Open reduction and internal fixation (ORIF) with a locking plate is a popular surgical treatment for proximal humeral fractures (PHF). This study aimed to assess the occurrence of complications in elderly patients with PHF treated surgically using ORIF with a locking plate and to investigate the potential differences between patients treated by shoulder surgeons and non-shoulder surgeons. Methods: A retrospective study was conducted using a single-center database to identify patients aged ≥70 years who underwent ORIF for PHF between January 1, 2011, and December 31, 2021. Data on the Neer classification, follow-up, occurrence of avascular necrosis of the humeral head, implant failure, and revision surgery were also collected. Statistical analyses were performed to calculate the overall frequency of complications according to the Neer classification. Results: The rates of implant failure, avascular osteonecrosis, and revision surgery were 15.7%, 4.8%, and 15.7%, respectively. Complications were more common in patients with Neer three- and four-part fractures. Although the difference between surgeries performed by shoulder surgeons and non-shoulder surgeons did not reach statistical significance, the rate of complications and the need for revision surgery were nearly two-fold higher in the latter group. Conclusions: PHF are highly prevalent in the elderly population. However, the ORIF surgical approach, as demonstrated in this study, is associated with a considerable rate of complications. Surgeries performed by non-shoulder surgeons had a higher rate of complications and a more frequent need for revision surgery. Future studies comparing surgical treatments and their respective complication rates are crucial to determine the optimal therapeutic options. Level of evidence: III.

Objective: To evaluate the null hypothesis that there is no difference in a set of clinical predictors of potentially impacted canines between low-risk patients with and without displaced canines. Methods: The normal canine position group consisted of 30 patients with 60 normally erupting canines ranked in sector I (age, 9.30 ± 0.94 years). The displaced canine group comprised 30 patients with 41 potentially impacted canines ranked in sectors II to IV (age, 9.46 ± 0.78 years). Maxillary lateral incisor crown angulation, inclination, rotation, width, height, and shape, as well as palatal depth, arch length, width, and perimeter composed a set of clinical predictors, which were evaluated on digital dental casts. Statistical analyses consisted of group comparisons and variable correlations (p < 0.05). Results: There was a significant association between sex and mesially displaced canines. Unilateral canine displacement was more prevalent than bilateral displacement. The crown of the maxillary lateral incisors was significantly angulated more mesially and rotated mesiolabially in low-risk patients with displaced canines, who also had a shallower palate and shorter anterior dental arch length. Lateral incisor crown angulation and rotation, as well as palatal depth and arch length, were significantly correlated with the canine displacement severity. Conclusions The null hypothesis was rejected. Maxillary lateral incisor angulation inconsistent with the “ugly duckling” stage as well as a shallow palate and short arch length are clinical predictors that can significantly contribute to the early screening of ectopic canines in low-risk patients.

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young’s modulus and Poisson’s coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young’s modulus and Poisson’s coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young’s modulus and Poisson’s coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young’s modulus and Poisson’s coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.

Objective: To evaluate tooth displacement and periodontal stress generated by the dual action vertical intra-arch technique (DAVIT) for open-bite correction using three-dimensional finite element analysis. Methods: A three-dimensional model of the maxilla was created by modeling the cortical bone, cancellous bone, periodontal ligament, and teeth from the second molar to the central incisor of a hemiarch. All orthodontic devices were designed using specific software to reproduce their morpho-dimensional characteristics, and their physical properties were determined using Young’s modulus and Poisson’s coefficient of each material. A linear static simulation was performed to analyze the tooth displacements (mm) and maximum stresses (Mpa) induced in the periodontal ligament by the posterior intrusion and anterior extrusion forces generated by the DAVIT. Results: The first and second molars showed the greatest intrusion, whereas the canines and lateral incisors showed the greatest extrusion displacement. A neutral zone of displacement corresponding to the fulcrum of occlusal plane rotation was observed in the premolar region. Buccal tipping of the molars and lingual tipping of the anterior teeth occurred with intrusion and extrusion, respectively. Posterior intrusion generated compressive stress at the apex of the buccal roots and furcation of the molars, while anterior extrusion generated tensile stress at the apex and apical third of the palatal root surface of the incisors and canines. Conclusions DAVIT mechanics produced a set of beneficial effects for open-bite correction, including molar intrusion, extrusion and palatal tipping of the anterior teeth, and occlusal plane rotation with posterior teeth uprighting.