Periodontal status of mandibular incisors following excessive proclination A study in adults with surgically treated mandibular prognathism

Objective: To determine the initial compensation, preoperative decompensation, and postoperative compensation of the lower incisors according to the skeletal anteroposterior discrepancy and vertical type in skeletal Class III patients. Materials and Methods: The samples consisted of 68 skeletal Class III patients treated with twojaw surgery and orthodontic treatment. Lateral cephalograms were taken before preoperative orthodontic treatment (T0) and before surgery (T1) and after debonding (T2). According to skeletal anteroposterior discrepancy/vertical type (ANB, criteria 5 24u; SN-GoMe, criteria 5 35u) at the T0 stage, the samples were allocated into group 1 (severe anteroposterior discrepancy/hypodivergent vertical type, N 5 17), group 2 (moderate anteroposterior discrepancy/hypodivergent vertical type, N 5 17), group 3 (severe anteroposterior discrepancy/hyperdivergent vertical type, N 5 17), or group 4 (moderate anteroposterior discrepancy/hyperdivergent vertical type, N 5 17). After measurement of variables, one-way analysis of variance with Duncan's multiple comparison test, crosstab analysis, and Pearson correlation analysis were performed. Results: At T0, groups 3 and 2 exhibited the most and least compensated lower incisors. In group 2, good preoperative decompensation and considerable postoperative compensation resulted in different values for T0, T1, and T2 (IMPA, T0 , T2 , T1; P , .001). However, group 3 did not show significant changes in IMPA between stages. Therefore, groups 2 and 3 showed different decompensation achievement ratios (P , .05). Group 3 exhibited the worst ratios of decompensation and stability (24% and 6%, respectively, P , .001). Anteroposterior discrepancy/vertical type (ANB: P , .01 at T0 and T1, P , .001 at T2; SN-GoMe: P , .01, all stages) were strongly correlated with relative percentage ratio of IMPA to norm value. Conclusions: Skeletal anteroposterior discrepancy/vertical type results in differences in the amount and pattern of initial compensation, preoperative decompensation, and postoperative compensation of lower incisors in Class III patients. (Angle Orthod. 2011;81:64-74.)

Section: Discussionsupporting

confidence: 61%

“…However, for the amounts of Pre-DC, Å rtun et al 21 and Capelozza Filho et al 12 reported a value of around 10u, which was different from our values (5u to 8u). The reason why our results showed a smaller amount of Pre-DC seems to involve the different sample selection criteria, skeletal APD/VT, and biomechanics for Pre-DC.…”

Section: Discussioncontrasting

confidence: 56%

Skeletal anteroposterior discrepancy and vertical type effects on lower incisor preoperative decompensation and postoperative compensation in skeletal Class III patients

Ahn¹,

Baek²

2011

“…These bony defects were not evident on macroscopic inspection, and this can happen without excessive proclination of teeth in patients with narrow and high alveolar bones. 5 Unfortunately, little information about the alveolar bone loss in adult skeletal Class III patients undergoing orthognathic surgery is available.…”

Section: Introductionmentioning

confidence: 99%

Alveolar Bone Loss around Incisors in Surgical Skeletal Class III Patients

Kim

Park

Kook

2009

Objective: To test the hypothesis that there is no difference in the vertical alveolar bone levels and alveolar bone thickness around the maxillary and mandibular central incisors in surgically treated skeletal Class III malocclusion patients. Materials and Methods:The study sample comprised 20 Korean patients with skeletal Class III malocclusion with anterior crossbite and openbite (9 male, 11 female, mean ages 24.1). Threedimensional cone beam computed tomography images were taken at least 1 month before the orthognathic surgery, and sagittal slices chosen at the labio-lingually widest point of the maxillary and mandibular right central incisor were evaluated. Measurement of the amount of vertical alveolar bone levels and alveolar bone thickness of the labial and lingual plate at the root apex was made using the SimPlant Pro 12.0 program. Results:The mandibular incisors showed reduced vertical alveolar bone levels than the maxillary incisors, especially on the lingual side. The alveolar bone thickness was significantly greater on the lingual side in the maxillary incisors, whereas the mandibular incisors exhibited an opposite result (P Ͻ .05). The percentage of vertical bone loss to root length showed a statistically significant difference between the upper labial and lower labial alveolar bone and also between the upper lingual and lower lingual alveolar bone, showing more bone loss in the lower incisors (P Ͻ .001). Conclusions:The hypothesis is rejected. For the skeletal Class III patients undergoing orthognathic surgery, special care should be taken to prevent or not aggravate preexisting alveolar bone loss in the anterior teeth, especially in the mandible. (Angle Orthod. 2009;79:676-682.)

“…6 Excessive dental expansion and proclination can lead to periodontal problems. 7 MSDO has been analyzed as an effective treatment alternative for the treatment of mandibular crowding. 7 More recent research has supported MSDO as a treatment option when risks to periodontal health and esthetic outcomes contraindicate the use of more traditional approaches.…”

Section: Introductionmentioning

confidence: 99%

“…7 MSDO has been analyzed as an effective treatment alternative for the treatment of mandibular crowding. 7 More recent research has supported MSDO as a treatment option when risks to periodontal health and esthetic outcomes contraindicate the use of more traditional approaches. 8 At present, multiple distraction devices are available.…”

Section: Introductionmentioning

confidence: 99%

Skeletal and dental effects of tooth-borne versus hybrid devices for mandibular symphyseal distraction osteogenesis

Niculescu

King

Lindauer

2013

Objective: To evaluate and compare, retrospectively, the skeletal and dental effects of mandibular symphyseal distraction osteogenesis (MSDO) achieved through the use of tooth-borne versus hybrid distractors. Materials and Methods: Pretreatment (T1), predistraction (T2), postdistraction (T3), and posttreatment (T4) orthodontic records were collected and analyzed for 47 patients (20 toothborne, 27 hybrid). At each time point, records included intraoral photographs, study models, postero-anterior cephalometric radiographs, and lateral cephalometric radiographs. Submental vertex radiographs were taken at T2, T3, and T4. Changes in a total of 18 measurements were analyzed to compare patients undergoing tooth-borne versus hybrid distraction. Results: The cumulative effects of orthodontics and MSDO produced similar gains in measured arch widths, with a decreased irregularity index in both groups (P . .05). However, there were differences in the timing during which the expansion was achieved. The hybrid distractor group gained space during the distraction phase of treatment. The tooth-borne group showed greater gains during pre-and postdistraction orthodontics. Comparisons of intercanine and interbone marker widths demonstrated a more parallel separation of bone during distraction with the hybrid distractor (P , .001). Distraction with the tooth-borne distractor was disproportionate, with greater separation of the canines in alveolar bone than of the bone markers in basal bone. During postdistraction orthodontics, the tooth-borne distractor group showed statistically greater increases in measurements. Conclusion: Both skeletal and dental expansion was achieved with both appliances. Greater skeletal expansion was achieved with a hybrid distractor. Greater dental expansion was achieved with a tooth-borne distractor. (Angle Orthod. 2014;84:68-75.)