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Table of Content
01 August 2023, Volume 41 Issue 4
  • 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
    Abstract ( 5282 )   HTML ( 214 )   PDF(pc) (7679KB) ( 561 )   Save
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    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.

    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
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    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.

    Basic Research
    Liver macrophages show an immunotolerance phenotype in nonalcoholic fatty liver combined with Porphyromonas gingivalis-lipopolysaccharide infection
    Guo Lijia, Liu Yitong, Chen Yingyi, Xu Junji, Liu Yi
    West China Journal of Stomatology. 2023, 41(4):  385-394.  doi:10.7518/hxkq.2023.2023111
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    Objective This study aimed to explore the functions and potential regulatory targets of local macrophages in nonalcoholic fatty liver combined with Porphyromonas gingivalis (P. gingivalis)infection. Methods Single-cell RNA sequencing was used to analyze the phenotypes and functional changes in various cells in the liver tissue of nonalcoholic steatohepatitis (NASH) mice fed with P. gingivalis. Real-time polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay, and immunofluorescence staining were applied to observe the inflammation and expression levels of macrophage antigen presenting functional markers in the NASH liver. Oil red staining was performed to observe the accumulation of local adipose tissue in the NASH liver. Results were verified through RT-PCRand RNA sequencing using P. gingivalis-lipopolysaccharide treated mouse peritoneal macrophages. Results In comparison with healthy livers with Kupffer cells, the NASH liver combined with P. gingivalis infection-related macrophages showed significant heterogeneity. C1qb, C1qc, Mafb, Apoe, and Cd14 were highly expressed, but Cd209a, H2-Aa, H2-Ab1, and H2-DMb1, which are related to the antigen presentation function, were weakly expressed. Further in vivo and in vitro investigations indicated that the activation and infiltration of these macrophages may be due to local P. gingivalis-lipopolysaccharide accumulation. Conclusion P. gingivalis-lipopolysaccharide induces a local macrophage immunotolerance phenotype in nonalcoholic fatty liver, which may be the key mechanism of periodontitis pathogen infection that promotes NASH inflammation and pathogenesis. This study further clarifies the dysfunction and regulatory mechanisms of macrophages in the pathogenesis of P. gingivalis-infected NASH, thereby providing potential therapeutic targets for its clinical treatment.

    Effect of glycosaminoglycans with different degrees of sulfation on chondrogenesis
    Zheng Wen, Cai Ming-xiang, Peng Huizhen, Liu Minyi, Liu Xiangning
    West China Journal of Stomatology. 2023, 41(4):  395-404.  doi:10.7518/hxkq.2023.2023055
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    Objective This study aims to investigate the effects and mechanisms of chondroitin sulfate (CS), dermatan sulfate (DS), and heparin (HEP) on chondrogenesis of murine chondrogenic cell line (ATDC5) cells and the maintenance of murine articular cartilage in vitro. Methods ATDC5 and articular cartilage tissue explant were cultured in the medium containing different sulfated glycosaminoglycans. Cell proliferation, differentiation, cartilage formation, and mechanism were observed using cell proliferation assay, Alcian blue staining, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blot, respectively. Results Results showed that HEP and DS primarily activated the bone morphogenetic protein (BMP) signal pathway, while CS primarily activated the protein kinase B (AKT) signal pathway, further promoted ATDC5 cell proliferation and matrix production, and increased Sox9, Col2a1, and Aggrecan expression. Conclusion This study investigated the differences and mechanisms of different sulfated glycosaminoglycans in chondrogenesis and cartilage homeostasis maintenance. HEP promotes cartilage formation and maintains the normal state of cartilage tissue in vitro, while CS plays a more effective role in the regeneration of damaged cartilage tissue.

    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
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    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.

    Clinical Research
    Clinicopathological and immunohistochemical analysis of maxillofacial granular cell tumor
    Shen Zeliang, Yao Lihong, Jiang Hongjie, Li Mao, Tang Yaling.
    West China Journal of Stomatology. 2023, 41(4):  414-420.  doi:10.7518/hxkq.2023.2023035
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    Objective To analyze the clinicopathological features of maxillofacial granular cell tumors (GCT) with the aid of immunohistochemical staining. Methods Seven cases of maxillofacial GCT were retrospectively collated, and the microscopic morphology of maxillofacial GCT was analyzed. The expression of S-100, neuron-specific enolase (NSE), SOX-10, CD68, actin, desmin, and Ki-67 in GCT was detected by immunohistochemical staining. The cases were observed in the follow-ups after clinical treatment. Results All seven GCT tumors lacked envelopes and were poorly defined. Microscopically, the sizes of the tumor cells were large and appeared with inconspicuous cell membranes, forming a syncytium-like appearance. The cytoplasm was filled with characteristic eosinophilic granules. The immunohistochemical results showed that six cases were NSE-positive, five cases were S-100-positive, seven cases were CD68-positive, five cases were SOX-10-positive, one case was actin-positive, and seven cases were desmin-negative. The Ki-67 index did not exceed 5% in all cases. In the follow-up sessions, none of the six cases presented a recurrence. Conclusion Maxillofacial GCT has a characteristic histological structure. Immunohistochemical S-100, CD68, and other indicators can assist in diagnosis, and the prognosis is good after clinical resection.

