Top Read Articles
Published in last 1 year |  In last 2 years |  In last 3 years |  All
Please wait a minute...
For Selected: Toggle Thumbnails
Treatment of dentofacial deformities secondary to condylar hyperplasia
Luo En.
West China Journal of Stomatology    2023, 41 (4): 369-376.   DOI: 10.7518/hxkq.2023.2023059
Abstract5201)   HTML213)    PDF(pc) (7679KB)(523)       Save

Dentofacial deformities secondary to condylar hyperplasiais a kind of disease presenting facial asymmetry, malocclusion, temporomandibular joint dysfunction, and other symptoms caused by non-neoplastic hyperplasia of the condyle. The etiology is still unknown, and currently, pre- and post-operative orthodontics accompanied by orthognathic surgery, temporomandibular joint surgery and jawbone contouring surgery are the main treatment methods. A personalized treatment plan was developed, considering the active degree of condyle hyperplasia, the severity of the jaw deformity, and the patient’s will, to correct deformity, obtain ideal occlusal relationship, and regain good temporomandibular joint function. Combined with the author’s clinical experience, the etiology, clinical and imageological features, treatment aims, and surgical methods of condylar hyperplasia and secondary dentofacial deformities were discussed in this paper.

Table and Figures | Reference | Related Articles | Metrics
From “Empirical Surgery” to “Precision Surgery”: establishment and clinical application of precision orthognathic surgery system
Wang Xudong, Wei Hongpu, Li Biao.
West China Journal of Stomatology    2023, 41 (5): 491-501.   DOI: 10.7518/hxkq.2023.2023152
Abstract2327)   HTML589)    PDF(pc) (5441KB)(331)       Save

Orthognathic surgery, which involve osteotomy and repositioning of the maxillomandibular complex, has recently emerged as a crucial method of correcting dentofacial deformities. The optimal placement of the maxillomandibular complex holds utmost significance during orthognathic surgery because it directly affects the surgical outcome. To accurately achieve the ideal position of the maxillomandibular complex, with the rapid advancements in digital surgery and 3D-printing technology, orthognathic surgery has entered an era of “Precision Surgery” from the pervious “Empirical Surgery.” This article provides comprehensive insights into our extensive research and exploration of the treatment modality known as “precision orthognathic surgery” over the years. We also present the technical system and application in“Ortho+X” treatment modality to offer valuable references and assistance to our colleagues in the field.

Table and Figures | Reference | Related Articles | Metrics
Developments and trends of endoscopic salivary gland resection: from endoscope-assisted to full endoscopic
Zhu Guiquan, Li Chunjie.
West China Journal of Stomatology    2023, 41 (4): 377-384.   DOI: 10.7518/hxkq.2023.2023116
Abstract2120)   HTML271)    PDF(pc) (5020KB)(707)       Save

More than 30 years of rapid development of endoscopic surgery has led to the mainstreaming of this procedure in many surgical departments in China. Since the first report on endoscopy, it has been used in salivary gland resection for more than 20 years. The overall development of endoscopic surgery indicates that its use in oral and maxillofacial surgery is still in the early exploration stage; it has not yet been maturely developed or applied. Owing to the advancement of other disciplines and corresponding widening experiences in those fields, the development of endoscopic technology in oral and maxillofacial surgery will likely achieve a leapfrogging. Learning from the general development pattern of endoscopy, this research explores the application history, current situation, and future direction of the application of endoscopy in salivary gland surgery.

Table and Figures | Reference | Related Articles | Metrics
Clinical decision and related factors influencing implant direction in the esthetic area
Liu Yuting, Yuan Quan.
West China Journal of Stomatology    2023, 41 (5): 512-520.   DOI: 10.7518/hxkq.2023.2023151
Abstract1962)   HTML65)    PDF(pc) (3643KB)(522)       Save

Implant treatment in the esthetic area requires stable osseointegration and successful esthetic outcomes. Achieving this goal requires careful consideration of accurate implant axis and ideal three-dimensional position. Owing to the high esthetics and the special anatomical structure of the maxillary, a successful implant means a synthesized deli-beration of the residual bone dimensions, soft-tissue thickness, and the relationship of the residual alveolar ridge with the planned restoration. This article offers an in-depth analysis of the clinical decisions and key factors affecting the implant direction in the esthetic area.

Table and Figures | Reference | Related Articles | Metrics
Dental implant treatment in vascularized bone flaps after jaw reconstruction
Shan Xiaofeng, Cai Zhigang.
West China Journal of Stomatology    2023, 41 (2): 123-128.   DOI: 10.7518/hxkq.2023.2023005
Abstract1860)   HTML369)    PDF(pc) (2172KB)(827)       Save

Jaw defects caused by various reasons often seriously affect appearance and function. The goal of the treatment of oral and maxillofacial tumors should include the cure of the tumor and the restoration of premorbid function. The development of microsurgery and digital surgery technology has promoted the development of jaw reconstruction with vascularized free bone flap. Good appearance and improved predictability could be obtained with the help of preope-rative visual design. How to rehabilitate occlusal function on the reconstructed jaw and improve the quality of life of patients has become an important research direction. This article discusses the challenge of jaw reconstruction, the selection of vascularized bone flap, the choice of implant timing, the treatment of peri-implant soft tissue, and the influence of radiotherapy on implants after jaw reconstruction.

Table and Figures | Reference | Related Articles | Metrics
Combined micro-apical surgery and vital pulp therapy in mandibular second molars with external root resorption caused by impacted teeth
Song Dongzhe, Luo Yu, Liu Xian, Hu Pei, Huang Dingming
West China Journal of Stomatology    2023, 41 (2): 225-231.   DOI: 10.7518/hxkq.2023.2022427
Abstract1856)   HTML73)    PDF(pc) (3082KB)(460)       Save

Objective This study aimed to establish a new treatment of the mandibular second molars with external root resorption caused by impacted teeth to preserve the affected teeth and their vital pulps. Methods For mandibular second molars clinically diagnosed as external root resorption caused by impacted teeth, debridement and removal of the root at the resorption site via micro-apical surgery and direct capping of the pulp with bioactive material on the surface of the root amputation via vital pulp therapy were performed immediately after the impacted teeth were extracted. Results The external root resorption of the affected tooth was ceased. It was asymptomatic with intact crown, normal pulp, periapical alveolar bone reconstruction, normal periodontal ligament, continuous bone sclerosis, and no periapical translucency in radiographic examination at the 1-year postoperative follow-up, thus showing good prognosis. Conclusion Simultaneous combination of micro-apical surgery and vital pulp therapy after extraction of impacted teeth could successfully preserve mandibular second molars with ERR caused by impacted teeth and their vital pulps.

Table and Figures | Reference | Related Articles | Metrics
Clinical solutions for natural abutments with preexisting defected crown margin in the aesthetic area
Liu Feng, Zhan Yalin, Liu Xinran.
West China Journal of Stomatology    2023, 41 (6): 641-646.   DOI: 10.7518/hxkq.2023.2023281
Abstract1637)   HTML25)    PDF(pc) (1512KB)(260)       Save

Crown replacement has remained one of the difficult methods for installing fixed prosthesis but is often performed because of aesthetic factors and invasion of biological width. This article focuses on the clinical scenario in which preexisting crown margin has defects. Given that clinical decisions regarding restoration management and perio-dontal tissues have to be made with caution, a decision tree of the decision making process for natural abutments in aesthetic area with preexisting defected crown margin is presented. The re-establishment of a new crown margin is the key to the success of a new restoration, and the new margin should be located at the proper esthetic position and right biological position. It should have fine, smooth, and continuous morphology.

