Eruption Pattern of Third Molars in Orthodontic Patients Treated with First Permanent Molar Extraction: A Longitudinal Retrospective Evaluation.

The aim of this study was to evaluate angular and positional changes in the second (M2) and third molars (M3) of orthodontically treated patients undergoing a first molar (M1) extraction. A retrospective longitudinal study with a sample of 152 pre- and post-treatment panoramic radiographs was conducted. Thirty-nine patients (51.3%) were orthodontically treated with M1 extraction and thirty-seven (48.7%) were treated without extraction. Angulations of M2 and M3 relative to the infraorbital (IOP) and the palatal planes (PP) were measured and compared between the groups before orthodontic treatment (T1) and after the completion of orthodontic space closure (T2). The prognosis of M3 eruptions was evaluated by assessing their horizontal and vertical position (inclination) using different classification systems. The angular (p < 0.001) and inclination improvement (p < 0.01) of the maxillary M3 was significant for the M1 extraction group. The mandibular M3 inclination significantly improved (p < 0.01), whereas the groups' angulation and vertical position were not significantly different. These findings suggest that extraction therapy has a favorable effect on the maxillary M2 and M3 angulation, but not on the mandibular. M1 extraction showed a signi- ficant effect on the horizontal position of M3 and thus may improve the eruption space and prognosis.

Accuracy of palatal orthodontic mini-implants placed by conventionally or CAD/CAM-based surgical guides: a comparative in vitro study.

OBJECTIVES: To investigate and compare the transfer accuracy of five different surgical guides (SGs) for the insertion of orthodontic mini-implants (OMIs) in the anterior palate. MATERIALS AND METHODS: Stereolithographic files of 10 maxillary patient models and their corresponding lateral cephalograms were virtually matched and used for planning the position of two parallel OMIs in the paramedian region of the anterior palate. For each patient model, three 3-dimensional (3D)-printed and two conventional SGs were manufactured from different materials, and a total of 96 OMIs were transferred to the anterior palates of the respective 50 molded resin models. The planned (T0) and the actual (T1) OMI positions were analyzed and compared after superimposition of the digitized models. The deviations between the OMI positions in T0 and T1 were described as the distance between the head and the tip, respectively, of each OMI in millimeters and the deviating angle between the OMI axes for each patient and SG. RESULTS: The conventionally manufactured SGs of Pattern Resin LS (GC Europe N.V., Leuven, Belgium) showed the highest linear and angular transfer accuracy for the insertion of OMIs. The highest deviations were found with the SGs made of IMPRIMO LC Splint (3D-printed; Scheu-Dental, Iserlohn, Germany) and Memosil 2 (conventional SG; Kulzer, Hanau, Germany). CONCLUSIONS: The 3D-printed SGs did not reach the accuracy of the conventional SGs made of Pattern Resin but may provide sufficient accuracy for palatal OMI placement.

Angular and positional changes of the maxillary third molars after orthodontic treatment with different premolar extraction patterns.

OBJECTIVES: To evaluate the angular and positional changes of the maxillary second (M2) and third molars (M3) after orthodontic premolar extraction treatment according to patient skeletal classification and growth pattern. MATERIALS AND METHODS: Panoramic radiographs of patients treated with extraction of the first or second premolars (n = 116) and patients treated without extraction (n = 92), taken before orthodontic treatment (T0) and after completion of multibracket appliance therapy (T1) were analyzed. Angle classification, growth pattern, crowding, and incisor inclination were recorded. The palatal (PP) and interorbital planes (IOP) were used as reference lines. Changes in the M3 angulation relative to PP and IOP (T0-T1) within the same group were evaluated with paired t-tests. One-way analysis of variance (ANOVA) and Kruskal-Wallis tests were used for comparisons between the groups. Accordingly, pairwise comparisons were performed with Mann-Whitney U-tests or independent t-tests (P < .05). RESULTS: The M3 angulation related to the PP and the IOP did not differ significantly between the extraction and nonextraction groups. The M2 angulation improved in the premolar extraction group between T0 and T1 (M2/PP, P < .001). According to Archer's classification, the change in the vertical position of M3 differed significantly between the extraction and nonextraction groups (P < .001). CONCLUSIONS: The angulation of M3 improved over time regardless of the extraction decision. The vertical eruption pattern of M3 was positively influenced only in the extraction group. M2 became significantly more upright in the orthodontic extraction treatment groups.

Esthetic and functional rehabilitation of severe facial asymmetry and dental attrition in a patient with hemifacial microsomia: an interdisciplinary treatment outcome.

The treatment management of patients with hemifacial microsomia (HM) includes both surgical and nonsurgical approaches and depends primarily on the degree of deformity of the facial and skeletal structures. In this context, the combined efforts of the maxillofacial surgeon, the orthodontist, and the prosthodontist are essential for a satisfactory functional and esthetic outcome. Case presentation: A 31-year-old man presented with a chief complaint of facial asymmetry. The patient had been diagnosed with HM on the right side, with severe external ear deformity, and hypoplasia of the facial muscles and the zygomatic bone. The intraoral examination showed a Class I molar and canine relationship with a reduced horizontal overlap and an occlusal plane canting. The maxillary anterior teeth were severely worn due to traumatic occlusion. Orthodontic treatment in conjunction with combined orthognathic surgery was planned to address the facial asymmetry. Ramus distraction osteogenesis was carried out, followed by conventional presurgical orthodontic treatment. The treatment was completed by prosthetic rehabilitation for the reconstruction of the maxillary teeth and fine occlusal adjustment. Conclusion: The cooperation between the orthodontist, surgeon, and prosthodontist becomes indispensable when treating complex cases of HM. An interdisciplinary approach should be adopted from the start of treatment, promoting integrated customized care.

Apical root resorption after orthodontic treatment in patients with unilateral cleft lip and palate.

OBJECTIVES: The aims of this retrospective longitudinal study were to present the incidence of external apical root resorption (EARR) in the maxillary anterior teeth of patients with complete unilateral cleft lip and palate (CUCLP) and to evaluate the influence of orthodontic treatment variables on the development of EARR. MATERIAL AND METHODS: Forty-one patients with CUCLP participated in the study. Orthopantomograms (OPGs), taken before (T2) treatment with multiband orthodontic appliances (MBA), and periapical radiographs (PAs) of the maxillary anterior teeth taken at the end (T3) of orthodontic treatment (OT) were assessed for EARR. RESULTS: The incidence of EARR at T3 (97.6%) was considerably higher than at T2 (51.2%). Central incisors and canines on the cleft side showed a significantly higher score (p < 0.01, p < 0.05 respectively) of EARR in comparison to the same group of teeth on the non-cleft side. Preexisting EARR and abnormal root morphology were identified as predisposing factors for EARR. CONCLUSIONS: Patients with CUCLP treated with MBA have higher incidence of EARR on the maxillary anterior teeth of the cleft side. Severe EARR is rather rare but more often seen on central incisors of the cleft side. CLINICAL RELEVANCE: As most of the patients with cleft lip and palate undergo a challenging and long-term OT with MBA, it is of importance to identify the predisposing factors related to the special anatomical features of the bone and teeth located in the cleft area, as well as the special OT needs of these patients.