Ivana Savić Pavičin

Timing of emergence of the first primary tooth in preterm and full-term infants

Variations in the timing of emergence of primary teeth are under strong genetic control, but there is also a significant contribution from external factors. The aim of this study was to evaluate the influence of preterm birth, birth weight and length, and feeding practices during the first 6 months of life on the timing of emergence of the first primary tooth. Data on pregnancy duration, birth weight and length, feeding practice, time of emergence and first emerged primary tooth were collected by electronic questionnaires. The study included 409 parents and 592 children of both genders. The sample was divided into two groups according to pregnancy duration (<37 weeks and ≥37 weeks), three groups according to feeding practice (exclusively breastfed, exclusively bottle fed, and a combination of breast feeding and bottle feeding), three groups by birth length (<50, 50-53, >53cm), and four groups by birth weight (<1500, 1500-2500, 2501-3500, >3500g). Data were analyzed considering chronological and postmenstrual age-which is the gestational age plus the infants chronological age at the month of emergence of the first primary tooth. The mean time of first primary tooth emergence was 7.55±2.67 months when chronological age was considered. The first emerged tooth in most cases was a lower incisor (82.33%). There was a statistically significant difference in the timing of the first tooth emergence between preterm and full-term groups when chronological age was considered (p<0.005). However, no difference was found when age was adjusted. The age of emergence of the first tooth differed significantly when feeding, weight, and length groups (p<0. 05) were taken into account. In conclusion, the study indicates that shortened gestational age and very low birth weight are predictors for later ages of emergence of the first primary tooth.

Temporomandibular Disorders and Orthodontic Treatment – A Review with a Reported Clinical Case

Temporomandibular disorders (TMDs) are musculoskeletal disorders which affect the structures of the stomatognathic system. They include two separate entities of functional disorders: masticatory muscles disorder (tendomyopathy) and temporomandibular joint (TMJ) disorder (anterior disc displacement, osteoarthritis). Their shared symptomatology is pain related to masticatory muscles and/or TMJs, limited mouth opening and pathological noise in the TMJs (clicking, crepitations). In general, TMDs are considered to be multifactorial disorders with pain as the most pronounced symptom and the main reason for patients (from 75 – 90% female) to seek medical help. As the musculoskeletal form of the disorder and due to clinically pronounced pain, TMDs include a biopsychosocial component which is an important factor in creating a clinical picture, wherein the chronic aspect of musculoskeletal pain makes the relatively moderate clinical picture much worse. Therefore, like in many other musculoskeletal disorders in the body, their etiopathology is considered nonspecific, which is to say, they have an idiopathic cause on the level of the patient – individual. Clinical examinations, particularly manual examination techniques, are an integral part of TMD diagnostics and they serve to determine the indication for imaging techniques. Magnetic resonance imaging (MRI) has become the gold standard in diagnopstics and differential diagnostics of TMDs because it shows both hard and soft tissues of the TMJ (primarily of the disc) as well as joint effusion. Since the etiology of TMDs is mostly unknown, the indicated treatment methods are mostly symptomatic, noninvasive and reversible. These methods include the well known occlusal splint, physical therapy, cognitive-behavioral methods, acupuncture in cases of chronic pain and psychological treatment. Masticatory muscles and, especially, TMJs are directly connected to occlusal relations and due to that, TMDs are in correlation with occlusal disorders, ranging from obvious occlusal anomalies, variations of static and dynamic occlusal relations to loss of teeth. The Michigan type of the occlusal splint as the most widely used non-permissive splint serves as reversible initial treatment. Definitive occlusal treatment is not recommended for TMD patients as well as prosthodontic appliances and orthodontic treatments. Namely, orthodontic treatment by itself is not confirmed as a potential etiopathogenic factor of TMDs but it should not be performed in patients with a painful form of TMD. All irreversible and relatively long and expensive occlusal treatments, including orthodontic treatment, are never indicated without prior initial treatments. Manual examination techniques can be used as screening methods for detecting clinical symptoms of TMDs. Although a possibility of TMDs prevention is considered, the orthodontic, prosthodontic or any other form have not been scientifically proven because there is no consensus on the factors which cause TMD. Long-term follow-ups of patients undergoing orthodontic treatments did not show subsequent appearance of TMD and certain occlusal variables (cross bite, Angle class II/1, etc.) do not dominate the overall sample of TMD patients. In the review of literature, there is a clinical case described regarding a 5 year follow-up of a 26-year-old female patient who sought specialist prosthodontic help due to pain in the right TMJ and clicking in the left one with limited mouth opening. From patient history: 7 months ago a general dental practitioner referred her to an orthodontist due to clicking in the same joint and the specialist started treatment with a bimaxillary removable appliance (bionator). Namely, the patient previously had Angle class II/1 (prognate jaw) with a horizontal overlap of 11 mm and non-matching medial line of 1 mm. However, the patient did not realize at first that the pain in the TMJ was not being treated and the orthodontist did not realize that her intention was not to treat the orthodontic anomaly. In the course of orthodontic treatment her right TMJ became painful. The orthodontic appliance fixated the occlusion in an anterior (protrusive) position wherein the posterior teeth were in non-occlusion. A clinical examination confirmed the patient’s symptoms (left with reduction, right without reduction) and the anteriorly displaced disc was identified by MRI in habitual closed mouth position, a protrusive position conditioned by the orthodontic appliance and open mouth position. Besides stopping the orthodontic treatment, the patient initially wore the Michigan splint around 5 months and, after a year, still had pain in the right TMJ, with evident chronic character of pain. TMD treatment continued at home by physical therapy and oral exercises. At a recall 5 years later, the patient did not have pain in the TMJs and only felt discomfort in the right TMJ during wide mouth opening with clinically evidenced minor crepitations. MRI showed no change in the anterior disc displacement bilaterally with osteoarthritic changes in the right joint. Now, she does not have esthetic or functional needs for orthodontic treatment. In conclusion, TMD hinders orthodontic treatment and a prior initial treatment is necessary. Orthodontic treatment does not cause TMD symptoms in previously asymptomatic persons. Occlusal variables as well as anomalies and tooth loss have a limited proven direct connection with TMD appearance.