Table and Figures | Reference | Related Articles | Metrics
Imaging analysis of 1 138 supernumerary teeth by using cone-beam computed tomography
Liu Xiaolin, Ren Qun, Bai Jiuping, Kang Pei, Ren Guiyun, Li Xiangjun, Feng Xiaowei.
West China Journal of Stomatology    2023, 41 (6): 671-677.   DOI: 10.7518/hxkq.2023.2023110
Abstract1636)   HTML7)    PDF(pc) (1273KB)(126)       Save

Objective This study aims to analyze and summarize the characteristics of supernumerary teeth by using cone-beam computed tomography (CBCT). Methods A total of 718 patients with 1 138 supernumerary teeth were retrospectively collected. Age, gender, number, location, morphology, eruption status, and accompanying symptoms of the supernumerary teeth were statistically analyzed. The relationship relative to jaws, gender, and eruption status were analyzed and discussed. Results The average age of the patients was 9.54±5.32 years, and the male to female ratio was 2.88∶1. About 77.02% of the patients sought medical advice during the mixed dentition period, and 50.70% had one supernumerary tooth. These supernumeraries were most commonly conical in shape, and 85.76% of them were in the incisor region, 92.09% in the upper jaw, 46.75% in inverted position, and 86.20% unerupted. Overall, 65.29% of them had fully developed roots, and 60.63% had an impact on adjacent structures. Significant differences were found in eruption status, morphology, zoning, direction, root development, and impact on adjacent structures between the supernumerary teeth located in the upper and lower jaws (P<0.05). Significant differences were also detected in gender, morphology, zoning, orientation, root development, and impact on adjacent structures between erupted and unerupted teeth (P<0.05). The incidence of supernumerary teeth in the incisor region was higher in males than that in females. Moreover, the root of supernumeraries was more completely developed in males than in females (P<0.05). Conclusion For supernumerary teeth, CBCT images can provide accurate three-dimensional radiographic data and are valuable for clinical diagnosis and treatment planning.

Table and Figures | Reference | Related Articles | Metrics
Correlation between differences in intraoperative jumping gaps and soft tissue changes around immediate implant placement and provisionalization in the maxillary anterior region
Zhang Sui, Sun Yi, Huang Changbo, He Dongning
West China Journal of Stomatology    2023, 41 (6): 678-685.   DOI: 10.7518/hxkq.2023.2023153
Abstract1576)   HTML18)    PDF(pc) (4373KB)(135)       Save

Objective This study aims to evaluate the correlation between differences in intraoperative jumping gaps and soft tissue changes around immediate implant placement and provisionalization (IIPP) in the maxillary anterior region. Results will provide a basis for clinical evaluation of the change trend and long-term stability of the labial soft tissue contours of patients with different jumping gaps. Methods Thirty-two patients with single tooth loss in the maxillary aesthetic area were enrolled, and they all received immediate implant placement and restoration. All patients were divided into three groups: A, B, and C according to the size of the jumping gap, group A: horizontal defect dimension (HDD) ≤2 mm; group B: 2 mm<HDD≤3 mm; group C: HDD>3 mm. Geomagic studio 2013 was used to quantitatively analyze the contour volume of the soft tissue around the implant and the level of the labial gingival margin. The pink esthetic score (PSE) was used for the final aesthetic evaluation. Results All implants had osseointegration within 6 months after the surgery. The average thickness of soft tissue contour volume changed by 0.62 mm±0.15 mm, and the average PES was 11.09±0.99. The changes in the gingival mucosa levels in the three groups at 6 months after operation were 0.45 mm±0.11 mm, 0.40 mm±0.12 mm, and 0.35 mm± 0.11 mm, respectively. The changes in the average thickness of the soft tissue contour volume in the three groups at 6 months after the operation were 0.77 mm±0.16 mm, 0.63 mm±0.17 mm, and 0.54 mm±0.11 mm. A moderate negative correlation was found between the jumping gap size and the gingival mucosa level, and the average thickness changed. No significant correlation was found between size of jumping gap and PES. Conclusion Although the contour volume of the labial soft tissue continuously decreased within 6 months after IIPP in the maxillary anterior region, the surgical procedure can achieve a satisfactory aesthetic effect, and the level of soft tissue around the implant can be well maintained.

Table and Figures | Reference | Related Articles | Metrics
Three-dimensional finite element stress analysis of surface-mounted inlays in repairing pulp-penetrating non-carious cervical lesion of maxillary first premolar
Ma Dian, Qian Jie.
West China Journal of Stomatology    2023, 41 (5): 541-553.   DOI: 10.7518/hxkq.2023.2023123
Abstract1522)   HTML21)    PDF(pc) (11226KB)(191)       Save

Objective This study aimed to explore the stress distribution of surface-mounted inlays with two ceramic materials and different strategies for fiber post-restoration on pulp-penetrating non-carious cervical lesion in a maxillary first premolar to provide minimally invasive and reasonable restorative methods. Methods The cone beam computed tomography data of the standard right upper first premolar were selected. Healthy control (HC) and defective control (DC) finite element models were established. Then, eight experimental models were established according to two different ceramic materials (IPS e.max CAD [LD] and Lava Ultimate [LU]) and different locations of fiber post (without fiber post [NP], fiber post in buccal root canal [B], fiber post in palatal root canal [P], fiber post in both root canals [BP]), namely, LDNP, LDB, LDP, LDBP, LUNP, LUB, LUP, and LUBP. Axial load F1 and lateral load F2 were applied. Maximum principal stress and displacement of the buccal tip were investigated using finite element analysis software. Then, the percentage change of the following indicators in each experimental group was analyzed: stress of defective tip with group DC, stress of enamel and dentine, and displacement of buccal tips with group HC. It was considered similar when the percentage change was less than 5%. Results LD and LU groups could effectively reduce the stress of the defective tip, but the decreasing amplitude in the former was greater than that of the latter. For the stress of surface-mounted inlays and resin adhesive layer, LD groups were higher than LU groups, and no significant difference in stress peak was found among different experimental groups in the same material. In addition, fiber posts in double root canals could significantly reduce buccal tip displacement. Conclusion For pulp-penetrating non-carious cervical lesions, the restorative strategy of surface-mounted inlays could be applied. Compared with Lava Ultimate, IPS e.max CAD could better protect the defective tip tooth. Furthermore, fiber posts in double root canals could decrease overall deformation and increase the retention of surface-mounted inlays.

