BACKGROUND: Clear aligners (CA) are used 22 h daily, creating a bite-block effect. This work aims to (i) analyze occlusal changes before the beginning of treatment, after the first set of CA and after the use of additional aligners; (ii) compare planned occlusal contacts with the ones obtained after the first set of CA; (iii) analyze the occlusal changes occurred after reaching the orthodontic goals after 3 months of using CA only at night; (iv) evaluate and characterize which tooth movements did not allow the treatment to be completed at the end of the first set of aligners, and finally (v) verify the possible relation between the changes in occlusal contact and areas and parameters such as case complexity and facial biotype.
METHODS: A quantitative, comparative, and observational longitudinal cohort study design was implemented to evaluate the clinical data and the complexity levels of cases receiving CA. A non-probabilistic and convenience sample of 82 individuals was recruited. The orthodontic malocclusion traits were classified as simple, moderate, or complex corrections based on the basis of the Align® recommendations with the Invisalign® evaluation tool. According to the Invisalign® criteria, patients need only one complex problem for their case to be classified as complex. Meshlab® v. 2022.02, ClinCheck® version Pro 6.0, My-Itero® version 2.7.9.601 5d plus, and IBM® SPSS Statistics software (Statistical Program for Social Sciences), version 27.0 for Windows were the software® used.
RESULTS: A statistically significant decrease in area and occlusal contacts number were observed from before the start of orthodontic treatment (T0) to the end of treatment (T1). The changes in the occlusal area (from T0 to T1) were statistically different between hyperdivergent (28.24 [15.51-40.91]) and hypodivergent (16.23 [8.11-24.97]) biotypes (p = 0.031). A significant difference between the hyperdivergent (4.0 [2.0-5.0]) and normodivergent (5.5 [4.0-8.0]) group was found in T1 for the anterior contacts (p = 0.044). Anterior contacts obtained were significantly higher than the planned (p = 0.037) Between T1 and T2 statistically significant increases of occlusal areas, posterior and total contacts were observed.
CONCLUSIONS: Occlusal contact and area were decreased, either at the end of the first set or after the use of additional aligners. Anterior occlusal contacts obtained were higher than planned as opposed to posterior occlusal contacts obtained. The hardest tooth movements to achieve to complete the treatment were distalization, rotation, and posterior extrusion. After completing orthodontic treatment (T1) to 3 months after (T2) using additional aligners only at night, posterior occlusal contacts were significantly increased, which could be due to the natural settling of the teeth in this period.

OBJECTIVE: The aim of this study was to investigate the association between the changes in masticatory function and cognitive impairment by analyzing longitudinal data of older Korean patients.
METHODS: Patients aged over 60 years with dental records between 2005 to 2010 (baseline; T1) and 2014 to 2020 (follow-up; T2) were selected in a single medical center. Based on the dementia diagnosis after T2, the cohort was classified into two groups, the dementia group (n=122) and the control group (n=366). Changes in masticatory function were calculated using the total functional tooth unit (T-FTU) in both groups. The incidence of tooth extraction (%) and the subsequent rehabilitation during the observation period were also evaluated.
RESULTS: In the dementia group, T-FTU significantly decreased from T1 to T2 (9.81±2.78 to 9.11±3.16, respectively, p=0.008), while no significant change was observed in the control group. During the mean observation period of 9 years, significantly more teeth were extracted and neglected to be prosthetically restored in the dementia group than in the control group. Regression analysis revealed that the number of missing teeth neglected [odds ratio (OR)=1.195, 95% confidence interval (CI)=1.025-1.393, p=0.023] and previous alcohol consumption (OR=4.445, 95% CI=1.831-1.795, p=0.001) were the most significant risk factors of dementia.
CONCLUSIONS: There might be a causative relationship between the neglected missing dentition and the onset of dementia.

OBJECTIVE: To assess for functional improvement in outcomes following supermicrosurgical restoration across a cohort of patients with a spectrum of trigeminal nerve disorders.
METHODS: In a retrospective case series over three years (2016-18), twenty patients were included in a cohort of trigeminal nerve palsy patients. Eleven patients with corneal anaesthesia underwent corneal neurotisation procedures and were followed up using Cochet-Bonnet aesthesiometry. Six patients with sensory trigeminal nerve injuries had direct nerve coaptation and neuroma excision. Three patients with trigeminal motor nerve palsies were followed up with photography for contour improvement.
RESULTS: Regarding corneal neurotisation, there was evidence of significant improvement in protective corneal sensation and also blinking frequency. Regarding facial sensory disturbances, all patients had full resolution of painful trigeminal neuroma symptoms. In two cases of iatrogenic trigeminal motor palsies with contour defects, adipo-fascial variants of the superficial circumflex iliac artery (SCIP) free flap achieved excellent restoration of facial contour in lieu of facial lipofilling. In another case of a necrotising infection of the head and neck with loss of all masticatory muscles, a free functional muscle using a chimaeric vastus lateralis-ALT flap was used to restore masticatory and facial movement in a single stage procedure.
CONCLUSIONS: Using combinations and permutations of current surgical techniques, it is possible to successfully restore both form and function for patients with sensory as well as motor trigeminal nerve palsies. This sets a precedent for the expansion of cranial nerve surgery as an evolving sub-speciality.