BMC Oral Health最新文献

Background: We aimed to determine whether minor salivary flow (MSF) rate, measured via a rapid paper-based test, can serve as a reliable screening tool for detecting hyposalivation. This study, conducted in a real-world clinical setting, evaluated the diagnostic performance of MSF against unstimulated whole saliva (UWS) as the reference standard in individuals experiencing xerostomia due to medications.

Methods: We conducted a cross-sectional study of 135 adults aged 45-64 years with xerostomia and ongoing anticholinergic medication use. MSF was measured using a one-minute Shrimer strip placed in the upper labial vestibule, and reliability was assessed via triplicate measurements in a subsample (n = 40). UWS flow was used as the reference standard for reduced (hyposalivation) saliva secretion. The diagnostic performance of MSF was analyzed using Receiver Operating Characteristic (ROC) curves, and multivariable logistic regression assessed its predictive utility after adjusting for demographic and clinical covariates.

Results: MSF demonstrated high internal consistency (Cronbach's α = 0.94) and strong inter-replicate agreement (r = 0.83-0.87). Participants with hypo ratetion had significantly lower MSF than those without (mean difference = 2.41 µL/cm²/min, p < 0.001). At an optimal MSF cutoff, sensitivity was 80.0% and specificity was 54.5% (with Area Under the Curve; AUC = 0.726). In multivariable models, MSF and xerostomia severity were independent predictors of hyposalivation, with an overall model AUC of 0.827.

Conclusion: MSF, measured using a simple, non-invasive method, is a reliable and moderately accurate screening tool for identifying hyposalivation in adults with medication-induced xerostomia. These findings support its use in clinical settings; however, further refinement and validation are necessary to establish diagnostic thresholds and determine its applicability.

Background: This study aimed to explore the effect of attachment wear on maxillary canine rotation in clear aligner therapy through three-dimensional finite element analysis.

Methods: Finite element models, comprising the maxillary bone, periodontal ligament, upper dentition, attachments (initial and worn), and clear aligners, were created to simulate maxillary canine rotation. Two attachment types (vertical rectangular and rotation-optimized) with five wear levels (M0, M2, M4, M6, and M8) were considered for canine rotation analysis. Tooth displacement and equivalent stress in the roots and periodontal ligaments were analyzed.

Results: With increased attachment wear, both groups showed reduced canine rotation angles and lower stress levels in roots and periodontal ligaments. The most significant reduction in the canine rotation angles and stress values for the rectangular group occurred between M2 and M4, with the efficiency of canine rotation falling below 50% from M4 onward. In contrast, the optimized group experienced the most substantial decline between M6 and M8, with the efficiency of canine rotation falling below 50% at M8.

Conclusions: Attachment wear decreased maxillary canine rotation efficiency. It is preferable to use optimized rotation attachments when correcting maxillary canine rotation. After six months of optimized attachment use, if maxillary canines still require rotation, orthodontists should closely monitor attachment wear to ensure treatment effectiveness. Immediate restoration or re-bonding of the attachments is required if it is determined to be essential.

Background: Recent advances in orthognathic surgery-particularly the adoption of virtual 3D planning and patient-specific 3D-printed splints-have improved surgical precision, reduced operative time, and enhanced predictability of outcomes. Despite these developments, accurate intraoperative positioning of the mandibular condyle, especially the condylar head, during bilateral sagittal split osteotomy (BSSO), remains a major challenge. Although multiple techniques for condylar positioning have been proposed, their impact on postoperative condylar head position and joint space morphology has not been comprehensively assessed. This study aimed to evaluate postoperative changes in condylar head position and temporomandibular joint (TMJ) space using a Procrustes algorithm, and to investigate potential effects of surgeon handedness.

Methods: A retrospective cone beam computed tomography (CBCT) analysis was conducted on 40 patients (24 female, 16 male) who underwent orthognathic surgery. The cohort comprised 27 patients with Angle Class II and 13 with Angle Class III malocclusion. Eighteen patients underwent bimaxillary procedures, and 22 underwent monomaxillary osteotomies. Condylar position and joint space dimensions were measured, and Procrustes shape analysis was applied to quantify TMJ space deformation. Statistical tests assessed positional changes and correlations with skeletal class, displacement, and surgeon handedness.

Results: Significant postoperative changes were observed, with a bilateral reduction in cranial distances, reflecting a more caudal condylar head position, and a significant widening of the cranial joint space on the right side. Procrustes analysis confirmed measurable deformation of anterior and posterior TMJ compartments. Condylar heads were frequently positioned dorsally during initial registration, and results suggest that surgeon handedness may systematically influence condylar positioning.

Conclusions: Postoperative condylar head position and TMJ space morphology are influenced by intraoperative handling, with surgeon handedness emerging as a potential contributor. Incorporating shape analysis methods such as Procrustes algorithms into future digital workflows may improve condylar positioning strategies and enhance surgical outcomes in BSSO.