Updated: May 7, 2026

Finite Element Analysis Model for Assessing Expansion Patterns from Surgically Assisted Rapid Palatal Expansion
Published on: October 20, 2023
Lei Shi1, Zhi-Yong Zhang, Xiao-Jun Tang
1From the Department of Maxillofacial Surgery, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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This study examined a case where a chin implant made of expanded polytetrafluoroethylene (ePTFE) caused severe bone loss. While ePTFE is typically associated with minimal bone resorption, the patient in this case had significant erosion. The researchers suggest that this was due to excessive activity of the mentalis muscle, not the implant material itself. They found that the patient's dentofacial deformity likely contributed to the muscle hyperactivity. Based on this, the authors recommend genioplasty as a better option for patients with similar conditions. Their findings emphasize the importance of considering soft tissue dynamics when planning implant procedures.
Area of Science:
Background:
Chin augmentation procedures often rely on implants to enhance facial aesthetics. While expanded polytetrafluoroethylene (ePTFE) implants are widely used for their biocompatibility, prior research has shown they typically cause less bone resorption than solid silicone implants. However, some cases of significant bone erosion have been reported, though the causes remain unclear. It was already known that the choice of implant material influences long-term outcomes. No prior work had resolved the role of muscle activity in implant-related bone resorption. This gap motivated further investigation into how soft tissue dynamics might affect osseous stability. Prior studies have not fully addressed the interaction between implant placement and muscle hyperactivity. The lack of clarity on this mechanism has limited treatment recommendations for specific patient profiles. This uncertainty has driven the need for clinical observations to clarify contributing factors.
Purpose Of The Study:
The study found a case of severe bone resorption linked to mentalis muscle hyperactivity, not the implant material.
The researchers evaluated the patient's clinical history and observed repetitive contractions of the mentalis muscle.
Genioplasty is proposed as a better option because it may reduce the impact of muscle activity on bone resorption.
Radiographic imaging was used to confirm the extent of bone erosion around the implant site.
This study aimed to investigate the cause of severe bone resorption observed in a case of ePTFE chin augmentation. The specific problem addressed was the unexpected erosion of bone despite the use of a material known for minimal resorption. The motivation stemmed from the need to identify alternative contributing factors beyond implant composition. The researchers sought to determine whether muscle activity might play a role in such cases. They focused on a patient with reported mentalis muscle hyperactivity. The goal was to evaluate whether this condition could be linked to the observed bone loss. The study aimed to provide guidance on suitable treatment options for similar cases. The findings could help refine implant selection and surgical approaches for high-risk patients.
Main Methods:
The researchers conducted a clinical case analysis involving a patient who underwent chin augmentation with an ePTFE implant. They evaluated the patient's medical history and surgical outcomes. Radiographic imaging was used to assess the extent of bone resorption. The mentalis muscle activity was assessed through clinical observation and patient history. The team compared the patient's condition with typical outcomes of ePTFE implants. No experimental interventions were performed beyond diagnostic assessments. The analysis focused on identifying correlations between muscle hyperactivity and bone erosion. The findings were contextualized within existing literature on implant-related bone resorption.
Main Results:
The study found a case of severe bone resorption following ePTFE chin augmentation. The patient exhibited hyperactivity of the mentalis muscle, which was not previously documented in such cases. Radiographic evidence showed significant bony erosion around the implant site. This finding suggests a potential link between muscle activity and implant-related bone loss. The researchers observed no direct correlation with the type of implant material used. The mentalis muscle's repetitive contractions may have contributed to localized bone resorption. The patient's dentofacial deformity was identified as a contributing factor to muscle hyperactivity. These results highlight the importance of considering soft tissue dynamics in implant planning.
Conclusions:
The authors propose that mentalis muscle hyperactivity may be a significant factor in severe bone resorption following ePTFE chin augmentation. They suggest that this condition, rather than the implant material, could be the primary cause of the observed erosion. The findings imply that muscle activity should be evaluated in implant selection and placement. The researchers recommend genioplasty as a more suitable option for patients with mentalis hyperactivity. Their analysis supports the idea that surgical planning should account for soft tissue interactions. The study does not claim that ePTFE implants are inherently problematic. Instead, it emphasizes the need for patient-specific assessments. These conclusions are based on the observed case and should guide clinical decision-making.
Dentofacial deformity was identified as a contributing factor to mentalis muscle hyperactivity in the patient.
The authors advise evaluating muscle activity and considering genioplasty for high-risk patients.