The impact of COVID-19 pandemic on total treatment time of fixed appliances.

BACKGROUND: Several aspects of the orthodontic routine seem to have been affected since the emergence of SARS-CoV-2. We aimed to evaluate the impact of the COVID-19 pandemic on the duration of fixed orthodontic treatment. METHODS: This retrospective study evaluated consecutive cases of patients undergoing fixed orthodontic treatment that completed treatment before (n = 37) or during (n = 26) the COVID-19 pandemic. The impact of the pandemic on treatment time was adjusted for the patient's initial age, sex, number of debonds/breakages, number of missing teeth, initial PAR (Peer Assessment Rating) index (T0) and operator (n = 2), through multiple linear regression. The impact generated by months of treatment conducted during the pandemic period was also examined. Seven poorly finished cases were previously excluded, including five finished during the pandemic. RESULTS: Although the number of absences/missed appointments of patients treated during the pandemic was four months more than those treated in the previous period (p < 0.001), there was no significant effect of the pandemic on total orthodontic treatment time for both operators. There was also an effect of operator (ß = 10.42, p < 0.001) and gender, which was lower in females (ß = 4.77, p = 0.03), on treatment time (R2 = 0.27). The other variables showed no significant association (p > 0.05). CONCLUSION: The COVID-19 pandemic did not have a significant effect on total orthodontic treatment time, although a greater number of absences/missed appointments were observed.

Prevalence of non-carious cervical lesions and orthodontic treatment: a retrospective study.

BACKGROUND: This study aimed to assess the distribution of non-carious cervical lesions (NCCLs) by tooth type, investigate the prevalence of NCCLs in patients undergoing orthodontic treatment, and identify the possible associated factors. MATERIAL AND METHODS: A total of 160 patients were enrolled in this retrospective study. Data on the following variables were collected from pre-and post-orthodontic treatment records: age, sex, Angle's malocclusion, facial pattern, number of activation sessions, compensatory treatment, and retreatment. Frontal, right and left lateral intraoral photographs of each patient were evaluated to identify the presence or absence of NCCLs in each tooth and assess the distribution of NCCLs in the 3840 teeth from the enrolled patients. Furthermore, patients were classified as NCCLs present, irrespective of the number of NCCLs on the teeth or NCCL absent. Bivariate and multivariate Poisson regression analyses with robust variance were used to assess the association between the NCCLs and each independent variable. Prevalence ratio and 95% confidence intervals were calculated and p < 0.05 was considered statistically significant. RESULTS: The prevalence of NCCLs before and after orthodontic treatment was 22.71% and 30.91%, respectively. Premolars were the most affected teeth, followed by the first molars, canines, and incisors. After statistical analysis, age was found to be the variable factor that influenced the prevalence ratio, with NCCL being the most prevalent when orthodontic treatment was performed in adulthood. CONCLUSIONS: Premolars were most commonly affected by NCCLs. Furthermore, age seemed to contribute to the increased prevalence of NCCLs in adults undergoing orthodontic treatment.

Evaluation of the condylar position in younger and older adults with or without temporomandibular symptoms by using cone beam computed tomography.

STATEMENT OF PROBLEM: Recent studies in young adults have questioned the influence of discrepancies between central and maximal intercuspal positions in temporomandibular disorders (TMDs). However, whether this finding was because this type of etiologic agent requires time for the development of changes in the condylar position is unclear. PURPOSE: The purpose of this clinical study was to use cone beam computed tomography (CBCT) to evaluate the presence or absence of discrepancies between the centric relation (CR) and maximum intercuspation (MI) in younger and older adults in populations with or without TMDs. MATERIAL AND METHODS: The sample was composed of 80 volunteers, 40 younger individuals aged 18 to 25 years (27 women and 13 men), half with and half without TMD symptoms, and 40 older participants aged 35 to 50 years (30 women and 10 men), half with and half without TMD symptoms. The TMD symptoms were diagnosed by using the diagnostic (standard) criteria for TMD research (RDC/TMD). Two CBCT scans were performed on each participant, one in MI and another in CR. Measurements of the joint space were performed in coronal and sagittal cuts of the temporomandibular joints, and the collected data were statistically analyzed by using the Mann-Whitney U test (α=.05). RESULTS: No significant differences were found when the CR and MI positions and the presence or absence of TMD symptoms were compared in the younger and older groups. However, when the younger and older groups were compared, significant differences were found in all measures used in this study. CONCLUSIONS: The condyle and mandibular fossa do not seem to be influenced by the CR or MI positions or by the presence or absence of TMD symptoms, but age seems to lead to a quantitative increase in the relationship between these structures.

Fractured alveolar process displacement evaluation-Effect of the rigidity of wire-composite splints.

BACKGROUNDS/AIMS: Traumatic dental injuries with bone fractures require rigid splinting. The degree of rigidity of the wire-composite splints can be challenging. The aim of this study was to evaluate the effect of the rigidity of different wire-composite splints on alveolar process displacement. MATERIAL AND METHODS: A model was created using polystyrene resin to simulate the anterior maxilla, bovine incisors to simulate maxillary incisors, and polyether impression material to simulate the periodontal ligament. An alveolar process fracture was created, while maintaining the labial bone connection with the PDL. Four wire-composite splints (0.3, 0.6, 0.9, and 1.2 mm in diameter) were compared with models without splints and with no fracture (n = 5). The alveolar process displacement was measured (3 times per model/per splint type) at the fractured and adjacent central incisor regions using a deflectometer (Instron) under functional cycling and static loading (100 N). Data (µm) were analyzed using RM ANOVA, followed by Tukey's HSD test (α = 0.05). RESULTS: The displacement at the region of the adjacent incisor was not influenced by the splint during static and cycling load (P > .05). The Tukey test demonstrated that the model without splints had significantly higher alveolar process displacement at the traumatized teeth than that of all other splint models (P < .001). Increasing the wire diameter from 0.3 mm to 0.9 mm significantly reduced the alveolar process displacement (P < .001). No difference was observed between the 0.9 mm (P = .123) and 1.2 mm (P = .219) wire-composite splints irrespective of the measured tooth regions. CONCLUSIONS: The rigidity of the wire-composite splint significantly influenced the mobility of the fractured alveolar process. The use of at least 0.9 mm wire was effective in reducing the fractured alveolar process displacement to a level that was similar to the adjacent teeth.