1.Restorative strategies for complex crown-root fractures in the esthetic zone: a risk assessment based on the restoration-tooth-periodontium interface.
Ao SUN ; Baiping FU ; Huiyong ZHU
Journal of Zhejiang University. Medical sciences 2025;54(5):573-582
Complex crown-root fractures in the esthetic zone refer to a type of dental trauma occurring in the anterior region, characterized by concurrent fractures involving both the crown and the root, with associated pulp exposure and periodontal tissue injury. These injuries consistently exhibit critical anatomical features, including a fixed palatal fracture location below the alveolar crest, compromised residual tooth structure, and frequent encroachment of the biological width. To predict treatment outcomes, a risk assessment framework based on the restoration-tooth-periodontium interface was developed. Resistance risk was evaluated by assessing the type of residual dentin ferrule and the length of the root within the alveolar bone, while periodontal risk was assessed according to gingival phenotype and alveolar bone morphology. Based on these risk dimensions and the principles of aesthetics, stability, and minimally invasive treatment, a diagnostic classification system was established to categorize fractures into three types: favorable, intervention and high-risk. Type-specific management strategies were proposed: for favorable cases, crown lengthening combined with deep margin elevation to reduce periodontal risk is recommended; for intervention cases, orthodontic extrusion or surgical extrusion is applied to simultaneously address both ferrule deficiency and biological width violation; for high-risk cases, extraction followed by implant restoration is advised due to limited root preservation value. The presented classification enables clinicians to adopt a scientific and structured approach to treatment planning for these complex crown-root fractures in the aesthetic zone.
Humans
;
Tooth Fractures/therapy*
;
Tooth Root/injuries*
;
Risk Assessment
;
Tooth Crown/injuries*
;
Periodontium
;
Esthetics, Dental
;
Dental Restoration, Permanent/methods*
2.Clinical efficacy of in-situ crown reattachment technique combined with pulpotomy in the treatment of complica-ted crown-root fractures of young permanent anterior teeth.
Xuelong SU ; Qingyu GUO ; Meiyue REN ; Fei LIU
West China Journal of Stomatology 2025;43(4):499-504
OBJECTIVES:
This study aimed to evaluate the clinical application value of in-situ crown reattachment technique combined with pulpotomy in the treatment of complicated crown-root fractures in young permanent anterior teeth.
METHODS:
A prospective study was conducted on 50 children with complicated crown-root fractures in young permanent anterior teeth, who were treated at the Pediatric Dentistry Department, Hospital of Stomatology, Xi'an Jiaotong University from June 2023 to June 2024. All patients underwent in-situ crown reattachment technique combined with pulpotomy. Clinical examinations, radiographic evaluations, and subjective satisfaction surveys (using a Likert scale of 1-10) were conducted at 1, 6, and 12 months postoperatively. Data were analyzed using SPSS 23.0.
RESULTS:
The loss-to-follow-up rate was 12% (6/50), with 44 cases completing the 12 months of evaluation. The clinical success rate was 93.18% (41/44), and the radiographic success rate was 97.73% (43/44). The subjective satisfaction scores showed a significant improvement in masticatory function from 7.03±0.52 at 1 month to 8.07±0.92 at 12 months postoperatively (P<0.05), whereas the scores for aesthetics, comfort, and quality-of-life impact showed no statistically significant differences (P>0.05).
CONCLUSIONS
In-situ crown reattachment technique combined with pulpotomy effectively treats complicated crown-root fractures in young permanent anterior teeth, demonstrating a high short-term clinical success rate, significantly improved masticatory function, and minimally invasive preservation of pulp vitality and root development potential. This technique provides an optimized treatment option for dental trauma in children, although its long-term efficacy requires further validation.
Humans
;
Pulpotomy
;
Tooth Fractures/surgery*
;
Child
;
Prospective Studies
;
Male
;
Female
;
Tooth Root/injuries*
;
Tooth Crown/injuries*
;
Treatment Outcome
;
Incisor/injuries*
;
Child, Preschool
3.Resin short post retention for reattachment of a fractured crown in a young permanent tooth with complicated crown-root fracture and root fracture: a case report.
