Buccal rotation for wholly impacted maxillary third molar extraction.

BACKGROUND: Extracting wholly impacted maxillary 3rd molars faces difficulty due to the narrow surgical field, adjacent teeth resistances and risk of oroantral communication. This study is designed to introduce and evaluate the applicability of a novel method-buccal rotation to extract maxillary 3rd molars. MATERIALS AND METHODS: In this cohort study, from October 1st 2020 to September 30th 2021, 72 wholly impacted maxillary 3rd molars were included. Based on the crowns with coronal 1/3, middle 1/3, apical 1/3 of the adjacent teeth roots, teeth were classified into position I, II, III. Based on the angles < 30°, ≥ 30°but < 60°, ≥ 60° to the adjacent teeth, teeth were classified into angulation A, B, C. Traditional method and novel method-buccal rotation were applied based on the surgical simulations. Surgical results were recorded. To analyze the data, Chi-square test was applied. RESULTS: 82.00% of teeth in position I and 50.00% in position II were designed to use traditional method, 83.33% in position III were using the novel method (p < 0.05). 81.25% of teeth in angulation A and 52.63% in angulation B were designed to use traditional method, 80.00% in angulation C were using the novel method (p < 0.05). Four cases got temporary complications. CONCLUSION: Buccal rotation was applicable to extract the deep impacted maxillary third molars with large angles towards the adjacent teeth.

Pathologies associated with the mandibular third molar impaction.

To evaluate the associations of impaction patterns of mandibular third molars (M3Ms) with pathologies caused by them. In this study, 262 patients with 432 impacted M3Ms who referred in Shanghai Xuhui District Center were reviewed. The pathologies include pericoronitis, mandibular second molar (M2M) caries, and M2M distal periodontal pathology. The impaction patterns of M3Ms and the pathologies were examined, while the M2M outcomes after surgeries were evaluated. A χ2 test was used to analyze the data, with a p value of <0.05 being considered statistically significant. Pericoronitis was the major symptom in all patients, whereas the propensities of M2M distal caries and periodontal pathologies increased in older patients. Soft tissue impacted and vertically angulated teeth were more associated with pericoronitis (p < 0.05); mesio-angular impacted teeth in less deep positions had greater risks of M2Ms distal caries (p < 0.05); mesio-angular and horizontal impacted teeth in relative deep positions were more likely to cause M2Ms distal periodontal pathologies (p < 0.05). Extractions of soft tissue impacted teeth in vertical angulations should be considered, while removals of mesially and horizontally angulated or bony impacted teeth could be delayed.

Mesiolingual root rotation for horizontal mandibular third molar extraction: position classification and surgical simulation.

Extracting horizontal mandibular 3rd molars face considerable difficulty due to the large bone and adjacent tooth resistances. This study aims at evaluating the effectiveness of a novel method-mesiolingual root rotation to extract wisdom teeth of this type. In this study, 73 horizontal teeth extracted using piezosurgery were reviewed and classified based on impaction depth: position I, II, III refers to the highest portion of the crown on a level with upper 1/3, middle 1/3, lower 1/3 of the 2rd molar's root. Based on the surgical simulations on their 3D CBCT reconstructions, traditional method(crown distal rotation) and novel method(root mesiolingual rotation) are applied. 79.17% of teeth in position I and 57.89% of teeth in position II were designed using traditional method, 83.33% teeth in position III were designed using the novel method(p < 0.05). The surgeries were performed according to the designs. Two cases in position II using traditional method were found temporary inferior alveolar nerve(IAN) injury; while only one case in position III using novel method got temporary IAN and lingual nerve injury. Our study suggested that root mesiolingual rotation is an effective method to extract the horizontal mandibular 3rd molars, especially the deep impacted ones.

Adjacent tooth trauma in complicated mandibular third molar surgery: Risk degree classification and digital surgical simulation.

