Relationship between the Surgical Access Line of Maxillary Posterior Teeth and the Maxillary Sinus Floor

IntroductionThe aim of this study was to use cone-beam computed tomographic imaging to investigate the relationship between the surgical access line (SAL) of maxillary posterior teeth and the maxillary sinus floor (MSF) in endodontic microsurgery.MethodsCone-beam computed tomographic scans of 190 subjects with clear and integrated maxillary posterior teeth and sinus floors on both sides were evaluated. The correlation of the average distance between the SAL and the MSF with age was analyzed. Three types of relationships between the SAL and MSF were classified. The minimum vertical distance between the SAL and the MSF for the type 1 relationship was measured.ResultsA total of 1134 teeth, including 758 premolars and 376 first molars, were evaluated. The average distance between the SAL of maxillary posterior teeth and the MSF increased with age, except in the 31- to 40-year-old group. The highest rates of the SAL touching the MSF and protruding into the maxillary sinus occurred among first molars at 25.6% and 8.1%, respectively. For the type 1 relationship, the mean distance from the SAL of the first and second premolars and the first molar to the MSF was 7.11 ± 4.40, 4.92 ± 3.69, and 4.76 ± 3.61 mm, respectively.ConclusionsKnowledge of the relationship between the SAL and the MSF of maxillary posterior teeth could provide an important reference for surgeons to evaluate surgical difficulty and decrease the risk of maxillary sinus perforation.     

Multidisciplinary Management of a Severe Maxillary Midline Diastema: A Clinical Report

A maxillary midline diastema (MMD) is a common form of incomplete occlusion and often is a primary complaint of patients during dental consultations. MMD is considered to be a multifactorial phenomenon and can therefore be best restored with a multidisciplinary approach. This clinical report presents a multidisciplinary approach to the management of a 4.0‐mm MMD by using limited orthodontics combined with periodontal and prosthodontic treatments.     

Maxillary Midline Diastema: a case report involving a combined orthodontic/maxillofacial approach

Abstract

This paper presents an orthodontic case of a large (14.5 mm) maxillary midline diastema that was related to the presence, and subsequent removal of 2 median maxillary supernumerary teeth and resulting bone loss. A combined orthodontic and maxillofacial approach involving bone grafting and fixed appliances was used to close the space. This episode of care was organized as interceptive treatment during development of the permanent dentition.     

Relationship Between Pterygomaxillary Notches and Maxillary Anterior Teeth

Purpose: Selection of the appropriate size of maxillary anterior teeth in complete dentures may be difficult, as there is no universally accepted method that can be used reliably. The aim of this study was to investigate whether there is a relationship between the total mesiodistal width of the six maxillary anterior teeth and the interpterygomaxillary notch distance. Material and Methods: One hundred and ten maxillary impressions were made on dental students (67 women, 43 men; 19 to 22 years old) using stock tray and irreversible hydrocolloid impression material. The mesiodistal width of the six maxillary anterior teeth and the distance of the interpterygomaxillary notch were measured by digital caliper on stone casts (on two separate occasions by two independent observers). The results were analyzed using correlation regression tests. Results: The mean mesiodistal width of the six maxillary anterior teeth was 46.02 (±2.8) mm, and the mean distance of the interpterygomaxillary notch was 42.38 (±3.47) mm. A significant correlation was found between mesiodistal width of the maxillary anterior teeth and the interpterygomaxillary notch distance (p= 0.003; r = 0.28). Standardized coefficient was found to be low (28%) to predict the appropriate size of maxillary anterior teeth. Conclusion: Total mesiodistal width of the maxillary anterior teeth correlated with the distance between pterygomaxillary notches; however, measurement of the interpterygomaxillary notch could not be used for tooth selection reliably due to the low standardized coefficient. Within the limitations of this study, the interpterygomaxillary notch distance is not useful for the selection of six maxillary anterior teeth in edentulous patients.     