Table and Figures | Reference | Related Articles | Metrics
The removal of three kinds of occlusal veneers by Er: Yag laser
Zhu Jianyu, Hong Feifei, He Lianghang, Wen Wei, Lei Xianlin, Zhang Zhisheng, Yin Lu
West China Journal of Stomatology    2023, 41 (5): 568-572.   DOI: 10.7518/hxkq.2023.2023038
Abstract1478)   HTML12)    PDF(pc) (1946KB)(87)       Save

Objective This study aimed to remove occlusal veneers of varied thicknesses and compositions by Er:Yag laser in vitro and analyze the interfacial microstructure between veneers and tooth that irradiated by laser, by which experimental evidence could be provided to support the non-invasive removal of occlusal veneerby laser. Methods Fresh mandibular premolars extracted for orthodontic requirements were collected for tooth preparation. Three kinds of ceramic materials (Vita Suprinity, Vita Mark Ⅱ, and Upcera Hyramic) were selected to fabricate occlusal veneer with different thicknesses (1.0, 1.5, and 2.0 mm). One week later, Er:Yag laser (2.5 W and 3.5 W) was used to irradiate and remove the occlusal veneer and recorded the timespan. After the removal operation, the micro-morphologies of samples were examined by scanning electron microscope. Results Upcera Hyramic veneer failed to be removed (>20 min); the operation span at 2.5 W, Vita Suprinity (96.0 s±16.0 s) was longer than Vita MarkⅡ(84.5 s±19.5 s) in the 1.0 mm group (P<0.05), and Vita Suprinity (246.5 s±13.5 s) was longer than Vita MarkⅡ(170.0 s±14.0 s) in the 1.5 mm group (P<0.05). At 3.5 W, Vita Suprinity (381.0 s±24.0 s) was longer than Vita MarkⅡ(341.5 s±26.5 s) in the 2.0 mm group. Conclusion Increasing laser power could shorten the operation span and facilitate the removal of occlusal veneers with the same thickness and composition. The occlusal veneer was sustained when insufficient laser power was applied. With the same laser power and ceramic thickness, laser penetration could interfere with the integral of the ceramic structure when the laser interacted with the bonding layer. With the same ceramic composition and laser power, the operation span and laser power increased with the thickness of the occlusal veneer. However, the laser was incapable of removing occlusal resin veneer directly.

Table and Figures | Reference | Related Articles | Metrics
Simultaneous implantation and tooth preparation technology guided by 3D-printed guide
Hu Nan, Liu Chunxu, Gao Jing, Xie Chenyang, Yu Jiayi, Jia Luming, Yu Haiyang.
West China Journal of Stomatology    2023, 41 (4): 483-490.   DOI: 10.7518/hxkq.2023.2022027
Abstract1467)   HTML11673)    PDF(pc) (5241KB)(547)       Save

Using digital technologies in concurrently performing missing tooth implantation and preparation of remaining teeth is a solution to reduce the number of visits and improve efficiency. This paper proposes a digital process for simultaneously implanting and preparing teeth. It integrates implant surgical guide and 3D-printed tooth preparation guide into a single guide and completes guided implant placement and precise tooth preparation. Based on “repair-oriented” virtual implant planning, the implant surgical guide can improve the efficiency and predictability of implant placement, and its linear accuracy is about 1 mm. The tooth preparation guide precisely guides tooth preparation and restoration space visualization, ensuring the quality of the tooth preparation. The two guides have different design accuracy requirements, and thus their combination improves the overall guiding accuracy requirements. The concurrent application of the two guides minimizes the clinical operation time, number of visits, and economic burden of patients.

Table and Figures | Reference | Related Articles | Metrics
Treatment strategies for periodontitis patients with systemic disease
Lin Li, Li Zhaorong, Jin Yining, Yin Shou-cheng.
West China Journal of Stomatology    2023, 41 (5): 502-511.   DOI: 10.7518/hxkq.2023.2023181
Abstract1439)   HTML414)    PDF(pc) (841KB)(356)       Save

Periodontitis is a chronic inflammatory disease that destroys the integrity of tooth-supporting tissue. Periodontitis is listed as a major oral disease by the World Health Organization and is a public-health problem affecting global oral and systemic health. The fourth national oral health epidemiological survey has revealed that periodontitis is one of the most common oral problems in China. With the development of science and medicine, increased attention is being paid to the importance of oral health and its influence on general health. Accordingly, stomatologists are required to master more relevant information on clinical diagnosis and treatment, as well as to pay more attention to the diagnosis and treatment methods of patients with different systemic diseases. This article expounds the diagnosis and treatment strategy of patients with systemic disease periodontitis. We aimed to help stomatologists make more reasonable diagnosis and treatment decisions.

Reference | Related Articles | Metrics
The infection control of post-and-core crown restoration
Huang Cui, Zhu Jiakang, Wang Qian
West China Journal of Stomatology    2023, 41 (3): 247-253.   DOI: 10.7518/hxkq.2023.2023030
Abstract1430)   HTML546)    PDF(pc) (800KB)(807)       Save

Post-and-core crown is one of the most common forms of restoration of tooth after root canal therapy (RCT). Infection control is the core objective of RCT, which is usually well realized by endodontists. However, many prosthodontists often neglect the infection control of the tooth and the maintenance of the curative effect of RCT during the process of post-and-core crown, which may lead to the failure of the final restoration. The concept of integrated crown-root treatment advocated recently requires clinicians to consider the RCT and final restoration as a whole, rather than simply divided into two parts—endodontic treatment and restorative treatment. As the core content of integrated crown-root treatment, infection control should be taken seriously by clinicians and implemented throughout the whole treatment process, especially in the restorative treatment that is easily overlooked after RCT. Therefore, this article describes the infection control of post-and-core crown restoration, classifies the tooth requiring post-and-core crown restoration, and puts forward the measures of infection control before and during post-and-core crown restoration, in order to provide reference and guidance for clinical practice.

Reference | Related Articles | Metrics
Feasibility analysis of digital method for measuring supracrestal tissue height crest around implant
Li Luxin, Liu Honghong, Chen Jia, Zhang Zhihong, Sang Xiao, Zhang Lili, Wang Yuantian.
West China Journal of Stomatology    2023, 41 (4): 426-433.   DOI: 10.7518/hxkq.2023.2023089
Abstract1290)   HTML28)    PDF(pc) (3333KB)(305)       Save

Objective This study aimed to investigate the feasibility of measuring the soft tissue height of bone cristae around implant by digital method. Methods A total of 36 patients with dental implants were selected from the Dental Medicine Center of the First Affiliated Hospital of University of Science and Technology of China (Anhui Provincial Hospital) from August 2022 to December 2022. A total of 43 dental implants were enrolled. All postoperative cone beam CT (CBCT) imaging data and intraoral digital impressions obtained before surgery were immediately obtained by the patients on the day of completion of oral implant surgery and they were imported into oral implant surgery planning software for image fitting. Then, virtual implants of the same specification were placed in the planting area, and the implant position was adjusted to overlap with the implant shadow in the CBCT image. Supracrestal tissue height (STH) was measured at the implant view interface (digital group). During the operation, implant holes were prepared step by step in accordance with the standard preparation method, and implants were implanted. The upper edge of the implant was flushed with the crest of the alveolar ridge. STH was measured by perio-dontal probing (periodontal probe group). Paired t-test was used to compare the STH differences between the digital and periodontal probe groups. Bland-Altman test was used to analyze the consistency of the two methods. Intra-group correlation coefficient (ICC) was used to verify the reliability of the results measured by different surveyors using di-gital methods. Results No statistical significance was observed in the STH difference between the two methods (P>0.05). Bland-Altman test showed good consistency between the two methods, but the measurement of mandibular posterior teeth showed that the results of periodontal probe were greater than those of digital method. The ICC and 95%CI of the STH results measured digitally by different surveyors are 0.992 (0.986-0.996). Conclusion The digital me-thod is in good agreement with the periodontal probe method in measuring the soft tissue height of the bone cristae around the implant.

Table and Figures | Reference | Related Articles | Metrics
Vital pulp therapy of permanent teeth with irreversible pulpitis
Wang Jun.
West China Journal of Stomatology    2023, 41 (6): 622-627.   DOI: 10.7518/hxkq.2023.2023193
Abstract1227)   HTML77)    PDF(pc) (738KB)(673)       Save

Traditionally, vital pulp therapy (VPT) is mainly indicated for young permanent teeth. However, in recent years, VPT has been increasingly applied to mature permanent teeth. VPT was previously thought to be effective only for teeth with normal pulp or reversible pulpitis. However, an increasing body of evidence has demonstrated that VPT can successfully manage permanent teeth with irreversible pulpitis or apical periodontitis. This work discusses which teeth with irreversible pulpitis or apical periodontitis are suitable for VPT, the recommended method to evaluate and select this kind of case, and the clinical procedure involved to operate such a case.