Yuanyuan WANG ; Huihui CHANG ; Birong ZHANG ; Zhiqing LIAO
West China Journal of Stomatology 2025;43(4):525-529
This report presents a case of a 9-year-old child with a complicated crown-root fracture of the maxillary central incisor, accompanied with a root fracture. The treatment strategy was minimally invasive, focusing on vital pulp preservation, root fracture recovery, and crown restoration. The fractured crown was reattached using resin short posts to enhance retention, resulting in aesthetic and functional restoration of the anterior teeth. A 2-year follow-up revealed favorable clinical and radiographic outcomes.
Humans
;
Child
;
Tooth Fractures/therapy*
;
Tooth Root/injuries*
;
Incisor/injuries*
;
Tooth Crown/injuries*
;
Post and Core Technique
;
Dental Restoration, Permanent/methods*
;
Maxilla
4.Heterotopic replantation and delayed implant restoration following complete avulsion of maxillary central incisors: a case report.
Zizhen YANG ; Qiang LI ; Yunqing PANG
West China Journal of Stomatology 2025;43(4):534-540
Dental trauma is one of the relatively common emergencies in clinical dental practice, with a high incidence rate, and the maxillary central incisors are the most frequently affected. This article reports a case of a 17-year-old female patient who suffered traumatic complete avulsion of teeth 11 and 21, with tooth 21 lost after avulsion. The prognosis for replantation was poor due to the absence of the buccal alveolar bone wall of tooth 11. Therefore, tooth 11 was treated with extracorporeal root canal therapy and then replanted into the alveolar socket of tooth 21, which had better conditions, followed by elastic splint fixation. After 20 months of follow-up observation, the affected tooth maintained a stable functional position, with no periapical inflammation or ankylosis observed. Subsequently, delayed implant restoration at the site of tooth 11 was performed, ultimately achieving a favorable treatment outcome. This case may provide new insights and references for future clinical practices in tooth replantation.
Humans
;
Female
;
Tooth Replantation/methods*
;
Incisor/injuries*
;
Adolescent
;
Tooth Avulsion/therapy*
;
Maxilla
;
Root Canal Therapy
5.Management of accidental tooth root displacement into the mandibular canal during tooth extraction.
West China Journal of Stomatology 2025;43(6):789-796
The accidental displacement of tooth roots into the mandibular canal is a serious complication during tooth extractions in oral and maxillofacial surgery, often resulting in direct damage to the structural and functional integrity of the inferior alveolar neurovascular bundle (IANB). This article reviews the anatomical features of the mandibular canal, the IANB, and adjacent tooth roots; identifies high-risk factors and anatomically vulnerable sites for root displacement; and outlines the clinical manifestations and radiographic characteristics of intraoperative root intrusion into the mandibular canal. Furthermore, management principles, surgical approaches and techniques, inferior alveolar nerve injury treatment, and prognostic considerations are discussed. The aim of this review is to provide a comprehensive clinical reference for improving surgical outcomes, and reducing postoperative complications.
Humans
;
Tooth Extraction/adverse effects*
;
Mandible/surgery*
;
Tooth Root
;
Mandibular Nerve/anatomy & histology*
;
Postoperative Complications/prevention & control*
;
Intraoperative Complications
;
Mandibular Nerve Injuries/etiology*
6.Treatment of root fracture of immature maxillary permanent central incisor combined with impacted supernumerary tooth in the apical region: a case report.
Jingyi SUN ; Hong QIAN ; Xiaoming WU ; Hedi LIU ; Qiong LIU
West China Journal of Stomatology 2025;43(6):888-894
Dental trauma is a common oral condition in children. For single-type trauma to young permanent teeth, timely treatment often results in a high survival rate for both the teeth and the pulp. However, in cases of complex dental trauma or when supernumerary teeth are impacted near the apex of the injured tooth, the prognosis is less predictable. This article reports a case of root fracture in an immature maxillary permanent central incisor combined with impacted supernumerary tooth in the apical region. After supernumerary tooth extraction and pulp revascularization therapy, the case demonstrated a good treatment outcome over a nearly 10-year follow-up period.
