Pertti Mikael Pirttiniemi

• DDS, PhD, Docent, Specialist in Orthodontics
• Professor emeritus at University of Oulu

Background: Different oral motor appliances have been used in connection with speech therapy to improve oral motor function and speech development, but no consensus has been reached on the effectiveness of the appliances. The objective was to systematically review the effectiveness of oral motor appliances on oral motor function and speech in chil...

Background: Dental arch effects after cervical headgear (CHG) treatment have been researched from several different perspectives. However, the long-term effects of CHG timing are still unknown. Objectives: To analyse the long-term effects of CHG timing on dental arches. Material and methods: A total of 67 children with Angle Class II malocclus...

Objective: Mandibular condylar cartilage (MCC) of the rat was examined with the Fourier-transform infrared (FITR) spectroscopic imaging to study the effects of ageing, oestrogen level and altered dietary loading on the structure of MCC. Materials and methods: The Sprague-Dawley rats (n = 96) aged 5 and 14 months were divided into 12 subgroups ac...

Objective: This study aimed to evaluate the association between temporomandibular disorders (TMD) and oral health-related quality of life (OHRQoL) in an adult population. Methods: The data included 1,768 adults 46 years of age in the Northern Finland Birth Cohort 1966 (NFBC1966) study. The symptoms, signs and diagnoses of TMD were assessed using...

Objectives This prospective, population-based cohort study aimed to investigate the development of facial asymmetry up to 6 years of age using a three-dimensional (3D) soft tissue imaging method in a normal population. In addition, the study sought to identify potential predisposing factors to facial asymmetry. Methods A total of 102 newborns were...

Purpose The aim of this case–control study was to investigate occlusal characteristics, received orthodontic treatment, oral health-related quality of life (OHRQoL), and satisfaction with dental esthetics in adults operated due to sagittal synostosis. Methods The study group consisted of 40 adults (25 males, 15 females, mean age 27.4 years, range...

Aim The aim of this study was to investigate the gender-specific associations between dental aesthetics, oral health-related quality of life (OHRQoL), and satisfaction with dental aesthetics in an adult population. Materials and methods The study population consisted of 1780 individuals (822 males and 958 females) from the Northern Finland Birth C...

Objective Hormonal factors have been suggested to contribute to female dominance among subjects with temporomandibular disorders (TMD). Aim of the study was to examine the association of climacteric status with TMD amongst female participants in the Northern Finland Birth Cohort (NFBC) 1966 at 46 years of age. Material and Methods Among female sub...

The aim of this study was to investigate changes in facial soft tissue asymmetry over time after orthognathic surgery in Class III patients using three-dimensional stereophotogrammetry. The study included 101 patients with a skeletal Class III malocclusion (72 female, 29 male; age range 19–53 years, mean age 28.6 years) who underwent orthognathic s...

Objective: To examine the prevalence of sagittal relationships, asymmetries and midline shift, and their associations with temporomandibular disorders (TMD) in the Northern Finland Birth Cohort 1966 (NFBC1966). Materials and methods: 1845 subjects participated in a clinical examination at the age of 46. Occlusal measurements were performed using...

Objective To analyze the associations between the widths and forms of dental arches, malocclusions and crowding in middle-aged adult population. Materials and Methods The study material is part of the Northern Finland Birth Cohort 1966 (NFBC1966); the subjects were examined at the age of 46 years. A total of 781 adults with full dentition and no o...

Aim The aim of this study was to investigate malocclusion severity and its associations with oral health-related quality of life (OHRQoL) among middle-aged adults. Materials and methods The study material consisted of 1786 subjects from the Northern Finland Birth Cohort 1966 who attended dental and oral examination as part of the 46-year-old follo...

Aim To study the influence of different force magnitudes on dental arches in cervical headgear (CHG) treatment. Material and methods In this controlled clinical trial, patients (n = 40) were treated with CHG with light (L, 300 g, n = 22) or heavy force (H, 500 g, n = 18) magnitude. Subjects were asked to use CHG for 10 hours a day for 10 months. T...

