New model for dental age estimation: Willems method applied on fewer than seven mandibular teeth.

Willems method measures the developmental stages of the seven left permanent mandibular teeth and is frequently used for dental age estimation. The aim of this study was to test its accuracy on a large sample of the Croatian population and to develop new models for estimation based on one to seven mandibular teeth. The developmental stages were evaluated on the digital, standardized orthopantomograms of 1868 Croatian children aged 5 to 16. Univariate regression was used for age estimation based on one tooth and regression with forward and backward elimination for selection of the best combination on two to six teeth. Tested in parallel with Willems method, the accuracy of the new models was assessed within intervals of ± 0.5, ± 1, ± 1.5 and ± 2 years and shows the percentage of correct estimations. Using Willems method, the average overestimation was 0.41 years for boys and 0.22 years for girls. Newly developed models that use two to seven teeth proved to be significantly more accurate (p < 0.001). The accuracy of age estimation increases significantly with the number of teeth in a model. Predictably, within the interval ± 0.5 years, a model with three teeth has 3% fewer accurate age estimations than a model including seven teeth. In both theory and practice, Willems method has been considered suitable for age estimation among Croatian children. However, these newly developed models significantly surpass its accuracy. Models using two to seven teeth represent a simple, reliable, and accurate method for age estimation, even in cases with missing mandibular teeth.

Facial aging trajectories: A common shape pattern in male and female faces is disrupted after menopause.

OBJECTIVES: Despite variation in lifestyle and environment, first signs of human facial aging show between the ages of 20-30 years. It is a cumulative process of changes in the skin, soft tissue, and skeleton of the face. As quantifications of facial aging in living humans are still scarce, we set out to study age-related changes in three-dimensional facial shape using geometric morphometrics. MATERIALS AND METHODS: We collected surface scans of 88 human faces (aged 26-90 years) from the coastal town Split (Croatia) and neighboring islands. Based on a geometric morphometric analysis of 585 measurement points (landmarks and semilandmarks), we modeled sex-specific trajectories of average facial aging. RESULTS: Age-related facial shape change was similar in both sexes until around age 50, at which time the female aging trajectory turned sharply. The overall magnitude of facial shape change (aging rate) was higher in women than men, especially in early postmenopause. Aging was generally associated with a flatter face, sagged soft tissue ("broken" jawline), deeper nasolabial folds, smaller visible areas of the eyes, thinner lips, and longer nose and ears. In postmenopausal women, facial aging was best predicted by the years since last menstruation and mainly attributable to bone resorption in the mandible. DISCUSSION: With high spatial and temporal resolution, we were able to extract a shared facial aging pattern in women and men, and its divergence after menopause. This fully quantitative three-dimensional analysis of human facial aging may not only find applications in forensic and ancient human facial reconstructions, but shall include lifestyle and endocrinological measures, and also reach out to studies of social perception.

Anatomical variations of the frontal sinus and its relationship with the orbital cavity.

The anatomy of the frontal sinus is highly variable and its variations affect the occurrence/course of pathological processes. We investigated its size and relationship to the orbit, searching for patterns that would allow it to be classified anatomically. Cone beam computed tomography was applied to 91 skulls (age range 21-86 years) to determine sinus height, width, length, and length of contact with the orbit in the coronal and sagittal planes. In addition, orbital roof pneumatization in the coronal plane was categorized as: none; only medial part pneumatized; the medial and a portion of the central part pneumatized; roof predominantly pneumatized. Sinus dimensions varied widely (mm): height 6.2-50.0; width 3.7-54.0; length 2.4-45.0; frontal orbital contact 4.0-41.6; sagittal orbital contact 0.0-41.2. Pneumatization of the orbital roof (coronal plane) mostly affected the medial and a portion of the central part (50%), or the roof was predominantly pneumatized (32%). Three "types" of sinus (cluster analysis) were distinguished by the extent of pneumatization of the orbital roof in the coronal plane: "small", pneumatization absent or only of the medial part; "medium-sized", pneumatization of the medial and a portion of the central part; "large", roof predominantly pneumatized. All dimensions were significantly different among the types (P < 0.001). Sinus type was fairly predictive of the extent of contact with the orbit in the sagittal plane (not routinely assessed clinically). The data confirm the variability of frontal sinus anatomy and suggest a simple and straightforward classification with potential clinical relevance. Clin. Anat. 31:576-582, 2018. © 2017 Wiley Periodicals, Inc.