上颌窦口扩大手术与蝶腭动脉分支关系的外科解剖研究

目的：了解人体上颌窦口扩大手术与蝶腭动脉分支的解剖关系。方法：30侧动脉灌注乳胶10%福尔马林固定的成人头部标本,不计性别和年龄,在立体放大镜下观察鼻中隔,中鼻道的结构和血管分布。结果：上颌动脉在蝶腭孔处分为蝶腭动脉一终支,经蝶腭孔到鼻腔。其分支供应鼻腔外侧壁,鼻窦及鼻中隔。蝶腭动脉的分支,鼻后外侧动脉的外径为（1.05±0.09）mm,其分支至中鼻甲动脉和下鼻甲动脉,其外径分别为（0.91±0.09）mm和（0.96±0.09）mm。蝶腭动脉的下鼻甲分支在下鼻腔后端前方的距离约为（11±3）mm。在行上颌窦口开放手术时,若距中鼻甲后约1.5cm的距离,不易伤及鼻后外侧动脉。结论：上颌窦口扩大手术中不能单纯以上颌窦开口位置,作为向后上扩大的自然标志,在中鼻甲后端1～1.5mm处,开放上颌窦口较为安全,同时应避免伤及蝶腭动脉的分支及鼻后外侧动脉。     

上颌复合体与颅部位置关系的头影测量研究——角度与线距的相关关系及补偿机制

目的 :本研究通过X线头影测量阐述上颌复合体与颅部位置关系中角度与线距的相关关系和补偿机制。方法 :采用 92例侧貌正常的恒牙列者的X线头影测量图进行测量分析。结果 :在影响面中部突度的各项角度、线距之间及其内部均存在明显的相关关系和较为密切的补偿关系。结论 :上颌复合体与颅部位置关系中的相关关系及补偿机制保证了颅面结构及侧貌的美观、协调、平衡。对口腔正畸医生而言 ,要对临床病例进行综合、全面的分析。     

快速扩弓联合前方牵引治疗上颌发育不足的临床体会

目的 探讨快速扩弓联合前方牵引在治疗替牙晚期、恒牙早期骨性前牙反He中的作用。方法 选择8例替牙后期到恒牙早期前牙反He患者，采用快速扩弓联合前方牵引治疗，拍摄治疗前后头颅定位侧位片，作X线头影测量分析。结果 治疗后6～14月内，所有患者解除前牙反He。X线分析显示：SNA↑，SNB↓，ANB↑，FMA↑。结论 快速扩弓联合前方牵引通过促进上颌骨发育，使下颌下旋、后移，生长方向转为后下，上前牙前倾，下前牙舌倾，能有效地纠正替牙晚期．恒牙早期上颌骨发育不早的前牙反He患者．改善侧貌。     

伴上颌窦囊肿的上颌窦底提升牙种植临床分析

目的:探讨囊液抽取法在伴有上颌窦囊肿的上颌后牙区,同期行上颌窦底提升与即刻种植的临床效果。方法 :收集伴有上颌窦囊肿且需行上颌后牙区种植术患者12例,术区剩余骨高度不足4 mm,共植入25枚种植体,术后3、6、12个月通过CBCT及临床检查,评价种植体骨结合情况。结果 :12例患者术后6~9个月行二期修复,其中9例囊肿完全消失,3例囊肿大小较术前明显减小,术后1年25枚种植体均正常行使咀嚼功能,且未发现异常松动,种植体骨结合良好。结论:在上颌后牙区行上颌窦底提升术,对于伴上颌窦囊肿的种植修复患者,在无副鼻窦炎症状的前提下,可仅对囊液进行抽吸,同期行上颌窦提升与种植一期手术,能获得良好的骨整合效果。     

Maxillary Sinusitis Caused by Dental Implants Extending into the Maxillary Sinus and the Nasal Cavities

This report describes the case of a patient who underwent osseointegrated dental implant placement. The implants were misplaced inside the nasal fossae and in the right maxillary sinus, causing chronic purulent sinusitis. CT scan without contrast showed signs of right maxillary sinusitis and confirmed the misplacement of four dental implants that surfaced into the nasal cavities. The imaging also revealed the presence of another implant that emerged inside the maxillary sinus. The patient underwent functional endoscopic sinus surgery with complete symptom remission at the long‐term follow‐up. We propose that sinusitis caused by protrusion of implants and by sinus floor lift procedures could share common physiopathological patterns and predisposing factors.