The importance of upper first permanent molars position for the orthognatic occlusion

Development of the dental arches and occlusion in permanent dentition can be divided into several stages and has to be observed regularly. The first permanent molar eruption is related to the onset of significant changes in the developing occlusion. Although this tooth is seen as the `key to occlusion` its value as an anchorage is debatable.The aim of the article is to study the correct position of the upper first molars in the two planes of space - the sagittal and transverse planes.In this article the position of the first upper molar is examined with the aid of diagnostic records, such as study cast, orthopantomogram (OPG), and lateral cephalometrics. A literature review includes Bulgarian and foreigner authors.Angle, who in 1899 referred to the maxillary first permanent molars as the `key to occlusion`, was the first to mention their importance within the dentition. According to Angle, the line passing through the middle of the mesiobuccal cusp of the upper first molar coincides with the line passing through the buccal groove of the lower first molar. After Angle, other authors have discussed the position of upper molars from different point of view, such as their relation or position in the maxilla, anteroposterior axial inclination and rotation. As indicated by Lamons and Holmes molar rotations commonly exist in Class II malocclusions. The molars are usually rotated around an axis lingual to their central fossae. In an ideal occlusion the buccal surfaces of the upper first molars are usually parallel to each other.On the OPG Kurol and Bjerklin measured the axial mesial inclination of upper first molar. The tipping of the molars is measured by the angle formed between the tangent line to the mesial surfaces of the root and crown and the line through the lower margins of the left and right orbits.According to Sassouni, the mesial contour of upper first molar should to lie on the 4th arc - the temporal arc. If the molar is anterior to this arc, a treatment with distalization could be initiated. The temporal arcnasion distance measured on the radius is equal to the distance from point ANS to the upper first molar. The position of the upper first molar varies with the position of the upper central incisors. The basic hypothesis is that if the upper first molar has a fixed position in the face, any increase in the total upper dental arch length will be transferred to the incisor area. Any change in the anteroposterior position of the upper first molar could influence the position of the mandibular- leading to Class II malocclusion.Ricketts pointed out that the average distance from the pterygoid vertical (PTV) to the distal surface of upper first molar is the sum of the age of the patient + 3mm, in a growing patient. This diagnostic method can help the orthodontist to decide whether to extract teeth or to distalize the molars.Any loss of space in the arch is a justification for early orthodontic treatment. Mediopalatal rotation of the upper molar is an additional problem in the final phase as well. The rotation of upper first molars is measured by the angles formed by the intersection of lines going over the tips of the mesiopalatal and distobuccal cusps of each molar (Ricketts line) with a straight line marked over the palatine raphe.The problem of reduced arch length has an impact on the final treatment stage when the major orthodontic goal is establishing a tight teeth intercuspation. The molars influence the transfer of occlusal forces to the facial skeleton. The upper first molar tolerates more changes in the position than the lower one. The correct position of the upper molar ensures a stable occlusion with significantly low grade of relapse

The correlation between the rotation of upper first permanent molars and malocclusions in the individual dental arch and in the occlusion

IntroductionMalocclusions disturb the integrity of the dental arch and the interdental/occlusal relationship. All this leads to a change in the position of the upper molars in the sagittal, transversal and vertical plane. The rotation of the upper first molar leads to a shift of position of molar cups in a mesio-distal direction demonstrated by the great impact on the distribution of occlusal forces.AimThe rotation of upper first molars should not be underestimated in the biometrical analysis of diagnostic dental casts as this can lead to incomplete and improper treatment plan.Ðœaterials and MethodsOur study investigated 681 children aged 7-10 years who attended the Department of Orthodontics at the Faculty of Dental Medicine in Varna. All children were clinically evaluated and biometrical assessment of diagnostic dental casts was performed. Diagnostic records included also photo-analysis and measurements of diagnostic dental casts. The relationship between the rotation of upper first permanent molars and the transversal and sagittal dimension, and also the overjet were assessed. The degrees of rotation were classified using the Friel and Vigano methods.ResultsA regressional statistical analysis was conducted to determine the frequency of malocclusion and to establish the relationship between the rotation of upper first permanent molar and the length of the arch, the intercanine distance, and the overjet. The comparative analysis demonstrated inverse relationship not only between the rotational position of the molars and the length of the arch, but also between the canine distance and the rotation of the upper molars (p<0.01). It is reported that when an overjet up to 4 mm is present,  the mediopalatal rotation of the molars is negatively affected.ConclusionLosing the length of the arch leads to compression of the dental arch, medialization of permanent molars and crowding of the frontal teeth. The problem of mesiopalatal rotation of upper first permanent molars is manifested through increased overjet and increased overbite