Dose area product in estimation of effective dose of the patients undergoing dental cone beam computed tomography examinations.

OBJECTIVE: To investigate the relationship of the effective dose and dose area product (DAP) in dental cone beam computed tomography (CBCT) examinations and to propose conversion factors for estimation of effective doses of the patients using DAP. Dependence of organ doses on DAP was also investigated. MATERIALS AND METHODS: Different exposure geometries in Cranex3Dx CBCT device were simulated using Monte Carlo simulation and computational anthropomorphic phantom. Then organ doses and effective dose for every exposure geometry was compared to DAP and analysed. RESULTS: The effective dose in all simulated CBCT protocols and positions with 180° tube rotation ranged from 5 µSv for 50 × 50 mm2 field of view (FOV) localised on one tooth using lowest resolution to 265 µSv for the largest FOV and highest resolution. In case of 360° tube rotation the effective dose ranges from 6 to 332 µSv for the same FOV sizes and positions as well as resolutions as in 180° tube rotation. CONCLUSIONS: Though the DAP introduces a large uncertainty in the risk measure in dental CBCT, it represents the dose and FOV size which are the most important scanning parameters affecting the dose. To decrease uncertainty in the risk measure, the effective dose has to be estimated for usual clinical positions of the FOV.

Effect of photodynamic therapy on the healing of periapical lesions after root canal retreatment: 1-year follow up randomized clinical trial.

BACKGROUND: The aim of this randomized clinical trial was to evaluate the effects of photodynamic therapy (PDT) after traditional activated final irrigation protocol (ultrasonically activated irrigation, UAI) on periapical lesion healing after single-visit root canal retreatment. METHODS: We included 36 patients with asymptomatic chronic apical periodontitis with periapical lesions larger than 5 mm and teeth sensitive to percussion and palpation, who had previous root canal treatment. All patients who signed informed consent underwent cone-beam computed tomography (CBCT) to determine and calculate the preoperative volume of the periapical lesion. Patients were randomly distributed into two groups according to the final disinfection protocol: Group 1; UAI (NaOCl, EDTA, and NaOCl), Group 2; UAI + PDT. All patients underwent single-visit root canal retreatment using rotary instrumentation and standardized irrigation (3 %NaOCl) by the same endodontist. The root canals were filled with epoxy resin-based sealer and single-cone gutta-percha, followed by control radiography. After one year, a new CBCT scan of the teeth was performed to calculate the reduction in the initial periapical lesion as a measure of periapical healing. For the statistical analysis, the chi-square test variants, Fisher's exact test and the Fisher-Freeman-Halton test were used at the level of significance set at 5 %. RESULTS: There were no significant differences between the groups in terms of age, sex, preoperative and postoperative lesion volume (p > 0.05), and reduction of periapical lesion volume (median, 86.98 % for UAI and 79.72 % for UAI+PDT) (p = 0.970). Additional use of PDT after UAI did not contribute to the healing of periapical lesions. CONCLUSION: The UAI and UAI+PDT protocols had equal effects on healing of periapical lesion.

Unnecessary prescribing of antibiotics to healthy/asymptomatic school-age carriers of potentially pathogenic bacteria.

