الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Introduction: Currently, the non-extraction treatment philosophy is gaining popularity among orthodontic patients and this has affected therapeutic modifiability. The different techniques employed in treating patients in this manner have their effects on the profile, the periodontium, as well as the stability of treatment results. Chiefly, labial movement of mandibular incisors has traditionally been considered a risk factor for periodontal problems predominantly, gingival recession. The present study investigated the effects of unraveling mandibular crowding on the periodontium utilizing two of the non-extraction treatment modalities namely; dental expansion and interproximal enamel stripping following orthodontic treatment in adult orthodontic patients. Material and methods: The sample consisted of 20 adult patients (16 Females, 4 Males) divided among 2 groups. In group 1, patients were treated by means of dental expansion while in group 2, interproximal enamel stripping was performed to resolve the crowding. All patients selected in both groups shared common selection criteria of: Class I Molar crowding cases according to Angle’s classification with moderate crowding in the mandibular arch (4-8 mm), a healthy systemic condition, proper oral hygiene prior to the treatment as well as periodontal health in terms of absence of bleeding on probing, absence of periodontal pockets, as well as no attachment loss. Further selection criteria required to assign patients to the treatment groups included: the degree of axial inclination of the mandibular incisors relative to the mandibular plane, the soft tissue profile analysis, as well as Bolton Index discrepancy in the mandibular arch, and triangular shaped morphology of the mandibular teeth. All subjects received a full mouth strap-up of the dentition using a straight wire appliance utilizing the Roth prescription 0.022 ” slot bracket system. In group 2, interproximal enamel stripping was performed to relief crowding using diamond-coated safe sided metal strips of a medium grain size coating used manually. Following the completion of treatment, a permanent fixed lingual retainer was placed for all patients in both arches to stabilize the treatment results. The following records were collected before and after cessation of the orthodontic treatment: digital dental models, CBCT images as well as a set of extra- and intra- oral photographs. The assessed parameters were the alveolar bone height, width, and depth in the anterior mandible, as well as the axial inclination of the mandibular incisors relative to the mandibular plane. The amount of mandibular arch expansion was calculated by measuring the values of mandibular intercanine, interpremolar and intermolar width before and after treatment. Moreover, clinical periodontal assessments of Plaque Index, Gingival Index, probing depth, attachment loss and gingival recession were performed in both groups before and following the cessation of treatment. Results: Paired t- test was used to compare between the measured parameters pre- and post- orthodontic treatment. Patients treated with expansion (group 1) showed significantly higher increase (P value ˂ 0.05) in ICW, IPW, & IMW compared to IPR group (group 2), despite common finishing phases. Significant changes in alveolar bone dimensions (P value ˂ 0.05) occur with both treatment modalities following treatment. Both interproximal enamel stripping and expansion treatment result in significant proclination of lower incisors (P value ˂ 0.05). On the short-term, the changes in IMPA showed no correlation to changes in alveolar bone height, thickness and width in both groups following treatment. Conclusions: Significant changes in alveolar bone dimensions in terms of reductions in alveolar bone height, width, and thickness occur following non extraction orthodontic treatment using both expansion as well as interproximal stripping techniques. Although radiographic changes in bone height, width, and thickness occurred with both interventions, no clinically evident changes were noted on the periodontium.