The Impact of Orthodontic Retainers on Gingival Recession: A Best-Evidence Review.

Retention is a critical phase of orthodontic therapy and aims to maintain occlusal stability and avoid crowding relapse. This best-evidence article reviews the effects of the different types of orthodontic retention appliances, fixed and removable, on the development and progression of gingival recession at the mandibular anterior teeth. Searched databases included PubMed, Scopus, Cochrane Library, Embase, and Dentistry and Oral Sciences. Eleven qualifying publications, including retrospective, prospective, and cross-sectional studies, were included in this review. These studies either did not demonstrate an association between orthodontic retainers and gingival recession or reported that the resulting recession defects were minimal when an association was shown. An important consideration is that recession could be a late finding following the placement of a retainer and, therefore, may be incipient or absent in short-term evaluations. Prospective studies that specifically address the role that properly positioned fixed retainers may have on gingival recession are needed before a definitive conclusion can be generalized with regard to recommended retention protocols. Factors such as duration of retainer use, number of bonded teeth, and position of fixed retainers relative to their proximity to gingival tissues are not fully elucidated but may have influencing roles on gingival recession. The use of retainers should be based on orthodontic indications to maintain a stable dental arch form, esthetics, and occlusion. Effective oral hygiene and follow-up regimens remain the gold standard in maintaining periodontal health and preventing gingival recession.

The new periodontal disease classification: Level of agreement on diagnoses and treatment planning at various dental education levels.

PURPOSE/OBJECTIVES: Using the periodontal diseases classification published in 2018, this study evaluated the level of agreement among predoctoral and postgraduate students of different education levels and specialties in the diagnosis and treatment planning of periodontal conditions. METHODS: Second-year (D2) and fourth-year (D4) dental students, postgraduate orthodontic students (OS), and periodontology students (PS) were presented with an anonymous survey of 10 cases, each with five choices of diagnosis and seven therapeutic approaches. The cases included a patient summary, photographs, radiographs, periodontal charting, and ranged from health to periodontitis. Consensus diagnosis, used as a gold standard, was established between two experienced periodontists. Diagnosis and treatment choices for each case were compared across educational groups using Fisher's exact test. The level of agreement among educational groups was assessed using a multirater kappa coefficient. RESULTS: The survey was completed in 2020 with a 72.4% overall response rate (57-D2, 45-D4, 17-OS, and 12-PS). The overall level of agreement on diagnosis was fair (κ = 0.24, p <.0001) with PS showing the most agreement (κ = 0.55, p <.0001). There were tendencies to prioritize stage over grade and extent in assigning diagnoses and to overdiagnose disease severity and underdiagnose localized periodontitis. Nonsurgical periodontal therapies had the highest overall agreement (κ = 0.63 for scaling/root planing and κ = 0.44 for maintenance, p <.0001). Response distribution per case and per level of education indicated that PS more consistently agreed with the gold standard than any other group. CONCLUSIONS: OS, D2, and D4 students demonstrated inferior agreement levels compared to PS, successfully recognized health from disease, suggested appropriate treatment plans, and tended to overdiagnose milder periodontal conditions.

Evaluation of preferred lip position according to different tip rotations of the nose in class I young adult subjects.

INTRODUCTION: The mouth plays an important role in the overall aesthetic appearance of the face. The aims of this study were to determine the optimal antero-posterior (AP) lip position relative to various rotations of the nasal tip and assess the impact of the nasolabial angle on facial aesthetics. MATERIAL AND METHODS: Three-dimensional facial volumes, in motion, of one Caucasian male and one Caucasian female with a Class I malocclusion and an orthognathic profile were modified to alter the nasal tip rotation (3 rotations) and the AP lips position (6 positions). 72 generated models were created in two and three-dimensions. Generated models were rated online by 60 dentists, 60 orthodontists and 60 laypeople, using a Visual Analogue Scale. Scores were analysed according to lip position, rater's profession and gender. RESULTS: General agreement was found between all groups on the most and least preferred lip positions. No differences between male and female raters were found. All raters were more influenced by the 3-dimensional rotating facial volume than by 2-dimensional angles. Similar angular values for the nasolabial angles were found in the most and least preferred profiles, showing that the most influential factor in facial aesthetics was the lip position, and stressing the need to evaluate each component of the nasolabial angle independently. CONCLUSION: The lip position was the determinant factor in facial aesthetics with little influence of the nose tip rotation. Three-dimensional evaluation of the nose and lip were needed to establish a soft tissue-based treatment plan.