Background Pain related to temporomandibular disorders (TMD) can be linked with multiple site pain (MSP), and may associate with increased pain sensitivity, more frequently among women than men. The aim of the study was to examine the associations of pressure pain threshold (PPT) and tolerance (PPTo) with TMD and associated MSP in the Northern Finl...

Objective: To determine the anterior Bolton ratio for a Finnish adult population and to investigate its associations with overjet. Material and methods: This study is part of the Northern Finland Birth Cohort 1966. Clinical oral investigations, including three-dimensional intraoral scanning and registration of occlusion, were performed in connec...

Aim: To study the effect of force magnitude on the maxillary first and second molars in cervical headgear (CHG) therapy. Material and methods: In this controlled clinical trial, patients (n = 40) were treated with CHG with a light (L, 300 g, n = 22) or a heavy force (H, 500 g, n = 18) magnitude. The subjects were asked to wear CHG for 10 hours a...

Aim: To explore profile shape variation in a large population of middle-aged individuals and investigate features of sexual dimorphism. Materials and methods: Facial profile photographs of 1776 individuals (964 females and 812 males; 46 years old), members of the Northern Finland Birth Cohort 1966 (NFBC1966), were uploaded and digitized with Vie...

Background: The aim of this study was to assess the effect of overjet and overbite on profile shape in middle-aged individuals. Methods: The study population comprised 1754 46-year-old individuals, members of the 1966 Northern Finland Birth Cohort. Their profile images were digitized using 48 landmarks and semi-landmarks. The subsequent landmark...

Background and Objectives Multilevel statistical models represent the existence of hierarchies or clustering within populations of subjects (or shapes in this work). This is a distinct advantage over single-level methods that do not. Multilevel partial-least squares regression (mPLSR) is used here to study facial shape changes with age during adol...

Background and objectives: The need to evaluate the condylar remodeling after orthognathic surgery, using three-dimensional (3D) images and volume rendering techniques in skeletal Class III patients has been emphasized. The study examined condylar positional, structural, and volumetric changes after bimaxillary or single-jaw maxillary orthognathic...

Purpose The goal was to study the effects of early cervical headgear treatment on maxillary and mandibular dental arch area, shape and interarch dimensions. Methods The total study group comprised 67 children aged 7.6 years (standard deviation 0.3) with Angle class II malocclusion collected between 1992 and 1996. The children were randomly divided...

Aims: To investigate how estrogen level, dietary loading, and aging affect cartilage structure and the expression of major collagens (types I, II, and X) in rat mandibular condylar cartilage (MCC). Methods: A total of 96 outbred Sprague Dawley female rats were randomly divided into two groups by ovariectomy (OVX) at 7 weeks old. One week later,...

Objectives To compare the impact of primary canine and primary first molar extractions with extractions of only the primary canine regarding correction of palatally displaced canines (PDCs). Materials and Methods Thirty-two children aged 9.5–13.5 years with 48 PDCs were randomly allocated to either the double-extraction group (DEG) or single-extra...

Objective: The purpose of this study was to investigate the occlusal characteristics in Finnish adults at 12-year follow-up based on the Northern Finland Birth Cohort 1966 (NFBC1966) subjects. Methods: The occlusal analyses were performed at ages 34 and 46 years of facial pain cases (n = 52) and controls (n = 49) by two different methods. Results:...

Deformational plagiocephaly (DP) is considered a risk factor for facial asymmetry. This cohort-based, prospective, follow-up study used three-dimensional (3D) stereophotogrammetry to assess the development of facial asymmetry in a normal birth cohort and to investigate the impact of DP on facial asymmetry for the age range of one to three years. Th...

