Kirsti Hurmerinta

Development of spinal posture in a cohort of children from the age of 11 to 22 years

Spinal posture and the resultant changes during the entire pubertal growth period have not been reported previously. No cohort study has focused on the development of spinal posture during both the ascending and the descending phase of peak growth of the spine. The growth and development of a population-based cohort of 1060 children was followed up for a period of 11 years. The children were examined 5 times, at the ages of 11, 12, 13, 14 and 22 years. A total of 430 subjects participated in the final examination. Sagittal spinal profiles were determined using spinal pantography by the same physician throughout the study. Thoracic kyphosis was more prominent in males at all examinations. The increasing tendency towards thoracic kyphosis continued in men, but not in women. The degree of lumbar lordosis was constant during puberty and young adulthood. Women were more lordotic at all ages. Thoracic hyperkyphosis of ≥45° was as prevalent in boys as girls at 14 years, but significantly (P<0.0001) more prevalent in men (9.6%) than in women (0.9%) at 22 years. The degree of mean thoracic kyphosis and the prevalence of hyperkyphosis increased in men during the descending phase of peak growth of the spine, but decreased in women.

Maximal bite force and its association with signs and symptoms of TMD, occlusion, and body mass index in a cohort of young adults.

ABSTRACT The purpose of this population-based cohort was to measure maximal bite force (MBF) in the molar and incisal regions and to examine whether MBF was associated with TMD, gender, occlusion (in terms of overjet, overbite, and total number of occluding contacts), and body mass index (BMI). MBF in the molar and incisal regions was measured using a calibrated method in 384 (196 males, 188 females) and 357 (181 males, 176 females) subjects, respectively. Two attempts in each region (right molar, left molar, and incisal) were made in random order. The subjects completed a multiple-choice questionnaire including subjective symptoms of TMD and were subsequently clinically examined. Helkimos clinical dysfunction index and BMI were calculated. The mean MBF value in the molar region was significantly higher in males (878 N, SD 194) than in females (690 N, SD 175) (p<0.001). The incisal forces were 283 N (SD 95) and 226 N (SD 86) (p<0.001), respectively. According to multiple linear regression, TMJ discomfort was significantly negatively associated with MBF in the molar region (p<0.05) and overjet was significantly negatively associated with maximal incisal bite force (p<0.05). No significant associations between MBFs and body mass were found. The results demonstrate that in a population-based cohort of young adults signs, and symptoms of TMD and studied occlusal factors, unlike body mass, associate independently with MBF.

Orthopedic Cervical Headgear with an Expanded Inner Bow in Class II Correction

Forty consecutively referred children, 20 boys and 20 girls, with a Class II division I malocclusion and protrusive maxilla were treated with orthopedic cervical headgear with a 10 mm expanded inner bow and a long outer bow bent 15 degrees upwards. The mean age of the children at the beginning of treatment was 9.3 years (SD 1.3, range 6.6 to 12.4 years), and the average treatment time was 1.8 years (SD 0.6, range 0.8 to 3.1 years). In all patients Class II molar relationships were successfully corrected to Class I molar relationships. This was accompanied by a marked widening of both maxillary and mandibular dental arches. The cephalometric analysis suggested that the observed improvement of the occlusion was due to an inhibition of forward growth of the maxilla and anterior downward rotation of the palate.

Development of trunk asymmetry in a cohort of children ages 11 to 22 years.

