Changes in the facial soft tissue profile after maxillary orthognathic surgery

OBJECTIVES To compare the changes of the soft tissue profile in relation to the displacement of the underlying hard structures in maxillary orthognathic surgery and to contribute to the esthetic prediction of the facial profile after surgical procedures. MATERIALS AND METHODS We analyzed the sagittal changes in the facial soft tissue profile related to surgical changes in skeletal structures after maxillary osteotomy in a retrospective study. The study sample comprised 115 adult patients between the ages of 18-50 years who had undergone maxillary orthognathic surgery and interdisciplinary orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. LeFort I osteotomy cases in both maxillary monognathic and bignathic osteotomy procedures were included. All subjects had received rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed and the correlations between hard tissue and soft tissue change ratios were evaluated using a bivariate linear regression analysis. A vertical line through the landmark sella (S) perpendicular to the nasion-sella line (NSL) served as the reference plane. RESULTS The subnasale (Sn) followed the A point (A) by 57%, the soft tissue A point (A') followed the A point (A) by 73% and the upper lip, represented by the landmark labrale superius (Ls) followed the upper incisor (Is) by 73%; all three in a linear correlation with a mean prediction error of nearly 2 mm. CONCLUSION The scatterplots show a linear correlation with a wide spread for all three pairs of reference points. The wide spread and the high prediction error of almost 2 mm indicate low predictability of the expected lip position and Sn.ZUSAMMENFASSUNG ZIELE: Die Veränderungen des Weichgewebeprofils in Relation zur Verlagerung der darunter liegenden Hartgewebe durch maxilläre orthognathe Chirurgie zu vergleichen und einen Beitrag zur ästhetischen Prognose des Gesichtsprofils nach chirurgischen Maßnahmen zu leisten. MATERIAL UND METHODE In einer retrospektiven Studie analysierten wir die sagittalen Veränderungen des fazialen Weichgewebeprofils in Beziehung zu den chirurgischen Veränderungen der skelettalen Strukturen nach maxillärer Osteotomie. Die Studienprobe besteht aus 115 erwachsenen Patienten im Alter von 18–50 Jahren, die sich interdisziplinär maxillärer orthognather Chirurgie und kieferorthopädischer Therapie an der Poliklinik für Kieferorthopädie der Ludwig-Maximilians-Universität München unterzogen hatten. LeFort-I-Osteotomie-Fälle sowohl maxillärer monognather als auch bignather Osteotomieverfahren wurden in die Studie aufgenommen. Alle Patienten hatten eine starre Fixierung erhalten. Es wurde eine kephalometrische Analyse von präoperativen und postoperativen Fernröntgenseitenbildern durchgeführt, die Korrelationen zwischen Hart- und Weichgewebeveränderungen wurden mittels einer bivariaten linearen Regressionsanalyse ausgewertet. Als Referenzebene diente eine vertikale Linie durch den Referenzpunkt Sella (S), rechtwinklig zur Nasion-Sella-Linie (NSL). ERGEBNISSE Der Punkt Subnasale (Sn) folgte dem A\hbox-Punkt (A) um 57 %, der Weichgewebe-A-Punkt (A′) folgte dem A-Punkt (A) um 73 %, und die Oberlippe, repräsentiert durch den Referenzpunkt Labrale superius (Ls), folgte dem Inzision superius (Is) um 73 %, alle 3 in einer linearen Korrelation bei einer mittleren Abweichung von fast 2 mm. FAZIT Die Punktdiagramme zeigen eine lineare Korrelation mit einer breiten Streuung aller 3 Referenzpunktpaare. Die breite Streuung und die hohe mittlere Abweichung von fast 2 mm lassen auf eine schwache Vorhersagbarkeit der zu erwartenden Position von Oberlippe und Sn schließen

Five‐year study of mandibular overdentures on stud abutments : clinical outcome, patient satisfaction and prosthetic maintenance : influence of bone resorption and implant position

