Different anchorages can affect the position of maxillary third molars in extraction treatment / 中国组织工程研究

BACKGROUND: In orthodontic treatment, different anchorage controls will make different effects on the maxillary third molar. Whether this can affect the normal eruption of maxillary third molar remains unclear. OBJECTIVE: To explore the effect of Physiologic Anchorage Spee-Wire System (PASS) treatment on impacted maxillary third molars, and to provide reference for clinical application. METHODS: Thirty patients with maxillary third molars were treated with PASS and 30 patients were treated with McLaughlin, Bennett, and Trevisi (MBT). All patients chose the plan of extracting four first premolars. The angles and distances were measured before and after treatment and statistical analysis was performed. The study was in accordance with the ethical requirements of the Fifth Affiliated Hospital of Xinjiang Medical University. All participants and their guardians signed the informed consents. RESULTS AND CONCLUSION: (1) In the PASS group, the ∠UM3-HP, ∠UM2-HP and U-ES were significantly increased (P=0.00), and the UM3-OP was significantly decreased (P=0.00), indicating that the maxillary second molar and third molar became more upright, and larger eruption space contributed to eruption. (2) Compared with the PASS group, the obliquity of the maxillary third molar in the MBT group showed significant change, while the vertical eruption rate in the PASS group was relatively larger. (3) These results imply that both PASS and MBT can improve the eruption angle and space of the third molar, and make it easier to erupt in orthodontic treatment of extraction of the first premolar.

Rare Morphology of The Third Maxillary Molar and Potential Complications in its Extraction

@#There is a wide variation in the morphology of third maxillary molar which can be difficult to be identified radiographically. We present a case of a 26 year-old Yemeni female patient presented with difficult extraction of her left maxillary third molar. The extracted tooth showed a rare variation of root morphology, having four roots with three roots curving palatally at the apices. This report emphasized the potential complex morphological variation of maxillary third molar which may lead to the difficulty of a routine straight forward procedure thus needing careful extraction maneuvering to prevent any complications.

The research progress of maxillary third molar anatomical morphology / 口腔疾病防治

@#Third molars, late-eruption permanent teeth in humans, have commonly been extracted in clinical treatments. However, with the development of oral medicine, the value of maxillary third molars in clinical treatments, as well as in oral prosthetics, orthodontics, and oral implant applications, has gradually become recognized. This paper summarizes the research on the morphology of the crown, root, root canal and root tip of the maxillary third molar in a review to facilitate related research and clinical treatments.

Impacted Maxillary Third Molar: Report of Two Cases

The aim of this case report was to review two cases of patients with impacted maxillary third molars. Both were symptomatic and presence of pathology clinically and radiographically. Surgical extraction of these third molars with accessible positions requires a bone removal. Moreover, it contains a high risk of displacement of the third molars into the maxillary sinus. The postoperative period for both cases was without complications

A study of root canal morphology in maxillary third molars using cone-beam computed tomography / 口腔疾病防治

Objective@#This study investigated root canal morphology in maxillary third molars by CBCT to provide an anatomical guideline for clinical treatment.@*Methods@#CBCT images of 397 maxillary third molars were collected. The root canal morphology was analysed, including the number of roots and the type of canals.@*Results @# In 397 maxillary third molars, three roots were the most frequently type, accounting for 43.07% and the fused root teeth were the second, accounting for 40.30%. For the root canal type, three canals were the most common, accounting for 47.86%, followed by single canal, accounting for 28.21%. According to the Vertucci root canal classification, 89.6% of the root canals were typeⅠ, the rest were typeⅡ, typeⅢ, type Ⅴ, and other types of root canals which were difficult to deal with in clinical treatment.@*Conclusion @#The root canal morphology of the maxillary third molar is various and the root canal system was complicated.

The relationship between maxillary sinus floor and the roots of maxillary third molar observed by CBCT / 实用口腔医学杂志

Cone-bine CT(CBCT)images of 2 130 maxillary third molars were divided into 3 groups according to the impaction position. The relationship between the floor of maxillary sinus and the roots of maxillary third molar was analyzed and compared.In low,median and high impaction groups the probability of the root tip of maxillary third molar higher than the floor of maxillary sinus was 4.5%,10.3% and 14.6% respectively.

Maxillary third molar with three canals in mesiobuccal root:A case report / 实用口腔医学杂志

This case report presents an extracted maxillary third molar,which have 3 separate roots with 5 canals,the canal configuration in mesiobuccal root are 3 separate orifices and canals,1 apical foramen.The clinician should be aware of this anatomical variation,avoid the missed canals.