STUDY DESIGN A cohort study with a follow-up period of 11 years. OBJECTIVES To study the growth of the spine with a focus on the development of trunk asymmetry and scoliosis. SUMMARY OF BACKGROUND DATA Trunk asymmetry, a common phenomenon at adolescence, can be considered the clinical expression of scoliosis. The importance of the pubertal growth spurt has been stressed in the natural history of scoliosis. However, no cohort studies have focused on the ascending and descending phase of the spines peak growth and the development of trunk asymmetry. METHODS The cohort consisted of all the fourth-grade school children in the Western school district of Helsinki, Finland, in the spring of 1986. These 1060 children (515 girls and 545 boys), from the average age of 11 to 14 years, were invited to undergo annual examinations. The 855 children (80.7%) who had participated in the study at the age of 14 years were invited to a reexamination at the age of 22 years. This invitation was accepted by 430 (208 women and 222 men; 54%) of those invited. The forward bending test, the spinal pantography, and the anthropometric measurements were carried out by the same author (M.N.) throughout this study. RESULTS At 22 years of age, 30% of the adults were found to be symmetric, with a hump less than 4 mm in the forward bending test, whereas 51% had a hump of 4 to 9 mm, and 19% had a hump 10 mm or larger (major asymmetry). The directional asymmetry of trunk surface, a skew to the right at the thoracic level and to the left at the lumbar level at puberty, remained constant at adult age. The prevalence of major trunk asymmetry at adult age was the same in both women and men, in contrast to the female predominance at puberty in this cohort. There were close correlations in the degrees of thoracic and lumbar asymmetry between puberty and adult ages. CONCLUSIONS The shape of the back develops mainly during the pubertal growth spurt at ages 12 to 14 years in girls and boys. Trunk asymmetry (and mild scoliosis) seems as prevalent in young adult women as in men, although at puberty idiopathic scoliosis was twice as prevalent among girls as among boys in this cohort.

Five-Year Follow-Up of Maxillary Distraction Osteogenesis on the Dentofacial Structures of Children With Cleft Lip and Palate

PURPOSE To determine the long-term outcomes of maxillary distraction osteogenesis (DO) on skeletal and dental structures of growing children with cleft lip and palate. PATIENTS AND METHODS Severe maxillary deficiencies were treated with a rigid external distractor device followed by a consolidation period. Preoperative and postoperative orthodontic treatment lasted a mean of 14 months and 16 months, respectively. The landmarks on standard lateral cephalometric x-rays were digitized and angular and linear measurements were compared by Students t test to assess the changes before distraction, after distraction, after consolidation, at 1-year follow-up, and at 2-year follow-up. Long-term follow-up (5 years) was interpreted according to mean values because of the small sample size. RESULTS During DO, the maxilla was horizontally advanced and moved downward as indicated by the significant changes at the SNA and ANB angles (13 degrees) and at maxillary points A, ANS, and PNS. The increase at the divergence between the maxilla and mandible (ANS-PNS/Me-Go) was found to be significant. The mandible (B, Pg, Me) also moved downward (2-4 mm) and backward (Gn) significantly because of mandibular autorotation. The overjet increased (mean increase, 13.7 mm) and the overbite decreased significantly. The advancement of the upper incisors (13.3 mm) and upper molars (12.3 mm) was slightly more than the skeletal points. In a long-term follow-up (5 years), the ANB angle and horizontal overjet continued to decrease but both values remained positive, indicating a Class I relationship. CONCLUSIONS This cephalometric study of young adolescents with cleft lips and palates found great improvement in dentofacial structure after maxillary DO and stability in maxillary skeletal advancement. During a 5-year follow-up, the achieved dentoskeletal treatment outcome was partly diminished. The extreme need for maxillary advancement or facial correction because of psychosocial stress and providing an easier approach for finalizing osteotomy are the major 2 indications for DO treatment.

Five year follow-up of mandibular distraction osteogenesis on the dentofacial structures of syndromic children