Smile dimensions in adult African American and Caucasian females and males.

OBJECTIVES: To test smile dimension variations in adult African American and Caucasian females and males. SETTING AND SAMPLE POPULATION: The University of Alabama at Birmingham School of Dentistry and Hospital. Three hundred and ninety-four participants were recruited; African American females and males distributed over five age groups: 20-30, 30-40, 40-50, 50-60 and older than 60. MATERIAL & METHODS: Three-dimensional surface imaging was used to acquire two images of each participant, one at rest and one upon smile. Landmarks were plotted on the lips and linear distances measured to assess the length of the upper and lower lips, mouth width at rest and upon smile, gingival and dental display upon smile. RESULTS: Linear dimensions are larger in males than in females, and in African Americans than in Caucasians, except for the length of the upper lip that does not differ between male African American and Caucasian males, in any given age group. Gingival display and dental display decrease with age in all groups. CONCLUSION: Norms should reflect race, age and sex in order to optimize treatment goals.

Optimal antero-posterior position of the maxillary central incisors and its relationship to the forehead in adult African American females.

OBJECTIVES: To determine an optimal anteroposterior (AP) position of the maxillary central incisors and their relationship to the forehead in adult African American (AA) females. MATERIALS AND METHODS: Smile profile photographs of 150 AA females were acquired and divided into an optimal control group (N = 48) and a study group (N = 102) based on the position of the maxillary central incisors, as judged by a panel of orthodontists and orthodontic residents. The AP position of the maxillary central incisors and the forehead inclination (FI) were measured relative to Glabella vertical (GV). A two-sample t-test was used to compare the incisor AP position and the FI between the two groups. Linear regression was used to quantify the relationship between the incisor AP position and the FI. RESULTS: In all groups, the maxillary incisors were anterior to GV. However, a significant difference was found in the incisor AP position between the groups (8.58 ± 3.96 mm for the control group and 11.2 ± 4.48 mm for the study group; P = .001). Furthermore, the control group demonstrated a positive association between the optimal AP position of the maxillary central incisors and FI ( P < .0001). CONCLUSIONS: GV is a reliable landmark with which to access the AP maxillary incisor position in AA females. The optimal AP position of the maxillary central incisors is significantly associated with FI; the greater the FI, the more anterior the optimal maxillary incisor position. A prediction equation to determine the optimal position of the maxillary incisors relative to GV for AA females is proposed.

The validation of a novel index assessing canine impactions.

AIM: The aims of this study are to determine the level of agreement of orthodontists in the management of impacted maxillary canines and test this agreement against a novel three-dimensional (3D) classification system (KPG index). MATERIALS AND METHODS: A total of 55 clinicians evaluated 18 impacted maxillary canines of variable complexity. For each case, they used a panoramic and maxillary standard occlusal radiographs derived from cone beam computed tomography. Clinicians were asked to rate each canine in one of four categories: Easy, moderate, difficult and extremely difficult. The obtained scores were tabulated and compared with a novel index rating the difficulty of canine impactions. Statistical package for the social science 17.0 was used to analyze the datasets and the kappa score was used to determine levels of agreement. RESULTS: The kappa score was 0.437. The levels of agreement in the novel index and the clinician scoring were as follows; easy (62.73%), moderate (60.59%), difficult (61.80%) and extremely difficult (72.72%). CONCLUSIONS: THE FOLLOWING CONCLUSIONS CAN BE DRAWN FROM THIS STUDY: (1) Clinicians are variable in rating the complexity of canine impactions using traditional radiographic techniques. (2) The novel index shows a good level of agreement with the clinician's perception of difficulty in orthodontic cases especially at the extremes of the spectrum. (3) This index based on the 3D coordinates of the spatial arrangement of the canine may be incorporated into clinical practice.