Reference | Related Articles | Metrics
Two-stage alveolar bone grafting for nasal floor reconstruction in adult cleft patients
Li Chenghao, Shi Bing.
West China Journal of Stomatology    2023, 41 (2): 129-133.   DOI: 10.7518/hxkq.2023.2022344
Abstract1189)   HTML296)    PDF(pc) (3518KB)(432)       Save

Alveolar cleft is one of the key links of cleft lip and palate reconstruction due to its close relationship with tooth and jaw coordination and nasolabial deformity. The alveolar bone graft repairs the hole in the gum ridge and stabilizes the bone arch, providing better support for the base of the nose and new bone for the roots of the developing teeth to grow into. Unfortunately, bone graft failure in the traditional way, even among minor clefts, bony hypoplasia, or absence that affects the nasal base and piriform rim, is common. Two-stage alveolar bone grafting, which has advantages in addressing the underlying skeleton and deficiency, could be an optional surgical procedure for nasal floor reconstruction in adult patients with a broad alveolar cleft.

Table and Figures | Reference | Related Articles | Metrics
Orthodontic program design based on aesthetic
Ma Yanning, Jin Zuolin.
West China Journal of Stomatology    2023, 41 (6): 628-634.   DOI: 10.7518/hxkq.2023.2023231
Abstract1168)   HTML37)    PDF(pc) (963KB)(236)       Save

Orthodontics is a discipline that is based on aesthetics. It coordinates the relationship among nose, lip, and chin through the movement of teeth and the adjustment of jaw relationship. Orthodontists need to fully analyze the patient’s soft tissue profile before treatment. They also need to analyze the existing problems and those that may be solved or caused during orthodontics to guide the design of orthodontic treatment and effectively improve the clinical effect of orthodontics. This article reviews the aesthetic preconditions that guide the design of orthodontic treatment from the perspective of orthodontists.

Reference | Related Articles | Metrics
Modified tragus edge incision and transmasseteric anteroparotid approach to condyle reconstruction
Tang Hui, Wang Lang, Wang Lei, Rao Pengcheng, Luo Daowen, Fu Guangxin, Xiao Jingang
West China Journal of Stomatology    2023, 41 (3): 290-296.   DOI: 10.7518/hxkq.2023.2022496
Abstract1160)   HTML13)    PDF(pc) (4789KB)(196)       Save

Objective This study aimed to analyze the application value of a modified tragus edge incision and transmasseteric anteroparotid approach to condyle reconstruction. Methods Condyle reconstruction was performed in 16 patients (9 females and 7 males) with modified tragus edge incision and transmasseteric anteroparotid approach. After regular follow-up, the function of condyle reconstruction was evaluated by clinical indicators, such as parotid salivary fistula, facial nerve function, mouth opening, occlusal relationship, and facial scar. The morphology of rib graft rib cartilage was evaluated by imaging indicators, such as panoramic radiography, CT, and three-dimensional CT image reconstruction. Results At 6-36 months postoperative follow-up, all patients had good recovery of facial appearance, concealed incisional scar, no parotid salivary fistula, good mouth opening, and occlusion. One case had temporary facial paralysis and recovered after treatment. Radiographic evaluation further showed that costochondral graft survived in normal anatomic locations. Conclusion The modified tragus edge incision and transmasseteric anteroparotid approach can effectively reduce parotid salivary fistula and facial nerve injury in condylar reconstruction. The surgical field was clearly exposed, and the incision scar was concealed without increasing the incidence of other complications. Thus, this approach is worthy of clinical promotion.

Table and Figures | Reference | Related Articles | Metrics
Effectiveness of iliac cancellous bone grafting in alveolar cleft repair and analysis of factors affecting it
Jing Bingshuai, Shi Bing, Zheng Qian, Li Chenghao.
West China Journal of Stomatology    2023, 41 (3): 284-289.   DOI: 10.7518/hxkq.2023.2022446
Abstract1129)   HTML93)    PDF(pc) (1607KB)(262)       Save

Objective To review the effectiveness of secondary alveolar bone grafting using iliac cancellous bone in patients with unilateral complete alveolar cleft and to investigate the factors influencing it. Methods A retrospective study of 160 patients with unilateral complete alveolar clefts who underwent iliac cancellous bone graft repair at the Department of Cleft Lip and Palate Surgery, West China Hospital of Stomatology, Sichuan University, was conducted. Eighty patients in the young age group (6-12 years) and 80 in the old age group (≥13 years) were included. Bone bridge formation was determined using Mimics software, and the volume was measured to calculate the iliac implantation rate, residual bone filling rate, and resorption rate. The factors that affected bone grafting in both subgroups were investigated. Results Using bone bridge formation as the clinical success criterion, the success rate for the entire population was 71.25%, with a significant difference of 78.75% and 63.75% for the young and old age groups, respectively (P=0.036). The gap volume in the latter was significantly larger than that in the former (P<0.001). The factors that influenced bone grafting in the young group were the palatal bone wall (P=0.006) and history of cleft palate surgery (P=0.012), but only the palatal bone wall affected the outcome in the old age group (P=0.036). Conclusion The results of alveolar bone grafting for the old age group were worse than those for the young age group. The palatal bone wall was an important factor that affected alveolar bone grafting, and alveolar bone grafting in the young patients was influenced by the history of cleft palate surgery.

Table and Figures | Reference | Related Articles | Metrics
One-year clinical observation of the effect of internal bleaching on pulpless discolored teeth
Peng Bibo, Huang Jialin, Wang Jian.
West China Journal of Stomatology    2023, 41 (2): 190-196.   DOI: 10.7518/hxkq.2023.2022349
Abstract1100)   HTML70)    PDF(pc) (1720KB)(333)       Save

Objective This study aimed to observe the color rebound and rebound rates of non-pulp discolored teeth within 1 year after routine internal bleaching to guide clinical practice and prompt prognosis. Methods In this work, the efficacy of bleaching was observed in 20 patients. The color of discolored teeth was measured by using a computerized colorimeter before bleaching; immediately after bleaching; and at the 1st, 3rd, 6th, 9th, and 12th months after bleaching. The L*, a*, and b* values of the color of cervical, mesial, and incisal parts of the teeth were obtained, and the color change amounts ΔE*, ΔL*, Δa*, and Δb* were calculated. The overall rebound rate (P*) and the color rebound velocity (V*) were also analyzed over time. Results In 20 patients following treatment, the average ΔE* of tooth color change was 14.99. After bleaching, the neck and middle of the teeth ΔE* and ΔL* decreased in the 1st, 3rd, 6th, 9th, and 12th months, and the differences were statistically significant. Meanwhile, from the 9th month after bleaching, the rebound speed was lower than that in the 1st month, and the difference was statistically significant. The incisal end of the tooth ΔE* and ΔL* decreased in the 6th, 9th, and 12th months after bleaching, and the differences were statistically significant. No significant difference was found in the rebound speed between time points. However, this rate settled after the 9th month, with an average color rebound rate of 30.11% in 20 patients. Conclusion The results indicated that internal bleaching could cause a noticeable color change on pulpless teeth. The color rebound after bleaching was mainly caused by lightness (L*), which gradually decreased with time, and it was slightly related to a* and b*. The color of the teeth after internal bleaching rebounded to a certain extent with time, but the color rebound speed became stable from the 9th month. Clinically, secondary internal bleaching can be considered at this time according to whether the colors of the affected tooth and the adjacent tooth are coordinated and depending on the patient’s needs.

