Evaluation of the aesthetics and clinical findings in patients with missing maxillary lateral incisors treated with a 10-year interval

INTRODUCTION

The most common treatment approaches for patients missing maxillary lateral incisors are implant replacement (IT) and orthodontic space closure (SC). Treatment techniques change and improve over time, and it is of interest to know if improvements differ between the methods.

AIM

To compare the aesthetic outcome and other clinical findings in patients with one or two missing maxillary lateral incisors who were treated with a 10-year difference in time, with either orthodontic space closure or implant replacement.

MATERIAL AND METHODS

A total of 88 patients were included in the study. Forty-four patients treated between 2011 and 2018 were included as the latter cohort (LC). The LC was compared to the early cohort (EC; n = 44), treated between 2001 and 2008. A total of 132 teeth was analysed: 62 teeth in the EC (28 teeth in IT cases and 34 teeth in SC cases) and 70 teeth in the LC (34 teeth in IT cases and 36 teeth in SC cases). Long-term clinical and aesthetic outcomes were evaluated.

RESULTS

An improvement over time was found in crown length, BoP, papilla, the inclination of incisors, and overall appearance in IT cases and in crown colour and overbite in SC cases. A deterioration over time was found in crown length and BoP among the SC cases.

CONCLUSION

Among the IT cases, an improvement in outcomes was noted over time. When comparing SC cases the colour of the crown and overbite had improved, while crown length and BoP had deteriorated over time.

A cost analysis of orthodontic space closure and implant treatment in patients missing maxillary lateral incisors with a long-term perspective

OBJECTIVE

Few studies within orthodontics present both economic and clinical findings. Missing maxillary lateral incisors is a frequently occurring anomaly. The treatment alternatives most used are orthodontic space closure and prosthetic replacement of the missing tooth. Our aim is to compare the total societal costs of orthodontic space closure (SC) and implant therapy (IT) in patients missing maxillary lateral incisors.

METHODS

Records of 32 patients treated with SC (n = 18) or IT (n = 14) due to missing maxillary lateral incisors were retrieved from the archives. Direct costs and indirect costs in the short- and long-term were analysed using a cost analysis with a societal perspective up of to 12 years post-treatment.

RESULTS

Comparing cases treated with SC and IT, the difference in direct short-term costs for treatment is €735.54, whereas SC is the least costly. There is no difference between SC and IT in short-term parent loss of productivity, long-term loss of productivity, costs for transportation, or direct long-term costs. A difference was found between SC and IT-in favour of SC-when comparing patients' loss of productivity (P = 0.007), short-term societal costs (P < 0.001), long-term societal costs (P = 0.037), and total societal costs (P < 0.001).

LIMITATIONS

There is a limited number of patient records. Local factors such as subsidies, urban versus rural areas, taxes, etc. can influence monetary variables, so the transferability to other settings may be limited.

CONCLUSION

Patients treated with SC have a lower total societal cost compared to patients treated with IT. There was a difference in productivity loss for patients between SC and IT; however, concerning other indirect parameters and direct long-term costs, there was no difference between the two treatments.

Pain and discomfort during the first week of maxillary expansion using two different expanders: patient-reported outcomes in a randomized controlled trial

BACKGROUND

Quad Helix (QH) is the appliance most preferred by orthodontists to correct unilateral posterior crossbite in the early mixed dentition while other orthodontists suggest rapid maxillary expansion (RME) on deciduous teeth in these patients.

OBJECTIVES

To evaluate and compare perceived pain intensity, discomfort, functional jaw impairment, and analgesic consumption during the first week of treatment with either RME or QH appliances.

TRIAL DESIGN

Two-arm parallel group, two-centre, randomized controlled trial.

MATERIAL AND METHODS

Seventy-two patients, mean age 9.5 (SD ±0.8) years, with unilateral posterior crossbite requiring maxillary expansion were randomly allocated to either the RME (22 boys, 14 girls) or QH (22 boys, 14 girls) group. Validated questionnaires were used to assess pain intensity, discomfort, jaw function impairment, and analgesic consumption, on the first, fourth, and seventh days after appliance insertion and activation.

BLINDING

Due to clinical limitations, only the outcome assessors were blinded to the groups to which the patients were allocated.

RESULTS

Seventy patients completed the questionnaires. Pain from the tongue and chafe from the appliance were significantly higher in the QH group on the first day of treatment (P = 0.003 and P = 0.000, respectively). On the fourth day, the chafe from the appliance was still significantly higher in the QH group (P = 0.007). Speech was affected in both groups on day 1; this impairment continued and was significantly higher in the RME group days 4 and 7. No significant difference in analgesic consumption was found between the groups at any time. The analgesic consumption was highest at day 1 of treatment.

HARMS

No harm was observed in any patient.

LIMITATIONS

Double blinding was not possible due to the clinical limitations.

CONCLUSION

During the initial 4 days of treatment, pain from the tongue and chafe from the appliance caused the most reported inconvenience in the patients in the QH group. A majority of reported visual analogue scale values were in the lower mid-range, suggesting low to moderate pain and discomfort in both groups.

CLINICAL TRIAL REGISTRATION

NCT04458506.

Malocclusions, pathologic tooth migration, and the need for orthodontic treatment in subjects with stage III-IV periodontitis. A cross-sectional study

BACKGROUND

Literature is scarce on malocclusion prevalence and orthodontic treatment need (OTN) in subjects with stage III-IV periodontitis. Study aims were to assess prevalence of primary and secondary malocclusions in subjects with stage III-IV periodontitis and OTN based on pathologic tooth migration (PTM) and occlusal trauma of anterior teeth (AT).

SUBJECTS AND METHODS

One hundred and twenty-one subjects with stage III-IV periodontitis were examined. A comprehensive periodontal-orthodontic examination was performed. Exclusion criteria: age <30 years, removable prosthetics, uncontrolled diabetes, pregnancy/lactation, and oncologic disease.

