IJCRR

IJCRR - 4(10), May, 2012

Pages: 133-142

Date of Publication: 25-May-2012

ASSESSMENT OF GINGIVAL BIOTYPES IN SOUTH INDIAN POPULATION - A PROSPECTIVE STUDY

Author: PSG Prakash, D.J. Victor, G. Keerthi Priya

Category: Healthcare

Abstract:Aim: To determine the gingival biotypes in south Indian population. Materials and Method: Two
hundred and forty patients are examined in the department of Periodontics, SRM Dental College in which one hundred and twenty patients are examined visually and one hundred and twenty patients by transgingival probing method using University of North Carolina -15 probe to determine the gingival biotypes whether it is thick, thin. Results: The evaluation of gingival biotype and comparison of gingival recession using probing method in which out of 87 thick gingival biotype patients, 27 had gingival recession and out of 33 thin gingival biotype patients, 18 had gingival recession (table 8). The comparison of prevalence of percentage of gingival recession using visual method had high statistical significance, where 10% of the people who had thick gingival biotype had gingival recession and 54.5% of patients who had thin gingival biotype using visual method had gingival recession.
In probing method, 20% of the patients who had determined as thick gingival biotype had gingival
recession and 50% of the patients who had thin gingival biotype had gingival recession which was quite
highly statistically significant.

Keywords: Gingival biotypes, Gingival recession, Transgingival probing, Gingival inflammation, Probing depth

Full Text:

INTRODUCTION
The current progress of dental treatment in implant and perioplastic surgery has led to further expectations among patients to the better esthetics results. Predictability of post operative success is a major consideration in treatment planning both for periodontal and implant treatment. Therefore a careful understanding and analysis of the surrounding tissues is neccessary1 . Recently, the dimensions and other characteristics of masticatory gingival has become the subject of considerable interest in the field of periodontics. Over a long time, an inadequate zone of keratinized tissue was suggested as the risk factor of development of gingival recession2 . The gingival morphology of anterior region plays an important role in determining the final esthetics outcomes. Tissue biotype were said to be associated with outcomes of periodontal therapy3 , root coverage procedures4,5 and implant esthetics6,7 . In 1969, OCHSENBEIN & ROSS8 indicated that there were two main type of gingival morphology namely scalloped and thin or flat and thick. They also proposed that the contour of gingival closely followed the contour of the underlying alveolar bone. It was in the year 1989, that SEIBERT & LINDHE9 termed it as periodontal biotype and categorized the gingival into “thick-flat” & “thin-scalloped” biotypes. CLAFFEY & SHANLEY3 defined the thin tissue biotype as a gingival thickness of < 1.5mm and thick tissue biotype was referred to as having a tissue thickness of >/=2mm. It was suggested that gingival or periodontal diseases were more likely to occur in patients with thin gingival biotype.3 Similarly, in root coverage procedures a flap thickness of 0.8- 1.2mm was associated with predictable prognosis.4,5 Likewise, in implant restoration the thick flat tissue biotype was a important factor for the successful esthetic outcome.10 This opinion have been seriously questioned by several investigators. MIYASATO et al. & WENNSTROM et al in their study observed that areas even with narrow zone of keratinized tissue had minimal gingival inflammation and the level of attachment can be maintained even in the absence of attached gingival provided that the patient maintain a proper oral hygiene. An initial gingival thickness was found to be the most significant factor associated with the complete root coverage. In another study, by EVANS et al, he observed that in immediate single tooth restorations patients with thin scalloped mucosa often had more tissue recession. These observations suggested that tissue biotype play a significant factor influencing esthetic treatment outcomes. All the studies and meta-analysis has spoken a lot about Caucasians, European and Asian population, but there are not many studies in Indian population. Thus, this study aims to determine thickness of soft tissue in the maxillary and mandibular anterior regions and to establish the association between tissue biotype and the progression of periodontal diseases in South Indian Population.

MATERIALS AND METHODS
Subjects
Randomized clinical controlled study done in the department of periodontology and oral implantology, SRM Dental college, Ramapuram, Chennai, Tamil Nadu, India. A total of 240 patients were examined who visited the department, in which 120 patients were examined visually and 120 patients were examined using probing method to determine the periodontal biotype. Patients were randomly selected and odd nos (1,3,5,7,9..) for visual method and determined whether they are thick or thin and patients with even nos (2,4,6,8..) were examined using UNC-15 probe, based on the transparency of the probe, they are determined whether is thick or thin. The study population was predominantly under the age group of 20-45yrs with a average of 24.7. THE ETHICAL CLEARANCE FOR THIS STUDY WAS OBTAINED FROM THE ETHICAL COMMITTEE BOARD OF SRM UNIVERSITY, BHARATI SALAI, RAMAPURAM, CHENNAI-89

Clinical Measurements
Assessment of tissue biotype
The tissue biotype was evaluated and categorized by a single examiner. The evaluation of tissue biotypes was based on TRAN of the periodontal probe (UNC-15) through the free gingival margin.10 If the outline of the underlying periodontal probe could be visualized through the free gingival it would be categorized as thin gingival biotype. The visual method was also performed by a single examiner who clinically evaluated using a naked eye and decided to categorize it as thick and thin periodontal biotype 

Probing depth
Measurements were made using a Williams Periodontal probe and determined to the nearest mm.

Bleeding on probing
The measurements are performed with a criteria by AINOMO & BAY.13

Plaque index
The measurements was performed with a criteria by LOE & SILLNESS.14

Gingival recession
The distance was measured from gingival margin to cement enamel junction

Clinical photographs
Clinical photographs were taken to confirm the thick and thin gingival biotype categorization using visual method. All the subjects who participated in the study were detailed about the study protocol and their informed consent were obtained. The authors report no conflict of interest related to the study.

