Clinical Implications of Mandibular Symphysis Block Graft for Dental Implants: A 10-year Long Term Prospective Observational Study

The aim of this study was to perform a 10-year long term prospective descriptive analysis regarding the clinical implications of mandibular symphysis block graft for dental implants and to evaluate the long term success of dental implants placed into such augmented sites.

This study was conducted in the department of oral and maxillofacial surgery. Patients with alveolar crestal ridge width of less than 5 mm in maxillary anterior edentulous ridges and desiring implant-based single tooth replacement were selected and they underwent mandibular symphysis block grafting for ridge augmentation and implants were placed into successfully augmented sites after 6 months. Further, the patients were followed up for a post-operative period of 10 years, and a descriptive analysis regarding the amount of augmentation, graft resorption, immediate, early and late complications of block grafting, and success of dental implants placed in to such sites was carried out.

A total of nine patients who underwent ridge augmentation using mandibular symphysis block graft in the maxillary anterior edentulous region were followed up for a period of 10-year postoperatively. The success rate of the above-mentioned procedure was 88.88% (eight out of nine cases were successful). Tooth sensitivity and non-vitality were seen in one out of eight cases (12.5%). Flap dehiscence and graft exposure were seen in one out of eight cases (12.5%). Scarring/loss of labial vestibular depth was seen in one out of eight cases (12.5%). Further, none of our patients exhibited nerve paresthesia as evaluated by 1) Pin Prick test and 2) Light touch test by using cotton wisp during immediate and late post-operative period. The pre-operative CBCT dimension of ridge width (W) (mm) Avg = 5.23 + 0.94 (+ 18.09%) mm. (A) Immediate post-augmentation ridge dimension (I) (mm) Avg = 7.88 + 1.12 (+ 14.20%) mm, 6-month post-operative CBCT ridge dimension (O) (mm) Avg = 7.78 + 1.11 (+ 14.26%) mm, ridge resorption (RR = I-O) (mm) Avg = 0.1 ± 0.5 (± 1.1.11%) mm (Table 1, Fig. 11). All nine dental implants (100%) placed in to successful symphysis block grafted sites demonstrated good osseointegration and none of them exhibited clinical signs of inflammation or excessive bone loss according to Albrektsson’s criteria over a period of 10 years. The follow-up results demonstrated a high implant survival rate and stable bone levels with minimal complications.

Within the limitations of this study, it can be concluded that mandibular symphysis block grafting is a predictable, gold standard method of ridge augmentation. However, the associated morbidities can be minimized or avoided even by a novice dental surgeon, if careful attention is given to pre-operative planning and meticulous surgical execution of the same is carried out and the success rate of dental implants placed into such augmented sites is excellent.