Table and Figures | Reference | Related Articles | Metrics
Dental erosion caused by glucocorticoid therapy in a patient with optic neuritis: a case report
Shang Mengyao, Wei Yuqi, Yu Meijiao, Zhang Jin, Cui Pingping.
West China Journal of Stomatology    2023, 41 (2): 243-246.   DOI: 10.7518/hxkq.2023.2022373
Abstract1051)   HTML63)    PDF(pc) (1686KB)(223)       Save

Dental erosion is characterized by progressively destroyed teeth, which has no relation to bacteria but to chemicals. Some internal factors, such as gastroesophageal reflux induced by bulimia, anorexia, gastrointestinal diseases, or drugs, and external factors, such as diet, drugs, and occupational acid exposure, are considered promotive factors for this disease. This article presents a patient suffering from severe dental erosion in the whole dentition, especially in the maxillary teeth, due to gastroesophageal reflux induced by glucocorticoid therapy for optic neuritis. This article discusses the mechanism between optic neuritis glucocorticoid therapy and dental erosion.

Table and Figures | Reference | Related Articles | Metrics
Structural design of gradient porous dental implant based on orthogonal test
Wang Liangtao, Li Shan, Lu Doudou, Chen Zheng.
West China Journal of Stomatology    2023, 41 (6): 647-652.   DOI: 10.7518/hxkq.2023.2023188
Abstract758)   HTML9)    PDF(pc) (1339KB)(46)       Save

Objective To solve the current problems of loosening and dislodging caused by the high elastic modulus of solid implants, we attempted to study a gradient porous dental implant that can lower the stress concentration and reduce the elastic modulus. Methods SolidWorks software was utilized to design the abutment and mechanical structure of the gradient porous implant. The mechanical properties of the gradient porous implant were evaluated by an orthogonal experimental design from four aspects: pore shape, pore diameter, porous layer height, and circumferential distribution. ANSYS software was used to evaluate the distribution of Von-Mises stress in the implant and its surrounding bone tissues under different structural combination parameters to derive the optimal combination of gradient porous implant parameters. Results The effects of the four factors, namely, pore shape, pore diameter, porous layer height and pore distribution, on the maximum Von-Mises stress on the implant were as follows. As the pore shape became smaller and the circumferential distribution decreased, the Von-Mises stress decreased significantly. The pore diameter went from 500 μm to 600 μm and then to 700 μm. The Von-Mises stress decreased and then increased. It increased with the increase in the height of the porous layer. Conclusion The final optimal combination of parameters for the gradient porous implant was as follows: square pore shape, pore diameter of 600 μm, porous layer height of 3 mm, and quadratic step in pore distribution.

Table and Figures | Reference | Related Articles | Metrics
Audit to assess the quality of 916 prosthetic prescriptions of removable partial dentures
Zhang Na, Mao Bochun, Dai Yunhan, Chen Shengkai, You Ziying, Zhang Junjing, Chen Xin, Dong Haoyue, Yue Li, Yu Haiyang
West China Journal of Stomatology    2023, 41 (3): 315-322.   DOI: 10.7518/hxkq.2023.2021565
Abstract729)   HTML26)    PDF(pc) (2021KB)(201)       Save

Objective The objectives of this study were to assess the quality of prosthetic prescriptions of removable partial dentures (RPDs) and to analyze the current situation of the communication and information delivery between clinicians and technicians. Methods All RPD prosthetic prescriptions received by a major dental laboratory in 4 weeks were involved in a quality audit, and the prescriptions were divided into three groups in accordance with the grades of clients. The filling of prosthetic prescriptions was recorded. The items in the prescriptions for audit included the general information of the patient, the general information of the clinician, the design diagram information, other detailed information, and the return date. The prescriptions were categorized into four levels on the basis of their quality by two quality inspectors who have been working for more than 10 years. Results A total of 916 prescriptions were collected and assessed. The names in the general information of the patient and the clinician were filled out best, both at the rate of 97.6% (n=894). The return date was filled out worst, only at the rate of 6.4% (n=59). Of those prescriptions, 86.8% (n=795) exhibited inadequate design diagram information. The results of the quality assessment demonstrated that 74.2% of prescriptions were assessed as noncompliant ones and failed to meet the acceptable clinical quality standard. Conclusion At present, the overall quality of RPD prosthetic prescriptions is poor. The responsibilities of clinicians and technicians are unclear, and the communication between them is not ideal.

Table and Figures | Reference | Related Articles | Metrics
Malignant peripheral nerve sheath tumor of tongue: a case report
Liu Yibo, Wu Di, Lun Xiaohan, Dai Wei.
West China Journal of Stomatology    2023, 41 (3): 361-364.   DOI: 10.7518/hxkq.2023.2022402
Abstract670)   HTML106)    PDF(pc) (1642KB)(312)       Save

Malignant peripheral nerve sheath tumor (MPNST) is a rare neurogenic malignant tumor. MPNST has aty-pical clinical symptoms and imaging presentations, difficult diagnosis, a high degree of malignancy, and poor prognosis. It usually occurs in the trunk, approximately 20% in the head and neck, and rarely in the mouth. This paper reports a case of MPNST of the tongue. A summary of the clinical features, diagnosis, and treatment of MPNST is presented in combination with a literature review to provide a reference for the diagnosis and treatment of this disease.

Table and Figures | Reference | Related Articles | Metrics
Prediction model of dental caries in 12-year-old children in Sichuan Province based on machine learning
Yan Xinmiao, Sun Taolan, Lu Yuhang, Tan Xin, Wang Zhuo, Li Miaojing
West China Journal of Stomatology    2023, 41 (6): 686-693.   DOI: 10.7518/hxkq.2023.2023124
Abstract658)   HTML7)    PDF(pc) (919KB)(90)       Save

Objective The machine learning algorithm was used to construct a prediction model of children’s dental caries to determine the risk factors of dental caries in children and put forward targeted measures and policy suggestions to improve children’s oral health. Methods Stratified cluster random sampling was adopted in this study. In accordance with different policies and measures in Sichuan Province, 12-year-old students from 3-4 middle schools in eight cities of Sichuan Province were randomly selected for questionnaire survey, oral examination, and physical examination. Multivariate logistic regression analysis of risk factors for dental caries in 12-year-old children was conducted. The dataset was randomly divided into training set and validation set at a ratio of 7∶3. Four machine learning algorithms, including random forest, decision tree, extreme gradient boosting (XGBoost), and Logistic regression, were constructed using R version 4.1.1, and the prediction effects of the four prediction models were evaluated using the area under receiver operating characteristic curve (AUC). Results A total of 4 439 children aged 12 years were included in this study. The incidence of permanent teeth caries was 50.93%. The results of multivariate logistic regression analysis showed that body mass index, highest educational background of the father, highest educational background of the mother, whether to brush teeth, how many times a day, use of toothpaste when brushing teeth, duration of brushing teeth, mouthwash after meals, eating before going to bed after brushing teeth, sweet drinks, snacks, going to dental clinic to examine teeth, and age of brushing teeth were the factors influencing children’s dental caries (P<0.05). The AUC values predicted by random forest, decision tree, Logistic regression, and XGBoost were 0.840, 0.755, 0.799, and 0.794, respectively. In the random forest model, the variable with the highest contribution was eating before bed after brushing. Conclusion A prediction model of dental caries in children was established on the basis of random forest, showing good prediction effect. Taking preventive measures for the main factors affecting the occurrence of dental caries in children is beneficial.