Diagnostic approach to the incorrect position of lower second premolars

Abstract: The lower second premolar is regarded as the third most common impacted tooth after lower wisdom teeth and upper canines. The aim of the present study is to apply objective diagnostic methods to help determine the impaction likelihood of lower second premolars and their distal inclination. For the purpose of this study 137 panoramic radiographs (OPGs) have been examined of children aged 8 - 16 years. The methodology used in this study helped measure the inclination and angle between the lower second premolar and the crown and axis of the first permanent molar and the mandibular plane. Prevalence of the distal inclination of lower second premolars was observed. Indicators for the impacted lower second premolar proved to be the germ inclination of the lower fifth tooth in relation to the first molar of more than 30° and the intersection of the crown of the sixth tooth by the axis of premolar as well as the inclination towards the mandibular plane of less than 68°. Early extraction of deciduous molars, reserving or creating space when there is a lack of space, allow for favourable conditions for altering the eruption path of the premolar

Epidemiological research on the incidence of malocclusions among mouth-breathing children with primary and mixed dentition

Introduction: A literature review established that the number of mouth-breathing children varies between 5-75%. Girls are more often diagnosed with this condition compared to the boys. In the 19th century Linder-Aronson established the relationship between mouth-breathing and malocclusions. The recognition of the mouth-breathing pattern and the habitual mouth breathing as factors in developing malocclusions requires prophylaxis and timely treatment.Aim: The purpose of this study is to establish the incidence and type of malocclusions among mouth-breathing children with primary and mixed dentition.Materials and Methods: A total of 412 children diagnosed with mouth breathing and 317 children diagnosed with habitual mouth breathing aged 3-12 years were examined. The dental occlusion of every child was assessed in the three planes of space - sagittal, transverse and horizontal in both segments - frontal and buccal.Results: In both groups a statistically significant difference in dental malocclusions was demonstrated (p<0.001) depending on type of dentition. In both groups the vast majority of children were diagnosed with class II Angle malocclusion in both primary and mixed dentition. The children with primary dentition were more often diagnosed with class I Angle malocclusion.Conclusion:In both groups the most frequent malocclusions present were class II Angle, overjet, bilateral posterior crossbite, open bite within 3 mm in the frontal segment. In primary dentition the most frequent type of malocclusion was class I Angle.Introduction: A literature review established that the number of mouth-breathing children varies between 5-75%. Girls are more often diagnosed with this condition compared to the boys. In the 19th century Linder-Aronson established the relationship between mouth-breathing and malocclusions. The recognition of the mouth-breathing pattern and the habitual mouth breathing as factors in developing malocclusions requires prophylaxis and timely treatment.Aim: The purpose of this study is to establish the incidence and type of malocclusions among mouth-breathing children with primary and mixed dentition.Materials and Methods: A total of 412 children diagnosed with mouth breathing and 317 children diagnosed with habitual mouth breathing aged 3-12 years were examined. The dental occlusion of every child was assessed in the three planes of space - sagittal, transverse and horizontal in both segments - frontal and buccal.Results: In both groups a statistically significant difference in dental malocclusions was demonstrated (p<0.001) depending on type of dentition. In both groups the vast majority of children were diagnosed with class II Angle malocclusion in both primary and mixed dentition. The children with primary dentition were more often diagnosed with class I Angle malocclusion.Conclusion:In both groups the most frequent malocclusions present were class II Angle, overjet, bilateral posterior crossbite, open bite within 3 mm in the frontal segment. In primary dentition the most frequent type of malocclusion was class I Angle

Influence of adenotomy/adenoidectomy on the respiration and occlusion in mouth-breathing children