RESULTS

Class II malocclusion was found in 49.6% (Class II div 1-20.7%, Class II div 2-9.9%, subdivision Class II-19.0%), Class I-31.4%, Class III-10.7%, no malocclusion-8.3% of subjects. PTM was observed in 74.4% of maxillary and 60.3% of mandibular AT. Spacing and extrusion were the main types of PTM of AT. Odds ratio for PTM of maxillary AT was 9.3 in cases with >30% of sites with clinical attachment loss ≥5 mm (P = 0.001). Spacing of maxillary AT was influenced by periodontitis, Class III malocclusion, and lost teeth. Tongue habit had impact on spacing of mandibular AT. Dental Health Component of Index of Orthodontic Treatment Need yielded that OTN was found in >50% and OTN due PTM, occlusal trauma and impaired function in 66.1% of subjects.

CONCLUSIONS

The most prevalent malocclusion was Class II. Spacing and extrusion were prevalent types of PTM of AT. OTN was found in more than half of the subjects. The study highlights the need for preventive measures for PTM in subjects with stage III-IV periodontitis.

Laypeople and dental professionals' perception of the aesthetic outcome of two treatments for missing lateral incisors

Objective

To investigate laypeople and dental professionals' opinions of the aesthetic outcome from implant therapy (IT) and orthodontic space closure (SC) for missing maxillary lateral incisors.

Material and methods

Evaluation was performed by three groups: laypeople 20–30 years of age (n = 26), laypeople 50–70 years of age (n = 26) and orthodontists (n = 25). The assessors viewed photographs of 44 different cases treated with IT or SC, and made an evaluation of the aesthetics.

Results

The gingival color adjacent to the replaced tooth was rated as having better aesthetics in the SC cases (p = 0.000). The orthodontists preferred the aesthetics of the dentition in the SC cases (p = 0.042). The young laypeople, compared to the older laypeople and orthodontists, were more dissatisfied with the color of the tooth replacing the missing lateral incisor in SC cases (p = 0.043).

Conclusion

The color of the gingiva adjacent to the implant‐supported crowns had a lower aesthetic rating than the SC group. Laypeople rated both treatments as equally good. The orthodontists had a slight preference for the aesthetics in the SC cases.

Open and closed surgical exposure of palatally displaced canines: a cost-minimization analysis of a multicentre, randomized controlled trial

OBJECTIVE

To evaluate the costs of open and closed surgical exposure and subsequent orthodontic treatment for the correction of palatally displaced canines (PDCs).

TRIAL DESIGN

A multicentre, two-arm parallel group randomized controlled trial.

METHODS

One hundred twenty adolescents between 9 and 16 years of age, from three orthodontic specialist centres, were randomized to one of the two surgical exposure interventions. The randomization was conducted according to a two-arm parallel group 1:1 allocation ratio, using computerized lists with block randomization. In both the surgical techniques, whole mucoperiosteal flaps were raised, and bone covering the PDCs was removed. In the open technique, glass ionomer was built up on the PDC crown - reaching above the mucosa through a hole punched in the flap - to allow the canine to erupt autonomously. After eruption, the canine was orthodontically moved above the mucosa. In the closed technique, an eyelet was bonded onto the PDC, the flap was repositioned and the canine was orthodontically moved beyond the mucosa. The trial ended when the PDC was successfully aligned in the dental arch.Cost analysis was performed including costs for surgery, orthodontic treatment, emergency visits, and material, as well as costs for transports and time spent in connection with every appointment.

BLINDING

Patients and caregivers could not be blinded due to obvious limitations of the clinical setting, while outcome assessors and data analysts were blinded.

RESULTS

A cost-minimization analysis was performed since both exposure groups succeeded equally well in terms of treatment effects. The two different surgical exposures and following orthodontic treatments did not differ significantly in terms of costs.

GENERALIZABILITY AND LIMITATIONS

Costs are estimated in the Swedish setting, which needs to be considered if applying the results in other settings. Calculations of total cost do not include finishing, debonding, retention, and follow-up.

CONCLUSION

There is no significant difference in costs between closed and open surgical exposure with following orthodontic treatments in PDCs.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02186548.

Open vs closed surgical exposure of palatally displaced canines: a comparison of clinical and patient-reported outcomes-a multicentre, randomized controlled trial

OBJECTIVES

To compare treatment time, patients' perceptions during orthodontic treatment, dental fear and side effects, between open and closed surgical exposures in patients with palatally displaced canines (PDCs).

TRIAL DESIGN

Multicentre, randomized controlled trial, with random 1:1 allocation of two parallel groups.

MATERIALS AND METHODS

One hundred and twenty patients from three different orthodontic centres were randomized into one of the two intervention arms, open or closed surgical exposure. Both techniques had mucoperiosteal flaps raised and bone removed above the PDCs. In open exposure, tissue was removed above the canine, and glass ionomer - reaching above soft tissue - was built on the crown. The canine was then left to erupt spontaneously, prior to orthodontic alignment. At closed exposure, a chain was bonded to the canine and orthodontic traction was applied under the mucosa until eruption. Orthodontic alignment of the canines was undertaken after eruption into the oral cavity, with fixed appliances in both groups. All participants were treated according to intention to treat (ITT).

BLINDING

Due to the nature of this trial, only outcome assessors could be blinded to the intervention group.

RESULTS

One hundred and seventeen patients completed the trial. All PDCs were successfully aligned. Total treatment time was equal in the two techniques, mean difference -0.1 months (95% CI -3.2 to 2.9, P = 0.93). The closed group experienced more pain and discomfort during the active orthodontic traction. Dental fear, root resorption and periodontal status did not show any clinically significant differences between the groups.

