Gingival Height Research Articles

Periodontal status of mandibular central incisors after orthodontic proclination in adults

Some animal and human studies showed that periodontal recession occurs after incisor proclination, but other authors disagree. The purpose of this study was to assess the periodontal status of mandibular central incisors that were proclined during orthodontic treatment. The sample comprised 34 adults who had completed treatment over periods of 7 months to 3 years 11 months. The proclination and vertical movement of these teeth were analyzed by 6 measurements from lateral cephalometric radiographs taken before and after treatment. The thickness and height of the symphysis were recorded from pretreatment lateral cephalometric films. Crowding was determined based on the irregularity index from the initial cast. The following periodontal clinical parameters were assessed: plaque and gingival bleeding indexes, probing pocket depth, clinical levels of attachment, and recession of selected teeth and of the mandibular central incisors. The height of the keratinized tissue and the thickness of the facial gingival margin of these incisors were also measured. The Pearson and Spearman correlation analyses, the Fisher exact test, and the Kruskal-Wallis test were applied. Statistical analyses showed no correlation between recession and the plaque and gingival bleeding indexes, probing pocket depth, and total quantity of labial movement (P >.05). Recession was negatively correlated with keratinized gingival height and thickness of the facial gingival margin on the mandibular central incisors. Final inclination (>95 degrees ) and free gingival-margin thickness (>0.5 mm) showed greater and more severe recession on the mandibular central incisors. Nevertheless, when comparing thickness to the final inclination, thickness had greater relevance to recession.

Platelet‐Derived Growth Factor Stimulates Bone Fill and Rate of Attachment Level Gain: Results of a Large Multicenter Randomized Controlled Trial

Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing. Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups. CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments. To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.

Augmentation of faciolingual gingival dimensions with free connective tissue grafts before labial orthodontic tooth movement: An experimental study with a canine model

The aim of this study was to determine in an animal model whether any increase in gingival thickness after placement of free connective tissue autografts is maintained after labial orthodontic tooth movement. In a split-mouth technique, the maxillary second and third incisors of 4 adult greyhounds were used as experimental, control, and sham-control teeth. The experimental teeth underwent gingival augmentation surgery. Two to 3 months later, the teeth were moved with a bonded orthodontic appliance over 2 to 3 months. Baseline and 2-month retention clinical measurements of gingival height were taken before the animals were killed. Histometric measurements recorded the free gingival height and the gingival thickness at 5 graduated levels down the teeth. Clinical measurements of changes in gingival margin position revealed a mean coronal shift of 0.44 mm over grafted teeth, with 50% of nongrafted teeth and 100% of the sham-control teeth experiencing small amounts of gingival recession. The histometric results showed that gingival thickness measurements for the grafted teeth were, on average, between 0.13 and 0.18 mm thicker at all levels of measurement than for the nongrafted teeth (P < .01). Free connective tissue grafts placed on the labial aspect of incisors might help prevent the faciolingual thinning of the gingival tissues that can occur as a result of labial orthodontic tooth movement. Further research is required to confirm these results in a larger sample and determine the long-term benefits of preorthodontic gingival augmentation to prevent gingival recession.

Repositioning of the gingival margin by extrusion

In this case report, orthodontic intervention was used to move the gingival margin of a maxillary canine incisally by almost 9 mm to mimic a lateral incisor. Increasing the thickness of the labial plate of bone of the canine and subsequently increasing the thickness of the attached gingiva before extrusion prevented gingival recession at a later stage. In many situations, orthodontic treatment can achieve results that could not be attained by restorations and other means of cosmetic dentistry, especially when dealing with gingival margins and gingival height. A step-by-step approach to achieving these treatment objectives is described. (Am J Orthod Dentofacial Orthop 2002;122:95-102)

Measurement of gingival swelling from dental casts by generation of a moiré pattern with laser light.

The aim of the study was to develop a sensitive measuring method enabling direct evaluation of gingival swelling to be made as registered on dental casts. On two separate occasions, when different degrees of severity of gingival inflammation were present in the same subject, reversible hydrocolloid impressions were taken of the mandible. The casts obtained were located successively in identical three-dimensional relationships in a field of interference fringes generated by two intersecting beams of collimated helium-neon laser light, and were photographed. The evaluation of the moiré pattern obtained directly by superimposition of the two images of the surface studied indicated that a decrease in gingival height of 0.38 mm in the direction of the camera had occurred between the two occasions. The use of a computer-based image-processing system considerably improved the visibility of the pattern. The reproducibility of the impression technique, as well as the relocation and superimposing techniques, proved satisfactory at the moiré resolution used (0.19 mm). The method has potential application in clinical experimental research, and therefore warrants further evaluation.

Disparities in gingival height in the mandibular central incisor region of children aged 6--12 years.

An investigation of disparate gingival heights of the mandibular central incisor region in 93 children aged from 6 to 12 years was undertaken. Unaffected paired teeth demonstrated an age-associated increase in clinical crown length, similar to previous reports, suggesting a gradual remodelling of soft tissues. Affected teeth displayed a rapid increase in clinical crown length suggesting that by age 10 years true recession had occurred. Significant associations with gingival inflammation (at the 0.1% level), and with anterior crowding (at the 0.2% level), occurred. Frenal involvement did not influence the position of the gingival margin.

Clinical and Materials Sciences

evices were used for gingival retraction prior to impression-taking procedures. The effects of these retraction methods upon blood pressure and loss of gingival tissue height were evaluated on three Rhesus monkeys. Chamfer finishing lines were prepared on all of the teeth and penetrating into the gingival sulcus. All the retraction devices were used to produce the desired amount of retraction which would allow an acceptable impression. Contralateral teeth, on which a chamfer was cut but no retraction performed were used as control teeth. The only retraction device which had no effect on blood pressure and caused no tissue loss was the nonepinephrine retraction cord. The 8% r-epinephrine string and the two electrosurgical devices caused elevated blood pressures. With the 8% r-epinephrine retraction cord, no tissue loss was observed and complete healing occurred within nine days. Both electrosurgical devices caused tissue loss. The fully rectified current device caused a slight loss in gingival tissue height, while the spark gap generator caused a marked amount of tissue height to be lost. The Hyfrecator should not be used for gingival retraction because of the tissue damage that results. It appears that the safest retraction device is the retraction cord, when used properly. Further research is recommended to establish the possible systemic effects of the electrosurgical techniques.

Gingival height of lower central incisors, orthodontically treated and untreated.

Abstract No Abstract Available. Given before the Midwestern Component of the Angle Society, January 1967.