Analysis of adjacent tooth resistance is essential in wisdom teeth extraction to prevent adjacent tooth trauma, however it lacks adequate attention nowadays. This study aims at suggesting special extraction methods based on adjacent tooth resistance analysis for prevention of adjacent tooth damage. In this study, 136 complicated mandibular third molars extracted using piezosurgery were reviewed and classified based on the adjacent teeth resistances shown in orthopantomogram (OPG) during their mesio-distal rotations: degree I refers to teeth with no adjacent teeth resistance; degree II refers to teeth with resistance released after mesial-half crown sectioning; degree III refers to teeth which still had resistance after mesial-half crown sectioning. With the use of surgical simulations using cone beam computerized tomography (CBCT) reconstruction, all teeth in degree I were designed to rotate mesio-distally; 86.36%(38/44) teeth in degree II were designed to rotate mesio-distally after mesio-half crown sectioning; 69.09%(36/55) teeth in degree III were designed to rotate bucco-lingually. All teeth were extracted successfully, and only one adjacent tooth was subluxated due to the incomplete bone removal. Our study suggested that in order to prevent adjacent teeth trauma, complete bone removal is of importance, and impacted teeth with higher adjacent teeth trauma risks should consider bucco-lingual rotations.

A Novel Surgical Technique for Augmented Corticotomy-Assisted Orthodontics: Bone Grafting With Periosteum.

PURPOSE: To introduce grafting fixed with the periosteum (dumpling technique) as an alternative surgical technique for augmented corticotomy-assisted orthodontics in the lower anterior region and evaluate the preliminary outcomes. MATERIALS AND METHODS: Eleven patients (9 women, 2 men; mean age, 21.4 yr) with a thin alveolus or alveolar defect in the lower anterior region by clinical and radiographic examination underwent an augmented corticotomy using the new dumpling technique. Cone-beam computerized tomography was used to evaluate morphologic changes of the lower anterior ridge before treatment (T0) and 1 week (T1) and 6 months (T2) after the bone-augmentation procedure. Repeated-measures analysis of variance with Bonferroni multiple-comparison test was used to compare variables at each time point. RESULTS: No severe postsurgical complications occurred in any patient. The mean alveolar bone thickness of the labial plate increased from T0 to T1 (P < .001) and decreased from T1 to T2 (P < .001). However, compared with T0, there was still a significant increase in horizontal bone thickness at T2 (P < .05). The vertical alveolar bone level increased from T0 to T1 (P < .001) and was maintained from T1 to T2 (P > .05). No significant differences were found in root length of the lower anterior teeth at these 3 time points (P > .05). CONCLUSIONS: In this preliminary study, the dumpling technique for augmented corticotomy-assisted surgical orthodontics showed alveolar bone augmentation by increasing the vertical alveolar height and the horizontal bone thickness in the labial aspect of the anterior mandibular area. However, long-term follow-up is necessary.

Juxta-articular Myxoma of the Temporomandibular Joint.

The juxta-articular myxoma represents a benign mesenchymal neoplasm that arises from tissue within or adjacent to a joint space. There have been a number of reported cases involving myxomas of the knee, shoulder, elbow, wrist, and hip. To our knowledge there, however, have been no reported cases of juxta-articular myxomas of the temporomandibular joint (TMJ). This report describes the case of a 57-year-old woman with a juxta-articular myxoma of the left TMJ extending into the infratemporal fossa (ITF). Access to the tumor was accomplished via a preauricular incision and low condylar osteotomy which allowed for displacement of the condyle for direct visualization and excision of the tumor. The postoperative course was benign and the patient demonstrated no cosmetic or functional limitation. Likewise, follow-up at 30 months showed no evidence of recurrence. Benign encapsulated tumors of the ITF can be effectively accessed by means of a modified preauricular incision, low condylar osteotomy, and anterior meniscal release. This direct approach allows for excellent surgical exposure, minimal surgical site morbidity, and maintenance of physiologic joint function and occlusion.

Digital resection and reconstruction of TMJ synovial chondrosarcoma involving the skull base: report of a case.

Synovial chondrosarcoma (SCS) is a very rare malignant cartilaginous tumor. To the best of our knowledge, only three reported studies presented the involvement of the temporomandibular joint (TMJ). Hereby, we present a case of surgical management of a SCS of the TMJ, arising from SC and involving the skull base. The surgical procedure includes digital design, resection guided by digital templates, as well as immediate reconstruction with free iliac bone graft (IBG) and pedicled sternoclavicular joint (SCJ). At 1-year follow-up, the TMJ function and form were improved with no sign of local recurrence or metastasis to bone or other joints. However, its distant metastasis to lung was observed.