ORIGINAL ARTICLE Augmentation of faciolingual gingival dimensions with free connective tissue grafts before labial orthodontic tooth movement: An experimental study with a canine model Howard D. Holmes, a Marc Tennant, b and Mithran S. Goonewardene c Cannington and Nedlands, Australia Purpose: 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. Material: 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. Results: 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). Conclusions: 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. (Am J Orthod Dentofacial Orthop 2005;127:562-72) L ocalized gingival recession is an unesthetic condition that is usually observed over the labial aspect of prominent teeth. 1,2 Although no single factor or mechanism has been implicated for the etiology of this problem, a number of predisposing elements have been identified. Biometric studies have described a direct correlation between the presence and extent of alveolar bone dehiscences and the magnitude of associated gingival recession defects. 3 Thin gingival tissues overlying these dehiscences are very friable and might be prone to recede in response to traumatic insults, such as plaque-related inflammation and trau- matic toothbrushing. 4,5 Other factors, such as high muscle attachments or frenal pull, iatrogenic restorative or periodontal procedures, 1 thin and narrow gingival phenotype, and scar tissue contracture after orthog- nathic surgery, have also been associated with reces- sion of the marginal tissues. Consanguinity between orthodontic tooth move- ment and gingival recession has also been a common anecdotal observation in both the periodontic and orthodontic literature. 6-8 However, experimental evi- dence suggests that orthodontic tooth movement does not actually “cause” gingival recession but might create an environment that predisposes some people to the condition, particularly if teeth are repositioned in a facial direction and alveolar bone dehiscences are created. 9 Prophylactic management of gingival recession in at-risk orthodontic patients remains a controversial issue. Widespread use of prophylactic gingival grafts to prevent recession in orthodontic patients has been reported, 8,10-12 as well as a more cautious “watch-and- wait” approach. 13-15 In view of the more recently documented high predictability of various surgical root a Private practice, Cannington, Australia. b Director, Centre for Rural and Remote Oral Health, University of Western Australia, Nedlands. c Program director, Orthodontics, Oral Health Centre of Western Australia, University of Western Australia. Partially funded by a grant from the Australian Society of Orthodontists’ Foundation for Research and Education. Reprint requests to: Dr Mithran S. Goonewardene, Oral Health Centre of Western Australia, University of Western Australia, 17 Monash Ave, Nedlands, WA 6907, Australia; e-mail, mithran@ohcwa.uwa.edu.au. Submitted, March 2003; revised and accepted, April 2004. 0889-5406/$30.00 Copyright © 2005 by the American Association of Orthodontists. doi:10.1016/j.ajodo.2004.04.023 562