Lisen Espeland

Factors influencing the predictability of soft tissue profile changes following mandibular setback surgery.

The objective of this cephalometric study was to assess long-term changes in the soft tissue profile following mandibular setback surgery and investigate the presence of factors that may influence the soft tissue response to skeletal repositioning. The subjects enrolled were 80 consecutive mandibular prognathism patients operated with bilateral sagittal split osteotomy and rigid fixation. Lateral cephalograms were taken at 6 occasions: immediate presurgical, immediate postsurgical, 2 and 6 months postsurgical, and 1 and 3 years postsurgical. The subjects were grouped according to gender and magnitude of setback. Ratios of soft tissue to hard tissue movements were calculated for the subgroups. Females generally demonstrated greater ratios than males with a statistically significant difference for the upper lip and chin (P < .05). Postsurgical alterations in the profiles were more predictable in patients with larger setbacks compared to patients with smaller ones. Skeletal relapse had a profound influence on long-term profile changes. Based on these findings, it is proposed that the database used in prediction software be adjusted to account for such factors in an attempt to improve the accuracy of computerized treatment simulations.

Three-year follow-up of bimaxillary surgery to correct skeletal Class III malocclusion: stability and risk factors for relapse.

INTRODUCTION The purpose of this study was to evaluate long-term skeletal and occlusal stability after bimaxillary surgery to correct skeletal Class III malocclusion. METHODS The sample comprised 81 consecutively treated patients. All subjects had received a combined 1-piece LeFort I and bilateral sagittal split ostotomies with rigid fixation between 1990 and 2003 and were followed for 3 years. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery. RESULTS The mean setback was 6.9 mm in the mandible, and the maxilla was moved forward 3.7 mm. In most patients, the posterior maxilla was impacted. Relapse of maxillary advancement was insignificant (0.1 mm), whereas relapse at B-point was on average 1.7 mm (P <0.010). After 3 years, mean overjet and overbite amounts were 2.0 and 1.9 mm, respectively. Skeletal relapse of the mandible increased significantly with the surgical setback (P <0.001) and the change in the vertical position of the posterior maxilla (P = 0.010) (multivariate regression analysis). CONCLUSIONS Bimaxillary surgery resulted in good occlusal stability. Maxillary advancement was stable, whereas relapse of the mandibular setback varied. Risk factors for horizontal relapse of the mandible were large setback and inferior repositioning of the posterior maxilla.

Three-year stability of open-bite correction by 1-piece maxillary osteotomy.

INTRODUCTION The purpose of this retrospective cephalometric study was to evaluate the long-term vertical stability of anterior open-bite correction by 1-piece Le Fort I osteotomy and rigid fixation. METHODS The sample comprised 40 consecutively treated patients from the files of the Department of Orthodontics, University of Oslo, Norway. All subjects had received a 1-piece Le Fort I osteotomy as the only surgical procedure from 1990 through 1998 and were followed for 3 years according to a protocol for data collection. Lateral cephalograms were obtained before surgery and at 5 occasions after surgery. RESULTS The mean open bite before surgery was 2.6 mm; at the 3-year follow-up, 35 patients had a positive overbite, and the remaining 5 patients had an open bite between 0.2 and 0.9 mm. Impaction of the posterior maxilla >or=2 mm relapsed on average by 31%, and inferior repositioning of the anterior maxilla >or=2 mm relapsed by 62%. Maxillary vertical skeletal changes during the postsurgery period were compensated for by orthodontic dentoalveolar adaptation. Most of the skeletal relapse occurred during the first 6 months after surgery and always in the direction opposite to the surgical movement. The relative contribution of mandibular and maxillary changes in anterior open-bite closure was approximately 3:1. CONCLUSIONS Surgical correction of anterior open bite was generally stable over a 3-year period, and skeletal relapse was counteracted by dentoalveolar compensation.

Obstructive sleep apnea: a canonical correlation of cephalometric and selected demographic variables in obese and nonobese patients.