GENERALIZABILITY

Results of this randomized controlled trial (RCT) can be generalized only to a similar population aged 9-16 years, if exclusion criteria are met.

CONCLUSION

The closed exposure group experienced more pain and discomfort mostly during active orthodontic traction. All other studied outcomes were similar between the two exposure groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

Outcome of periodontal–orthodontic treatment in subjects with periodontal disease. Part II: a CBCT study of alveolar bone level changes

Aim

To examine alveolar bone level (ABL) changes before (T1) and after (T2) orthodontic treatment (OT) in subjects with periodontal disease.

Methods

The study included 50 subjects with periodontal disease. All patients received subgingival debridement following baseline examination. Control group patients received final periodontal treatment before the start of OT. For the test group patients final periodontal treatment was performed simultaneous to OT. OT was performed with a straight-wire appliance. Micro-implants or temporary crowns on implants were used for posterior anchorage when needed. ABL measurements of 3821 tooth surfaces were performed on cone beam computed tomography images.

Results

No difference was observed between mean ABL at T1 and T2. ABL remained unchanged on 69 per cent of surfaces. A mean of 15.6 (SD 7.4) per cent of surfaces experienced ABL gain, and a mean of 15.1 (SD 7.5) per cent was found with ABL loss. Small significant median ABL difference was observed on mesial and distal surfaces (P < 0.001). A significant difference was found between median ABL changes on mesial/distal in comparison to buccal/lingual surfaces (P < 0.01). Significantly more buccal (17.9 %) and lingual (18.5 %) surfaces experienced ABL loss when compared with mesial (11.3 %) and distal (12.0 %) surfaces (P < 0.001). Significant difference was found in the median ABL change of intruded (0.5 (IQR 0.94) mm) and non-intruded (−0.4 (IQR 1.07) mm) maxillary incisors (P = 0.04). Significant median ABL gain was found on the lingual surface of maxillary incisors, which were retroclined more than 8.6 degree and intruded more than 1.6 mm.

Conclusions

ABL changes after periodontal–orthodontic treatment in patients with periodontal disease were small. ABL gain was more observed on mesial and distal surfaces and ABL loss on buccal and lingual surfaces. Larger orthodontic movements of maxillary incisors influenced ABL gain.

Outcome of orthodontic treatment in subjects with periodontal disease. Part III: a CBCT study of external apical root resorption

Background

No evidence is present on the risk for external apical root resorption (EARR) during orthodontic treatment (OT) of adult patients with periodontal disease.

Aim

To examine EARR after OT in subjects with periodontal disease and to analyse how intrusion and change in inclination of the most proclined maxillary incisors influence EARR.

Methods

The study included 50 patients with periodontal disease. Sub-gingival debridement by ultrasonic instrumentation supplemented with hand instruments was performed by experienced dental hygienist after baseline examination for all patients. For the control group, final periodontal treatment (PT) was performed before orthodontic tooth movement. For the test group patients, final PT was performed after levelling and alignment phases were finished, before the active space closure with elastic chain and/or inter-arch elastic traction for sagittal correction was started. OT was performed with a straight-wire appliance. Micro-implants or implants were used for posterior anchorage. Cone beam computed tomography examinations were performed before and after OT. EARR of all single-rooted teeth were measured. EARR of the most proclined maxillary incisor was related to intrusion and change in inclination angle.

Results

EARR after OT was observed in median 80.7 per cent (interquartile range 22.02) of single-rooted teeth [mean 1.2 (standard deviation 0.44) mm]. In 82.3 per cent of teeth, EARR was 2 mm or less. Severe EARR was found in 8 per cent of patients and five maxillary incisors (less than 1 per cent of all teeth). The amount of intrusion and change in inclination angle of the most proclined maxillary central incisor influenced the extent of EARR. Mean EARR was significantly higher when OT lasted more than 18 months (P = 0.02).

Conclusions

OT in conjunction with PT in periodontal patients resulted in EARR in 81 per cent of all single-rooted teeth. Intrusion and change in inclination angle of the most proclined maxillary central incisor influenced the extent of EARR, as did longer OT.

Perception of orthodontic treatment need among Swedish children, adolescents and young adults

OBJECTIVE

Perceptions of orthodontic treatment need and perceptions of dental aesthetics was investigated among subjects ages 10, 15 and 19.

MATERIALS AND METHODS

A total of 489 subjects completed a questionnaire after inspecting 10 photographs in the Aesthetic Component scale of the Index of Orthodontic Treatment Need to (i) reveal the lower limit for orthodontic treatment need and (ii) rate their dental aesthetics by selecting the most similar photo.

RESULTS

The mean lower limit for orthodontic treatment need was significantly higher (and closer to literature-based standards) among subjects, age 10 (4.2 ± 1.5), than among subjects, age 15 (3.6 ± 1.2) (p = .0009), and subjects, age 19 (3.5 ± 1.2) (p = .00002). Among subjects ages 15 and 19, the lower limit for orthodontic treatment need was lower in groups with (i) self-perceived orthodontic treatment need (p = .002 and .001, respectively) and (ii) previous orthodontic treatment (p = .005 and .035, respectively). Self-perceived orthodontic treatment need was present in more than one-third of subjects, age 19, who had previously received orthodontic treatment. Subjects of foreign origin reported that their dental aesthetics were worse (p = .002) and those same subjects, age 19, set the lower limit for orthodontic treatment lower (p = .047) than Swedes, age 19.

CONCLUSIONS

The lower limit for orthodontic treatment need among subjects, age 10, was higher - compared to subjects, ages 15 and 19 - and closer to literature-based standards. Subjects with self-perceived orthodontic treatment need, subjects with previous orthodontic treatment, and subjects age 19 of foreign origin, have higher aesthetic demands.

