Viet Anh Nguyen

Objectives: To evaluate the reliability and educational applicability of a digital three‐dimensional surface‐deviation workflow for assessing soap‐carved tooth morphology in first‐year dental students. Materials and Methods: Ninety‐eight students completed the dental anatomy module. After written research consent and specimen eligibility screening, 41 students with complete evaluable sets of eight right‐side tooth carvings were included (328 student‐tooth models). Instructor‐carved teeth served as reference models. Models were scanned with a Medit i700 and analysed in Medit Design. The primary outcome was root mean square deviation (RMS); secondary outcomes were percentages of surface area within 0.3–0.7 mm tolerance thresholds. Rater 1 repeated measurements after 2 weeks; Rater 2 independently measured the dataset once. Reliability was evaluated overall and by tooth type. Results: Pooled RMS intra‐rater and inter‐rater ICCs were 0.866 and 0.860, respectively. Tooth‐stratified RMS ICCs ranged from 0.646 to 0.938 for intra‐rater and 0.643 to 0.925 for inter‐rater agreement. Overall mean RMS was 0.848 ± 0.365 mm. Mandibular central incisors showed the lowest mean RMS (0.553 ± 0.276 mm), whereas maxillary first molars showed the highest (1.357 ± 0.358 mm). At 0.5 mm, the overall mean surface within tolerance was 64.8%. Conclusion: Digital surface‐deviation analysis provided reproducible quantitative feedback overall, although reliability varied by tooth type. RMS and tolerance‐based metrics can complement faculty judgement in manual tooth‐morphology training but should not be interpreted as standalone grades.

Rationale: Tooth ankylosis is difficult to diagnose and monitor because clinical signs are nonspecific, and radiographs provide only static information. Patient concerns: An adult female was referred after prolonged orthodontic failure involving a nonresponsive mandibular left canine, severe anterior open bite, negative overjet, lower midline deviation, and repeated debonding of a stock lingual bracket. Diagnoses: The patient was diagnosed with partial ankylosis of the mandibular left canine, likely related to previous segmental osteotomy and fixation-screw proximity, together with a dental Class III relationship on a skeletal Class II base. Interventions: Controlled luxation was performed, followed by stiff rectangular mechanics, miniscrew-anchored mandibular distalization, and serial intraoral scan superimposition. After repeated bracket failure, a scan-guided customized lingual bracket pad was fabricated and bonded. Outcomes: After just over 5 months, the canine was derotated, uprighted, and positioned within the arch. Bilateral Class I occlusion, normal overjet and overbite, midline correction, and lower occlusal plane leveling were achieved. The incisor mandibular plane angle decreased from 122.5° to 104.4°. Electric pulp testing remained positive, and no additional mandibular incisor root resorption was detected compared with the referral baseline. Lessons: Serial intraoral scan superimposition may provide useful radiation-free evidence of post-luxation tooth movement, although registration error and crown-only assessment must be considered. A customized lingual bracket pad can improve bond reliability when heavy mechanics are required.

Rationale: Adult skeletal class III patients who decline orthognathic surgery may be treated with nonsurgical dentoalveolar camouflage. Extra-alveolar anchorage on the mandibular buccal shelf enables en-masse total-arch distalization and clinically meaningful sagittal correction without relying on patient compliance. Patient concerns: A 19-year-old male presented with an edge-to-edge anterior relationship and generalized spacing. He was satisfied with his facial appearance and declined surgery. Diagnoses: The patient was diagnosed with a borderline adult skeletal class III malocclusion characterized by a mildly hypodivergent pattern, concave profile, bilateral angle class III canine and molar relationships, edge-to-edge anterior relationship, anterior spacing, maxillary incisor proclination, and mild mandibular incisor lingual inclination. Interventions: Fixed self-ligating brackets were used with proactive torque control including lower incisor brackets inversion to express positive torque and 0.019 × 0.025-in stainless-steel archwires with added torque. After extraction of the mandibular third molars, 2 buccal-shelf miniscrews with power arms delivered distalizing forces. Outcomes: Bilateral class I relationships, space closure, and positive overjet were achieved. Cephalometric changes indicated approximately 4 to 5 mm of mandibular dentoalveolar distalization with controlled tipping and lingual root movement, while the Wits appraisal improved substantially despite slight changes in anteroposterior skeletal measures. Favorable sagittal changes were interpreted cautiously because they may reflect mandibular clockwise rotation and dentoalveolar effects rather than true basal skeletal correction. Lessons: In carefully selected borderline adult class III patients, buccal-shelf miniscrew–anchored en-masse mandibular distalization can deliver upper-range camouflage when torque- and vertical-control biomechanics are actively maintained. Soft-tissue improvements remain limited compared with orthognathic surgery.