03 July 2019

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Connective tissue graft: maxillary tuberosity is the first choice where to perform the sampling?

Giulia Palandrani

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The connective tissue graft (CTG) is considered the material of choice in treating gingival or mucosal recessions around teeth and implants. Nowadays it is mainly used to recreate/augment keratinized tissue (KT) width, which is most important for dental implants for patient comfort and plaque control. It has been shown that CTG is able to induce the keratinization of the overlying epithelium, especially if mainly composed by lamina propria and collagen fibers. On the contrary, a CTG from the deep palate seems not to have the same potential of inducing keratinization as superficial CTG, cause of the large amount of adipose and glandular tissue. Nevertheless, the choice of harvesting technique is usually dictated by the anatomy of the site (such as, the palatine artery, shape of the palatal vault, palatal thickness), the required graft thickness, and the clinician's preference. 
Which is the best location for obtaining a graft and the ideal harvesting technique that minimizes the patient's morbidity?

•  Soft tissue graft around natural teeth: when compared to a palatal CTG in the bilaminar technique, the graft from the maxillary tuberosity (tCTG) has shown similar mean root coverage outcomes and a greater gain in tissue thickness.  Moreover it is important to highlight that the tuberosity donor site may heal faster than the palatal donor site and leads to much less morbidity (based on visual analog scales and painkiller consumption).
• Soft tissue graft for dental implant: the treatment of soft tissue dehiscences around implants often results in lower outcomes than root coverage in natural teeth. The graft quality and composition may play a crucial role. Indeed, Roccuzzo et al. show a 96.3% and 89.6% in mean dehiscence coverage obtained with a CTG from the superficial palate and tCTG respectively (both mainly composed of lamina propria), as opposed to clinical trials that used a subepithelial connective tissue graft (SCTG) from the deep palate (rich in fatty and glandular tissue) that reported a tendency of graft shrinkage over time and less percentage of mean dehiscence coverage. 

Histologic and molecular analysis of tuberosity soft tissue graft
Compared to the SCTG, the tCTG present a denser lamina propria (72.79% for the tCTG vs. 51.08% for the SCTG). The letterature reported that the high amounts of submucosa tissue may result in more graft shrinkage and less volume gain, for this reason it is possible to consider tCTG as a viable alternative to a deep palatal CTG. However tCTG resembles a more fibrotic tissue with a tendency for a hyperplastic response and, therefore, as suggested by Dellavia et al., its thickness should be limited to <3 mm. Conclusions The maxillary tuberosity is a valid donor site for harvesting a soft tissue graft. Nevertheless, this procedure may result in an unesthetic hyperplastic response, for this reason when esthetic concerns are of primary concern, a CTG harvested from the palate may provide better outcomes.  

For more informations:
Is a soft tissue graft harvested from the maxillary tuberosity-The approach of choice in an isolated site?