    Three-dimensional reconstruction reveals the correlation between the extent of alveolar clefts and secondary nasal deformity in adults
    Luo Xiao, Chen Yu, Shi Bing, Zheng Qian, Li Chenghao.
    West China Journal of Stomatology. 2023, 41(4):  421-425.  doi:10.7518/hxkq.2023.2022466
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    Objective This study aimed to explore the relationship between alveolar cleft and secondary nasal deformity post unilateral cleft lip repair in adults. Methods A total of 27 patients aged 16-30 years old with unilateral secondary nasal deformity and alveolar cleft were included, 13 of whom underwent bone grafting. Spiral CT data of all preoperative and postoperative patients who had alveolar bone grafting were collected. Then, Mimics software was used for three-dimensional reconstruction to evaluate the correlation between the width, height, and volume of the alveolar cleft and those of the nasal deformity. The difference in nasal deformity before and after alveolar bone grafting was also explored. Results The width of the alveolar cleft was positively correlated with the difference in bilateral nostril floor width (P<0.05). As the effective depth of the alveolar cleft increased, the sub-alare inclination angle largened (P<0.05). However, no significant difference was found in the nasal deformity between before and after alveolar bone grafting. Conclusion Alveolar cleft is closely related to secondary nasal deformities post unilateral cleft lip repair, especially nasal floor deformities. Alveolar bone grafting benefits adult patients for the improvement of secondary nasal deformities post unilateral cleft lip repair.

    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
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    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.

    Application of modified articular disc anchorage in treating the perforation and rupture of temporomandibular joint disc
    Wang Tiebiao, Zhou Wuchao, Xiao Yin, Cheng Jialong, Ouyang Zhoucheng, Cheng Chen, Xi Weihong.
    West China Journal of Stomatology. 2023, 41(4):  434-442.  doi:10.7518/hxkq.2023.2022495
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    Objective This study aimed to use modified articular disc anchorage in treating old irreducible temporomandibular joint (TMJ) disc displacement with perforation and rupture, as well as to explore its efficacy. Methods A total of 31 patients (34 sides) with 47 TMJ disc perforations who underwent surgical treatment in the Affiliated Stomatolo-gical Hospital of Nanchang University from January 2018 to December 2021 were selected. According to the location of disc perforation, it has five types: posterior disc perforation (typeⅠ), anterior disc perforation (typeⅡ), lateral disc perforation (type Ⅲ), composite disc perforation, and destruction disc perforation. The modified methods of disc anchoring were divided into two types according to the location of the perforation. TypesⅠandⅢ disc perforation were trea-ted by posterior anchoring method. For posterior ancho-ring, a screw was implanted into the posterolateral side of the condylar neck, and the disc was fixed on the screw by horizontal mattress suture. TypeⅡdisc perforation and compo-site disc perforation combined typeⅡperforation were treated by anterior and posterior double-anchoring method. For anterior anchoring, anchor screws or holes were placed at the anterior edge of the condylar neck, and horizontal mattress suture was performed at the posterior edge of the anterior perforation with an anchor wire. The articular disc was then fixed on the anchor screws or holes. For the posterior anchoring method, it was the same as the previous one. Paired t test was used to analyze the visual analog scale (VAS), maximum interincisal opening (MIO), and TMJ disorder index (CMI) of the patient before surgery and 1, 3, and 6 months after surgery. Disk-condyle position relationship by magnetic resonance imaging and postoperative quality of life in postoperative were analyzed. Results The incidence of perforation was 41.2% (14/34) in typeⅠ, 11.8% (4/34) in typeⅡ, 8.8% (3/34) in typeⅢ, 29.4% (10/34) in composite type, and 8.8% (3/34) in destruction type. The VAS, MIO, and CMI at 3, 6 months after operation significantly improved compared with those before operation (P<0.05). The effective reduction rate of disc was 96.77% (30/31). The quality of life at 6 months after surgery was 47.22±2.13, and the rate of excellent evaluation was 96.4% (27/28). Conclusion Modified articular disc anchorage achieves a good curative effect for treating temporomandibular joint disc perforation and rupture. Nevertheless, its long-term effect requires further observation.

    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
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    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.

