CODSJOD Kharidhi L Vandana, Pragya Goswami 10.5005/jp-journals-10063-0022 REVIEW ARTICLE Gingival Thickness: Critical Clinical Dimension of Periodontium 1Kharidhi L Vandana, 2Pragya Goswami ABSTRACT the teeth, and is attached to alveolar processes. Clinical Clinical appearance of normal gingival tissue in part reflects appearance of normal gingival tissue in part reflects the 1 the underlying structure of epithelium and lamina propria. It underlying structure of epithelium and lamina propria. has been described that particular shape, topographical distri- It has been described that particular shape, topographical bution, and width of gingival are clearly functions of presence distribution, and width of gingival are clearly functions of and position of erupted teeth. Moreover, tooth shape seems to presence and position of erupted teeth. Moreover, tooth have an important impact on the clinical features of surrounding gingiva and probably also underlying tooth-supporting periodon- shape seems to have an important impact on the clinical tal tissue. The thickness of masticatory mucosa was studied features of surrounding gingiva and probably also under- in a descriptive manner by conventional histology on cadaver lying tooth-supporting periodontal tissue.2 jaws. Others assessed the mucosal thickness in edentulous It has been long known that clinical appearance of patients using invasive method of injection needle, macroscopic healthy marginal periodontium differs from subject to measurement of histologic sections, a graduated periodontal probe or cephalometric radiographs. Noninvasive methods were subject and even among different tooth types. Many fea- performed with ultrasonic devices. A-mode ultrasonic device tures are genetically determined; others seems to be influ- was used to measure tissue thickness in edentulous patients. enced by tooth shape, size, and position and biological B-mode was used to visualize soft and hard tissue relationships phenomenon, such as growth or aging. It was observed while also measuring soft tissue thickness. Among the various that GT strongly depended on periodontal probing depth, macroscopic features of gingiva, the gingival thickness (GT) is 1 least discussed and not mentioned in the standard textbooks width of gingiva, and tooth type. and journals. There are few terminologies which are not well The inter- and intraindividual variation of gingival defined in periodontal literature like periodontal phenotype, width has been subject of numerous investigations, gingival phenotype, gingival architecture, gingival morphology, whereas GT has commanded considerable attention only and GT; hence, this review article will put some light on these recently. In recent years, dimensions of different parts of terminologies and literature review related to the clinical impor- tance and relevance on masticatory mucosa thickness, chiefly masticatory mucosa, especially GT, have become a subject on palatal mucosa and gingiva. of considerable interest in Periodontics, both from an Keywords: Gingiva, Gingival thickness, Mucosal thickness, epidemiologic and a therapeutic point of view. Peri-implant mucosa. The hidden role of GT is being realized as the visible dimension wherein many of the clinical issues are depen- How to cite this article: Vandana KL, Goswami P. Gingival Thickness: Critical Clinical Dimension of Periodontium. CODS dent. There are several studies on GT, palatal thickness, J Dent 2016;8(2):108-120. and keratinized mucosa available in the literature. Its importance is multifaceted in the interdisciplinary treat- Source of support: Nil ment approaches, such as periodontics, restorative den- Conflict of interest: None tistry, prosthodontics, orthodontics, and implantology. Hence, in this paper, the thickness of masticatory mucosa INTRODUCTION (gingiva and palatal mucosa) is reviewed and its clinical relevance is discussed. The gingiva (i.e., the marginal periodontium) is that portion of oral mucous membrane which in a complete Terminologies posteruptive dentition of a healthy individual, surrounds There are few terminologies which are not well defined in periodontal literature like periodontal phenotype, gin- 1Senior Professor, 2Postgraduate Student gival phenotype, gingival architecture, gingival morpho- 1,2Department of Periodontics, College of Dental Sciences logy, and GT. Differences between various terminologies Davangere, Karnataka, India are shown in Table 1. However, most often, the terms Corresponding Author: Kharidhi L Vandana, Senior Professor phenotype and biotype are used either for gingival width Department of Periodontics, College of Dental Sciences or thickness alone which is not ideal. Hence, it is recom- Davangere, Karnataka, India, Phone: +91819230432, e-mail: mended to use the appropriate term like GT or width [email protected] according to the need of the study. 