Statistical analysis
The datas for each of the examined parameters were averaged and decided into the groups of thick and thin gingival and mean values for subjects in group thick and thin were compared by means of a student t test. The association between the groupings with measured data and arbitarary determination of biotype by the examiners was tested by means of chi-squared test. Values of P<0.01 that considered statistically significant.

RESULTS
The mean age group of male and female age group for visual method of analysis of gingival thickness was from 15-60yrs in which predominantly the age group range was between 20-35yrs (fig 1). The mean age group of male and female using probing method for assessing the gingival thickness was between 16-70yrs where the predominantly group was falling under 20-35yrs (fig 2). The male to female ratio in both visual and probing group was 1:1 (visual 54M/66F; probing 69M/51F) (fig 3). The individual mean value of parameters in all subjects are presented in table 3 and the result of student t test with clinical parameters presented in table 4. The difference between the groups are statistically significant, where P values <0.01. The bleeding on probing in visual method, out of 54M, 42M had bleeding on probing and out of66F, 36F had bleeding on probing. In probing method out of 69M, 63M had bleeding on probing and out of 59F, 24F had bleeding on probing (table 5). The average plaque score in visual method male were 1.2 and females were 1.4. In probing method, the average plaque scores of male is 1.5 and females were 2.0 (table6). The frequency of subjects determined as thick biotype using visual method was 90 out of 120 and thin were 30 out of 120. In probing method, there were 87 people who had thick out of 120 and 33 had thin gingival biotype. The results from Chi-square test was not statistically significant. Evaluation of gingival biotype and comparison of gingival recession using visual method in which out of 90 thick gingival biotype patients, 9 patients had gingival recession which was statistically significant, and out of the 35 thin gingival biotype patients, 15 patients had gingival recession which was also statistically significant (table 7). The evaluation of gingival biotype and comparison of gingival recession using probing method in which out of 87 thick gingival biotype patients, 27 had gingival recession and out of 33 thin gingival biotype patients, 18 had gingival recession (table 8). The comparison of prevalence of percentage of gingival recession using visual method had high statistical significance, where 10% of the people who had thick gingival biotype had gingival recession and 54.5% of patients who had thin gingival biotype using visual method had gingival recession (table 9). In probing method, 20% of the patients who had determined as thick gingival biotype had gingival recession and 50% of the patients who had thin gingival biotype had gingival recession which was quite highly statistically significant(table 10,11).

DISCUSSION
The most challenging procedure in clinical dentistry is the restoration of gingival harmony and dental esthetics in the anterior area where the dentogingival interface is clearly visible. Gingival morphology plays an important role in final esthetic outcome. Tissue biotype were associated with outcomes of periodontal disease therapy majorly root coverage and implant esthetics (CLAFFEY etal 1986)15; ZIGDON etal (2oo8)15,16 In the year 1969, OCHSENBEIN & ROSS 17 , indicated that there are two types of gingival morphology namely thick with flat gingival and thin with scalloped gingival. In the present investigation, attempt were made to confirm the reliability of arbitrary determining of gingival biotype and to correlate them with clinical parameters and the results showed significant relationship between the arbitrary determining of groups and gingival biotype. WEISGOLD .etal18 suggested that there were two basic periodontal forms, the more prevalent, the thick flat type occurred in 87% of population and the other thin scalloped type occurred in <15% of cases. Our study is in accordance with WEISGOLD study were, we also had 82.3% of thick gingival biotype in our population and 17.7% of thin gingival biotype. On visual examination, out of 120 subjects, 90 subjects had thick gingival biotype and 30 had thin gingival biotype. Out of the 90 subjects of thick gingival biotype, 9 had gingival recession which contributes to 20% of disease progression and out of the 30 subjects of thin gingival biotype, 15 subjects had gingival recession, which contributes to 50% of disease progression. This report is in concurrence with the study done by DE ROUCK T19 etal in the year 2009 on Brazilian population (53.26%). In probing method, out of 120 subjects, 87 subjects had thick gingival biotype and out of which 21 subjects had gingival recession which again contributes to about 10% of disease progression and out of 120 subjects, 33 subjects had thin gingival biotype and out of which 18 subjects had gingival recession which contributes about 56% which is again in concurrence with DE ROUCK T etal19 (2009) (57%). From the articles reviewed , it is apparent that not only periodontal biotype focus an important factor in disease progression but also a bearing on mean and complete root coverage gain from desperate treatment modalities. One drawback of this study was the width of keratinized gingiva was not taken into account which can play a role significantly determining the thickness in the upper and lower incisors. It is tough to sum up based on the study and say that South Indian population subjects have more of thick and flat gingival biotype subjects and are less prone for disease progression, a bigger sample size including multiple parameters could make it a more conclusive.

CONCLUSION
Determining of gingival biotype is clinically useful in treatment planning. Different biotypes have different characteristics that may influence the result of periodontal therapy. Since, thick and thin gingival biotypes are associated with thick and thin osseous patterns, they have different patterns of osseous remodeling when subjected to trauma and even after extraction or implant procedures.

So, by understanding the nature of the tissue biotype, the clinicians can employ the periodontal and surgical procedure to minimize the alveolar bone resorption and provide a more favorable tissue environment for root coverage procedures and implant placement. This is especially important in patients with thin gingival biotypes where thin alveolar plate is highly susceptible to remodeling.

ACKNOWLEGEMENT
Authors acknowledge the immense help received from the scholars whose articles are citied and included in references of this manuscript. The authors are also grateful to authors/ editors/publishers of all those articles, journals and books from where the literature for this article has been review and discussed. The authors also thank and his staff in the Department of Periodontology, SRM University for their support throughout the study.

References:

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