    Comparison of the efficacy and long-term stability of tunnel technique and coronally advanced flap in the treatment of gingival recession: a Meta-analysis
    Cheng Xiaoming, Tang Rui, Ge Zili
    West China Journal of Stomatology. 2023, 41(4):  450-462.  doi:10.7518/hxkq.2023.2023045
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    Objective This study aimed to evaluate the efficacy and long-term stability of tunnel technique (TUN) and coronally advanced flap (CAF) combined with connective tissue graft (CTG) in treating gingival recession. Methods Databases including PubMed, Web of Science, Embase, and CNKI were electronically searched to collect randomized controlled trial (RCT) of CAF+CTG compared to TUN+CTG in the treatment of Miller class Ⅰ or Ⅱ gingival recession on September 1, 2022. Results There were 8 RCTs with 305 patients (454 recession sites) participating. The results of the Meta-analysis revealed that, in terms of mean root coverage (MRC) of main indicators, no significant difference was found between the CAF group and the TUN group in both short- and long-term results, which were [MD: 1.45%, 95%CI (-2.93%, 5.82%), P=0.52] and [MD: -0.70%, 95%CI (-6.41%, 5.00%), P=0.81]. However, the CAF group outperformed the TUN group in the long term [MD: 5.69%, 95%CI (0.87%, 10.50%), P=0.02], and the results of complete root coverage (CRC) analysis were similar to those of MRC. In the short term, the TUN group grew keratinized gingiva significantly faster than the CAF group [MD: -0.38 mm, 95%CI (-0.67 mm, -0.10 mm), P=0.008]. Long-term findings revealed no significant difference between the two groups [MD: -0.26 mm, 95%CI (-0.94 mm, 0.43 mm), P=0.46]. The TUN group’s secondary index root coverage esthetic score (RES) was statistically significantly higher than the CAF group’s [MD: 0.62, 95%CI (0.28, 0.96), P=0.000 3]. Given that there were few results included in the literature and the heterogeneity was too great, no significant difference was observed in the postoperative VAS pain index score [MD: 0.53, 95%CI (-1.96, 3.03), P=0.68]. Conclusion This study discovered that both CAF+CTG and TUN+CTG can achieve good root coverage in treating gingival recession, with CAF outperforming TUN and both groups achie-ving good long-term stability. After the operation, the TUN group had a higher RES than the CAF group. Given the limitations of this study, more high-quality studies are needed in the future to demonstrate the efficacy of TUN in gingival retraction surgery.

    Meta-analysis of condylar changes produced by a Twin-block appliance in Class Ⅱ malocclusion
    Li Yulin, Xu Jingchen, Jiang Xiaoge, Chen Song.
    West China Journal of Stomatology. 2023, 41(4):  463-470.  doi:10.7518/hxkq.2023.2023052
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    Objective To evaluate the effects of a Twin-block appliance on the condyles of patients with ClassⅡmalocclusion by conducting a systematic review and a Meta-analysis. Methods Pubmed, Embase, Cochrane Library, Chinese BioMedical Literature Database, China National Knowledge Infrastructure, and VIP Database were electronically searched. Randomized controlled trials, controlled clinical trials, and single-arm trials on condylar changes produced by a Twin-block appliance in patients with ClassⅡmalocclusion were included. Two reviewers independently extracted and assessed the risk of bias. Meta-analyses were conducted with Review Manager 5.3. Results Eight studies were included; among which, seven were of high quality. After treatment with a twin block appliance, condyles moved anteriorly. The anterior joint spaces decreased (P<0.000 01), whereas the posterior spaces increased (P<0.000 01). The superior spaces were not changed (P=0.11). Moreover, a significant difference was observed in the increase of the condylar space index (P<0.000 01). After treatment, the anteroposterior diameters of the condyles and condylar height increased (P=0.000 2 and P<0.000 01, respectively). By contrast, no significant changes were discovered in the medial external diameters of the condyles (P=0.42). Conclusion A Twin-block appliance can promote the growth of a condyle in the posterior and upper direction and move it forward in favor of the correction of Class Ⅱ malocclusion.

    Case Report
    Intentional replantation for the retreatment of mandibular second molar: a case report
    Cai Meijuan, Xiang Shaowen, Xie Chengjie, Ouyang Chuhong, Tong Fangli
    West China Journal of Stomatology. 2023, 41(4):  471-477.  doi:10.7518/hxkq.2023.2022487
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    When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.

    A case of intramandibular epidermoid cyst and literature analysis
    Ren Bihui, Dai Jieting, Xu Yehao, Guo Shuigen, Wei Hongwu, Mao Weihua.
    West China Journal of Stomatology. 2023, 41(4):  478-482.  doi:10.7518/hxkq.2023.2022465
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    Epidermoid cysts are generally benign neoplastic lesions, the etiology of which is unclear and is mainly related to epithelial cells left in the tissues during the embryonic period and traumatically implanted in the tissues. The most common intraosseous sites are the phalanges and the skull. Epidermoid cysts occurring in the jaws are clinically rare. In this paper, we report a case of epidermoid cyst occurring in the mandible with embedded teeth and discuss the etiology, clinical manifestations, diagnosis, and treatment of epidermoid cysts in the jaws in the context of the relevant literature.

    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
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    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.