Orthodontic treatment in periodontitis-susceptible subjects: a systematic literature review

The aim is to evaluate the literature for clinical scientific data on possible effects of orthodontic treatment on periodontal status in periodontitis-susceptible subjects. A systematic literature review was performed on studies in English using PubMed, MEDLINE, and Cochrane Library central databases (1965-2014). By manually searching reference lists of selected studies, we identified additional articles; then we searched these publications: Journal of Periodontology, Periodontology 2000, Journal of Clinical Periodontology, American Journal of Orthodontics and Dentofacial Orthopedics, Angle Orthodontist, International Journal of Periodontics & Restorative Dentistry, and European Journal of Orthodontics. Search terms included randomized clinical trials, controlled clinical trials, prospective and retrospective clinical studies, case series >5 patients, periodontitis, orthodontics, alveolar bone loss, tooth migration, tooth movement, orthodontic extrusion, and orthodontic intrusion. Only studies on orthodontic treatment in periodontally compromised dentitions were included. One randomized controlled clinical trial, one controlled clinical trial, and 12 clinical studies were included. No evidence currently exists from controlled studies and randomized controlled clinical trials, which shows that orthodontic treatment improves or aggravates the status of periodontally compromised dentitions.

Twelve-year follow-up of mandibular incisor stability: Comparison between two bonded lingual orthodontic retainers

OBJECTIVE

To compare the long-term outcome 9 years after removal of two different types of fixed retainers used for stabilization of the mandibular anterior segment.

MATERIALS AND METHODS

Sixty-four children who had undergone orthodontic treatment with fixed appliances in both arches were divided into two groups depending on which kind of retainer being used. Twenty-eight of the patients had a canine-to-canine retainer bonded to the canines and 36 had a bonded twistflex retainer 3-3, bonded to each tooth. Measurements were made on study models and lateral head radiographs, before and after treatment, 6 years after treatment, and 12 years after treatment, with a mean of 9.2 years after removal of the retainers.

RESULTS

No significant differences were found between the two groups at the long-term follow-up according to Little's Irregularity Index or available space for the mandibular incisors. The overjet and overbite were reduced after treatment in both groups and stayed stable throughout the observation period. Also, no differences in bonding failures between the two retainers were found.

CONCLUSIONS

Both a canine-to-canine retainer bonded only to the canines and a twistflex retainer 3-3 bonded to each tooth can be recommended. However, neither of the retention types prevented long-term changes of mandibular incisor irregularity or available space for the mandibular incisors after removal of the retainers.

Orthodontic treatment need, outcome and residual treatment need in 15- and 20-year-olds

The aim of the study was to investigate orthodontic treatment need and the outcome of orthodontic treatment in 15-, and 20-year-olds in Jönköping, Sweden, with special reference to residual treatment need. An offer to participate in a clinical investigation was extended to random samples of 130 15-year-olds and 130 20-year-olds. Ninety-six of the 15-year-olds (73.3%; 45 boys and 51 girls) and 82 of the 20-year-olds (62.6%; 47 males and 35 females) accepted and presented for examination The participants filled in a questionnaire and impressions were taken for study models, which were graded according to the ICON index. In all, 39 (40.6%) of the 15-year-olds and 38 (46.3%) of the 20-year-olds had undergone or were currently undergoing orthodontic treatment. Ninety-one per cent of the 15-year-olds and 84% of the 20-year-olds considered that the orthodontic treatment goals had been fully or almost fully attained. Two of the 15-year-olds and two of the 20-year-olds currently wanted orthodontic treatment. This indicates a residual treatment demand of about 2%.

Autotransplantation of teeth in 215 patients. A follow-up study

OBJECTIVE

To evaluate the success rate of autotransplantation of teeth in consecutive patients and to analyze factors affecting the outcome.

MATERIALS AND METHODS

The subjects consisted of 215 consecutive patients (101 women and 114 men; aged 9.1-56.4 years, median age 15.2 years [P(10) = 11.4, P(90) = 19.7]) who had undergone transplantation of a total of 269 teeth, all by the same surgeon. In patients with multiple transplants, only the first transplant was included, to ensure that all transplanted teeth were independent units. The transplants were recorded as unsuccessful if the tooth had been extracted or was surviving but with root resorption or ankylosis. The interval between transplantation and final follow-up was a median 4.8 years (P(10) = 2.0, P(90) = 5.5) for successful transplants and a median of 2.4 years (P(10) = 0.4, P(90) = 7.7) for unsuccessful transplants.

RESULTS

One-hundred seventy-five (81%) of the transplantations were recorded as successful and 40 (19%) as unsuccessful. Twenty-five teeth had been extracted and 15 had survived but did not fulfill the criteria for success.

CONCLUSIONS

The success rate of 215 consecutively transplanted teeth was 81%. The highest success rate was for transplantation of premolars to the maxillary incisor region (100%). Complications at surgery such as difficult extraction, deviant root anatomy, or damaged root periodontium affected the outcome. During growth, a successful transplant preserves alveolar bone.

A qualitative study of the influence of poor dental aesthetics on the lives of young adults

OBJECTIVE

Although many countries offer some publicly funded orthodontic treatment for children, not all conditions receive treatment and some adolescents enter adulthood with persisting poor dental aesthetics or malocclusions. The aim of this study was to generate a theory highlighting the main concerns of young adults, either native-born or of immigrant background, with poor dental aesthetics and the measures they adopt to manage their condition in everyday life.

MATERIAL AND METHODS

A qualitative method, classic grounded theory, was applied in order to generate a substantive theory highlighting the main concerns and managing mechanisms of 13 strategically selected 19- and 20-year-olds with poor dental aesthetics. Open interviews were conducted with each participant, the topics covering different aspects of social and dental conditions.

