American Journal of Orthodontics and Dentofacial Orthopedics最新文献

Introduction: Cleidocranial dysplasia (CCD) is a genetic disorder characterized by distinctive oral manifestations, making dental anomalies a key diagnostic criterion and treatment focus.

Methods: We retrospectively enrolled 32 patients diagnosed with CCD with detailed dental records (19 males and 13 females; mean age, 20.5 years). The detailed characteristics of impacted permanent teeth and supernumerary teeth were analyzed, and treatment considerations and outcomes for the abnormal dentition were summarized.

Results: Among permanent teeth, 43.53% were impacted. A significant variation in the likelihood of tooth impaction was observed depending on the tooth position. On the basis of nonlinear regression analysis, this study identified a clear trend correlating the probability of impacted teeth with the sequence of permanent tooth eruption, with this probability exhibiting a distinct increase followed by a decrease (with R² values in female and male patients of 0.65 and 0.84, respectively). In addition, 27 patients (84.4%) had supernumerary teeth, with 206 supernumerary teeth identified, predominantly of the supplemental premolar type (75.73%). There was a correlation between the morphology of supplemental teeth and their locations in the dentition. Among 10 patients with follow-up periods of >2 years, 117 impacted teeth were recorded, 61 teeth were involved in the treatment, 16 (26.23%) erupted after the extraction of retained deciduous or supernumerary teeth, and 33 teeth (54.10%) were successfully erupted through orthodontic traction. However, orthodontic treatment requires an extended period, and the periodontal conditions of treated teeth may require long-term maintenance.

Conclusions: This study reveals a potential relationship between tooth impaction and the sequence of tooth eruption. It also distinguishes the distribution and morphologic characteristics of supernumerary teeth in patients with CCD from those in the general population. In addition, by analyzing clinical data, this study provides a summary of treatment considerations and outcomes for abnormal dentition in patients with CCD.

Introduction: Microimplant-assisted rapid palatal expansion appliances have been used for the treatment of orthodontic patients with maxillary deficiency. A new design named ATOZ (applicable from A to Z) was recently introduced to expand the scope of treatment in early permanent dentition. The objective of this study was to analyze the biomechanical performance of the ATOZ expander with various microimplants configurations using finite-element method.

Methods: Nine ATOZ models were designed based on the number of microimplants configurations on the palate. For skeletal maturation, stage B midpalatal suture (MPS) maturation classification was chosen. A displacement along the sagittal axis, parallel to the MPS, of 0.15 mm was applied on each side of the device to simulate a 1 jackscrew turn of 0.3 mm.

Results: Configurations 1, 2, 6, and 7 achieved a quasi-parallel skeletal movement with a uniform distribution of displacement in the maxilla. The highest posterior nasal spine to anterior nasal spine ratio of 95.95% was found with configuration 6, indicating an optimum quasi-parallel expansion. For configuration 2, microimplants 1 and 2 exhibited stresses of 619.18 MPa and 656.49 MPa, respectively, whereas microimplants 7 and 8 showed stresses of 609.64 MPa and 658.30 MPa, respectively. Maximum stress in zygomatic bone was 0.69 MPa. Higher stresses were more distributed in the zygomaticofrontal suture than in zygomaticotemporal and zygomaticomaxillary sutures.

Conclusions: In terms of posterior nasal spine to anterior nasal spine ratio, skeletal-to-dental ratio, and MPS deformation, ATOZ with configurations 1, 2, and 6 outperform other configurations, and thus, they can be recommended for correction of maxillary deficiency in patients with skeletal maturation of stage B or earlier.

Introduction: This cross-sectional case-control observational study aimed to use lateral cephalometric radiographs to examine the 1-year follow-up results of 3 different treatment methods during Class II correction.

Methods: The authors evaluated the lateral cephalometric records of patients treated with the Forsus fatigue-resistant device (group 1, n = 28), cervical headgears (CHG; group 2, n = 28), and maxillary first premolar extraction with fixed orthodontic appliances (group 3, n = 28). Each group was followed at pretreatment, posttreatment, and 1-year posttreatment. The data obtained were analyzed using the 1-way analysis of variance and Kruskal-Wallis methods.

Results: At posttreatment, the ANB angle decreased significantly (P = 0.001) in the CHG group compared with the Forsus and extraction groups. The lower and upper facial heights of the CHG group were significantly increased (P <0.001) at posttreatment compared with the other groups. The mandibular incisor protrusion in the Forsus group was significantly higher (P = 0.005) than in the extraction patients, and extrusion of the mandibular incisors was significantly higher (P = 0.002) in the CHG group than in the Forsus group at posttreatment.

Conclusions: All 3 methods were effective in correcting Class II malocclusion, mainly at the dentoalveolar level, but some amount of relapses occurred after 1-year of follow-up. Distance of mandibular incisors and the mandibular plane changed significantly, increasing in CHG and extraction groups after 1-year of follow-up.

Annual plastic production worldwide has reached unprecedented levels, whereas the amount of plastic being recycled remains significantly low compared with production rates. This trend is similarly reflected in the use of clear aligners, which are becoming increasingly popular. The purpose of this review, which was one of the topics discussed at the AAO 2023 Winter Conference, is to raise awareness among patients and orthodontists regarding the environmental impact of aligners, assess whether aligners pose a threat to our planet, and propose potential solutions to the existing challenges.

Introduction: This study aimed to compare the efficiency of maxillary protraction achieved through facemask treatment with either a hybrid-hyrax (HH) or an acrylic cap splint (ACS) appliance when used in conjunction with alternate rapid maxillary expansion and constriction (Alt-RAMEC) or conventional rapid maxillary expansion (RME) protocols.

