The aim of this article is to explore the medium- to long-term consequences of onlay-type facial prosthesis applications. The rationale is that inserting a prosthesis, made of any material, eliminates the physiological mechanical stimulation of muscles and neuromuscular dynamics, leading to negative remodeling of the bones on which the prosthesis is placed.
Radiographic and clinical literature consistently documents mandibular bone resorption beneath chin implants across materials and techniques, with prevalence ranging from incidental, asymptomatic shallow imprints to clinically relevant cortical loss (Yeung & Wong, 2022; Sciaraffia et al., 2018).
Systematic review data show that most series report mean resorption <2 mm within mostly <5-year follow-ups, while deeper defects tend to appear as follow-up lengthens (Yeung & Wong, 2022). Case-based and small clinical series repeatedly illustrate cortical erosion under silastic chin implants, often discovered incidentally on panoramic/cephalometric imaging or CBCT and sometimes progressing toward apices or mental foramen (Polo, 2017; Abrahams & Caceres, 1998; Muttanahally & Tadinada, 2023).
A long-term radiographic cohort found bone erosion in 14/15 patients, typically ≤2 mm, underscoring that minor but measurable resorption is common and usually asymptomatic (Sciaraffia et al., 2018).
Resorption has been documented years after augmentation, including severe cortical loss occasionally linked to local cofactors (e.g., high positioning onto thin cortex, bulky/unstable implant, or concomitant odontogenic pathology) (Yamazaki et al., 2019; Ramalho et al., 2001; Muttanahally & Tadinada, 2023).
Imaging pathway: screening with lateral cephalogram or panoramic views can reveal the “imprint,” while CBCT best defines depth, relation to roots/mental foramen, and surgical planning (Yeung & Wong, 2022; Muttanahally & Tadinada, 2023).
Mechanistic contributors discussed across reports include subperiosteal pressure/micromotion, superior/high implant placement over thin labial cortex, and mentalis/lip dynamics in the highly mobile symphysis region (Yeung & Wong, 2022; Sciaraffia et al., 2018; Ahmed et al., 2023). Across broader facial implant reviews, bone resorption/erosion is mainly a lower-face (chin) silicone-implant complication; pooled complication tables enumerate resorption/erosion among silicone cases in the lower face (Ahmed et al., 2023; Kauke-Navarro et al., 2025).
Clinical implications include potential root injury, altered tooth vitality, and neuropathic symptoms if resorption approaches root apices or the mental foramen, so periodic radiographic follow-up is advised even in asymptomatic patients (Yeung & Wong, 2022; Muttanahally & Tadinada, 2023).
Risk-modifying factors suggested by narrative and tabulated data include reducing implant mobility (e.g., fixation), careful inferior positioning (avoiding high placement), and tailored implant dimensions to limit pressure on thin cortex (Ahmed et al., 2023).
The pathophysiological mechanism that determines the erosion and atrophy of the bone cortex on which an onlay prosthesis is inserted lies in the cancellation of physiological muscular mechanostimulation, an essential element for maintaining and stimulating adequate bone regeneration according to the consolidated principles of Mechanobiology and Morphodynamic Cosmetic Surgery (Rizzo 2025).
References
Abrahams JJ, Caceres C. Mandibular erosion from silastic implants: evaluation with a dental CT software program. AJNR Am J Neuroradiol. 1998;19(3):519–522.
Ahmed MG, AlOtaibi N, Banabilh SM, et al. Silicone facial implants, to fixate or not to fixate: a narrative review. Cureus. 2023;15(2):e34933. (Includes tables of complications with bone resorption/erosion for chin silicone implants.)
Kauke-Navarro M, Knoedler L, Baecher T, et al. A systematic review of implant materials for facial reconstructive and aesthetic surgery. Frontiers in Surgery. 2025;12:1548597. (Complication synthesis; bone resorption/erosion reported particularly for lower-face silicone implants.)
Muttanahally KS, Tadinada A. Should a clinician be worried about bone resorption under a chin augmentation site? Cureus. 2023;15(4):e37041. (CBCT-documented cortical erosion beneath a silastic chin implant; asymptomatic.)
Polo M. Bone resorption under chin implants: the orthodontist’s role in its diagnosis and management. Am J Orthod Dentofacial Orthop. 2017;151(2):201–208. (Incidental radiographic detection; orthodontic workflow.)
Ramalho G, et al. Bone reabsorption associated with silicone implants in mentoplasty: clinical case report. Rev Bras Cir Plást. 2001;16: (two cases; anterior cortical resorption).
Sciaraffia CE, Ahumada MF, Parada FJ, et al. Bone resorption after use of silicone chin implants: long-term follow-up with lateral chin radiography. Plast Reconstr Surg Glob Open. 2018;6(7):e1850. (14/15 with erosion; max 2 mm; asymptomatic.)
Yamazaki F, Takahashi K, Aoki A, et al. Bone resorption after alloplastic chin augmentation found incidentally in a patient with a toothache: case report. J Oral Maxillofac Surg Med Pathol. 2019;31(4):237–240. (Severe resorption with local cofactors.)
Yeung AWK, Wong NS. Mandibular bone resorption following chin augmentation: a systematic review. Frontiers in Surgery. 2022;9:815106. (28 human studies; deeper resorption associated with longer follow-up; mean often <2 mm.)
Rizzo A., The Role of Mechanobiology in Regenerative Aesthetic Medicine. Chirurgia Cosmetica Morfodinamica. (Available on line) https://www.chirurgiacosmeticamorfodinamica.it/2025/10/21/the-role-of-mechanobiology-in-regenerative-aesthetic-medicine-and-morphodynamica-cosmetic-surgery-mdcs/