Table and Figures | Reference | Related Articles | Metrics
Three-dimensional finite element study of mandibular first molar distalization with clear aligner
Kang Fujia, Yu Lei, Zhang Qi, Li Xinpeng, Hu Zhiqiang, Zhu Xianchun.
West China Journal of Stomatology    2023, 41 (4): 405-413.   DOI: 10.7518/hxkq.2023.2023021
Abstract591)   HTML20)    PDF(pc) (3762KB)(389)       Save

Objective This study aimed to construct the finite element model of the mandibular first molar with the invisible appliance and explore the dentition movement characteristics of the mandibular first molar when using micro-implant anchorage and different initial positions of the first molar. Methods Models of the mandible, tooth, periodontal membrane, and invisible appliance were constructed using cone beam computed tomography (CBCT) data. The two groups were divided into the non-anchorage group and the micro-implant group (between the roots of the first molar and the second molar) based on whether the elastic traction of the micro-implant was assisted or not. The two groups were divided into the following conditions based on the starting position of the first molar: Working condition 1: the distance between the first molar and the second premolar was 0 mm; working condition 2: the distance between the first molar and the second premolar was 1 mm; working condition 3: the distance between the first molar and the second premolar was 2 mm; working condition 4: the distance between the first molar and the second premolar was 3 mm. The data characte-ristics of total displacement and displacement in each direction of dentition were analyzed. Results In the non-ancho-rage group, all the other teeth showed reverse movement except for the first molar which was moved distally. Meanwhile, in the micro-implant group, except for a small amount of mesial movement of the second molar in wor-king condition 1, the whole dentition in other working conditions presented distal movement and anterior teeth showed lingual movement, among which the distal displacement of the first molar in working condition 4 was the largest. With the change of the initial position of the first molar to the distal, the movement of the first molar to the distal, the premolar to the mesial, and the anterior to the lip increased, while the movement of the second molar to the mesial decreased. Conclusion The micro-implant can effectively protect the anterior anchorage, increase the expression rate of molar distancing, and avoid the round-trip movement of the second molar. The initial position of the first molar movement is related to the amount of distancing and the remaining tooth movement.

Table and Figures | Reference | Related Articles | Metrics
Study on the effect of chin morphology on orthodontic treatment
Fu Yu, Li Ziwei, Zhao Menghan, Shi Ruixin.
West China Journal of Stomatology    2023, 41 (4): 443-449.   DOI: 10.7518/hxkq.2023.2022508
Abstract550)   HTML21)    PDF(pc) (1224KB)(240)       Save

Objective To investigate the effect of different soft-tissue morphologies on the treatment of skeletal class Ⅰ malocclusion patients by analyzing measurement data before and after treatment. Methods Pre- and post-treatment lateral cephalograms of 55 adult female Angle class Ⅰ patients were collected in the Department of Orthodontics, Hospital of Stomatology, Jilin University from January 2012 to December 2020. Chin soft-tissue morphologies in the lateral cranial radiographs were used to divide the patients into an abnormal chin morphology group (flat and retracted chins, n=27) and a normal chin morphology group (rounded and prominent chins, n=28). Relevant soft- and hard-tissue indexes were selected to study in-group varieties and intergroup differences in the varying chin morphologies before and after treatment. Results The chin-lip angle, mandibular chin angle, mandibular chin vertex angle, PP-MP, LL-E, UL-E, Po-Pos, and B-B’ thickness in the abnormal chin morphology group were significantly higher than those in the normal chin morphology group (P<0.05). Furthermore, m∶BMe and n∶B’Mes in the abnormal chin morphology group were signi-ficantly lower than those in the normal chin morphology group (P<0.05). After treatment, the mandibular chin angle, mandibular chin vertex angle, U1-SN, L1-MP, LL-E, UL-E, SNA, SNB, and B-B’ thickness of the abnormal chin morphology group significantly decreased (P<0.05), whereas the nasolabial angle, m∶BMe, n∶B’ Mes, and Po-Pos significantly increased (P<0.05). In the normal chin morphology group, the U1-SN, L1-MP, LL-E, UL-E, and B-B’ thicknesses decreased significantly (P<0.05), whereas the nasolabial angle significantly increased (P<0.05). Among them, m∶BMe and n∶B’ Mes were positively correlated. Conclusion Chin morphology affects the formulation of treatment plans. Compared with the normal chin morphology group, the abnormal chin morphology group required a larger retraction of incisors. Although the chin of soft-tissue morphology is related to the morphology of bones, the changes in soft tissue chin after treatment cannot be directly predicted according to the bone changes. Soft-tissue chin morphology affects the aesthetic assessment of the soft-tissue lateral profile and the change in soft tissue before and after treatment. The method of predicting the change in soft-tissue chin after treatment should consider the morphology of the soft-tissue chin.

Table and Figures | Reference | Related Articles | Metrics
Personal understanding of the extraction or rescue on severe periodontitis teeth
Wang Qintao, Ma Zhiwei, Wang Jinjin.
West China Journal of Stomatology    2023, 41 (6): 635-640.   DOI: 10.7518/hxkq.2023.2023274
Abstract530)   HTML51)    PDF(pc) (2810KB)(356)       Save

To keep or extract severe periodontitis damaged teeth is one of the controversial topics in the dentistry from ancient times to present. From different perspectives, professions, technologies, time, and economics, there may be different choices with unidentified consensus. Based on the author’s own understanding, experience, literature review, and other aspects, this article proposes some exchange views on influencing factors, abandoning consideration, preserving possibility, and how to detect and prevent the development of lesions. The aim is to stimulate more thinking and accumulate clinical evidence-based data among peers, in order to facilitate cooperation and promote oral health.

Table and Figures | Reference | Related Articles | Metrics
Root canal treatment of type Ⅱ and ⅢA double dens invaginatus in maxillary lateral incisor: a case report
Li Chengxi, Song Weijian.
West China Journal of Stomatology    2023, 41 (2): 232-236.   DOI: 10.7518/hxkq.2023.2022390
Abstract486)   HTML68)    PDF(pc) (3512KB)(361)       Save

Dens invaginatus is a rare developmental anomaly of the teeth that is caused by the infolding of enamel organs or the penetration of their proliferations into dental papillae before calcification has occurred. The presence of double dens invaginatus is extremely rare. This paper describes the use of cone beam computed tomography in the evaluation of a maxillary lateral incisor with double dens invaginatus and periapical periodontitis. The tooth was treated through microscopic root canal therapy. The tooth was free of clinical symptoms, and the periradicular lesion narrowed during the follow-up period of 1 year.

Table and Figures | Reference | Related Articles | Metrics
Study on the mechanism of curcumin in the treatment of periodontitis through network pharmacology and mole-cular docking
Yang Jingmei, Zhou Ziliang, Wu Yafei, Nie Min
West China Journal of Stomatology    2023, 41 (2): 157-164.   DOI: 10.7518/hxkq.2023.2022370
Abstract471)   HTML48)    PDF(pc) (3930KB)(446)       Save

Objective This study aims to explore the therapeutic targets of curcumin in periodontitis through network pharmacology and molecular docking technology. Methods Targets of curcumin and periodontitis were predicted by different databases, and the protein-protein interaction (PPI) network constructed by String revealed the interaction between curcumin and periodontitis. The key target genes were screened for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Molecular docking was performed to analyze the binding potential of curcumin to periodontitis. Results A total of 672 periodontitis-related disease targets and 107 curcumin-acting targets were obtained from the databases, and 20 key targets were screened. The GO and KEGG analyses of the 20 targets showed that curcumin might play a therapeutic role through the hypoxia-inducible factor (HIF)-1 and parathyroid hormone (PTH) signaling pathways. Molecular docking analysis showed that curcumin had good binding potential with multiple targets. Conclusion The potential key targets and molecular mechanisms of curcumin in treating periodontitis provide a theoretical basis for new drug development and clinical applications.