The surgical and orthodontic management of cherubism in a growing child.

Cherubism is a rare non-neoplastic disease that affects the jaws causing significant destruction and disfigurement. The disease also affects the normal eruption, occlusion and function of the dento-alveolar complex. Cherubism may radiographically and histologically resemble central giant cell granuloma, fibrous dysplasia and other giant cell lesions. The case of a 15-year 4-month-old girl with no obvious facial swelling or signs of cherubism is described in this report. The patient presented with a dental malocclusion that included the ectopic eruption and displacement of teeth caused by the lesion. The radiographic findings derived from Cone Beam Computed Tomography (CBCT) technology are described. This case report details the orthodontic and surgical diagnosis and management of a teenager during the post growth period.

Cone beam computed tomography analysis of dentoalveolar changes immediately after maxillary expansion.

AIM: Rapid maxillary expansion (RME) splits the midpalatal suture to correct maxillary transverse discrepancies and increase the arch perimeter. The goal of this paper is to evaluate the immediate effects of RME with Hyrax appliances on the dentoalveolar complex using cone beam computed tomography (CBCT). METHODS: Twenty-eight patients (19 females and 9 males) requiring maxillary expansion therapy were included (mean age, 14.1 years; range, 13 to 20 years). CBCT images were taken at T1 (before maxillary expansion) and T2 (immediately after expansion) as part of clinical records. Maxillary arch width, posterior segment angulation, and buccal bone thickness at the level of the first premolar and first molar were evaluated. Paired t tests determined statistical significance (P < .05). RESULTS: The mean ± SD amount of expansion achieved was 4.7788 ± 2.8474 mm for the maxillary premolars and 4.6943 ± 3.2198 mm for the molars. Significant tipping of the palatal roots of the maxillary right and left premolars as well as that for the maxillary left molar was observed. When present, the thickness of the buccal plate decreased on all observed roots. CONCLUSION: There is a significant increase in interpremolar and intermolar distance with RME. The increase in root angulation suggests that the movement is more tipping than translation. The thickness of the buccal plate decreases immediately after RME. Therefore, the level of inflammation should be closely monitored to avoid periodontal destruction. There is a need to define standardized reference planes and comparable methodology to achieve compatible results among studies.

Porphyromonas gingivalis in dental plaque and serum C-reactive protein levels in pregnancy.

BACKGROUND: The periodontopathogen Porphyromonas gingivalis (Pg) has been reported as a risk factor for preterm labour. Its pathogenesis and role in pregnancy have not been investigated in Lebanon. Elevated C-reactive protein (CRP) levels in pregnant women with periodontitis also appear to mediate preterm labour. METHODOLOGY: The study included 20 pregnant women with periodontitis and 20 with normal periodontium. PCR was done for Pg detection in oral plaque and vaginal samples. Serum CRP levels were determined by ELISA. RESULTS: Pg was detected in the oral plaque of 13 of 20 pregnant subjects with clinical periodontitis (patients) and 2 of 20 controls with a healthy periodontium. Vaginal swabs were all Pg-negative, ruling out systemic infection. Serum CRP levels were elevated in 12 of 20 patients and 8 of 20 controls. None of the participants experienced preterm labour. CONCLUSIONS: This is the first report that implicates Pg in Lebanese periodontitis patients. Preliminary results do not indicate a relationship among Pg, periodontitis, CRP levels and preterm labour.