THE WIDTH OF THE ATTACHED GINGIVA AND ITS VARIABILTY IN PEOPLE WITH HEALTHY PERIODONTAL STATUS

Uvod: Gingiva je deo sluzokože koja pokriva avleolarne grebene vilica i okružuje vratove zuba. Anatomske karakteristike gingive su veoma važne u planiranju lečenja oboljenja parodonta. Pripojna gingiva je važna za održavanje parodonta u zdravom stanju. Ovom studijom merene su normalne vrednosti širine pripojne gingive kod parodontalno zdravih osoba. Cilj rada bio je procena širinepripojne gingive različitim metodama. Materijal i metode: Širina pripojne gingive merena je korišćenjem parodontalne sonde kod parodontalno zdravih osoba. U zavisnosti od starosti pacijenata, formirane su četiri grupe (I ≤ 14 god; II 15-30 god; III 31-45 god i IV 46-60 god.). Deskriptivna statistička analiza urađena je za određivanje srednjih vrednosti pripojne gingive , koje će predstavljati normalne vrednosti širine pripojne gingive za osobe sa zdravim parodontom. Rezultati: Kod ispitanika starosti od 15-30 godina, nađena je najveća širina pripojne gingive, kao i kod osoba ženskog pola u odnosu na mušku grupu ispitanika. Srednje vrednosti širine pripojne gingive varirale su u zavisnosti od područja usne duplje: najveća širina pripojne gingive zabeležena je u predelu gornjih centralnih sekutića, dok je najmanja širina zabeležena u predelu prvih molara gornje i donje vilice. Zaključak: Širina pripojne gingive varira u odnosu na starost i pol osobe, kao i od mesta u usnoj duplji.


Introduction
The attached gingiva is one of the most important anatomical and functional parts of the tooth supporting apparatus.Although there is insufficient literary data on the role of the attached gingiva in maintaining periodontal health, the absence or small width of the attached gingiva may lead to faster spread of inflammation in people who do not maintain good oral hygiene 1 .
Healthy attached gingiva is of light pink color with an area that is dotted.Attached gingiva, together with the palatal mucosa is one of the masticatory tips of mucous membranes.For these reasons, it is covered by keratinized epithelium.Part of the attached gingiva was annexed to the cement teeth, while the larger part was annexed to the alveolar bone.
The width of the attached gingiva is the distance from the bottom edge of the free gingiva in the bottom of the gingival sulcus to the gingival line in the vestibulum 1 .Despite various opinions regarding the appropriate amount of keratinized tissue to maintain periodontal health, mucogingival line serves as an important landmark in the clinical assessment of periodontium 2 .Mucogingival line is a discrete line representing the boundary between mobile and immobile mucous membranes in the passive movement of the lips and cheeks 3 .Methods for locating gingival lines are visual method (VM), functional (FM) and Shiler'method (ŠM) 4 .
Visual method is based on the difference in color between the gingival and alveolarmucous membrane 5 .In the functional method, the mucogingival line is estimated as a border between the movable and immovable tissue where the mobility of tissue is determined using a periodontal probe that is positioned horizontally by pressing gently in the lobby of the lips to the edge of the gingiva 3 .Mucogingival line can be assessed visually after staining the mucogingival complex with Lugol solution (iodine test).Alveolar mucosa differs from the gingival curettage in glycogen, acid phosphatase, and the non-specific esterase, and an increased amount of elastic fibers, resulting in a positive reaction on iodine [6][7][8][9] .The attached gingiva, which is keratinized, does not contain glycogen so that the surface layer provides a negative iodine reaction.Thus, the Lugol's solution stains only the alveolar mucosa and clearly demarcates the gingival line.
The width of the attached gingiva varies considerably, ranging from one to nine millimeters.The width varies in the area of individual tooth; it is wider in the upper jaw than in the lower one and is narrower near the milk teeth 10 .
Increasing the width of the attached gingiva has a great role in periodontal plastic surgery.There are very few studies that have examined the width of the attached gingiva in periodontal healthy population.Measuring the width of the attached gingiva will assist in assessing the risk of the emergence and worsening of periodontal disease in a periodontally healthy population.
The objectives of this study were to estimate the width of the attached gingiva in full dental arch in the mouth and to assess the differences between visual methods determined with the help of periodontal probes and visual methods determined after Schiller's probe.