RESULTS

A core category and three conceptual categories were generated. The core category was labelled "Being under the pressure of social norms" and was related to categories explaining three different ways in which these young adults handle their main concern: (1) avoiding showing their teeth; (2) minimizing the importance of appearance; and (3) seeking orthodontic treatment. The theory offers the potential for improved understanding of young adults who, despite poor dental aesthetics, are managing well with life, and also of those who have not adjusted well.

CONCLUSIONS

In early adolescence it may be problematic to make decisions about orthodontic treatment. Undisclosed dental fear can be an important barrier. Some of the young adults in the present study would probably benefit from treatment.

Self-perceived orthodontic treatment need and prevalence of malocclusion in 18- and 19-year-olds in Sweden with different geographic origin

Orthodontic treatment need and demand in 19-year-olds in Sweden has not previously been analysed in relation to geographic origin. The aim of this follow-up study was to examine the prevalence of self-perceived treatment need, malocclusion, earlier orthodontic treatment, self-perceived dental aesthetics and prevalence of symptoms indicative oftemporomandibular disorders in 18-19 year-olds and to analyze any differences between native born and immigrants. Body esteem and psychological wellbeing were also evaluated. The subjects, n=316, were grouped according to family origin: Group A: both parents born in Sweden (98 girls, 80 boys); Group B:the subject or at least one parent born in Eastern /South Eastern Europe (24 girls, 26 boys) and Group C: Asia (44 girls, 44 boys). Two hundered and sixty-eight participants presented for clinical examination and answered the full questionnaire, and 48 who rejected clinical examination,were interviewed by telephone using selected questions from a questionnaire. The results show that adolescents of Asian origin had a higher self-perceived treatment need than adolescents of Swedish origin. There were negligible inter-group differences with respect to frequency of malocclusion. Forty-four per cent of all participants had previously undergone orthodontic treatment, significantly more Swedish than Asian subjects. Dissatisfaction with dental aesthetics was attributed primarily to tooth colour (38 per cent) and irregular anterior teeth (34 per cent). Adolescents of Asian origin had a higher frequency of headache than those of Eastern/South Eastern European origin. Compared to boys, girls had a higher self-perceived treatment need, a higher frequency of headache and TMD and were more concerned about body appearance. Psychological wellbeing was reduced in nearly one quarter of the participants, predominantly girls: girls of Asian origin had the highest frequency. No association was found between self-perceived orthodontic treatment need and psychological wellbeing.

Pacifier-sucking and breast-feeding: a comparison between the 1960 s and the 1990 s

PURPOSE

Pacifiers and their forerunners have been condemned in past centuries, probably beginning in the 17(th) and 18(th) centuries when alcohol and opiates were incorporated as fillings in sucking rags in Great Britain. Nowadays, the modern pacifier is criticized for reducing breast-feeding time and encouraging weaning. The purpose of this study was to analyze if pacifier-sucking has been detrimental to breast-feeding in the past few decades.

METHODS

In the present study, 2 groups of young children born 30 years apart (1967 and 1995 to 1997) in the same geographic area were analyzed in the first 6 months of age regarding their sucking and feeding habits, including initial and prolonged pacifier-sucking and breast-feeding.

RESULTS

Findings do not support the commonly held opinion that pacifier-sucking reduces breast-feeding time. In the 30 years that separate the 2 groups, the pacifier-sucking habit increased by 32% and prolonged use of a pacifier increased. At the same time, breast-feeding at 6 months old has increased 20-fold in the contemporary group (born between 1995 and 1997) as compared with the 1967 group.

CONCLUSIONS

The results suggest that mothers might be unable to satisfy their child's sucking urge through breast-feeding alone, and that they use the pacifier as a supplement. Pacifier use does not negatively affect the prevalence of breast-feeding.

Malocclusion frequency in Swedish and immigrant adolescents--influence of origin on orthodontic treatment need

Sweden has become increasingly multicultural. In the year 2000, almost 25 per cent of the child and adolescent population was of foreign origin. Such a major change in demographics may lead to altered orthodontic treatment need in the community, with implications for planning appropriate levels of orthodontic resources. The aim of this study was to compare the frequency of malocclusion and orthodontic treatment need in 12- and 13-year olds of Swedish and immigrant background. The subjects, n = 493, were stratified into four groups according to family origin: (A) subject and both parents born in Sweden, and subject or at least one parent born in (B) Eastern Europe, (C) Asia, or (D) other countries. Registrations were based on available radiographs, patient records, and a clinical examination. Normative treatment need was based on a number of variables. Treatment need was expressed according to the dental health component (DHC) and aesthetic component (AC) of the Index of Orthodontic Treatment Need (IOTN). Group A exhibited the greatest space deficiencies and irregularities in the maxillary and mandibular anterior segments and also the greatest overjet. More primary molars had been extracted in groups B and C, with a positive correlation between early extraction of primary molars and retention of permanent successors. Self-assessed orthodontic treatment need, IOTN-AC, was highest in group A. For all four groups, the orthodontist's estimate of treatment need was significantly higher than the subjects' self-assessed need. This study confirms that, despite the change in demographics, variations in frequencies of malocclusion and treatment need among children of different cultural background are only minor and the overall orthodontic treatment need remains unchanged.

Long-term follow-up of orthodontically treated deep bite patients

The aim of this study was to evaluate the long-term stability of corrected deep bite and mandibular anterior crowding in a sample of 62 subjects (30 patients and 32 controls). The patients began treatment at a mean age of 12.2 years (SD 1.56). The treatment consisted of non-extraction and fixed appliances in 23 subjects and functional appliances in seven. The treatment group was compared with the control group with normal molar occlusion, normal overjet and overbite, no crowding, and without an orthodontic treatment need. The registrations were made on four occasions: before treatment (T1), after treatment (T2), and at two long-term follow-ups (T3 and T4). Four registrations were also made in the control group. All measurements were undertaken on plaster models and lateral cephalograms. Treatment was found to have normalized the overbite and overjet and to have eliminated the space deficiency in the mandibular anterior region. At T4, there was a minor relapse in overbite in the treatment group (mean 0.8 mm). In the control group, the overbite underwent reverse development (bite opening by 0.7 mm) during the same period. The available mandibular incisor space, however, was -0.9 mm in the treatment group and -1.8 mm in the control group. The long-term stability of the treatment results was thus good.