One hundred male obstructive sleep apnea (OSA) patients were classified into 2 groups on the basis of body mass index (BMI): 43 nonobese (BMI < 30 kg/m2) and 57 obese (BMI > or = 30 kg/m2) patients. A comprehensive cephalometric analysis with a multivariate statistical method was performed in order to define the different principal components (PCs) of cervico-craniofacial skeletal and upper airway soft tissue morphology in each group and how they contributed to selected elements of the patient demographic data, ie, apnea-hypopnea index (AHI), nocturnal oxyhemoglobin saturation, and BMI. Thirty cephalometric variables of cervico-craniofacial skeletal morphology were reduced to 8 PCs describing 84.4% and 85.4% of the total variance in obese and nonobese OSA patients, respectively. Sixteen cephalometric variables of hyoid bone position and head posture were reduced to 4 PCs describing 84.4% and 85.9% of the total variance in obese and nonobese OSA patients, respectively. Twenty cephalometric variables of upper airway soft tissue morphology were reduced to 7 PCs describing 89.5% and 84.6% of the total variance in obese and nonobese OSA patients, respectively. For further analysis of PCs, a stepwise multiple regression analysis was chosen. Two dependent variables of interest are the minimal distance of the posterior pharyngeal airway space (PASmin) and AHI. PASmin accounted for 95.3% (obese OSA group) and 74.3% (nonobese OSA group) with 7 PCs and AHI for 46% with 3 PCs in both groups. Three canonical variables and their correspondents with different loadings were established differently for both OSA groups. A canonical correlation successfully clarified the complexity of simultaneous relationship of the relevant variables. These analyses are proved useful to demonstrate the relationship of cervico-craniofacial skeletal and upper airway soft tissue morphology and selected demographic data. This lays down a basis for understanding the complicated pathogenic components of obese and nonobese OSA patients.

Retention: type, duration and need for common guidelines. A survey of Norwegian orthodontists.

AIMS To survey retention protocols and need for practical retention guidelines among orthodontists in Norway and to compare the results with similar studies in other countries. METHODS A questionnaire was mailed to all members of the Norwegian Association of Orthodontists. It included questions about their background and their current retention protocol, as well as their perceived need for common retention guidelines. RESULTS The response rate was 77.7% (69.3% males and 30.7% females). The most common maxillary retainer was a combination of a fixed and removable retainer, followed by a clear thermoplastic retainer. In the mandible, a fixed retainer bonded to all anterior teeth was most common (66.4%). Retention in the maxilla lasted 2 to 3 years (34.7%) or 3 to 5 years (23.8%). In the mandible, 41.5% of the orthodontists left the retainer in place for >5 years. When retention lasted more than 3 years, 70% of the orthodontists left the responsibility for retainer checkups to the patients or the general practitioners. The main reason for choosing a certain retention protocol was clinical experience (57.4%). Only 3.5% of the orthodontists based their protocols on information from the literature. Half?of the orthodontists, significantly women, expressed a need for common retention guidelines. CONCLUSIONS In Norway, bonded retainers alone were reported to be most commonly used in the mandible, while bonded retainers used in combination with a removable retainer appear to be the most commonly used appliances in the maxilla. This is similar to the most frequently used retainers in other countries, but there are disparities in duration and follow-up protocols. Most female orthodontists desire common retention guidelines.

Bedarf und Wunsch nach kieferorthopädischer Behandlung bzw. Wiederbehandlung bei 35jährigen Norwegern