Material and Methods
This study involved a total of 120 people selected from the Department of Periodontology and Oral Medicine, Dental Clinic School of Medicine in Nis.For the selection of participants, a disproportionate stratified random method was used.Along with this method, the criteria for inclusion and exclusion were also applied.Patients up to the age of 60 years with good general health, healthy gingival tissue (no loss of attachment) and those who did not have some kind of periodontal treatment in the last six months were included in the study.Pregnant and lactating women, patients with systemic diseases, and those taking drugs that may affect the condition of the gingiva were excluded from the study.
Patients were informed about the study protocol, and those who agreed with the examination terms submitted the written informed consent.Depending on the age of the patient, the following groups were formed: I ≤ 14 years III 31-45 years II 15-30 years IV 46-60 years.
The width of the attached gingiva was measured with the use of periodontal probes Michigan 0 and dental mirror artificial light in the dental chair.
Slika 1. Vizuelna metoda Figure 1.Visual method and 1 g of a crystal of iodine in 60 ml of distilled water 11 .
Measuring the width of the attached gingiva was performed in the central position of the buccal surface of the central incisors, canines, first premolars and first molars, i.e. a total of 16 teeth.The entire procedure was carried out by one examiner.
To assess the width of the attached gingiva, mucogingival line is indicated as follows: • visual method -Method 1 (Figure 1) • visual method after a Schiller's probe -staining is performed using a coating cotton palette, applying a slight pressure over the gingival and alveolar mucous membrane to a sharp demarcation between the subgingival curettage and alveolar mucosa (Figure 2).
The width of subgingival curettage is measured as the distance from the gingival edge to the mucogingival line.Sulcus depth was measured as the distance from the gingival edge to the bottom edge of the free gingiva (bottom of the gingival sulcus).With these values, the width of attached gingiva was calculated as the difference sulcus depth and width keratinized tissue.

Statistical analysis
All collected data was analyzed by SPSS 15.0.The mean value and standard deviation of the results were determined.The data show homogeneity and differences between the groups analyzed using ANOVA test.The difference between groups was analyzed using post-hoc test.The criteria for statistical significance was accepted at the probability level of p < 0.05.

Results
A total of 120 respondents participated in the survey, of which 74 (61.67%) were female.
Female respondents had a greater average width of the attached gingiva (3.65 mm) than men in whom the average width of width of the attached gingiva was 2.42 mm (Table 1).
The maxillary central incisors had a maximum width of the attached gingiva with an average of 3.57 mm, while the mandibular first molars had a minimal width of the attached gingiva (2.35 mm).The width of the central incisors in the mandible was 2.48 mm, 2.99 mm of the maxillary premolars, 2.67 mm of the mandibular premolars, while the width of the maxillary first molars was 2.58 mm (Table 2).
Visual assessment of the attached gingiva width in different age groups using the method 1 revealed that the width of the gingiva increases with age, where the average width of the maxillary teeth in the first age group (≤14 years of age) was 1.73 mm, with an increase of 2.25 to 2.89 in the second group (15-30 years) and the third age group (31-45 years), while in the age group of 46-60 years it was 3.25 mm.
Similarly, in the lower teeth in the first age group (≤14 years) the average width was 1.35 mm, increasing to 2.13 mm in the second and 10.2 mm in the third age group (15-45 years) and 2.45 mm in the age group of 45-60 years (Table 3).
Assessment of the width of the attached gingiva in different age groups by visual method after Schiller's probe showed that the average width of the attached gingiva was 2.11 mm in the first age group (≤14 years) i.e. 3.25 mm in the age group of 45-60 years of age for the upper jaw.In the lower teeth, the mean width of the attached gingiva in the first age group (≤14 years of age) was 1.64 mm, while in the oldest age group of 45-60 years it was 2.48 mm (Table 2).
There was no statistically significant difference in the width of the attached gingiva in both jaws in the age group (≤14 years), regardless of the method used for the assessment (Table 5).
Comparison of two different methods of different teeth in the age group of 15-30 years did not show any significant differences, though the widest zone of the attached gingiva was found for incisors by the application of both methods (method 1 -4.07, method 2 -3.85),whereas the minimum zone width was seen in the premolar region (method 1 -1.92, method 2 -2.07).Such variations are similar in the lower teeth as well (Table 6).
Similar values for the maximum width of the upper incisors and the lower premolars were observed in other age groups, i.e. in groups of 31 -45 years and the group of 46-60 years, so there was not a significant difference between the two methods ( Table 7 and 8).