Craniofacial and dentofacial development in pigs fed soft and hard diets

INTRODUCTION

Several authors have found a correlation between reduced chewing activity and malocclusion. In animal experiments, it has been possible to correlate a diet of low chewing resistance to narrower arches, which predispose the subject to crowding and irregular teeth.

METHODS

In this study, 17 pigs were weaned at 5 weeks of age and divided into 2 groups according to diet and housing. The soft-diet, indoor group was housed in conventional pens, and the animals were fed aliquots of barley and oats with soya and a mineral-vitamin premix added. The food was mixed with water at a dry matter content of about 25%. The hard-diet, outdoor group was kept outdoors; the pigs were fed solid food and also ate organic matter in the soil. All pigs were killed at 22 months of age. The skulls were dissected, and transverse and sagittal craniofacial and dentofacial dimensions were measured.

RESULTS

Chewing hard food caused considerable occlusal and approximal attrition in the experimental animals. The dental arches were shorter due to this attrition and to mesial migration of the molars and premolars. The approximal attrition also reduced the tendency for crowding and rotation of the teeth. Posterior crossbite was more common among the hard-chewing animals.

CONCLUSIONS

The increase in arch width in the hard-diet animals reported in the literature was not duplicated in this study. On the contrary, the soft-diet pigs had significantly wider arches than the hard-diet animals. This was most pronounced in the premolar region and could be the result of an atypical tongue habit, caused by the nonphysiologic feeding of the pigs. The soft-diet pigs also had a greater tendency to postnormal occlusion, especially in the canine region.

Effect of food consistency on temporomandibular joint morphology: an experimental study in pigs

AIMS

To investigate whether there are any correlations between increased masticatory loading, degree of tooth wear, and the size, form, and macroscopic surface of the temporomandibular joints (TMJs).

METHODS

The degree of tooth wear and different TMJ variables were compared in 2 groups of domestic pigs. One group of 8 pigs had been raised indoors (ID group), and the other group of 9 pigs had been raised outdoors (OD group). The pigs in the ID group were fed a soft diet and were not provided any straw in their pens. The OD group was fed a solid diet and could also grub in the soil, resulting in an exposure to more abrasive components and to greater chewing demands. All pigs were sacrificed at the age of 22 months.

RESULTS

The pigs in the OD group exhibited significantly more tooth wear compared to the ID group. No difference in mediolateral size of the condyles could be found between the 2 groups. Form and surface changes of the TMJs varied substantially between individuals, but not between the 2 groups. No correlation could be found between the degree of tooth wear and any of the TMJ variables.

CONCLUSION

Exposure to a tougher diet containing more abrasive substances has a significant impact on the degree of tooth wear but seems to have no consequences either for the size of the TMJ condyles or for form or surface changes of the TMJs.

Secular changes in tooth size and dental arch dimensions in the mixed dentition

Secular changes in the mixed dentition were studied. Permanent tooth size and dental arch dimensions were examined in Norwegian children born in the 1960s and 1980s, Swedish children born in the 1960s and 1980s, Norwegian Sami children born in the 1980s, and a sample of Norwegian skulls dating from the 14th to the 19th century. The Norwegian Sami children were nomadic in the summertime. A sample of pigs was studied before and after a maceration process to determine what dimensional changes might occur in such a process. A shrinkage of 0.3%-1.7% was found. This information was used when the skulls were compared with the modern groups. Lateral dental arch lengths were shorter in the children born in the 1960s compared with the children born in the 1980s. This was a result of the higher prevalence of caries in the second deciduous molars in the 1960s groups. Children who had lost a deciduous canine prematurely were found to have smaller dental arch perimeters. When compared with other data, this was blamed on a pre-existing crowding. Permanent tooth size was smaller in the skulls compared with the modern groups. Improved nutrition is considered to be the main reason for the difference. Relative dental arch space differed in the group born in the 1960s from that in the other groups, indicating a greater prevalence of crowding in the former. Relative dental arch space in the skulls and in the group born in the 1980s was similar. A more traditional way of living, as practised by the Sami group in this thesis, was not favorable for relative dental arch space. The transverse intermaxillary relation in boys changed from the 1960s to the 1980s, which indicated that the 1980s group ran a greater risk of developing a posterior cross-bite. Before the same conclusion could be made in the girls, the mesial drift of the first permanent molars had to be corrected for, because of a higher prevalence of caries in the 1960s group. The sex-pooled analysis of the skulls and the contemporary groups revealed that the risk for developing a posterior cross-bite in the 1980s group was greater than in the skulls. The skulls had smaller arch depths than the modern groups.

The effect of maceration on the dental arches and the transverse cranial dimensions: a study on the pig

The dimensional change of the dental arches and the transverse cranial dimensions were studied in the pig to gain information on cranial post mortem changes and thus improve the possibilities of comparison between modern and skeletal samples. Dental arch dimensions were registered in 17 pigs within 30 minutes after they had been killed. The following day, the skulls were registered on lateral and axial radiographs. The animals were prepared, and storage and preparation included freezing and treatment in hot water. The water temperature did not exceed 65 degrees C. After this process, the skulls were again registered on lateral and axial radiographs. The skulls were then allowed to dry for 2 weeks and the direct measurements were repeated. The dimensions showed shrinkage of between 0 and 3.3 per cent. The mandible showed a greater change transversally in the posterior region than the cranium, which may have been due to its shape. The more deviant values for dimensional change were probably due to technical errors and the shrinkage may be expected to vary from 0.3 to 1.7 per cent, with greater values occurring in the posterior transverse parts of the mandible. A differential shrinkage in the maxilla could not be excluded and the values varied between 0.3 and 1.9 per cent. The results indicate that the crania in skeletal samples can be expected to be 0.3-1.7 per cent smaller than in vivo.