Introduction: Difficult nasal breathing is a common problem, which may be a result of multiple factors, leading to physiological disturbance and/or anatomical disorders of the nose and paranasal sinuses. One of the most frequent reasons in childhood age is adenoid hypertrophy.Aim: The aim of the current article is to determine the influence of adenotomy and adenoidectomy on the respiration and occlusion of children with difficult nasal breathingMaterials and Methods: A total of 412 children, diagnosed with difficult nasal breathing, took part in the study. Of them, 139 underwent a second clinical examination in the period of 1 to 3 months to determine the way of breathing after adenotomy/adenoidectomy.Results: In primary dentition, after removing the etiological factor for difficult nasal breathing, 68.00% of the children began to breathe spontaneously through the nose. In mixed dentition, there was a higher percentage of children, who maintained mouth breathing as a bad habit. In comparison to the dental class after adenotomy/adenectomy, there was a higher percentage of Angle class II. In the saggital plane there was an increase of the frequency of the overjet from 1 to 3mm, which led to preservation of mouth breathing.Conclusion: After adenotomy/adenectomy we have determined that in primary dentition a higher percent of children begin to breathe spontaneously through the nose, whereas in mixed dentition mouth breathing is preserved as a bad habit. In children with preserved mouth breathing, there is an increase in the degree of severity of orthodontic deformations and complications of the deformation

The influence of socio-demographic characteristics on maxillary first molar derotation in children with mixed dentition

Естетиката и стабилният резултат са крайна цел на всяко ортодонтско лечение. В основата на стабилния резултат стои ортогнатната оклузия и идеалната зъбна дъга. Постигането на този резултат се влияе и от правилно проведената първична и вторична профилактика още от ранно смесено съзъбие.Целта на настоящото изследване е да се направи социодемографска характеристика на деца с изменения в ротацията на горен първи молар при смесено съзъбие.Материал и методи: Изследвани са общо 681 деца на възраст между 7 и 10 г. Ротацията на горния първи молар е измерена според методите на Frie, Henry и Vigano и резултатите са представени според пол, възраст и големината на ротация на горните първи молари според зъбния клас при молари. Резултатите са обработени статистически, като са използвани дескриптивен, вариационен и сравнителен анализ.Резултати и обсъждане: Статистически значима разлика беше намерена по отношение на показателя пол, като при момичетата се наблюдава по-съществено ротиране на горните първи молари в сравнение с ротацията при момчетата. И при десните, и при левите молари момичетата са с по-голяма ротация на моларите. Не беше намерена съществена разлика според възрастовия показател въпреки вариациите в ротацията. Най-често срещана е двустранната медиопалатинална ротация на горните първи молари.Заключение: Възрастта на децата не се явява фактор при ротирането на горните първи молари. От друга страна полът е показател при ротирането на горните първи молари, като при момичетата се констатира по-голямо ротиране в сравнение с момчетата.Esthetic facial appearance and long-term stability of normal occlusion are the major goals of orthodontic treatment. Meeting these goals is based on orthognathic occlusion and a well-aligned arch. The accomplishment of these goals depends on proper and well-timed prophylaxis performed in early mixed dentition.AIM: The purpose of this study was to evaluate the influence of socio-demographic characteristics on maxillary first molar rotation in mixed dentition.MATERIALS AND METHODS: The sample included 681 untreated patients aged 7-10 years who were evaluated with the aid of the Friel Henry and Vigano analysis methods for assessment of the magnitude of maxillary molar rotation. The results were summarized and presented by gender, age and dental class. Then they were processed statistically by using descriptive, variation and comparative analysis.RESULTS AND DISCUSSION: Statistically significant difference was observed in this study in two groups divided by gender - the incidence of upper first molar rotation is higher in girls than in boys regardless of the side - left or right. No significant impact of age on molar rotation was observed. The most frequently established malposition is bilateral mediolingual rotation of the upper permanent first molars.CONCLUSION: It appears that age is not a factor influencing maxillary permanent first molars but the gender is an important factor to be considered. The incidence of rotation is higher in girls than boys

Determining the main reasons for difficult nasal breathing among children with primary and mixed dentition