108 CODSJOD Gingival Thickness: Critical Clinical Dimension of Periodontium Table 1: Terminologies used interchangeably in periodontal literature Periodontal phenotype Periodontal biotype Gingival thickness Term to address a common clinical Periodontal biotype concentrates primarily • This term speaks about the volume of observation of great variation in thickness on gingival contour/architecture, such as the gingiva present at particular site in and width of facial keratinized tissues scalloped/flat along with description of a particular subject. gingival thickness. Width of keratinized tissue + thickness Contour + thickness • It mainly depends on the adjacent bone morphology and to a certain extent genetics play a role. The term gingival or periodontal phenotype was Histological Factors determining GT recently coined by Muller and Eger1 to address a common The thickness of the gingiva depends on the thickness of clinical observation of great variation in thickness and the epithelium and the connective tissue (lamina propria). width of facial keratinized tissues. The thickness of mas- Dimensions of the interdental papilla also depend on ticatory mucosa and gingival width strongly depends on epithelium, entire supra alveolar connective tissue (1 mm) gender and different periodontal phenotype. According to (supra alveolar connective tissue is composed of meso- Lindhe, the morphology/architecture of gingiva depends dermal structures of the gingiva like cells, fibers, and on various anatomic factors like: blood vessels embedded in amorphous ground substance • Dimension of the alveolar present coronal to the crest of the alveolar bone).5 process determines the Various methods to assess GT with their advantages • Form/anatomy of the teeth thickness of the and disadvantages are shown in Table 4. • Events during the tooth eruption gingiva directly Various studies done on GT or biotype are shown in • Inclination and position of the or indirectly Tables 5 and 6. erupted teeth.3 Types of gingival architecture with the teeth and osseous Clinical Importance of GT form are shown in Table 2 and the characteristics of thin and thick gingiva are shown in Table 3.4 Various studies have shown the clinical importance of thickness of gingiva for the evaluation of postoperative Table 2: Types of gingival architecture with the teeth and results as shown in Table 7. osseous form Pounced DISCUSSION scalloped type Flat biotype Teeth Long, slender, Square Age tapered The younger age group of 14 to 21 years had significantly Cervical convexity Delicate Pronounced thinner palatal mucosa of 2.8 ± 0.3 than older age group Free gingiva Thin Wide and voluminous 25 Buccal cortical wall Thick Thin with more of mean 3.1 ± 0.3 mm age 30 to 59 years. Palatal mucosa vertical distance was found thin in Younger age (16–30 years) ranging from (>4 mm) 2 to 3.1 mm, while in older age group (31–54 years), it was thick ranging from 3.2 to 3.7 mm. The mean thickness of Table 3: Characteristics of thin and thick gingiva the gingiva midbuccally in the maxillary and mandibu- lar arches ranged between 0.97 (±0.29) and 1.03 (±0.31) Thick gingiva Thin gingival Flat soft tissue and bony Highly scalloped and bony mm and between 0.93 (±0.37) and 1.07 (±0.40) mm at the 11 architecture architecture interdental papilla in the older age group (25–38 years). Dense fibrotic soft tissue Delicate friable soft tissue Relatively large amount of Minimum amount of attached Gender attached gingival gingival Thick underlying osseous form Thin underlying bone Gender did not influence the thickness of hard palate characterized by bony or tuberosity;6 females in the age range of 14 to 59 years dehiscence and fenestration had GT ranging from 2 to 3.6 mm, while males had 2.3 to Relatively resistant to acute Susceptible to trauma and 3.7 mm thick gingiva. In the age group of 14- to 21-year trauma and inflammation inflammation Reacts to disease with pocket Reacts to insults and disease females, it was found to be 2 to 3.5 mm and for males, formation and infrabony defect with gingival recession it was 2 to 3 mm. In the most elderly group, i.e., 30- to formation 59-year females, it was 2.3 to 3.7 mm and males had 2.7 to >2 mm <0.5 mm 3.6 mm thick gingiva.10 In the age group 16 to 24 years and CODS Journal of Dentistry, July-December 2016;8(2):108-120 109 Kharidhi L Vandana, Pragya Goswami Table 4: Various methods to assess gingival thickness Methods Author Advantages Disadvantages Visual evaluation Ochsenbein and Ross,6 Simple, Not reliable method as it cannot be used to Seibert and Lindhe,7 Noninvasive assess the degree of gingival thickness Olsson et al2 Easy to perform Probe transparency Kan