Transverse dental and dental arch depth dimensions in the mixed dentition in a skeletal sample from the 14th to the 19th century and Norwegian children and Norwegian Sami children of today

Secular changes in transverse dental arch dimensions and dental arch depth were studied. Four cohorts with mixed dentitions were selected. The skull group comprised 48 skulls dating from the 14th to the 19th century and belonging to The Schreiner Collection at the Department of Anatomy, University of Oslo. The 1980s Sami group was comprised of 39 boys and 34 girls born in 1987 and living in the northern part of Norway. The 1960s Oslo group was comprised of 31 boys and 30 girls born in 1963 and living in the southern part of Norway. The 1980s Oslo group was comprised of 32 boys and 26 girls born in 1983 and living in the same area in southern Norway as the previous Oslo group. Sex was unknown in the skeletal sample, and the groups were analyzed with the sexes pooled; separate descriptive values are presented for the modern groups. The mandibular intercanine distance was smaller in the skulls compared with the modern groups. The transverse intermaxillary difference between the molars was larger in the skull group than in the 1980s Oslo group. The difference between the maxillary and mandibular intercanine distances was larger in the skulls compared with the modern groups, although the small number of measurements in the skull group impeded further analysis. The arch depth was smaller in the skull group compared with the modern groups; the 1960s Oslo group deviated because of a higher prevalence of caries in the second deciduous molars. The overjet was smaller among the skulls. The arch form measured as the angle between the left and right molar tooth rows was more acute in the skulls than in the modern groups. It was concluded that smaller arch depths are found in skeletal samples at early ages and that attrition does not explain the more upright incisors found in skeletal samples. A secular trend was found in the intermaxillary relation, which indicated that children in the 1980s Oslo group were at greater risk of developing a posterior cross-bite than children born in the 14th to 19th centuries.

Dental arch space and permanent tooth size in the mixed dentition of a skeletal sample from the 14th to the 19th centuries and 3 contemporary samples

Dental arch space and permanent tooth size in the mixed dentition were studied in 4 cohorts: (1) 48 skulls from the 14th to the 19th centuries from The Schreiner Collection in the Department of Anatomy, University of Oslo; (2) 39 boys and 34 girls of Sami origin born in the 1980s living in northern Norway; (3) 31 boys and 30 girls born in the 1960s living in southern Norway; and (4) 32 boys and 26 girls born in the 1980s living in the same part of southern Norway as the previous group. The sexes were unknown in the skeletal sample, and the groups were analyzed with the sexes pooled. The crown sizes of the permanent teeth in the mixed dentition of the Norwegian children who had lived between the 14th and the 19th centuries were smaller than those of contemporary children living in the same country. Probable reasons for this increase in tooth size include improved nutrition and reduced morbidity, because this study ruled out attrition as a major cause of the discrepancy in tooth size. The relative space (arch perimeter minus tooth size) in the group born in the 1960s deviated from that in the other 3 groups, indicating a greater degree of crowding in this group. The relative space in the skulls did not differ significantly from that in the groups born in the 1980s. This means that the improved caries situation during the last decades has changed the dental arch space in these populations. The irregularity index of the 4 mandibular permanent incisors was larger in the skulls than in the modern samples.

Transversal dental arch dimensions in 9-year-old children born in the 1960s and the 1980s

The transversal arch dimension has been studied in 2 different cohorts of 9-year-old children, a group of 119 (56 girls and 63 boys) from Norway and a group of 133 (72 girls and 61 boys) from Sweden. Half of the children in each group were born in the 1960s and half in the 1980s. The maxillary and mandibular transversal dimensions did not differ between the 1960s groups and the 1980s groups when the maxilla and the mandible were studied separately. When the intermaxillary relationship was assessed, a significant reduction in the intermaxillary difference was found in the boys born in the 1980s compared with the boys born in the 1960s. This was confirmed with different measurement points. In the girls, the mesial drift of the first permanent molars, because of a greater prevalence of caries in the 1960s groups, masked this effect. When the mesial drift of the first permanent molars in the girls born in the 1960s was considered, the transversal intermaxillary difference showed the same secular pattern as in the boys. When the mesial drift of the first permanent molars was considered, the intermaxillary difference in the 1960s groups resembled that found in an American sample of northwest European ancestry born in the 1940s to a greater extent compared with the children born in the 1980s.

Anterior space relations and lower incisor alignment in 9-year-old children born in the 1960s and 1980s

The anterior arch spaces and the effect of early loss of deciduous canines have been studied in 2 different cohorts of 9-year-old children. One group of 119 children was from Norway and consisted of 56 girls and 63 boys, and 1 group of 133 children was from Sweden and consisted of 72 girls and 61 boys. Within these cohorts, half of the children were born in the 1960s and half in the 1980s. The 1960s group has been compared with the 1980s group to look for anterior arch changes occurring during this period of time. The children who had lost a lost deciduous canine at the age of 9 years were also compared with the children with all deciduous canines remaining. Groups were compared with analysis of variance. It was found that children with a lost deciduous canine at the age of 9 years belong to a group with less available arch space and are a crowded group when compared with an earlier study. For the girls, this was also associated with larger teeth. Anterior arch space did not differ between the 1960s and the 1980s groups except for the Swedish boys, where there was less available mandibular arch space in the 1980s group. The irregularity index for the 4 mandibular incisors was increased in the 1980s group compared with the 1960s group. This could indicate a secular trend toward an increased prevalence of malocclusion in the present population.