Developmental dysplasia of the hip (DDH) may require early abduction treatment with infants sleeping on their back for the first few months of life. As sleeping on back is known to cause deformational plagiocephaly, we assessed school age children treated for dislocation or subluxation of the hip-joint in infancy. Plagiocephaly was analyzed by usin...

mPCA Level 1 (ethnicity / sex) level: mode 1 from Finnish (mean - 3SD) to Welsh (mean + 3SD)

mPCA Level 3 (age) level: mode 1 from age 12 (mean - 3SD) to age 17 (mean + 3SD)

mPCA Level 1 (ethnicity / sex) level: mode 2 from Male (mean - 3SD) to Female (mean + 3SD)

mPCA Level 2 (all other "subject" variations) level: mode 1

Background and objectives: The study of age-related facial shape changes across different populations and sexes requires new multivariate tools to disentangle different sources of variations present in 3D facial images. Here we wish to use a multivariate technique called multilevel principal components analysis (mPCA) to study three-dimensional fa...

Introduction: Several studies have highlighted differences in the facial features in a White European population. Genetics appear to have a major influence on normal facial variation, and environmental factors are likely to have minor influences on face shape directly or through epigenetic mechanisms. Aim: The aim of this longitudinal cohort stu...

Preterm infants are at higher risk for both symmetrical and asymmetrical head molding. This study involved 3D stereophotogrammetry to assess the cranial growth, molding, and incidence of deformational plagiocephaly (DP) in preterm children compared to term born children. Thirty-four preterm infants and 34 term born controls were enrolled in this st...

Objective: The aim of this study was to assess the stability of Natural Head Position (NHP) over time using the 3dMDface System. Setting and sample population: This was an experimental study. Three-dimensional facial images of 40 students were captured on two different occasions, with an interval of at least two weeks. Materials and methods: T...

Background Cervical headgear (CH) is a commonly used orthodontic appliance and its dentoalveolar changes are known. However, the effects related to gender and timing have gained less attention. Objectives To examine dimensions of dental arches among children with Class II occlusion without posterior mandibular rotation according to timing of Kloeh...

Background: There is a lack of evidence based on longitudinal information in the field of Class II malocclusion management with cervical headgear (CH), especially in a randomized setting. Objectives: The main objective of this study was to evaluate skeletal facial changes, particularly in vertical dimensions, after Kloehn-type CH treatment in ch...

Aim: The aim of this cross-sectional study was to investigate gender-specific associations of different malocclusion traits with oral health-related quality of life (OHRQoL) among Finnish adults. Material and methods: The study material comprised 1885 subjects from the Northern Finland Birth Cohort 1966. A clinical oral examination including reg...

Aim: The main aim of this study was to study the impact of different force magnitudes on effectiveness in cervical headgear (CHG) therapy. Materials and methods: Forty patients were treated with CHG with light (L; 300 g) or heavy (H; 500 g) force in this controlled clinical trial. Patients were asked to wear CHG for 10 hours/day for 10 months. T...

Objective: To analyse the accuracy of a meta-analysis-based dental age assessment (DAA) method in Finnish paediatric patients and to compare the dental development between two generations of Finnish children. Methods: Panoramic radiographs of Finnish Caucasian healthy children from two generations (early: born 1981-1984; subsequent: born 1996-20...

Introduction: The aim of this study was to explore the association of soft tissue profile and severity of overbite and overjet in a large adult population. Methods: The study population consisted of 1630 adults (age, 46 years; 712 men, 919 women), all part of the Northern Finland Birth Cohort 1966. A clinical examination was performed on all subjec...

Single-level principal component analysis (PCA) and multi-level PCA (mPCA) methods are applied here to a set of (2D frontal) facial images from a group of 80 Finnish subjects (34 male; 46 female) with two different facial expressions (smiling and neutral) per subject. Inspection of eigenvalues gives insight into the importance of different factors...

Single-level Principal Components Analysis (PCA) and multi-level PCA (mPCA) methods are applied here to a set of (2D frontal) facial images from a group of 80 Finnish subjects (34 male; 46 female) with two different facial expressions (smiling and neutral) per subject. Inspection of eigenvalues gives insight into the importance of different factors...

Objective To explore the association of facial sagittal and vertical dimensions with aesthetic assessment by three panel groups. Materials and methods The study population comprised adult individuals from the Northern Finland Birth Cohort 1966 (NFBC1966). A clinical oral examination including digital facial photographs was performed. The study pop...