Table and Figures | Reference | Related Articles | Metrics
Prediction of pulp exposure risk of carious pulpitis based on deep learning
Wang Li, Wu Fei, Xiao Mo, Chen Yu-xin, Wu Ligeng
West China Journal of Stomatology    2023, 41 (2): 218-224.   DOI: 10.7518/gjkq.2023.2022418
Abstract452)   HTML72)    PDF(pc) (1388KB)(416)       Save

Objective This study aims to predict the risk of deep caries exposure in radiographic images based on the convolutional neural network model, compare the prediction results of the network model with those of senior dentists, evaluate the performance of the model for teaching and training stomatological students and young dentists, and assist dentists to clarify treatment plans and conduct good doctor-patient communication before surgery. Methods A total of 206 cases of pulpitis caused by deep caries were selected from the Department of Stomatological Hospital of Tianjin Medical University from 2019 to 2022. According to the inclusion and exclusion criteria, 104 cases of pulpitis were exposed during the decaying preparation period and 102 cases of pulpitis were not exposed. The 206 radiographic images collected were randomly divided into three groups according to the proportion: 126 radiographic images in the training set, 40 radiographic images in the validation set, and 40 radiographic images in the test set. Three convolutional neural networks, visual geometry group network (VGG), residual network (ResNet), and dense convolutional network (DenseNet) were selected to analyze the rules of the radiographic images in the training set. The radiographic images of the validation set were used to adjust the super parameters of the network. Finally, 40 radiographic images of the test set were used to evaluate the performance of the three network models. A senior dentist specializing in dental pulp was selected to predict whether the deep caries of 40 radiographic images in the test set were exposed. The gold standard is whether the pulp is exposed after decaying the prepared hole during the clinical operation. The prediction effect of the three network models (VGG, ResNet, and DenseNet) and the senior dentist on the pulp exposure of 40 radiographic images in the test set were compared using receiver operating characteristic (ROC) curve, area under the ROC curve (AUC), accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score to select the best network model. Results The best network model was DenseNet model, with AUC of 0.97. The AUC values of the ResNet model, VGG model, and the senior dentist were 0.89, 0.78, and 0.87, respectively. Accuracy was not statistically different between the senior dentist (0.850) and the DenseNet model (0.850)(P>0.05). Kappa consistency test showed moderate reliability (Kappa=0.6>0.4, P<0.05). Conclusion Among the three convolutional neural network models, the DenseNet model has the best predictive effect on whether deep caries are exposed in imaging. The predictive effect of this model is equivalent to the level of senior dentists specializing in dental pulp.

Table and Figures | Reference | Related Articles | Metrics
Diagnosis and treatment of apical cyst of deciduous teeth with infection: a case report
Zhang Yue, Liu Xiaowen, Yang Ran
West China Journal of Stomatology    2023, 41 (3): 356-360.   DOI: 10.7518/hxkq.2023.2022428
Abstract447)   HTML42)    PDF(pc) (2822KB)(405)       Save

There is a high incidence of chronic periapical periodontitis of deciduous teeth, however, there is a low incidence of the apical cyst. This paper reports a 7-year-old child with deciduous periodontitis caused by chronic periapical periodontitis of deciduous teeth. Through literature review, the etiology, imaging characteristics, diagnosis, differential diagnosis, and treatment methods were discussed to provide the basis for clinical diagnosis and treatment.

Table and Figures | Reference | Related Articles | Metrics
Mandibular advancement with clear aligners and functional appliances in the treatment of skeletal ClassⅡmalocclusion: a systematic review and meta-analysis
Yu Lei, Li Ziwei, Kang Fujia, Wang Songqing, Xie Zunxuan, Zhu Xianchun.
West China Journal of Stomatology    2023, 41 (3): 305-314.   DOI: 10.7518/hxkq.2023.2022453
Abstract431)   HTML51)    PDF(pc) (6910KB)(589)       Save

Objective This study aimed to conduct a meta-analysis of the efficacy of mandibular advance clear alig-ners with traditional functional appliances as the control group. Methods PubMed, Web of Science, Embase, Cochrane Library, China Biomedical Abstracts Database, China Knowledge Network Database, Wanfang Database, and Weipu Database were used in this study. The two groups of researchers screened the literature and extracted data based on the inclusion and exclusion criteria established by PICOS entries, and used the ROBINS-I scale for quality evaluation. Revman 5.4 and Stata 17.0 software were used for meta-analysis. Results Nine clinical controlled trials were included in this study with a total sample size of 283 cases. No significant difference was found in SNA, SNB, ANB, Go-Pog, U1-SN, Overjet, and other aspects between the invisible group and the traditional group in the treatment of skeletal class Ⅱ ma-locclusion patients; there was a 0.90° difference in mandibular plane angle between the two groups; the growth of the mandibular ramus (Co-Go) in the traditional group was 1.10 mm more than that in the invisible group; the lip inclination of the lower teeth in the invisible group was better controlled, 1.94° less than that in the control group. Conclusion The invisible group can better control the lip inclination of the mandibular anterior teeth when guiding the mandible. Furthermore, the mandibular plane angle (MP-SN) can remain unchanged, but the growth of the mandibular ramus is not as good as the traditional group, and auxiliary measures should be taken to improve it in clinical practice.

Table and Figures | Reference | Related Articles | Metrics
Clinical decision making of implant guidance methods guided by new classification of surgical area mouth ope-ning
Yu Haiyang, Wu Jiacheng, Hu Nan.
West China Journal of Stomatology    2023, 41 (2): 134-139.   DOI: 10.7518/hxkq.2023.2022386
Abstract428)   HTML212)    PDF(pc) (2172KB)(338)       Save

When selecting implant guidance methods or judging whether the patient can be implanted, many doctors ignore or only use visual inspection to estimate a patient’s mouth opening. This phenomenon often leads to failure to complete the implantation due to insufficient mouth opening or the deflection of the implant due to limited angle, resulting in the high incidence of corresponding complications. The main reason is that doctors lack accurate analysis and control of the overall geometric conditions of the intraoral surgical area, and three-dimensional position blocking of surgical instruments occurs during the operation. In the past, mouth opening was defined as the distance between the incisor edges of the upper and lower central incisors when the patient opens his mouth widely, and the implant area could be in any missing tooth position. When it is in the posterior tooth area, the specific measurement scheme of the mouth opening could not be simply equivalent to the previous measurement method in the anterior tooth area. However, how to measure quickly and conveniently the mouth opening of any surgical area to determine whether it could be implanted and meet the needs of the selected guidance method remains unclear. This paper introduces new concepts, establishes new classification and corresponding accurate measurement scheme of implant area, and establishes a decision tree of implant methods guided by the actually measured value. Results provide a quantitative basis for rational formulation and implementation of implant treatment.