Difference in dental lateral arch length between 9-year-olds born in the 1960s and the 1980s

This study was carried out in two cohorts of 9-year-olds, born in the 1960s and the 1980s in Sweden and Norway, to test the hypothesis that there has been a change in the lateral arch space conditions of the dentition during the last decades. In Norway, 61 children born in 1963 and 58 children born in 1983 were examined. In Sweden, 66 children born in 1961 and 67 children born in 1984 were examined. Children with a prolonged sucking habit, major dentofacial anomalies, history of orthodontic treatment, and ancestors of foreign origin were excluded to avoid influence of these factors on the development of the dentition. Linear measurements were performed between the mesial surface of the first permanent molars and the distal surface of the permanent lateral incisors in the maxillary and mandibular dental arches with use of a sliding caliper. The results showed that the children born in the 1980s had significantly larger lateral arch spaces in the maxillary dental arch (P <.05) and in the mandibular dental arch (P <.01) than did the children born in the 1960s. The amount of tissue loss in the second deciduous molars (the teeth having caries lesions or having been extracted) was greater in the 1960s groups than in the 1980s groups (P <.001). Thus, the hypothesis, that there has been a change in the lateral arch space conditions during the last decades, was confirmed. The most obvious reason is the decline in caries prevalence that has occurred in the same period; thus, there has been less loss of proximal tooth material of posterior teeth.

Orthodontic appliances in relation to nickel hypersensitivity. A review

Nickel hypersensitivity is an increasing problem in adolescents, especially in girls, with a prevalence of up to 30%. The presence of nickel in orthodontic appliances and the possibility of causing nickel hypersensitivity has been discussed in case reports. A review of the literature concerning nickel hypersensitivity in relation to orthodontic appliances has shown that the risk is very low for patients who are not nickel hypersensitive at the start of the treatment. A patient who is already nickel hypersensitive at the start of orthodontic treatment may in rare cases show adverse reactions induced by the appliance. The slow long-term release of nickel from orthodontic appliances may induce tolerance to nickel in individuals who are not hypersensitive at the start of orthodontic treatment.

Dummy-sucking behaviour in 3-year old Norwegian and Swedish children

Forty 3-year-old dummy-sucking children (22 Swedes and 18 Norwegians) together with one of their parents, were shown a specially prepared videotape for 15 minutes The child had free access to its dummy while watching the video. The dummy-sucking time and sucking reactions to the different film sequences were registered. The presence or absence of a posterior crossbite was recorded as well as the upper and lower intercanine arch widths. Dummy-suckers in these populations have earlier been reported to have different prevalences of posterior crossbite. The prevalence of posterior crossbite was especially high for Swedish girls. The results showed that Norwegian boys used their dummies significantly less, and the Swedish girls had significantly narrower upper dental arches than the other children. Dummy-sucking reactions to frightening, cheerful or boring parts of the video were not significantly different among the children. All the children showed compassion for the film characters, and all the children used the dummy when going to sleep. The study lends support to the hypothesis that dummy-sucking influences arch widths and increases the likelihood for development of a posterior crossbite.

The effect of sucking habits, cohort, sex, intercanine arch widths, and breast or bottle feeding on posterior crossbite in Norwegian and Swedish 3-year-old children

The upper and lower intercanine arch widths and the prevalence of posterior crossbite were registered for 445 3-year-old children with and without a continuing or previous dummy-sucking or finger-sucking habit in different areas in Sweden and Norway. Sami children from northern Norway also took part in the study, as well as 15 medieval skulls with intact deciduous dentitions. Compared with the nonsuckers, an increased prevalence of posterior crossbite was observed for the finger suckers, especially the Swedish girls. Stepwise logistic regression showed that posterior crossbite could be predicted with upper intercanine arch width alone. The finger sucking variable would not improve prediction; neither did other entities such as cohort (residential area), sex, lower intercanine arch width, nor the difference between upper and lower intercanine arch width. High prevalences of posterior crossbite were registered for dummy suckers (pacifiers) especially the Swedish girls (26%). Stepwise logistic regression showed that posterior crossbite in dummy suckers could be predicted with upper and lower intercanine arch width. Stepwise linear regression showed that both arches tended to be narrower in Swedes and girls, and that dummy sucking decreased the upper and increased the lower intercanine arch width. Analyses of covariance revealed that at least 2 years of dummy sucking is necessary to produce a significant effect in the upper jaw and 3 years in the lower jaw.

Rearing of Swedish, Norwegian, and Norwegian Sami children

A total of 362 3-yr-old Swedish, Norwegian, and Norwegian Sami (Lapp) children were examined, and their parents were asked about their children's present and previous sucking habits and how long they had been breast-fed and bottle-fed. They were also asked what the children's age was when porridge or puréed food or food with a soft chewing resistance was introduced, and when more ordinary foods such as well-diced meat and potatoes were introduced. The study revealed that breast-feeding has increased greatly both in prevalence and in duration in Sweden during the last decades. Despite this, Swedish children were breast-fed for a significantly shorter time than Norwegian children. The longest breast-feeding times were noted for Sami children. Swedish children were bottle-fed two to three times longer than Norwegian children. Sucking habits were correlated to breast-feeding only for Sami children.

Dummy- and finger-sucking habits in young Swedish and Norwegian children

The prevalence of dummy- and finger-sucking habits in 3-yr-old children was registered in four different areas of Sweden and Norway. In Norway 245 children were examined and in Sweden 171 children. The Swedish children were more prone to develop a dummy-sucking habit as well as to prolong it. About 10-19% of the children in the different groups become finger-suckers. Very few of these finger-suckers had stopped sucking at 3 yr of age. The highest rate of non-suckers was found among the children from Karasjok/Kautokeino in northern Norway, who were mainly of Lappish origin.