OBJECTIVES: To re-draw attention to the unnecessary prescribing of antibiotics. METHODS: We monitored nasopharyngeal colonization by 3 potentially pathogenic bacteria, Streptococcus pyogenes, Streptococcus pneumoniae, and Haemophilus influenzae type b in 81 children between the ages of 6 and 7 years who attended the same primary school. The children's health status was also monitored, without using antimicrobial treatment for healthy/asymptomatic carriers. Nasopharyngeal swabs were collected on 6 occasions during autumn months, from mid-September to mid-December 2016. The children who fell ill during the study were treated at the Ear, Nose and Throat Clinic, Sisters of Mercy University Hospital Center, Zagreb, Croatia. RESULTS: Four hundred and sixty-three  nasopharyngeal swabs were collected. Each child had at least one positive swab result. Bacterial colonization with Streptococcus pyogenes had the highest colonization rate. During the study, 83% of the children were healthy/asymptomatic carriers with no clinical signs of disease,  while 17% became ill. The statistical results showed that the increase in all examined bacteria was statistically significant. CONCLUSIONS:   Our  study results showed that positive bacterial findings in nasopharyngeal swabs from clinically healthy carriers were not an indication for antibiotic therapy.

The prevalence of lateral incisor hypodontia and canine impaction in Croatian population.

The study investigates the prevalence of second incisor hypodontia and canine impaction in Croatia. The study of incisor hypodontia encompassed 568 examinees (229 boys, 339 girls) aged 6-22 (X = 11.2, SD = 2.8) while for canine impaction, a subsample of 170 examinees older than 13 years was formed (68 boys and 102 girls). The participants were non-selected ambulatory patients of the Dental Clinic Zagreb and the School of Dental Medicine, University of Zagreb who voluntarily participated in the study. Investigated anomalies were registered from panoramic x-rays and dental records and a tooth was diagnosed as congenitally missing when no crown mineralization could be identified on dental panoramic tomogram and no evidence of extraction was found. For each examinee, the final dental panoramic tomogram evaluation was performed at the age of 13 years. Missing lateral incisors are found in 14 out of 568 participants, indicating the prevalence of 2.46%. With the M : F ratio 1 : 6, sex-specific prevalence are 0.87% and 3.54% for males and females respectively. The prevalence of missing lateral incisor is 1.76% in maxilla and 0.70% in mandible. The sex specific pattern as well as overall prevalence of lateral incisor hypodontia is within the range reported in other studies. On the other hand, the findings of bilaterally missing lateral incisor in six out of 14 examinees (or in 42.86% of hypodontia) is certainly the specificity of the here investigated population. The additional peculiarity is the finding of the bilateral aplasia of mandible canines registered in one child. Canine impaction is found in 8 participants of the present study (4.71%) and in all cases it was placed in maxilla. No sex specific differences in prevalence of impactions are found. In one case (or in 12.5%) a canine impaction is found bilaterally. Missing lateral incisors and canine impaction in the same examinee was not found in this study.

Prevalence of periodontal diseases in Zagreb population, Croatia, 14 years ago and today.

The aim of this study was to assess prevalence of periodontal diseases within Zagreb adult population in 2000. The sample comprised of 412 examinees of both sexes and all age groups. World Health Organization (WHO) methodology and Community Periodontal Index (CPI), (1997) were used. The data gained was statistically assorted and compared with the data from previously conducted research in 1986. Results showed relatively high prevalence of periodontal diseases. No healthy periodontium was recorded in the 45-and-above age group. Shallow periodontal pockets was registered in 12% of nineteen-year-olds, whereas this symptom was very evident in 45-54 age group (45.7%) and in older than 65 (48.2%). Over 90% of participants had insufficient oral hygiene and 80% required initial periodontal therapy. Approximately 20% needed complex periodontal treatment. Comparison of this data with the previous 1986 research showed improvement of periodontal status in up-to-44 age group due to more healthy persons and more subjects with the initial stages of disease. The possible reason for periodontal health improvement in the last 14 years, evident specially in younger age groups, were the effects of large preventive program measures conducted on schoolchildren in Croatia in 1980-ties and terminated in 1990-ties when the war in Croatia started. Following studies are needed to monitor whether deterioration in oral health will occur regarding to absence of organized preventive programs since 1990-ties.