Multilevel principal components analysis (mPCA) has previously been shown to provide a simple and straightforward method of forming point distribution models that can be used in (active) shape models. Here we extend the mPCA approach to model image texture as well as shape. As a test case, we consider a set of (2D frontal) facial images from a grou...

The cover image, by Anniina Launonen et al., is based on the Original Article 3D follow‐up study of facial asymmetry after developmental dysplasia of the hip, DOI: 10.1111/ocr.12230.

Objectives To evaluate the change in facial asymmetry among subjects treated for developmental dysplasia of the hip (DDH) from childhood to adolescence. Setting and sample population A total of 39 adolescents (26 females and 13 males), born and treated for DDH during 1997‐2001, participated in the first examination in 2007 (T1; at the age of 8.2)...

The systematic reviews and meta‐analyses tend to focus on a particular anomaly or condition, making a comparison between interventions or controls. This chapter provides a brief overview of genetic and environmental factors that may contribute to the shape of the face, which may have an influence on the outcome of any intervention. Craniofacial gen...

Objective: To investigate the association between risk factors and pain-related symptoms and clinical signs of temporomandibular disorders (TMD) in Northern Finland Birth Cohort (NFBC) 1966. Material and methods: A total of 1962 subjects (1050 women, 912 men) attended the follow-up study. The questionnaires included the subjects’ background informa...

Aims: To evaluate the usefulness of diet board feeding as a model for temporomandibular joint (TMJ) research, characterize dietary loading-related morphometric changes in the mandibular condylar cartilage of aging rats, and investigate changes in type I and type II collagen expression in different age, sex, and diet groups. Methods: Material was...

Objective: To test whether early headgear (HG) treatment and space conditions in the dental arch affect the eruption pathway of the maxillary canines in young children with mixed dentition. Subjects and methods: Data from two randomized controlled trials studying the effects of early HG treatment were pooled, yielding a study sample comprising 9...

BACKGROUND While sagittal synostosis is the most common craniosynostosis, long-term follow-up of these patients is lacking. OBJECTIVE To evaluate the results of surgical management of those patients with sagittal synostosis who attain adulthood. METHODS An outcome study of surgically treated isolated sagittal synostosis patients operated between...

Objective To investigate the role of occlusion in temporomandibular disorders (TMDs) in the Northern Finland Birth Cohort 1966 (NFBC 1966). Methods Subjects (n = 1962) participated in clinical medical and dental examinations. The association between TMD signs and diagnoses with occlusal disturbances, i.e. malocclusions and occlusal interferences,...

Objectives: To investigate hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF) expression under altered loading, and to explore the relationship between loading and hypoxia in the mandibular condylar cartilage of young rats. Setting and sample population: Eighty Sprague-Dawley rats. Material and methods: The...

Background: A Kloehn-type cervical headgear (CH) aims to correct skeletal jaw discrepancy in Class II children. A few studies have reported CH treatment effects on airway dimensions, but none of them have been randomized according to timing. Objectives: To evaluate related craniofacial structures and pharyngeal airway dimensions in children with...

Objectives: The purpose of this study was to evaluate the accuracy and reliability of inter-arch measurements using digital dental models and conventional dental casts. Methods: Thirty sets of dental casts with permanent dentition were examined. Manual measurements were done with a digital caliper directly on the dental casts, and digital measureme...

Objective Various measurements are used to quantify cranial asymmetry in deformational plagiocephaly (DP), but studies validating cut-off values and comparing the accuracy of such measurements are lacking. In this study, we compared the accuracy of four different measurements in classifying children with and without DP diagnosed by visual assessmen...

Background: Posterior cranial vault distraction (PCVD) is a technique widely used in surgical treatment of craniosynostosis when cranial expansion is required. It has proven to be safe and to allow a significant increase of intracranial volume. Objective: To evaluate increases in intracranial volume as a result of PCVD performed in Oulu Craniofa...

Aims: To investigate the prevalence of temporomandibular disorders (TMD) in the 46-year-old cohort subjects from the Northern Finland Birth Cohort 1966 (NFBC 1966). Methods: Altogether, 1,962 subjects (1,050 women, 912 men) participated in a clinical medical and dental examination and responded to questionnaires in 2012 to 2013. The stomatognath...