Child
;
Humans
;
Incisor/injuries*
;
Maxilla
;
Tooth Extraction
;
Tooth Fractures/complications*
;
Tooth Root/injuries*
;
Tooth, Impacted/surgery*
;
Tooth, Supernumerary/surgery*
7.Comparison of the efficacy and long-term stability of tunnel technique and coronally advanced flap in the treatment of gingival recession: a Meta-analysis.
Xiaoming CHENG ; Rui TANG ; Zili GE
West China Journal of Stomatology 2023;41(4):450-462
OBJECTIVES:
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].
CONCLUSIONS
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.
Humans
;
Gingival Recession/surgery*
;
Treatment Outcome
;
Tooth Root
;
Esthetics, Dental
;
Gingiva/surgery*
8.Intentional replantation for the retreatment of mandibular second molar: a case report.
Meijuan CAI ; Shaowen XIANG ; Chengjie XIE ; Chuhong OUYANG ; Fangli TONG
West China Journal of Stomatology 2023;41(4):471-477
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.
Female
;
Humans
;
Adult
;
Tooth Replantation
;
Root Canal Therapy
;
Dental Pulp Cavity
;
Gutta-Percha/therapeutic use*
;
Tooth Root
;
Molar/surgery*
;
Retreatment
9.Experimental study of subcutaneous adipose-derived stem cells inhibiting orthodontic root resorption.
Dan ZHANG ; Chunxian YANG ; Peng XU ; Nana TANG ; Shune XIAO ; Jiangtao ZHANG
Chinese Journal of Reparative and Reconstructive Surgery 2023;37(12):1533-1540
OBJECTIVE:
To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR.
METHODS:
Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 5 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining.
RESULTS:
The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05).
CONCLUSION
Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.
Rats
;
Male
;
Humans
;
Animals
;
Root Resorption/therapy*
;
Rats, Sprague-Dawley
;
Osteoclasts
;
Tooth Movement Techniques
;
Stem Cells
10.Photobiomodulation therapy assisted orthodontic tooth movement: potential implications, challenges, and new perspectives.
Jiawen YONG ; Sabine GRÖGER ; Julia VON BREMEN ; Márcia MARTINS MARQUES ; Andreas BRAUN ; Xiaoyan CHEN ; Sabine RUF ; Qianming CHEN
Journal of Zhejiang University. Science. B 2023;24(11):957-973
Over the past decade, dramatic progress has been made in dental research areas involving laser therapy. The photobiomodulatory effect of laser light regulates the behavior of periodontal tissues and promotes damaged tissues to heal faster. Additionally, photobiomodulation therapy (PBMT), a non-invasive treatment, when applied in orthodontics, contributes to alleviating pain and reducing inflammation induced by orthodontic forces, along with improving tissue healing processes. Moreover, PBMT is attracting more attention as a possible approach to prevent the incidence of orthodontically induced inflammatory root resorption (OIIRR) during orthodontic treatment (OT) due to its capacity to modulate inflammatory, apoptotic, and anti-antioxidant responses. However, a systematic review revealed that PBMT has only a moderate grade of evidence-based effectiveness during orthodontic tooth movement (OTM) in relation to OIIRR, casting doubt on its beneficial effects. In PBMT-assisted orthodontics, delivering sufficient energy to the tooth root to achieve optimal stimulation is challenging due to the exponential attenuation of light penetration in periodontal tissues. The penetration of light to the root surface is another crucial unknown factor. Both the penetration depth and distribution of light in periodontal tissues are unknown. Thus, advanced approaches specific to orthodontic application of PBMT need to be established to overcome these limitations. This review explores possibilities for improving the application and effectiveness of PBMT during OTM. The aim was to investigate the current evidence related to the underlying mechanisms of action of PBMT on various periodontal tissues and cells, with a special focus on immunomodulatory effects during OTM.
Humans
;
Inflammation
;
Low-Level Light Therapy/adverse effects*
;
Orthodontics
;
Root Resorption/therapy*
;
Tooth Movement Techniques

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