Dental Age and Tooth Development in Orthodontic Patients with Agenesis of Permanent Teeth.

Objective. To compare the development of permanent teeth in a group of children with the congenitally missing permanent teeth (CMPT) and corresponding nonaffected group. Methods. The formation stages of all developing permanent teeth were determined on 345 panoramic radiographs (OPTs) by the method of Haavikko (1970), and dental age was calculated. The paired samples t-test was used to compare the differences between dental age (DA) and chronological age (CA) in those with CMPT and those not affected. Spearman test was used to evaluate the correlation between DA-CA and the number of missing teeth. The Wilcoxon signed rank test was used to compare the development of the teeth adjacent to the place of the agenesis with matched pair in corresponding nonaffected group. Results. Dental age was significantly delayed in CMPT children compared to the nonaffected group (p < 0.001). The mean differences were -0.57 ± 1.20 years and -0.61 ± 1.23 years in males and females, without difference between sexes (p = 0.763). The number of missing teeth affected the delay only in females (p = 0.024). Only mesial teeth in females were significantly delayed in development when compared to the nonaffected group (p = 0.007). Conclusion. Our findings show that the development of the permanent teeth is delayed when compared to the nonaffected group of the same sex and age.

Dental Age in Orthodontic Patients with Different Skeletal Patterns.

Objective. To evaluate the difference between chronological and dental age, calculated by Willems and Cameriere methods, in various skeletal patterns according to Steiner's ANB Classification. Methods. This retrospective cross-sectional study comprised the sample of 776 participants aged between 7 and 15 years (368 males and 408 females). For each participant, panoramic images (OPT) and laterolateral cephalograms (LC) were collected from the medical database. On LC ANB angle was measured; on OPT dental age (DA) was calculated while chronological age (CA) and sex were recorded. The sample was divided into three subgroups (Class I, Class II, and Class III) with similar distribution based on the chronological age and ANB angle. CA was calculated as the difference between the date of OPT imaging and the date of birth, while DA was evaluated using Willems and Cameriere methods. ANB angle was measured on LC by two independent investigators using the cephalometric software. Differences between sexes and the difference between dental and chronological age were tested by independent and paired samples t-test, respectively; one-way ANOVA was used to test differences among ANB classes with Tukey post hoc test to compare specific pairs of ANB classes. Results. The significant difference was found between Class III and other two skeletal classes in males using both dental age estimation methods. In Class III males dental age was ahead averagely by 0.41 years when using Willems method, while Cameriere method overestimated CA for 0.22 years. Conclusion. In males with Class III skeletal pattern, dental development is faster than in Classes I and II skeletal pattern. This faster development is not present in females.

Dose- and time-dependent effects of clodronate on orthodontic tooth movement.

Orthodontic tooth movement is the result of bone remodeling that occurs in periodontal ligament and alveolar bone tissue as a response to mechanical loading of the tooth. The aim of this study is to investigate the time- and dose-response effects of locally administered clodronate on tooth movement. Sixty Wistar rats were randomly assigned to 4 groups of 15 specimens: E1 - application of 10 mMol of clodronate in 3-day intervals; E2 - application of 2.5 mMol of clodronate in 3-day intervals; E3 - application of 10 mMol of clodronate in 7-day intervals; E4 - application of 2.5 mMol of clodronate in 7-day intervals. A 50 µL clodronate solution was injected into a subperiosteal area to the right maxillary incisor. The left maxillary incisor served as a control, with an injection of saline solution. In 3-day interval application regime, there was no effect of clodronate dosing on tooth movement. In 7-day interval application regime, decreased tooth movement was observed with 10 mMol compared with 2.5 mMol clodronate concentration. However, decreased tooth movement was also observed when 2.5 mMol of clodronate was applied in 7-versus 3-day intervals. Conversely, no difference was observed when 10 mMol concentration was applied in 3- versus 7-day intervals. When clodronate is applied subperiosteally in the root area, it decreases the tooth movement. Tooth movement is impeded by the higher clodronate dosing, as well as by shorter application interval even with lower dosing. The purpose of future trials should, therefore, be to determine a safe therapeutic dose/interval application of clodronate in humans and their potential side effects.

