyze the association among all variables. RESULTS: A statistically significant level of agreement was observed between young adult's perception and orthodontist's perception in IOTN (kappa = 0.14). A positive relationship (p < 0.001)existed between the young adult's AC and the orthodontist' s AC (r = 0.275), and between the young adult' s AC and the normative need DHC (r = 0.195). The orthodontist's AC was strongly related to the normative need (r = 0.743, p < 0.001). Association between the young adult's AC and gender and EPQ-E were also observed. CONCLUSIONS: Young adults tend to be less critical in assessing orthodontic treatment needs than orthodontists. The orthodontist's AC reflecting subjective treatment need is strongly connected to the normative need. The adult's perception of aesthetic component is affected by factors such as gender and personality traits.

Effect of personality on oral health-related quality of life in undergraduates.

OBJECTIVES: To evaluate the effects of personality traits and other variables on oral health-related quality of life (OHRQoL) of Chinese undergraduates aged 17 to 24 years with no history of orthodontic treatment. MATERIALS AND METHODS: A total of 443 undergraduate students aged 17 to 24 years were selected and completed a two-section questionnaire: the Eysenck Personality Questionnaire Short Scale Chinese version and the Oral Health Impact Profile-14 Chinese version (OHIP-14). Malocclusion severity was assessed via clinical examination using the dental health component (DHC) and esthetic component of the Index of Orthodontic Treatment Need (IOTN). Severe dentofacial deformities that required orthognathic surgery were excluded. RESULTS: The total and all dichotomized OHIP-14 dimensions correlated closely with the neuroticism personality traits ( P < .001). The total and some subscales of OHIP-14 were related with psychoticism. Women had higher OHIP-14 scores than men, especially in the normal occlusion group. Nevertheless, men with more severe malocclusions had higher scores that were similar to those of women. OHRQoL was significantly different between the major of dentistry and other majors. CONCLUSIONS: Personality affects comprehensive OHRQoL, and the most significant predictor is neuroticism. Female young adults have worse OHRQoL than male young adults, especially among those with mild malocclusion.