Objectives: This prospective study analyses the 5-year clinical outcome, patient satisfaction and the technical outcome of a 2-implant overdenture on stud abutments. In addition, the influence of mandibular resorption and implant position on these outcomes was assessed. Material and methods: Patients received two implants in a one-stage delayed protocol. Final prosthesis on stud abutments was finalized after 3 months. Implant survival, bone loss, plaque and sulcus bleeding index, OHIP-14, technical outcome and costs were assessed after 5 years. The Cawood-Howell classification defined the mandibular resorption. Inter-implant distances and angles (frontal, sagittal) were digitally measured. The significance level was p < .05. Results: Fifty-six patients, 23 female and 33 males (mean age = 66.3, range 41-82), completed the follow-up. No implants were lost. Radiographical crestal bone loss was on average 1.25 mm (standard deviation SD 1.06), bleeding index was 0.75 (SD 0.73), and plaque index was 1.15 (SD 0.75) and higher for low mandibles (p = .001). The OHIP-14 reduction post-connection and after 5 years was significant (p < .001). Five-year maintenance required on average 6.7 (SD 4.8, range 0-25) interventions per patient. A larger inter-implant distance was associated with fewer replacement of retention inserts (p = .034) and less interventions (p = .006). Larger frontal (p = .023) and sagittal (p = .046) inter-implant angles (non-parallelism) required more inserts. The maintenance cost negatively influences the patient satisfaction (p = .004). 83% of the stud abutments showed wear. Conclusion: The implant overdenture on cylindrical stud abutments is a good and stable solution, irrespective of the resorption profile of the mandible. OHIP-14 improved permanently up to 5 years but is negatively influenced by complication cost. A small inter-implant distance, more frontal, sagittal inter-implant divergence increased maintenance

Five years follow‐up of mandibular 2‐implant overdentures on locator or ball abutments : implant results, patient‐related outcome, and prosthetic aftercare

Background: It is uncertain, which is the optimal attachment for a mandibular 2-implant overdenture (2IOD). Purpose: To assess 5 years clinical implant outcome, prosthetic maintenance, cost, and PROMs of two cohorts receiving 2IOD on ball or stud abutments in a comparative study. Materials and Methods: Ninety edentulous individuals were treated with balls (n = 34) or locator (n = 56). Implant survival, bone-to-implant level, prosthetic outcome, technical maintenance, and OHIP-14 were assessed. Statistics to compare between baseline and 1/5 years and between groups were t-test or Mann-Whitney (P < .05); chi-square was adopted to analyze plaque and technical maintenance or interventions between groups. Results: Five years implant survival was 98.7%, irrespective of attachment. Overall mean bone loss was 1.1 mm, probing pocket depth 1.92 mm, bleeding score 0.60, plaque score 1. Plaque accumulated more on locators (P = .023). OHIP-14 declined from 18.1 to 2.7 irrespective of attachment. Retention for balls was better (P < .005), locators required more maintenance (P < .001), caused by retention-adjustment (P < .001) or ulcers/pain (P = .014). Five years maintenance-cost was 11% of initial cost, irrespective of attachment. Conclusions: Balls and locators yield stable 5-years implant outcome and improved Oral Health Related Quality of Life (OHRQoL). Locators required more maintenance and resulted in a lower retention. Maintenance costs are minimal but may affect OHRQoL at least for stud abutments

A 5-year longitudinal cohort study on crown to implant ratio effect on marginal bone level in single implants

Background: A 5-year longitudinal cohort study was carried out to evaluate the influence of anatomical crown to implant ratio (CIR) on peri-implant marginal bone level (MBL) in single implants. Materials and Methods: The longest possible implants, according to the availability of pristine bone, were inserted, one per patient, among periodontally healthy teeth in consecutively recruited subjects. CIR and MBL changes were measured on standardized radiographs. The relationship between MBL and multiple predictors was investigated. A statistical analysis suitable for mixed type distributions was conducted: for the discrete component a logistic regression model was used and for the continuous component the impact of the variables on MBL was examined by using robust nonparametric comparison tests. Results: Seventy-eight dental implants were inserted in 34 mandibles and 44 maxillae, with one stage procedure in 40 cases and two stage in 38 cases. Thirty-five implants were &lt;10 mm, while 43 were ≥ 10 mm long; 28 implants had a CIR ≤1 and 50 had a CIR &gt;1. No drop-outs or implant loss were observed. Bone loss occurred only in a few cases, measuring less than 0.5 mm and being significantly more pronounced for implant length ≥10 mm, for lower CIR values and for the two stage procedure. Conclusion: Higher CIR values were not related to increased peri-implant bone loss; a &lt;10 mm long implant insertion may be safely considered for reduced bone heights