A Rare Case of Recurrent Mucoepidermoid Carcinoma of the Nasal Vestibule.

We report a rare case of a large recurrent mucoepidermoid carcinoma (RMEC) in an 81-year-old female smoker, which has originated in the right nasal vestibule. The recurrent tumour was inadequately treated for 6 years. It was a slow-growing tumour for 3 years and then began to enlarge at a higher pace. In the next three years it has covered a large part of the face. The patient had refused any medical treatment. The tumour caused breathing and swallowing difficulties. Because of the profuse bleeding from the tumour, the patient underwent emergency surgery. Surgical treatment consisted of rhinectomy and resection of the central upper lip and part of the right cheek. The facial defect was reconstructed immediately. Recovery from surgery was fast with no complications. Postoperative Multislice Computed Tomography scan showed no metastases so the patient did not receive any chemotherapy or radiotherapy. During a 2.5 years' follow-up period there was no recurrence of the disease.

Growth hormone positive effects on craniofacial complex in Turner syndrome.

OBJECTIVE: Turner syndrome occurs in phenotypic females with complete or partial absence of X chromosome. The leading symptom is short stature, while numerous but mild stigmata manifest in the craniofacial region. These patients are commonly treated with growth hormone to improve their final height. The aim of this study was to assess the influence of long-term growth hormone therapy on craniofacial morphology in Turner syndrome patients. DESIGN: In this cross-sectional study cephalometric analysis was performed on 13 lateral cephalograms of patients with 45,X karyotype and the average age of 17.3 years, who have received growth hormone for at least two years. The control group consisted of 13 Turner syndrome patients naive to growth hormone treatment, matched to study group by age and karyotype. Sixteen linear and angular measurements were obtained from standard lateral cephalograms. Standard deviation scores were calculated in order to evaluate influence of growth hormone therapy on craniofacial components. RESULTS: In Turner syndrome patients treated with growth hormone most of linear measurements were significantly larger compared to untreated patients. Growth hormone therapy mainly influenced posterior face height, mandibular ramus height, total mandibular length, anterior face height and maxillary length. While the increase in linear measurements was evident, angular measurements and facial height ratio did not show statistically significant difference. Acromegalic features were not found. CONCLUSIONS: Long-term growth hormone therapy has positive influence on craniofacial development in Turner syndrome patients, with the greatest impact on posterior facial height and mandibular ramus. However, it could not compensate X chromosome deficiency and normalize craniofacial features.

Sphenoid sinus types, dimensions and relationship with surrounding structures.

The human sphenoid sinus is an extremely variable cavity and an important landmark in hypophyseal surgery. The aim of this study was to investigate the relationship between the sphenoid sinus type, size, extent of pneumatization and occurrence of protrusions of the adjacent neurovascular structures. A total of 51 randomly selected skulls (≥20 years of age, 33 male; 102 sinuses) were analyzed using cone beam computed tomography to estimate pneumatization extension beyond the body of the sphenoid (planum sphenoidale, pterygoid process, greater wings, clivus, dorsum sellae) and protrusions of the maxillary, mandibular, optic or pterygoid nerve or the internal carotid artery. Difference in pneumatization type between the left and the right-sided sinus was observed in 45% of the skulls. Conchal pneumatization was registered in 2%, presellar in 24%, sellar in 41% and postsellar in 33% of total sinuses. Presellar sinuses frequently pneumatized planum sphenoidale and sporadically other structures, and were characterized by sporadic optic nerve protrusions. Sellar and particularly postsellar sinuses were characterized by simultaneous pneumatization extensions and neurovascular protrusions. In the case of postsellar-type sinuses, the probability of these multiple interactions was not affected by their actual size, while it increased with the increasing sinus dimensions in the case of sellar-type sinuses. A more detailed analysis indicated that increasing sinus height, length or width increased the probability of interactions and pneumatization of particular surrounding structures. Data suggest that the sphenoid sinus pneumatization type and dimensions might be used to estimate the risks of iatrogenic injury during transsphenoidal surgical procedures.

