Placement of free gingival grafts on denuded alveolar bone. Part II: microscopic observations

Long-term evaluation of peri-implant keratinized mucosa stability after free epithelialized graft and keratinized mucosa shifting procedures: A retrospective study up to 13 years

OBJECTIVES

This study aimed to assess the risk of less than 2 mm keratinized mucosa (KM) width occurrence after free epithelialized graft (FEG) and keratinized mucosa shifting (KMS) procedures using survival analysis. In addition, KM dimensional changes were evaluated.

MATERIALS AND METHODS

This study included 76 implants in 36 patients with insufficient KM (<2 mm). The implants underwent either FEG or KMS procedures. The mid-buccal KM width was measured from surgery to the end of a one 13-year follow-up period.

RESULTS

Mean follow-up durations were 9.2 ± 3.9 years for FEG and 6.3 ± 4.2 years for KMS. Two implants in FEG and nine implants in KMS exhibited a KM width of less than 2 mm during follow-up. The hazard ratios for KMS compared to FEG were 6.48 (crude) and 6.54 (adjusted), both statistically significant (p < .05). The incidence rate of KMS (4.06%) was higher than that of FEG (0.63%), with an average incidence time of 3.38 years for KMS and 8.82 years for FEG post-surgery. FEG showed a significant shrinkage within 6 months (33% ± 22%), whereas KMS demonstrated a gradual decrease over 13 years (34% ± 25%). FEG exhibited significantly greater width change than KMS during a 5-year follow-up (p < .05).

CONCLUSIONS

FEG and KMS enhanced PIKM but exhibited different long-term reduction patterns. FEG demonstrated rapid shrinkage, while KMS displayed gradual and continuous reduction. Moreover, KMS presented a higher risk and incidence of KM width less than 2 mm compared to FEG.

Periodontal phenotype modification of complexes periodontal-orthodontic case scenarios: A clinical review on the applications of allogenous dermal matrix as an alternative to subepithelial connective tissue graft

OBJECTIVES

The aim of this review is to address the potential applications of allogenous dermal matrix (ADM), as an alternative to subepithelial connective tissue graft (SCTG), in promoting periodontal phenotype modification (PPM) of challenging periodontal-orthodontic clinical scenarios.

OVERVIEW

The rationale behind the need of changing thin to thick gingival tissues is associated to the superior and more stable treatment outcomes promoted by PPM therapy. PPM, via soft tissue grafting, leads to clinical and histological changes of the pre-established original genetic conditions of the gingiva. Although SCTG-based procedures are recognized as the "gold standard" for the treatment of sites requiring root coverage and gingival augmentation, ADM has been recognized as the most suitable alternative to SCTG, particularly in clinical scenarios where the use of autogenous grafts is not possible. Thus, ADM is considered an optimal option for the treatment of patients with a history (or in need) of orthodontic tooth movement, due its two-fold potential indication: (1) the promotion of periodontal soft tissue phenotype modification; and (2) its use, as a barrier membrane, in hard tissues augmentation procedures.

CONCLUSIONS

ADM is a viable option for soft tissue augmentation, as well as for treatment approaches involving buccal bone gain.

CLINICAL SIGNIFICANCE

Periodontal phenotype modification therapy, when applied in challenging periodontal-orthodontic clinical scenarios, promotes root coverage and prevents the onset and development clinical attachment loss.

Effect of gingival augmentation procedure (free gingival graft) on reducing the risk of non-carious cervical lesions: A 25- to 30-year follow-up study

BACKGROUND

The aim of this long-term case series was to assess the development/prevalence of non-carious cervical lesions (NCCLs) at sites that have and have not been treated with gingival augmentation following free gingival graft (FGG).

METHODS

Fifty-two patients had at least one test and one control site: 1) test site showing absence of attached gingiva (AG) associated with gingival recession (GR) treated with FGG; and 2) contralateral site with or without AG. Patient/tooth/site-associated variables were recorded for each tooth/site at baseline (T0), 12 months after surgery (T1), during the follow-up period (T2) (15 to 20 years), and at the end of the follow-up period (T3) over 25 to 30 years. Mixed-effects logistic regression was used throughout the study.

RESULTS

Forty-nine patients/130 sites were available for analysis at T2 whereas 44 patients/120 sites at T3. Twenty-two NCCLs >0.5 mm were restored in the test sites and in 35 in the untreated sites. The development of NCCL over time appeared associated with sites with attached KT <2 mm (i.e., odds ratio [OR]: 3.80 [P = 0.045] and 3.47 [P = 0.046], 15- to 20- and 20- to 30-year follow-ups, respectively), as well as to teeth presenting a thin/non-modified periodontal phenotype (i.e., OR: 3.53 [P = 0.037] and 5.51 [P = 0.008], 15- to 20- and 20- to 30-year follow-ups, respectively).