Discussion
The assessment of the width of the attached gingiva is vital to assess the risk for the occurrence of periodontal disease.For the assessment of the width of the attached gingiva, mucogingival line serves as an important anatomical landmark, which can be delineated by various methods.As suggested by Fasske and Morgenroth, the exact location of this line can be seen after staining the mucosa with different solutions (such as Lugol iodine solution) which allow accurate determination of the line on which the keratinization ends 12 .For the purpose of elimination of the difference in probing, all measurements were performed by a single examiner.
There is a large number of studies that have examined the width of the attached gingiva.The most read studies related to the examination of the width of the attached gingiva are those authored by Bowers in 1963 13 and 1976 and Ainamo in 1976 14 .In this study, the measurement of the attached gingiva was performed using a periodontal probe similar to Tenenbaum 15 , and using a solution of iodine (Schiller's test) as Talari 16 , Ainamo 17 and Saario 18,19 did.Bowers 13 found that the width of the attached gingiva varies in different areas of the oral cavity, as it was found in this study.Ainamo 14 found the maximum width of the attached gingiva in the area of the maxillary incisors.Similar results were found in this study.Minimum width in this study was in the part of the first molar in the mandible, while Ainamo 14 found that the minimum width was in the region of the premolars in the mandible.Ainamo 14 and Vincent 20 found that the width of the attached gingiva increases with age, which is consistent with the results of this research.These results show that the maximum width of the attached gingiva was in the second age group (15-30 yrs.), while in the middle age group of 31-45 years the width of the attached gingiva was the smallest (Table 3).
The assessment of the width of the attached gingiva in different age groups using a visual method revealed that the width of the attached gingiva increases with age which is in accordance with the results obtained by Ainamo and Talari 16 and Vincent et al. 20 The width of the attached gingiva varies in different areas of the oral cavity, ranging from 1-9 mm, 21 1-4 mm, 22 , 0-5 mm 23 .
In this study, the extent of medium width of the attached gingiva can vary from 1 mm to 4 mm.Similar variations are seen in u predelu sekutića , a najmanja u predelu premolara, bez obzira na metod koji se koristi u proceni 21 .
The categorization of different types of teeth was done only in the last three age groups, while the participants of the first age group ≤14 years had a different configuration of the present teeth due to the presence of mixed dentition.The width of the attached gingiva cannot be compared in cases of mixed dentition because of the different nature of the present teeth.
The results of this study showed that there was no significant difference in the width of the attached gingiva obtained by measuring using the visual method or using visual methods implemented after Schiller probe.These results are consistent with the research of Guglielmone et al., 24 while Bernimoulin et al. 25 reported that performing the functional method gives a maximum width of keratinized gingiva.In addition, the visual method after staining the gingival tissue leads to the smallest disagreements in the values of the attached gingiva width compared to other methods of determining the width of the attached gingiva.
It is the widest in the area of incisors, and then it narrows in the premolar area to expand again slightly in the area of the molars.In terms of the width of the attached gingiva, there is a symmetry with the left and right sides of the face, while the difference between the sexes does not exist.The width of the attached gingiva is important for physicians and patients because it affects the prognosis of the disease.If the attached gingiva is narrow, the periodontal disease prognosis will be worse.Considering people with narrow attached gingiva, the process of destruction that occurs in the course of the disease reaches faster a mucogingival line.Then, there is a marked traction over the movable mucous membrane and further progression of the pathological process.Traction separates the edge of the gingiva from the teeth and facilitates the creation and retention of dental plaque, with all the adverse consequences.This problem becomes more noticeable if this is combined with the anomalies in the soft tissue.

Conclusion
Assessment of the width of the attached gingiva in full dental arch reveals different widths in different areas of the oral cavity.The maximum width is in the area of the maxillary incisors, while the smallest width is in the area of the lower first molar.Patients' age affects the width of the attached gingiva, while the females had greater width of the attached gingiva.
Further research is needed regarding the periodontally healthy people from different parts of Serbia in order to determine whether the geographical position may affect the different values of width of the attached gingiva.It is also necessary to perform this research on a larger number of participants to obtain a definite scope that could be defined as adequate or not, making it easier to treat periodontal disease.

Table 1 .
The width of the attached gingiva in men and women Širina pripojne gingive kod različitih zuba u vilicama

Table 3 .
Evaluation of the width of the attached gingiva in different age groups, using a

Table 5 .
Comparison of two different methods in the age group ≤ 14 years Poređenje dve različite metode u starosnoj grupi od 15 do 30 godina starosti

Table 6 .
Comparison of two different methods in the age group of 15-30 years Poređenje dve različite metode u starosnoj grupi od 31 do 45 godina starosti

Table 8 .
Comparison of two different methods in the age group of 46-60 years mean; SDstandard deviation; Fthe value of significance; pstatistically significant difference: n.s.-it is not statistically significant