What is known: • The prevalence of deformational plagiocephaly spontaneously decreases after the first months of life. • Limited neck range of motion and infant positional preference increase the risk of deformational plagiocephaly during the first months of life. What is new: • Positional preference at 3 months predicts an unfavorable spontaneous...

Infant skull deformation is analyzed using the distribution of head normal vector directions computed from a 3D image. Severity of flatness and asymmetry are quantified by functionals of the kernel estimate of the normal vector direction density. Using image data from 99 infants and clinical deformation ratings made by experts, our approach is comp...

Objective The aim of the study was to examine the prevalence of malocclusion traits and the extent of orthodontic treatment in a Finnish adult population. Materials and methods The study population comprised subjects (n = 1964) from the Northern Finland Birth Cohort 1966 living in the city of Oulu and within 100 km of it. A clinical oral and dental...

Introduction: Patients with juvenile idiopathic arthritis (JIA) have a high risk of temporomandibular joint (TMJ) involvement. Lesions in the TMJ appear early in the course of this disease. Evaluating the structure of the TMJ in JIA patients using cone beam computed tomography (CBCT) provides an understanding of the typical radiologic features of...

The 3D photography method allows a more visual presentation of the treatment outcomes with better prediction of the final treatment result. Differences in facial morphology can be evaluated in three dimensions with a 3D photo system. 3D photography is the future of cleft monitoring and represents a tremendous advance in the evolution of record qual...

To clarify the effect of estrogen and food hardness on condylar cartilage and the cartilage-bone interface. A total of 56 rats were divided into four groups: (1) ovariectomized rats fed a normal (pressed pellet) food, (2) ovariectomized rats fed a soft (powder) food, (3) control rats fed a normal (pressed pellet) food, and (4) control rats fed a so...

The aim was to evaluate the relationships of changes in facial pain, temporomandibular disorders (TMDs) and oral health-related quality-of-life (OHRQoL) in adults who underwent orthodontic or orthodontic/surgical treatment. Sixty-four patients (46 women, 18 men, range 18-64 years) with severe malocclusion and functional problems were treated in Oul...

To assess the incidence and severity of root resorption of maxillary incisors caused by ectopically and normally erupting maxillary canines and to analyse factors influencing root resorption of incisors using cone beam computed tomography. The study sample comprised 59 patients with a total of 80 canines. Forty-six of the canines, in 37 patients, w...

The aim of this study was to compare facial 3D analysis to DNA testing in twin zygosity determinations. Facial 3D images of 106 pairs of young adult Lithuanian twins were taken with a stereophotogrammetric device (3dMD, Atlanta, Georgia) and zygosity was determined according to similarity of facial form. Statistical pattern recognition methodology...

Deformational plagiocephaly (DP) occurs frequently in otherwise healthy infants. Many infants with DP undergo physiotherapy or helmet therapy, and ample treatment-related research is available. However, the possibility of preventing DP has been left with little attention. We sought to evaluate the effectiveness of intervention in the newborn's envi...

BACKGROUND. The need for appraisal of oral health-related quality of life has been increasingly recognized over the last decades. The aim of this study was to develope a Latvian and a Russian version and test the validity of the Oral Health Impact Profile (OHIP-49) for use among adults in Latvia. METHODS. The original English version of the OHIP-49...

In 1989, the ERASMUS Bureau of the European Cultural Foundation of the Commission of the European Communities funded the development of a new 3-year curriculum for postgraduate education in orthodontics. The new curriculum was created by directors for orthodontic education representing 15 European countries. The curriculum entitled 'Three years Pos...

Objective: To investigate the association between satisfaction with dental esthetics and quality of life, and esthetics satisfaction in relation to esthetic evaluations of three panel groups. Materials and methods: Fifty-two patients (36 women, 16 men; age 18-61 years) with severe malocclusion were treated in Oulu University Hospital. Of these,...