Table and Figures | Reference | Related Articles | Metrics
Clinical and imaging features of eight cases of Ewing sarcoma of the jaw
Feng Yinglian, Wang Tiemei, Lin Zitong, Zhang Lei, Huang Xiaofeng, Sun Guowen, Xia Shu
West China Journal of Stomatology    2023, 41 (2): 185-189.   DOI: 10.7518/hxkq.2023.2022325
Abstract424)   HTML54)    PDF(pc) (2343KB)(219)       Save

Objective This study investigate the clinical and imaging features of Ewing sarcoma (ES) of the jaw. Methods Eight cases of pathologically diagnosed ES of the jaw from January 2010 to June 2022 were included in the study. Clinical and radiological features were retrospectively analyzed. Results Among the eight cases, the mean age at onset was 29.4 years, and the male to female ratio was 7∶1. The predilecting site was the posterior part of mandible, accounting for 75% of the cases. The lesions often exhibited early numbness of the lower lip and lymphadenopathy. The main radiographic manifestation of mandibular lesions was ill-defined radiolucency, mixed with fibrous or brush-like tumor matrix, and soft tissue mass. The maxillary ES lesions mainly presented as lytic bone destruction accompanied by adjacent soft tissue mass. Periosteal ossification was rarely seen. Conclusion The clinical and imaging characteristics of ES in the jaw are helpful for its diagnosis.

Table and Figures | Reference | Related Articles | Metrics
A comparative study based on the mandibular movement track and the movement parameters of the virtual articulator in simulating occlusal adjustment
Ma Liya, Chao Jiarui, Liu Fei, Mei Jiansong, Shen Jiefei.
West China Journal of Stomatology    2023, 41 (3): 254-259.   DOI: 10.7518/hxkq.2023.2022452
Abstract409)   HTML617)    PDF(pc) (2687KB)(285)       Save

Objective This study aimed to compare the effects of virtual adjustment on occlusal interferences in mandibular posterior single crown and three-unit bridge restorations by using the mandibular movement track and the movement parameters of a virtual articulator. Methods Twenty-two participants were recruited. Digital casts of the maxillary and mandibular arches were obtained using an intraoral scanner, and the jaw registration system was used to record the data of the mandibular movement track and the movement parameters of the articulator. Four kinds of restorations with 0.3 mm occlusal interferences were designed with dental design software. In particular, single crowns were designed for teeth 44 and 46, whereas three-unit bridges were designed for teeth 44-46 and 45-47, and the corresponding natural teeth were virtually extracted. Virtual adjustment of the restorations was performed using two dynamic occlusal recordings, namely, the mandibular movement track and the movement parameters of the virtual articulator. A reverse-engineering software was used to measure the root-mean-square of the three-dimensional deviation of the occlusal surfaces between natural teeth and the adjusted restorations. The differences between the two methods of virtual-occlusion adjustment were compared and analyzed. Results For the same group of restorations, the three-dimensional deviation of the mandibular movement track group were lower than those of the virtual articulator group, and the differences were statistically significant (P<0.05). For the four groups of restorations adjusted by the same method, the three-dimensional deviation of the 46-tooth single crown was the largest and the smallest three-dimensional deviation was that of the 44-tooth single crown. Statistical differences existed between the 44-tooth single crown and the other groups (P<0.05). Conclusion For the occlusal design of posterior single crown and three-unit bridge, the mandibular movement track could be a more effective approach to virtual occlusal adjustment than the movement parameters of the virtual articulator.

Table and Figures | Reference | Related Articles | Metrics
Imaging study on the relationship between anterior and posterior occlusal planes and temporomandibular osteoarthrosis
Zhong Jiawei, Fan Peidi, Hu Shoushan, Gao Xinlin, Li Yijun, Wang Jun, Xiong Xin.
West China Journal of Stomatology    2023, 41 (3): 297-304.   DOI: 10.7518/hxkq.2023.2023032
Abstract407)   HTML99)    PDF(pc) (2509KB)(324)       Save

Objective The aim of this study was to compare the anterior and posterior occlusal plane characteristics of patients with different temporomandibular joint osseous statuses. Methods A total of 306 patients with initial cone beam CT (CBCT) and cephalograms were included. They were divided into three groups on the basis of their temporomandibular joint osseous status: bilateral normal (BN) group, indeterminate for osteoarthrosis (I) group, and osteoarthrosis (OA) group. The anterior and posterior occlusal planes (AOP and POP) of the different groups were compared. Then, the regression equation was established after adjusting for confounding factors, and a correlation analysis between the occlusion planes and other parameters was performed. Results SNA, SNB, FMA, SN-MP, Ar-Go, and S-Go were correlated with the occlusal planes. Relative to the BN and I groups, the FH-OP of the OA group increased by 1.67° on the average, FH-POP increased by 1.42° on the average, and FH-AOP increased by 2.05° on the average. Conclusion The occlusal planes were steeper in the patients with temporomandibular osteoarthrosis than in the patients without it, and the mandible rotated downward and backward. The height of the mandibular ramus, the mandibular body length, and the posterior face height were small. In clinical practice, attention should be given to the potential risk of temporomandibular joint osteoarthrosis in such patients. In addition, SNB, FMA, SN-MP, Ar-Go, S-Go, and occlusal planes had moderate correlations.

Table and Figures | Reference | Related Articles | Metrics
Effect of dental follicles in minimally invasive open-eruption technique of labially impacted maxillary central incisors
Huang Jiayue, Liu Xian, Wang Yan, Bao Chongyun.
West China Journal of Stomatology    2023, 41 (2): 197-202.   DOI: 10.7518/hxkq.2023.2022413
Abstract399)   HTML68)    PDF(pc) (2475KB)(341)       Save

Objective To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles. Methods Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy. Results A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05). Conclusion In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.

Table and Figures | Reference | Related Articles | Metrics
Analysis of congenital deciduous teeth absence and its permanent teeth phenotype
Qiu Fenfang, Tang Zichun, Meng Shan
West China Journal of Stomatology    2023, 41 (2): 203-207.   DOI: 10.7518/hxkq.2023.2021639
Abstract394)   HTML55)    PDF(pc) (1691KB)(260)       Save

Objective This study aimed to investigate the clinical characteristics of congenital deciduous teeth absence and its permanent teeth performance type by using panoramic radiographs. Methods A total of 15 749 panora-mic radiographs of 3-6-year-old children with deciduous dentition were collected from January 2020 to December 2021. The incidence of congenital deciduous teeth absence was observed, and the abnormality of permanent teeth was recor-ded. SPSS 24.0 software was used for statistical analysis. Results The incidence of congenital deciduous teeth absence was 2.54% (400/15 749), which was found in 217 girls and 183 boys, and the difference between the genders was statistically significant (P=0.003). The absence of one and two deciduous teeth accounted for 99.75% (399/400) of the subjects. In addition, 92.63% (490/529) of mandibular deciduous lateral incisor was congenitally absent, 44.80% (237/529) of deciduous teeth was absent in the left jaw, and less than 55.20% (292/529) was absent in the right; the difference between them was statistically significant (P=0.017). The absence of 96.41% (510/529) deciduous teeth in the mandibular was significantly more than that of 3.59% (19/529) in the maxillary, and the difference between was statistically significant (P=0.000). Furthermore, 68.00% (272/400) and 32.00% (128/400) of deciduous teeth were absent in unilateral and bilateral, respectively, and the difference was statistically significant (P=0.000). Four types of congenital deciduous teeth absence with permanent teeth were observed as follows: 1) 73.91% (391/529) of permanent teeth was absent; 2) 20.60% (109/529) of permanent teeth was not absent; 3) the number of fused permanent teeth accounted for 4.91% (26/529); 4) the number of supernumerary teeth was 0.57% (3/529). Conclusion Although the absence of congenital deciduous teeth is less common than that of permanent teeth, it affects deciduous and permanent teeth to some extent. Dentists should pay attention to trace and observe whether abnormalities are present in the permanent teeth and take timely measures to maintain children’s oral health.

Table and Figures | Reference | Related Articles | Metrics