Long-term outcome of orthodontic care systems may be studied by examining malocclusion and treatment need in groups of treated and untreated adults. The objective of the present work was to investigate the professionally defined need as well as the need perceived by the individuals in an attempt to study the outcome of orthodontic services. The material comprised data from 111 individuals collected from a random sample of 35-year-olds from Oslo, Norway. From a clinical examination and measurements on dental study casts, the subjects were classified into either of 4 levels of need according to the Need for Orthodontic Treatment Index (NOTI) used by the Norwegian Health Insurance System. Perceived need for treatment was analyzed from responses to questions about satisfaction with dental appearance and desire for orthodontic treatment presented in a questionnaire. Satisfaction with dental appearance was recorded in 85% and 92% of untreated and previously treated, respectively. Desire for treatment was expressed by 19% of the untreated and 3% of the treated individuals. Occlusal anomalies were present among both the treated and untreated subjects, and the clinical significance of the malocclusion traits observed is discussed.ZusammenfassungAnhand einer Untersuchung der Zahnfehlstellung und des Behandlungsbedarfs bei Gruppen von behandelten und unbehandelten Erwachsenen können die langfristigen Ergebnisse der kieferorthopädischen Therapie erforscht werden. Ziel der vorliegenden Arbeit war es, die Ergebnisse der kieferorthopädischen Behandlungen zu untersuchen, um sowohl den ärztlich definierten als auch den vom einzelnen empfundenen Bedarf zu ermitteln. Das Untersuchungsmaterial umfaßt Daten von 111 unselektierten 35jährigen aus Oslo, Norwegen. Anhand einer klinischen Untersuchung und Analysen von dentalen Studienmodellen wurden die Probanden in eine von vier Bedarfskategorien nach dem norwegischen Indikationssystem („Need for Orthodontic Treatment Index“ [NOTI]), das von der staatlichen Sozialversicherung angewendet wird, eingeteilt. Mittels eines Fragebogens wurde nach der Zufriedenheit mit der eigenen dentofazialen Ästhetik und dem Wunsch, sich einer kieferorthopädischen Behandlung zu unterziehen, gefragt. Danach wurden die Antworten hinsichtlich des vom einzelnen empfundenen Behandlungsbedarfs analysiert. Zufriedenheit mit der eigenen dentofazialen Ästhetik wurde bei 85% der unbehandelten und 92% der früher behandelten Probanden festgestellt, während der Wunsch nach einer Behandlung bei 19% der unbehandelten und 3% der behandelten Probanden bestand. Okklusale Anomalien wurden sowohl bei behandelten als auch bei unbehandelten Probanden festgestellt, und die klinische Signifikanz der Befunde in bezug auf Zahn/Kiefer-Fehlstellungen wird erörtert.SummaryLong-term outcome of orthodontic care systems may be studied by examining malocclusion and treatment need in groups of treated and untreated adults. The objective of the present work was to investigate the professionally defined need as well as the need perceived by the individuals in an attempt to study the outcome of orthodontic services. The material comprised data from 111 individuals collected from a random sample of 35-year-olds from Oslo, Norway. From a clinical examination and measurements on dental study casts, the subjects were classified into either of 4 levels of need according to the Need for Orthodontic Treatment Index (NOTI) used by the Norwegian Health Insurance System. Perceived need for treatment was analyzed from responses to questions about satisfaction with dental appearance and desire for orthodontic treatment presented in a questionnaire. Satisfaction with dental appearance was recorded in 85% and 92% of untreated and previously treated, respectively. Desire for treatment was expressed by 19% of the untreated and 3% of the treated individuals. Occlusal anomalies were present among both the treated and untreated subjects, and the clinical significance of the malocclusion traits observed is discussed.

Soft tissue response after Class III bimaxillary surgery

OBJECTIVE To analyze the impact of surgical change in anterior face height and skeletal relapse on the long-term soft tissue profile. MATERIALS AND METHODS Cephalometric radiographs of 81 patients taken before surgery and at five time points during a 3-year follow-up period were analyzed. All patients had Le Fort I and bilateral sagittal split osteotomies. The patients were divided into three subgroups according to the change in anterior face height during surgery. Calculations of soft to hard tissue ratios were based on the long-term soft tissue response relative to the surgical repositioning. RESULTS The horizontal surgical repositioning varied considerably, depending on whether anterior face height was increased or decreased. For upper lip prominence, the pattern of long-term change was the same irrespective of change in face height. In all groups, upper lip thickness decreased in both the short term and the long term, particularly in patients with surgical increase in face height. Lower lip thickness increased in the short term but decreased during the follow-up period. There were significant associations between horizontal soft tissue and corresponding hard tissue changes, except for soft tissue A-point and upper lip, when face height was increased. The ratios were higher for mandibular variables than for maxillary variables, particularly for B-point and pogonion when anterior face height had decreased. CONCLUSION A change in facial height influences the soft tissue response. The mandibular soft tissues closely follow skeletal relapse beyond 2 months postsurgery. The findings have clinical implications for the relative maxillary and mandibular repositioning when planning surgery.

