Association of Facial Phenotype, Dental Characteristics and Skeletal Pattern with Gingival Biotype

AIM

To evaluate the association between Facial Phenotype, Dental Characteristics and Skeletal

Pattern with gingival tissue biotypes.

OBJECTIVES

1.      1. To determine the association between Facial Phenotype and Gingival Biotype.

2. To determine the association between Dental Characteristics with Gingival biotype.

3.      3. To determine the association between Skeletal Pattern with Gingival biotype.

MATERIAL AND METHODS

Measurement Of Gingival Biotype

Gingival Biotype evaluation for every objective will be done at 3 sites

Maxillary Right Central Incisor labial region

Maxillary Right Central Incisor palatal region

Mandibular Right Central Incisor labial region

Method 1, TRAN This evaluation method is based on whether the periodontal probe is visible through the gingival margin while probing the sulcus, of both maxillary and mandibular central incisors as thick or thin.

Method 2  Gingival thickness of the tooth will be measured by piercing the soft tissue perpendicular to the long axis of the tooth using endodontic K file with a rubber stopper until the alveolar bone is reached. If the gingival thickness measures less than 1 mm, the gingiva will be classified as thin biotype; if it is more than 1 mm, the gingiva will be classified as thick biotype.

THIS STUDY HAS 3 OBJECTIVES

OBJECTIVE 1

To determine the association between Facial Phenotype and Gingival Biotype.

Facial Phenotype Evaluation

The operator will record Facial measurements by using a Bow caliper. Morphological facial height will be measured from the Nasion landmark,  to the Gnathion landmark, .

Facial width, will be measured from the right zygon to the left zygon using Bow Caliper.

Formula for The Prosopic Index calculation

Prosopic facial index  facial height X 100 divided by bizygomatic breadth

Classification of the facial phenotypes

Euryprosopic or Brachyfacial, Low and wide face; prosopic index of 84.9 or less.

Mesoprosopic or Mesofacial, Face neither wide nor narrow; prosopic index ranges from

85.0 to 89.9.

Leptoprosopic or Dolichofacial, High and narrow face; prosopic index of 90 or more.

 OBJECTIVE 2

To determine the association between Dental Characteristics and Gingival Biotype.

A Evaluation of Parameters with the help of ImageJ Software

The NIKON digital camera with the resolution of 15 megapixels and 50 mm camera body will be used in the study to acquire the photographs of the participants. First photograph will be captured with the patient during a maximum smile in the non-reflective blue background. The opaque white ruler will be placed on the left side of the photo perpendicular to the floor. Second photograph in frontal view with complete exposure of maxillary teeth with the help of retractors will be obtained. Operator will place the graduated periodontal probe alongside the maxillary incisor, perpendicular to the occlusal plane.

The purpose of using opaque ruler and the periodontal probe is to calibrate the scale in ImageJ analytical software, will be used to measure and analyse all the images for tooth shape, gingival angles, and smile line determination.

Smile line classification

The operator will import patient photograph during the forced smile to the ImageJ software. He will assess the average of the tooth and gingival visibility in both central incisors to designate the individual smile line. The display of more than 2 mm of contiguous gingiva while smiling regarded as high smile line, while average smile line will be with a display of 75 to 100 percent clinical crown height. The subject with a display of less than 75 percent maxillary central incisor clinical crown height will be considered as low smile line.

Tooth shape evaluation

The distance between most apical portions of the tooth to the incisal edge of the tooth will be measured along the long axis to determine the crown length, CL. The contact surface area, CS will be determined by measuring the most apical portion of contact area to the most incisal portion on the mesial surface. The CS X 100 divided by CL ratio will determine the tooth shape. The ratio less than 43 percent will be categorized as triangular, the ratio ranging between 43 percent and 57 percent will be considered as tapered, and the ratio more than 57 percent will be defined as square shaped tooth.

Gingival angle

It will be ascertained by the determining the angle at the intersection of the line drawn from most apical portion of labial gingival margin to the apical position of mesial and distal contact points of maxillary right central incisor.

B Evaluation of Width of Keratinized Gingiva in Individuals with different types of Malocclusion

The participants in this part of study will be divided into three groups Angle Class I, Angle Class II, and Angle Class III according to dental malocclusion. Keratinized gingival widths of the maxillary and mandibular central incisor tooth region will be determined by the distance between free gingival margin and mucogingival junction also gingival recession will be recorded with the same teeth with which Gingival Biotype will be recorded. All these measurements will be achieved using a Williams graduated periodontal probe.

 OBJECTIVE 3

To determine the association between Skeletal pattern and Gingival Biotype.

Skeletal patterns with the help of Steiners analysis, Inclination and position of the maxillary and mandibular incisors will be assessed on lateral cephalometric radiographs. The cephalogram images will be traced by one investigator, and the landmarks used are shown in. The measurements that are illustrated in will be used to do Stainer’s analysis and to calculate the maxillary and mandibular incisor inclination and position.

Skeletal Pattern Analysis, Stainer’s Analysis

A Maxilla

SNA Angle. The angle formed by the intersection of a line from sella to nasion with a line from nasion to A point, NA. This angle is used to determine the Antero-posterior position of the maxillary arch, mean 82 degree Based on these angular readings Maxillary arch position will be classified as,

a Normal Maxilla, between 80 degree to 84 degree

b Protrusive Maxilla, more than 84 degree

c Retrusive Maxilla, less than 80 degree

B Mandible

SNB Angle. The angle formed by the intersection of a line from sella to nasion with a line from nasion to B point, NB. This angle is used to determine the Antero-posterior position of the mandibular arch, mean 80 degrees. Based on these angular readings Mandibular arch position will be classified as,

a Normal Mandible, between 78 degree to 82 degree

b Protrusive Mandible, more than 82 degree

c Retrusive Mandible, less than 78 degree

C Relation between Maxilla and Mandible

ANB Angle. The angle formed by the intersection of a line from point A to nasion, NA with a line from nasion to B point, NB. It provides a general idea of the anteroposterior discrepancy of the maxillary to the mandibular apical bases. Based on these angular readings relation of Maxillary arch position to Mandibular arch position will be classified as,

a Class I relation, between 0 degree to 4 degree

b Class II relation, more than 4 degree

c Class I relation, less than 0 degree

D Incisor Inclination and Position

Maxillary incisor inclination. The angle formed by the intersection of a line from nasion to A point, NA with a line drawn along the maxillary central incisor long axis, U1.

Maxillary incisor position. The distance formed from the most labial point on the upper central incisor, U1 to the NA line.

Mandibular incisor inclination. The angle formed by the intersection of a line drawn along the mandibular plane, Gonion-Menton with a line drawn along the mandibular central incisor long axis, L1.

Mandibular incisor position. The distance formed from the most labial point on the mandibular incisor, L1 to the NB line.