Dental stigmata and enamel thickness in a probable case of congenital syphilis from XVI century Croatia.

OBJECTIVE: To analyse the dental remains of an individual with signs of congenital syphilis by using macroscopic observation, CBCT and micro-CT images, and the analysis of the enamel thickness. DESIGN: Anthropological analysis of human skeletal remains from the 16th century archaeological site Park Gric in Zagreb, Croatia discovered a female, 17-20 years old at the time of death, with dental signs supportive of congenital syphilis: mulberry molars and canine defects, as well as non-specific hypoplastic changes on incisors. The focus of the analysis was on three aspects: gross morphology, hypoplastic defects of the molars, canines and incisors, as well as enamel thickness of the upper first and second molars. RESULTS: The observed morphology of the first molars corresponds to the typical aspect of mulberry molars, while that of the canines is characterised by hypomineralisation. Hypoplastic grooves were observed on the incisal edges of all incisors. The enamel of the first molars is underdeveloped while in the second molars a thick-enamelled condition is observed. CONCLUSIONS: Our observations for the dental and skeletal evidence are supportive to a diagnosis of congenital syphilis for this specimen from XVI century Croatia. The use of CT imaging helped documenting the diagnostic features and quantifying the effect of the dental stigmata on first molars.

Cameriere's third molar maturity index in assessing age of majority.

Estimation of chronological age of an individual is one of the main challenges in forensic science. Legally to be able to treat a person as a minor or an adult, it is necessary to determine whether their age of majority (if they are older or younger than 18, in most countries). Methods for estimating age are especially important when an individual in question lacks personal documents or other means of identification. As the dental age differs in various populations, the aim of this study was to evaluate applicability of third molar method for assessing age of majority in Croatia. Cameriere's third molar maturity index (I3M) value of 0.08, measured by the open apices of the teeth, was verified in sample of 1336 panoramic images aged between 14 and 23 years. Chronological age gradually decreased as I3M increased in both genders. Males showed statistically significant advanced maturation when I3M was between 0.0 and 0.3 value. The results indicate that the sensitivity of the test for 0.08 value was 84.3% (95%CI 80.6%, 87.5%) for females and 91.2% (95%CI 88.7%, 93.1) for males. Specificity was 95.4% (95%CI 92.5%, 97.5%) and 91.9% (95%CI 88.8%, 94.3%). The proportions of accurately classified males were 88.8% and that of females 91.5%. The estimated post-test probabilities, of individuals, in other word the probability that a Croatian individual with an I3M<0.08 is 18 years or older is 94.5% for females, and 96.5% for males. With high accuracy, the third molar maturity index should be used as a determinant of the age of majority in Croatia.

Longitudinal dental arch changes in the mixed dentition.

The purpose of this study was to investigate dental arch changes that occurred during the mixed dentition in 30 normal occlusion children. Two analyses were done. The first one was at the age of early mixed dentition and the second at the age of late mixed dentition. Most width variables were greater in the males, and depth variables greater in the female subjects. A directionally larger left side of the maxilla and right side of the mandible were observed. Our findings indicate that most arch width dimensions are established in the early mixed dentition. We conclude that the period between the early and late mixed dentition is suitable for environmental factors to disrupt the ideal symmetrical developmental pattern because more growth and developmental changes occur after a relatively stabile period of deciduous dentition.

Holistic anthropological research of Hvar Islanders, Croatia--from parish registries to DNA studies in 33 years.