OBJECTIVES To determine long-term treatment outcomes of mandibular distraction osteogenesis (DO) in syndromic children with severely hypoplastic lower jaws. DESIGN Descriptive clinical study. SETTING AND SAMPLE POPULATION Cleft Palate and Craniofacial Centre, Department of Plastic Surgery, Helsinki University Central Hospital. Ten children (mean age 7.6 years) with various syndromes (craniofacial microsomia, Treacher Collins syndrome, Nager syndrome). SUBJECTS AND METHODS Ten growing children with severely retrognathic lower jaws were distracted with an extraoral bicortically fixed DO device (mean, 34 days) followed by a consolidation period (mean, 9 weeks). Orthodontic treatment was performed pre- and/or postoperatively with fixed or functional appliances (mean 14 months). OUTCOME MEASURE The landmarks on standard lateral cephalometric X-rays were digitized and angular and linear measurements were compared using Students t-test to assess changes in pre-distraction, post-distraction, post-consolidation and 1 year follow-up. Long-term follow-up (2 and 5 years) was interpreted according to mean values. RESULTS The measurements of SNB, ANB, facial convexity angle, overjet and overbite, and soft tissue facial profile showed significant correction of the mandibular retrognathia and malocclusion. The mandibular divergence decreased and mandibular, corpus, and ramus lengths remained stable during the consolidation period. The regression of mandibular measurements towards pre-distraction values was observed in skeletal and dental parameters and soft tissue profiles during the first postoperative year and continued during the 2- to 5-year follow-up period. The achieved mandibular corpus and ramus lengthening was stable while the mandible displayed considerable posterior rotation but no further growth. Orthodontic treatment could not overcome the regression of mandibular measurements to their original values. The maxilla continued its normal growth during the long-term follow-up. Two patients had tracheostomies, but the tube was removed from both during or immediately after distraction. CONCLUSION - Excellent short-term structural results of mandibular DO are not stable during the growth of syndromic children because of restricted mandibular growth. Thus, a re-evaluation of DO timing in the improvement of facial aesthetics must be considered. However, mandibular DO in children with severe airway problems is recommended.

Maximal bite force and its associations with spinal posture and craniofacial morphology in young adults

Maximal bite force (MBF) and its associations with craniofacial morphology and spinal posture were studied in a group of young adults (46 M and 38 F) aged 21 to 23 years. MBF was recorded in molar and incisal regions. Sagittal spinal posture was measured by spinal pantography and trunk asymmetry at thoracic and lumbar levels by a forward-bending test. Craniofacial variables and posture of the cervical spine were examined from lateral cephalograms taken in a natural head position. No statistically significant correlations existed between MBF and spinal posture, but significant correlations did exist between MBF and craniofacial variables, especially in women.

Postural cephalometric analysis and Nasal resistance in sleep-disordered breathing

Objectives The study was designed to compare upright and supine cephalometric measurements in snorers and to evaluate the effects of mandibular position and nasal resistance on pharyngeal dimensions. Anthropometric, rhinomanometric, and cephalometric measurements were used to investigate predictors of apnea‐hypopnea index.

Associations between thoracic kyphosis, head posture, and craniofacial morphology in young adults

The aim of the present study was to investigate associations between thoracic hyper- and hypokyphosis, head posture, and craniofacial morphology in young adults. Using forward bending test and spinal pantographic measurements, 31 subjects, 16 with thoracic hyper- and 15 with hypokyphosis, were selected from a population-based cohort of 430 young adults. Lateral roentgen-cephalograms were taken in natural head posture and craniofacial and postural angular measurements were calculated. Any statistically significant differences between the groups - thoracic hyperkyphosis and thoracic hypokyphosis - were analysed using Students t test. Subjects with thoracic hyperkyphosis had a larger atlantocervical angle (At/CVT, P < 0.01) than subjects with thoracic hypokyphosis. However, head position (NSL/VER)was similar in both groups, probably owing to the visual perception control of craniovertical relation. There was no statistically significant difference in craniofacial morphology between the groups.

Unexpected events during mandibular distraction osteogenesis

Various unexpected events during mandibular distraction osteogenesis are described in 16 syndromic children with severely retrognathic or asymmetric lower jaws who were treated with unilateral or bilateral extraoral distraction. The mean total time with the distraction devices attached was 14 weeks (range 10–19). Although improvement in facial aesthetics and the desired occlusion was achieved in all but one case, there were unexpected events associated with mandibular distraction. These included pain not related to the operation, functional disturbance in movement of the jaw, dietary problems, weight loss, unfulfilled expectations of decannulation, temporary unilateral facial nerve palsy, and transient unilateral hypoaesthesia of the inferior alveolar nerve. Reoperation was required in 5 of the 16. In addition to these events, psychosocial problems within one family complicated the procedure. Patients and their families should be informed of the lesser‐known aspects of distraction osteogenesis before the procedure is used.