Relationship Between Osteonecrosis of the Jaw and Bisphosphonate Treatment

Povezanost osteonekroze čeljusti i terapije bisfosfonatima Terapija bisfosfonatima i njezina etiopatogenetska povezanost s aseptičkom osteonekrozom čeljusti važan je javnozdravstveni problem današnjice. Svrha je rada pregledom suvremene znanstvene literature utvrditi posljedice višestrukog djelovanja bisfosfonata (antiosteoklastična aktivnost, citotoksičnost na meka i koštana tkiva, antiangiogeneza, genski čimbenici, poremećena ravnoteža između osteoklasta i osteoblasta). Terapija bisfosfonatima jedan je od najčešćih uzroka razvoja osteonekroze čeljusti. Epidemiološki podaci pokazuju da se javlja u bolesnika koji su uzimali jedan ili kombinanciju nitrogenih bisfosfonata. Najvažniji čimbenici rizika za ovu nuspojavu su vrsta bisfosfonata (napose visokopotentni pamidronat i zoledronat koji se daju intravenski), njihova doza i duljina medikacije te vrsta bolesti zbog koje se propisuje terapija. Pojava osteonekroze čeljusti zabilježena je uglavnom u onkoloških bolesnika i u samo 5 % bolesnika s osteoporozom koji su liječeni bisfosfonatima. U patogenezi osteonekroze povezane s bisfosfonatima važno je, sa stajališta dentalnomedicinske prakse, dobro opće oralno zdravlje jer se osteonekroza javlja napose nakon prethodnoga parodontološkog i oralnokirurškog zahvata. Relationship Between Osteonecrosis of the Jaw and Bisphosphonate Treatment Bisphosphonate treatment and its aetiopathogenic association with aseptic osteonecrosis of the jaw is one of the more prominent public health issues today. The aim of this review is to see into the mechanisms of bisphosphonate effects on bones described in literature (anti-osteoclastic activity, cytotoxicity, antiangiogenesis, genetic factors, and imbalance between osteoclasts and osteoblasts). Bisphosphonate treatment is the dominant cause of jaw necrosis. Epidemiological data show an exclusive incidence of osteonecrosis of the jaw in patients who took one or a combination of nitrogen-containing bisphosphonates. Risk factors vary by the bisphosphonate potency (particularly risky are the highly potent pamidronate and zoledronate, which are given intravenously), dosage, duration of treatment, and the illness. Jaw necrosis is most common in oncology patients, and only 5 % in patients with osteoporosis. From a dental-medical point of view, a good oral health is important because osteonecrosis often appears after a periodontal or oral surgical procedure.

Diagnostics and Management of Temporomandibular Joint Disorder - A Reported Case with a Review of Literature

Department of Removable Prosthodontics, School of Dental Medicine, University of Zagreb, Zagreb, Croatia 2Department of Dental Anthropology, School of Dental Medicine, University of Zagreb, Zagreb, Croatia 3Department of Diagnostic and Interventional Radiology, Clinical Hospital Center “Sestre milosrdnice”, University of Zagreb, Zagreb, Croatia

Centric slide in different Angle's classes of occlusion

The purpose of this study was to test the possible differences in centric slide values between different Angles classes of occlusion. The study included 98 participants divided into four groups: Angles class I, Angles class II, subdivision 1, Angles class II, subdivision 2 and Angles class III. All recordings were obtained using an ultrasound jaw tracking device with six degrees of freedom. The distance between the maximum intercuspation (reference position) and the centric occlusion was recorded at the condylar level. Anteroposterior, superoinferior and transversal distance of the centric slide were calculated for each participant, and the data were statistically analyzed (analysis of variance and Newman-Keuls post hoc test). No statistically significant difference was found in the anteroposterior and transversal distance of the centric slide between tested groups, while Angles class II, subdivision 2 showed smaller vertical amount of the centric slide compared to Angles class I and class II, subdivision 1. None of the 98 participants showed coincidence of centric occlusion and maximum intercuspation. Our results suggest that coincidence of the maximum intercuspation with the centric occlusion should not be expected. Smaller extent of the vertical distance of the centric slide could be morphological and a functional expression characteristic of the Angles class II, subdivision 2.