The complexity of interactions between hereditary, environmental and cultural factors in determining human phenotypes is often underestimated in biomedical research. In this paper, we present 33 years of holistic anthropological research that was being conducted since 1971 in the island of Hvar, Croatia. During this period, detailed characterization of migrations, demography, isonymy, linguistic differences, anthropometric traits (head and body dimensions), physiological (cardio-respiratory) properties, quantitative and qualitative dermatoglyphic traits, radiogrammetric metacarpal bone dimensions and genetic traits (classical antigens, HLA diversity, DNA short tandem repeat -STR, mitochondrial DNA and Y-chromosome polymorphisms) was performed. The analysis of this large collection of data using both model-bound and model-free approaches showed that the complexity underlying human biological traits may be considerably greater than generally assumed, which has important implications for design of future studies into genetic determinants of complex traits.

Dental arch asymmetry in an isolated Adriatic community.

Developmental stability reflects the ability of a genotype to develop in the same way under varying environmental conditions. Deviations from developmental stability, arising from disruptive effects of environmental and genetic stresses, can be measured in terms of fluctuating asymmetry, a particularly sensitive indicator of the ability to cope with these stresses during ontogeny. In an inbred Adriatic island population, we expected dental arch fluctuating asymmetry 1) to be higher than in an outbred sample from the same island, and 2) within this population, to increase with the level of inbreeding. Due to environmental stress, we also expected to find higher fluctuating asymmetry in the outbred island population than in an urban reference group from the same country. The material consisted of 506 dental casts of 253 children from 1) the island of Hvar, and 2) Zagreb, Croatia. Three-dimensional coordinates of 26 landmarks spanning the arches were digitized. The analysis partitioned the asymmetry of arch forms into components for directional and fluctuating bilateral asymmetry, using the appropriate Procrustes method (geometric morphometrics). The results corroborated the hypotheses. Fluctuating asymmetry was found to be higher on the island than in Zagreb in all groups and in both jaws, and increased significantly with endogamy level in the lower jaw. There was no significant directional asymmetry in the Zagreb sample and likewise none in the upper jaws of the outbred island group, but significant directional asymmetry in both jaws of the inbred population and also in the lower jaws of the outbred island group. These results suggest an environmental as well as a genetic influence on dental arch asymmetry. Although the lower jaws expressed these two stresses almost additively, the upper jaws appeared to be better buffered. The role of directional asymmetry as a potential indicator of craniofacial developmental instability clearly merits further attention.

Orofacial analysis on the Adriatic islands: an epidemiological study of malocclusions on Hvar Island.

The prevalence of malocclusion was studied on the Hvar island, Croatia. This island is characterized by high rates of endogamy, inbreeding and reproductive isolation. The sample for this study comprised 224 children, 126 males and 98 females from all schools on the island of Hvar (20.2 per cent of the total public school population). The sample was selected according to age, sex distribution, and demographic characteristics. The Angle Classes, overjet, overbite, crowding, spacing, and the type of anterior bite were examined. Class I buccal relationship was found in 47.3 per cent of the subjects, Class II in 45.1 per cent, and Class III in 5.4 per cent. Normal overjet was the most frequent finding (69.9 per cent). Normal overbite was seen in 42.5 per cent, deep in 49.1 per cent, and very deep in 2.7 per cent of the cases. Open bite was diagnosed in seven subjects (3.1 per cent) and edge-to-edge bite in six (2.7 per cent). The frequency of crowding was 57.1 per cent, normal relationships were observed in 34.9 per cent, and spacing in 8 per cent. The results of this investigation showed that the inhabitants of Hvar, who are characterized by a high rate of inbreeding and traditional diet, have more Class II malocclusions, deep bites, and midline shifts than the general Croatian population but not higher than other modern urbanized groups. Since the lack of chewing stress in this population cannot be considered as the main explanation for the above phenomenon, the genetic influence on the development of these occlusal traits in the inbred population of Hvar requires further investigation.