Introduction: Difficult nasal breathing is the condition where there is a partial or full, temporary or permanent obstruction of the airways and the processes of inhalation and exhalation are carried out through the mouth.Aim: The aim of this paper is to define and analyse the reasons for mouth breathing among children with primary and mixed dentition.  Materials and Methods: A total of 1 667 children between the ages 3 and 12 years were examined. We used the methods of anterior and posterior rhinoscopy, acoustic rhinometry, and rhinomanometryResults: Among all the studied mouth-breathing children with deciduous dentition, the main reason for the difficult nasal breathing was allergic rhinitis. The children with first degree of obstruction predominated (54.50%), The second cause in this studied age group was adenoid hypertrophy. In early mixed dentition, the percentage distribution of second and third degree of obstruction was the same (45.70%). In the early mixed dentition, the most common cause of difficult nasal breathing was adenoid hypertrophy. The percentage of children in late mixed dentition who were with adenoid hypertrophy was lower.Conclusion: The main reason for difficult nasal breathing in primary dentition is allergic rhinitis, but in early mixed dentition it is adenoid hypertrophy. Our results showed that of all the children with difficult nasal breathing 24% had first degree of nasal obstruction, 39.30% had second degree, followed by 36.70% children with third degree

A CLINICAL CASE OF LOSS OF THE UPPER LATERAL INCISORS AS A RESULT OF CANINES IMPACTION.

The resorption of the lateral incisors after ectopic eruption of the permanent canines is one of the most common complications and may be detected in all cases of seriously altered route of eruption. The case presented is of a 10-year old boy with permanent dentition and extracted upper lateral incisors as a result of a severe degree of resorption of their roots due to improper eruption of the canines. This article aims at establishing that early detection and prompt preventive measures will lead to avoiding the critical complications arising out of the impacted canines and will preserve the morphological and functional integrity of the incisors and the dentition

Orthodontic extrusion with followed surgical extraction of high-risk lower third molar

lower third molar with sings that indicates high risk of postoperative complications. Materials and methods: We represent an orthodontic extrusion followed by surgical extraction of lower third molar. For precise diagnostics and approach to suitable method of treatment we used standard panoramic radiograph and CBCT. As a method of surgical treatment we chose assisted orthodontic extraction with individually manufactured ring with soldered bar, fixed to tooth 47. Results: In our clinical case we achieved traction of the impacted lower third molar to safe distance from the mandibular canal. On the second stage of the treatment we performed a classic odontectomy without affect or damaging the IAN. Conclusion: The classic odontectomy is surgical method with high risk of damaging the IAN when the impacted tooth is very close to the mandibular canal. The orthodontic extraction like an alternative surgical method of high-risk lower third molars is preventive method, by which there is minimal risk of damaging the nerve during the surgery. The orthodontic extrusion makes the following surgical extraction a safe and secure method for the patient

THE ROLE OF MOUTH BREATHING ON DENTITION DEVELOPMENT AND FORMATION

Introduction: The influence of mouth breathing on the development of the dentition and dento-facial deformities is a problem causes concerns among the medical specialists. Mouth breathing has a major impact on the development of the maxillo-facial region, occlusion and muscle tonus. Aim: The aim of this study is to assess the relationship between etiological factors, pathogenesis and disturbances in mastication in mouth breathing patients. Material and methods: For this article, data is obtained from 43 medical, literary sources. Results: Literature review demonstrated that mouth breathing habit affects mostly children aged 7 - 12 years. In the vast majority of studies, the authors established a relation between mouth breathing and the development of maxillo-facial region and occlusion. The malocclusions described include a distal occlusion, anterior open bite, increase overjet, posterior crossbite, crowding and average incisors inclination disturbances. These clinical conditions become more complicated in the late-mixed and permanent dentition if mouth breathing continues to persist. Conclusion: The habitual mouth breathing is a great medical problem nowadays. An increasing numbers of patients with this condition although the development of technology for early diagnostic is embarrassing. This condition is strongly related with different malocclusions such as anterior open bite, overjet, distal occlusion, underdeveloped and narrow upper jaw, increased anterior facial height