Methods: This study analyzed a total of 60 patients in 4 groups of 15 patients each and treated with HH-Alt-RAMEC protocol (HH-Alt, aged 10.38 ± 1.19 years), ACS-Alt protocol (aged 10.43 ± 0.99 years), HH-RME protocol (aged 9.74 ± 1.05 years) and ACS-RME protocol (aged 10.70 ± 0.98 years). Lateral cephalograms were taken before and after the facemask were compared. A 1-way analysis of variance with a Tukey honest significant difference post-hoc test was used for intergroup comparisons, whereas a paired sample t test was employed for intragroup comparisons.

Results: Correction of Class III skeletal malocclusion was achieved in all groups. HH-Alt showed significantly more maxillary protraction with an increase in AVRP of 4.02 mm compared with 2.65 mm in ACS-Alt and 2.3 mm in ACS-RME (P <0.001). HH-RME also showed a significantly more maxillary protraction in AVRP of 3.58 mm compared with 2.3 mm in ACS-RME (P <0.001). The rate of protraction was higher in HH-Alt (0.61 ± 0.16) and HH-RME (0.56 ± 0.29) than in ACS-RME (0.31 ± 0.12). The maxilla showed significantly more rotation in ACS-Alt (-1.66° ± 1.13°) and ACS-RME (-1.97 ± 1.75°) than in HH-Alt (-0.49° ± 1.18°) and HH-RME (-0.35° ± 1.86°), whereas the mandible showed significantly more clockwise rotation in ACS-RME (2.08 ± 1.71) than in HH-Alt (0.80 ± 0.94) and HH-RME (0.63 ± 1.82). The maxillary skeletal effect in the overjet correction was greater in HH-Alt (71.0%).

Conclusions: All treatment options achieved maxillary protraction. In the short term, hybrid groups (HH-Alt and HH-RME) provide more effective maxillary skeletal protraction than ACS-RME and demonstrate superior control in the vertical dimension than in tooth-borne groups. The Alt-RAMEC protocol improved the amount of maxillary protraction of the tooth-borne appliance group. The choice of anchorage of the appliance (skeletal or tooth-borne) is found to be more critical than the expansion method (RME or Alt-RAMEC).

Introduction: Norms for mandibular growth are well-established, but they have large variances, and no research has been conducted on how practitioners use them in clinical judgment to guide the treatment of individual patients.

Methods: Co-Pog projections of mandibular growth were combined from the Burlington and Michigan growth studies following statistical adjustments. Cervical measures were also evaluated. Photographs of complete records for 2 males and 2 females aged approximately 12 years with mandibular length matched age and sex norms were presented to 29 practicing orthodontics. Initial treatment plans and changes in treatment, if any, were noted across a projected range in 2-year mandibular growth.

Results: A large variance was noted in the growth norms. Stepwise multiple regression found insignificant improvements in predictions when cervical vertebral maturation scores were added to age and sex. Comparably large variation was also observed across practitioners in their initial treatment plans given common patient information. Moreover, 4 in 10 practitioners would not change their initially proposed treatment, given growth projections varying between 0-7 mm over 2 years. Others were sensitive only to small or large changes or used a range smaller than the variance in the norms. Between a quarter and a third of the variance in changed treatment plans was a function of differences between practitioners, whereas almost none was attributable to expected growth in patients.

Conclusions: This study represents the integration of the established literature with practitioner experience called for in the American Dental Association concept of evidence-based dentistry. It was found that there was substantial variance in both established norms for mandibular growth and the role claimed for precise estimates of growth play in treatment planning. The latter appears to be the larger of the two.

Introduction: The infrazygomatic bone crest and other extraalveolar regions represent a viable option for the placement of temporary anchorage devices when distalizing the maxillary arch. This approach allows for the movement of the dentition without concern for potential collisions among dental structures. Nevertheless, it is of the utmost importance to conduct a thorough examination of the anatomy of this region before the placement of mini-implants to prevent potential injuries, such as maxillary sinus perforations. The objective of this study was to quantify the depth of the infrazygomatic crest and evaluate its correlations with age, gender, skeletal classification, and vertical pattern.

Methods: The study sample of this cross-sectional, retrospective study consisted of 201 cone-beam computed tomography scans collected from patients treated at the master's program in orthodontics at the University of Valencia and at a private dental clinic. The cone-beam computed tomography scans were collected for 5 years, from January 2017 to May 2022. The total and intraalveolar lengths were defined and measured at 3 points: the distal roots of the maxillary second molars, the distal roots of the maxillary first molars, and the mesial roots of the maxillary first molars. These measurements were taken on both the right and left sides using the Carestream 3D Imaging System (Atlanta, Ga).

Results: The total length (TL) at the mesiobuccal level of the first molars was found to be significantly longer on both sides (P = 0.001). The intraalveolar length exhibited statistically significant differences between the right and left sides, with those of the left side exhibiting greater length (P <0.001). The normodivergent patterns demonstrated lower TL values than hypodivergent (P = 0.006) and hyperdivergent patterns (P = 0.033).

Conclusions: A statistically significant inverse relationship was observed between the distance from the cementoenamel junction to the vestibular bone crest and the total and intraalveolar lengths in the studied regions. The TL was greatest in the region of the mesiobuccal root of the maxillary first molars, followed by the region of the distal root of the second molars, and finally, the region of the distobuccal root of the maxillary first molars. Patients with normodivergent patterns exhibited the lowest total infrazygomatic ridge height.