A 57-year Follow-up Study of Occlusion

Objectives:To analyze changes in occlusion between the ages of 8 and 65 years in persons with a deep overbite at the age of 8 who did not receive orthodontic treatment. To describe their experiences regarding their own dentition as well as their opinions on dental esthetics and oral health. To compare these findings with those of the Normal Occlusion (N-Group) described in Part 1.Subjects and Methods:With one exception, the 20 persons in our cohort had not undergone orthodontic therapy. Our documentation was based on intraoral photographs taken at the two time points in addition to an interview and facial photos at the age of 65.Results:The overbite could be evaluated in 16 persons. In four persons various degrees of mucosal indentations in connection with the overbite had been registered. The average number of missing teeth was 3.4, compared to 1.6 in the N-group. All participants reported their oral health to be good or excellent and, similar to the N-group, nearly all considered dental esthetics to be important.Conclusion:The overbite had decreased during the observation period in nine, increased in five, and remained stable in two persons.ZusammenfassungZiel:Die Veränderungen der Okklusion zwischen dem 9. und 65. Lebensjahr bei Personen zu untersuchen, die mit 8 Jahren einen frontal tiefen Biss hatten und kieferorthopädisch nicht behandelt wurden. Gleichzeitig sollten die Erfahrungen erfasst werden, die diese Personen in Bezug auf ihre Dentition gemacht hatten sowie ihre Ansichten zu dentaler Ästhetik und oraler Gesundheit. Die Beobachtungen sollten mit denjenigen der Referenzgruppe (N-Gruppe; Teil 1) verglichen werden.Probanden und Methodik:Mit einer Ausnahme waren die 20 Personen der Stichprobe kieferorthopädisch nicht behandelt worden. Die angewandte Dokumentation bestand aus intraoralen Fotos von beiden Untersuchungszeitpunkten und im Alter von 65 Jahren zusätzlich aus einem Interview und Gesichtsfotos.Ergebnisse:Der tiefe Biss konnte bei 16 Personen analysiert werden. Vier Personen hatten verschiedene Grade an Schleimhautläsionen im Zusammenhang mit dem tiefen Biss. Im Durchschnitt fehlten 3,4 Zähne verglichen mit 1,6 Zähnen in der N-Gruppe. Alle Befragten beurteilten ihre Mundgesundheit als gut oder ausgezeichnet und alle sahen, wie in der N-Gruppe, dentale Ästhetik als wichtig an.Schlussfolgerung:Der Überbiss hatte sich bei neun Personen verkleinert, bei fünf vergrößert und war bei zwei Personen stabil geblieben.

Asymmetric mandibular prognathism: Outcome, stability and patient satisfaction after BSSO surgery. A retrospective study

PURPOSE To investigate surgical outcome, long-term stability, the time course of relapse, neurosensory disturbances, and patient satisfaction after BSSO for correction of mandibular asymmetry. Another objective was to examine whether osteotomies for transverse rotation of the distal segment represent an increased risk for nerve injury. SUBJECTS AND METHODS In a retrospective study lateral and postero-anterior cephalograms, information from patient files and questionnaires were analysed for 38 patients having more than 4 mm asymmetry at the chin pre-treatment (mean 8.4 mm). The radiographs were analysed preoperatively, postoperatively, after 6 months and 3 years. RESULTS Asymmetry of the chin to the facial midline improved on average by 56%. Skeletal relapse was about the same for transverse and antero-posterior surgical changes (10-15%). 58% of the patients had asymmetry of more than 3 mm at menton 3 years post-surgery. Discrepancy between upper and lower dental midlines improved on average 80%. Normal or near normal sensation to the lower lip/chin was reported by 44% of the patients which is similar to sensory disturbances after BSSO straight set-back performed by the same surgical team. A difference in the incidence of neurosensory disturbance between the two osteotomy sides was observed. Satisfaction with the treatment result was reported by all patients except for two. CONCLUSION Correction of mandibular asymmetry by BSSO is fairly stable. Although the risk for sensory impairment for the individual patient was similar to impairment in a sample having straight setback, rotation of the distal segment during surgery may represent an increased risk for sensory impairment on the deviating side (P = 0.06). Three years after surgery patients were generally satisfied with the result even if more than 3 mm of asymmetry at the chin remained for 58%. The findings have implications for treatment planning and the decision to elect one-jaw, bimaxillary surgery and/or additional genioplasty.

Extraoral vertical subcondylar osteotomy with rigid fixation for correction of mandibular prognathism. Comparison with bilateral sagittal split osteotomy and surgical technique

PURPOSE The aim was to compare outcome after extraoral vertical subcondylar osteotomy (EVSO) with rigid fixation and bilateral sagittal split osteotomy (BSSO) for correction of mandibular prognathism. The objectives were to examine treatment factors, postoperative results, and long-term stability. The surgical technique for EVSO is presented in detail. SUBJECTS AND METHODS Lateral cephalograms and information from patient files of 65 consecutively operated patients with EVSO and 65 matching patients operated with BSSO were analyzed preoperatively, postoperatively, after 6 months and 3 years. RESULTS No clinically significant differences were observed in long-term stability. The retromandibular scar inferior to the earlobe after EVSO was on average 25 mm long and 1 mm wide, and was of no concern for most of the patients. Normal or near normal sensation to the lower lip/chin was reported by half of the BSSO patients at the 3-year follow-up. CONCLUSION Because no major differences in outcome were observed, EVSO with rigid fixation may be considered as a viable alternative if it is important to avoid alterations in sensation, whereas BSSO may be preferred if retromandibular scar is of concern.