CONCLUSIONS

Periodontal phenotype modification achieved by FGG may prevent the development/progression of NCCL. Evidence suggests that the thickness and width of the AG had a direct influence on the need of restoring these lesions during the 25- to 30-year observation period.

Removal of Pre-Existing Periodontal Inflammatory Condition before Tooth Extraction Ameliorates Medication-Related Osteonecrosis of the Jaw-Like Lesion in Mice

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but detrimental intraoral lesion that predominantly occurs in patients with long-term use of antiresorptive agents, such as bisphosphonate and denosumab, a human anti-receptor activator of NF-κB ligand (RANKL) monoclonal antibody (Ab). Surgical intervention, such as tooth extraction, is a known risk factor for MRONJ, which is often performed to eliminate preexiting pathologic inflammatory conditions, such as periodontal diseases. Nonetheless, it remains unknown whether pre-existing periodontal disease condition exacerbates, or removal of such condition ameliorates, MRONJ development after tooth extraction. In this study, we combined the ligature-induced periodontitis and the tooth extraction mouse models under the administration of zoledronic acid (ZOL) or anti-RANKL Ab, and provide experimental evidence that a pre-existing pathologic inflammatory condition exacerbates MRONJ development after tooth extraction in mice. Under ZOL administration, tooth extraction alone induced ONJ lesions; however, extraction of a ligature-placed tooth further exacerbated ONJ development. When the ligature was removed and the inflammatory condition was deescalated, ONJ development was ameliorated. Anti-RANKL Ab administration resulted in similar outcomes. Interestingly, unlike ZOL-administered mice, anti-RANKL Ab-administered mice exhibited complete absence of osteoclasts, suggesting that physical presence of osteoclasts is not directly involved in ONJ development. Collectively, our study demonstrated that periodontal disease is a functionally linked risk factor that predisposes ONJ development after tooth extraction in the presence of bisphosphonate and denosumab.

Mucogingival surgery: where we stand today

Mucogingival problems are developmental and acquired aberrations in the morphology, position, and/or the amount of gingiva surrounding teeth. According to an academic report by American Academy of Periodontology, mucogingival therapy should be advocated for gingival augmentation and to create adequate vestibular depth in areas with insufficient attached gingiva. This paper provides an overview on mucogingival surgical procedures from its inception to the current time.

Microvascularization of gingival wound healing using corrosion casts

The healing process in a wound induced by removal of 6 X 6 mm of gingiva and periosteum from the maxillary attached gingiva of 48 adult mongrel dogs was observed to investigate the potential blood supply for grafts placed on denuded bone. Three-dimensional observations were performed over 12 weeks by scanning electron microscopy (SEM) following the manufacture of corrosion capillary casts by acrylic resin injection. Revascularization in the gingival wound was mainly through formation of new capillaries from those existing below the surrounding epithelium with little new capillary formation from the Volkmann canals. Moreover, the periodontium contributed greatly to the vascularization, which was fastest from the gingival margin. Further, simplification of new capillary loops was also fastest from this direction. Regeneration of the periosteum and periosteal vascular plexus was slow, taking about twice the time of connective tissue and capillaries below the epithelium. The results indicated that blood supply to grafts on denuded bone in the early postgraft period would mainly be provided by capillaries below the epithelium surrounding the recipient bed.

Loss of anterior interdental tissue: periodontal and prosthodontic solutions

The restoration of anterior spaces with a loss of interdental tissue has been reviewed. A surgical technique combining a subepithelial connective tissue autograft and a free gingival graft has been described. This preprosthodontic surgical approach is recommended as the treatment of choice. When surgery is contraindicated, the use of a cantilevered porcelain papilla is suggested.

Revascularization of gingival autografts placed on different receptor beds. A fluoroangiographic study

The revascularization of gingival autografts, placed either on fenestrated periosteum or on non-fenestrated periosteum, has been compared by means of 12 fluorescein angiographs, taken 8, 10 and 12 days postoperatively on 12 patients, 18-32 years of age. The grafts placed on periosteum (P-zone) showed a mean increase of fluorescence of 10.6% between the 8th and 10th day and of 19.4% between the 10th and 12th day. At that time the circulatory system in the graft seemed to be established for 97.7%. The grafts placed on fenestrated periosteum (B-zone) showed a mean increase of fluorescence of 13.2% between the 8th and the 10th day and of 13.5% between the 10th and 12th day. The revascularization reached 96.1% at that time. Between both groups no statistically significant difference has been found. It can be concluded that a periosteal receptor side is not a prerequisite for the formation of an even circulatory pattern in gingival autografts.