Aims: To study the effect of estrogen deficiency and altered temporomandibular joint loading on the histomorphology of condylar cartilage and on the expression of types II and X collagen and matrix metalloproteinase-3 (MMP-3). Methods: Thirty-six female rats were divided into four groups: ovariectomized rats on a normal diet, nonovariectomized c...

To study the effect of diet hardness on condylar cartilage thickness, extracellular matrix composition, and expression of matrix metalloproteinase (MMP) -3, -8 and tissue inhibitor of metalloproteinase-1 (TIMP-1), by using immunohistochemical and morphometric methods. Seventy-two female Sprague Dawley rats were exposed to different dietary hardness...

Background Universal recommendation of the evaluation of the temporomandibular joint (TMJ) involvements in juvenile idiopathic arthritis (JIA) is still not available. Aim To assess the valuability of TMJ symtoms or findings as an indicator of mandibular involvement. Subjects and methods 62 (42 girls) out of 305 children with JIA aged 3-17 years and...

The aim of this study was to compare the pharyngeal airway size in different cranio-cervical postures in children with sleep-disordered breathing (SDB) and asymptomatic control children. We tested the hypothesis that the site of the most constricted pharyngeal airway in SDB children is not affected by head posture. The study group comprised 29 chil...

The aim of this study was to examine the pathways between temporomandibular disorders (TMDs), occlusal characteristics, facial pain, and oral health-related quality of life in patients with severe malocclusion. The study comprised 94 (34 men and 60 women, mean age 38 years) adult patients who were referred for orthodontic or surgical-orthodontic tr...

The aim of this study was to evaluate the relationship between occlusal characteristics and oral health-related quality of life in adults who underwent orthodontic or orthodontic-surgical treatment. The study group consisted of 51 adult patients (35 women, 16 men) with severe malocclusion and considerable functional disorders. Thirty-six of the pat...

Interruption of treatment and poor compliance are problems in orthodontics, especially when the patient does not pay for treatment. The aim of this study was to develop a measure for orthodontists, regardless of type of practice, to assess their opinions about patient compliance. A questionnaire, based on an orthodontic patient cooperation scale, w...

To examine the effect of decreased estrogen level and altered diet hardness on condylar cartilage morphology of the rat temporomandibular joint (TMJ) and on the expression of condylar cartilage estrogen receptor alpha (ERa) and matrix metalloproteinase-8 (MMP-8). A total of 36 female rats was divided into four groups: ovariectomized rats fed a norm...

To test the hypothesis that the capability of two-dimensional lateral cephalogram in recognizing pharyngeal obstruction is poor compared with the capability of three-dimensional magnetic resonance imaging (MRI) and clinical observation of tonsillar size. The study participants were 36 prepubertal children (19 male, 17 female; mean age 7.3 ± 1.43 ye...

Heervä E, Peltonen S, Pirttiniemi P, Happonen R-P, Visnapuu V, Peltonen J. Short mandible, maxilla and cranial base are common in patients with neurofibromatosis 1. Eur J Oral Sci 2011; 119: 121–127. © 2011 Eur J Oral Sci Neurofibromatosis type 1 (NF1) is an autosomal-dominant neuro–cutaneous–skeletal syndrome. Neurofibromatosis type 1 is one of th...

Recent advances in laser scanning technology provide the opportunity to examine faces in three dimensions. The aim of this prospective clinical study was to explore facial symmetry in healthy growing individuals and determine whether asymmetric changes occur during adolescent growth. Non-invasive laser surface scanning was performed to capture faci...

Developmental dysplasia of the hip (DDH) has been associated with other congenital postural deformities and associated with asymmetric features in the body. The aim of this study was to examine the associations between developmental DDH and malocclusions in preschool and school children. The subjects were 60 children (40 girls and 20 boys) born dur...

The aims of the present study were to provide data on growth changes in the dental arches from age 7 to 32 in Finns with untreated normal Angle Class I occlusions. The material consisted of 33 series of dental casts of 18 women and 15 men. The subjects had been examined and study models taken at the ages of 7, 10, 12, 15, and 32. Dental arch width,...